| /* |
| * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| * Written by Alex Tomas <alex@clusterfs.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public Licens |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| */ |
| |
| |
| /* |
| * mballoc.c contains the multiblocks allocation routines |
| */ |
| |
| #include "mballoc.h" |
| /* |
| * MUSTDO: |
| * - test ext4_ext_search_left() and ext4_ext_search_right() |
| * - search for metadata in few groups |
| * |
| * TODO v4: |
| * - normalization should take into account whether file is still open |
| * - discard preallocations if no free space left (policy?) |
| * - don't normalize tails |
| * - quota |
| * - reservation for superuser |
| * |
| * TODO v3: |
| * - bitmap read-ahead (proposed by Oleg Drokin aka green) |
| * - track min/max extents in each group for better group selection |
| * - mb_mark_used() may allocate chunk right after splitting buddy |
| * - tree of groups sorted by number of free blocks |
| * - error handling |
| */ |
| |
| /* |
| * The allocation request involve request for multiple number of blocks |
| * near to the goal(block) value specified. |
| * |
| * During initialization phase of the allocator we decide to use the group |
| * preallocation or inode preallocation depending on the size file. The |
| * size of the file could be the resulting file size we would have after |
| * allocation or the current file size which ever is larger. If the size is |
| * less that sbi->s_mb_stream_request we select the group |
| * preallocation. The default value of s_mb_stream_request is 16 |
| * blocks. This can also be tuned via |
| * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms |
| * of number of blocks. |
| * |
| * The main motivation for having small file use group preallocation is to |
| * ensure that we have small file closer in the disk. |
| * |
| * First stage the allocator looks at the inode prealloc list |
| * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for |
| * this particular inode. The inode prealloc space is represented as: |
| * |
| * pa_lstart -> the logical start block for this prealloc space |
| * pa_pstart -> the physical start block for this prealloc space |
| * pa_len -> lenght for this prealloc space |
| * pa_free -> free space available in this prealloc space |
| * |
| * The inode preallocation space is used looking at the _logical_ start |
| * block. If only the logical file block falls within the range of prealloc |
| * space we will consume the particular prealloc space. This make sure that |
| * that the we have contiguous physical blocks representing the file blocks |
| * |
| * The important thing to be noted in case of inode prealloc space is that |
| * we don't modify the values associated to inode prealloc space except |
| * pa_free. |
| * |
| * If we are not able to find blocks in the inode prealloc space and if we |
| * have the group allocation flag set then we look at the locality group |
| * prealloc space. These are per CPU prealloc list repreasented as |
| * |
| * ext4_sb_info.s_locality_groups[smp_processor_id()] |
| * |
| * The reason for having a per cpu locality group is to reduce the contention |
| * between CPUs. It is possible to get scheduled at this point. |
| * |
| * The locality group prealloc space is used looking at whether we have |
| * enough free space (pa_free) withing the prealloc space. |
| * |
| * If we can't allocate blocks via inode prealloc or/and locality group |
| * prealloc then we look at the buddy cache. The buddy cache is represented |
| * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets |
| * mapped to the buddy and bitmap information regarding different |
| * groups. The buddy information is attached to buddy cache inode so that |
| * we can access them through the page cache. The information regarding |
| * each group is loaded via ext4_mb_load_buddy. The information involve |
| * block bitmap and buddy information. The information are stored in the |
| * inode as: |
| * |
| * { page } |
| * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]... |
| * |
| * |
| * one block each for bitmap and buddy information. So for each group we |
| * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE / |
| * blocksize) blocks. So it can have information regarding groups_per_page |
| * which is blocks_per_page/2 |
| * |
| * The buddy cache inode is not stored on disk. The inode is thrown |
| * away when the filesystem is unmounted. |
| * |
| * We look for count number of blocks in the buddy cache. If we were able |
| * to locate that many free blocks we return with additional information |
| * regarding rest of the contiguous physical block available |
| * |
| * Before allocating blocks via buddy cache we normalize the request |
| * blocks. This ensure we ask for more blocks that we needed. The extra |
| * blocks that we get after allocation is added to the respective prealloc |
| * list. In case of inode preallocation we follow a list of heuristics |
| * based on file size. This can be found in ext4_mb_normalize_request. If |
| * we are doing a group prealloc we try to normalize the request to |
| * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to |
| * 512 blocks. This can be tuned via |
| * /proc/fs/ext4/<partition/group_prealloc. The value is represented in |
| * terms of number of blocks. If we have mounted the file system with -O |
| * stripe=<value> option the group prealloc request is normalized to the |
| * stripe value (sbi->s_stripe) |
| * |
| * The regular allocator(using the buddy cache) support few tunables. |
| * |
| * /proc/fs/ext4/<partition>/min_to_scan |
| * /proc/fs/ext4/<partition>/max_to_scan |
| * /proc/fs/ext4/<partition>/order2_req |
| * |
| * The regular allocator use buddy scan only if the request len is power of |
| * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The |
| * value of s_mb_order2_reqs can be tuned via |
| * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to |
| * stripe size (sbi->s_stripe), we try to search for contigous block in |
| * stripe size. This should result in better allocation on RAID setup. If |
| * not we search in the specific group using bitmap for best extents. The |
| * tunable min_to_scan and max_to_scan controll the behaviour here. |
| * min_to_scan indicate how long the mballoc __must__ look for a best |
| * extent and max_to_scanindicate how long the mballoc __can__ look for a |
| * best extent in the found extents. Searching for the blocks starts with |
| * the group specified as the goal value in allocation context via |
| * ac_g_ex. Each group is first checked based on the criteria whether it |
| * can used for allocation. ext4_mb_good_group explains how the groups are |
| * checked. |
| * |
| * Both the prealloc space are getting populated as above. So for the first |
| * request we will hit the buddy cache which will result in this prealloc |
| * space getting filled. The prealloc space is then later used for the |
| * subsequent request. |
| */ |
| |
| /* |
| * mballoc operates on the following data: |
| * - on-disk bitmap |
| * - in-core buddy (actually includes buddy and bitmap) |
| * - preallocation descriptors (PAs) |
| * |
| * there are two types of preallocations: |
| * - inode |
| * assiged to specific inode and can be used for this inode only. |
| * it describes part of inode's space preallocated to specific |
| * physical blocks. any block from that preallocated can be used |
| * independent. the descriptor just tracks number of blocks left |
| * unused. so, before taking some block from descriptor, one must |
| * make sure corresponded logical block isn't allocated yet. this |
| * also means that freeing any block within descriptor's range |
| * must discard all preallocated blocks. |
| * - locality group |
| * assigned to specific locality group which does not translate to |
| * permanent set of inodes: inode can join and leave group. space |
| * from this type of preallocation can be used for any inode. thus |
| * it's consumed from the beginning to the end. |
| * |
| * relation between them can be expressed as: |
| * in-core buddy = on-disk bitmap + preallocation descriptors |
| * |
| * this mean blocks mballoc considers used are: |
| * - allocated blocks (persistent) |
| * - preallocated blocks (non-persistent) |
| * |
| * consistency in mballoc world means that at any time a block is either |
| * free or used in ALL structures. notice: "any time" should not be read |
| * literally -- time is discrete and delimited by locks. |
| * |
| * to keep it simple, we don't use block numbers, instead we count number of |
| * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. |
| * |
| * all operations can be expressed as: |
| * - init buddy: buddy = on-disk + PAs |
| * - new PA: buddy += N; PA = N |
| * - use inode PA: on-disk += N; PA -= N |
| * - discard inode PA buddy -= on-disk - PA; PA = 0 |
| * - use locality group PA on-disk += N; PA -= N |
| * - discard locality group PA buddy -= PA; PA = 0 |
| * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap |
| * is used in real operation because we can't know actual used |
| * bits from PA, only from on-disk bitmap |
| * |
| * if we follow this strict logic, then all operations above should be atomic. |
| * given some of them can block, we'd have to use something like semaphores |
| * killing performance on high-end SMP hardware. let's try to relax it using |
| * the following knowledge: |
| * 1) if buddy is referenced, it's already initialized |
| * 2) while block is used in buddy and the buddy is referenced, |
| * nobody can re-allocate that block |
| * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has |
| * bit set and PA claims same block, it's OK. IOW, one can set bit in |
| * on-disk bitmap if buddy has same bit set or/and PA covers corresponded |
| * block |
| * |
| * so, now we're building a concurrency table: |
| * - init buddy vs. |
| * - new PA |
| * blocks for PA are allocated in the buddy, buddy must be referenced |
| * until PA is linked to allocation group to avoid concurrent buddy init |
| * - use inode PA |
| * we need to make sure that either on-disk bitmap or PA has uptodate data |
| * given (3) we care that PA-=N operation doesn't interfere with init |
| * - discard inode PA |
| * the simplest way would be to have buddy initialized by the discard |
| * - use locality group PA |
| * again PA-=N must be serialized with init |
| * - discard locality group PA |
| * the simplest way would be to have buddy initialized by the discard |
| * - new PA vs. |
| * - use inode PA |
| * i_data_sem serializes them |
| * - discard inode PA |
| * discard process must wait until PA isn't used by another process |
| * - use locality group PA |
| * some mutex should serialize them |
| * - discard locality group PA |
| * discard process must wait until PA isn't used by another process |
| * - use inode PA |
| * - use inode PA |
| * i_data_sem or another mutex should serializes them |
| * - discard inode PA |
| * discard process must wait until PA isn't used by another process |
| * - use locality group PA |
| * nothing wrong here -- they're different PAs covering different blocks |
| * - discard locality group PA |
| * discard process must wait until PA isn't used by another process |
| * |
| * now we're ready to make few consequences: |
| * - PA is referenced and while it is no discard is possible |
| * - PA is referenced until block isn't marked in on-disk bitmap |
| * - PA changes only after on-disk bitmap |
| * - discard must not compete with init. either init is done before |
| * any discard or they're serialized somehow |
| * - buddy init as sum of on-disk bitmap and PAs is done atomically |
| * |
| * a special case when we've used PA to emptiness. no need to modify buddy |
| * in this case, but we should care about concurrent init |
| * |
| */ |
| |
| /* |
| * Logic in few words: |
| * |
| * - allocation: |
| * load group |
| * find blocks |
| * mark bits in on-disk bitmap |
| * release group |
| * |
| * - use preallocation: |
| * find proper PA (per-inode or group) |
| * load group |
| * mark bits in on-disk bitmap |
| * release group |
| * release PA |
| * |
| * - free: |
| * load group |
| * mark bits in on-disk bitmap |
| * release group |
| * |
| * - discard preallocations in group: |
| * mark PAs deleted |
| * move them onto local list |
| * load on-disk bitmap |
| * load group |
| * remove PA from object (inode or locality group) |
| * mark free blocks in-core |
| * |
| * - discard inode's preallocations: |
| */ |
| |
| /* |
| * Locking rules |
| * |
| * Locks: |
| * - bitlock on a group (group) |
| * - object (inode/locality) (object) |
| * - per-pa lock (pa) |
| * |
| * Paths: |
| * - new pa |
| * object |
| * group |
| * |
| * - find and use pa: |
| * pa |
| * |
| * - release consumed pa: |
| * pa |
| * group |
| * object |
| * |
| * - generate in-core bitmap: |
| * group |
| * pa |
| * |
| * - discard all for given object (inode, locality group): |
| * object |
| * pa |
| * group |
| * |
| * - discard all for given group: |
| * group |
| * pa |
| * group |
| * object |
| * |
| */ |
| |
| static inline void *mb_correct_addr_and_bit(int *bit, void *addr) |
| { |
| #if BITS_PER_LONG == 64 |
| *bit += ((unsigned long) addr & 7UL) << 3; |
| addr = (void *) ((unsigned long) addr & ~7UL); |
| #elif BITS_PER_LONG == 32 |
| *bit += ((unsigned long) addr & 3UL) << 3; |
| addr = (void *) ((unsigned long) addr & ~3UL); |
| #else |
| #error "how many bits you are?!" |
| #endif |
| return addr; |
| } |
| |
| static inline int mb_test_bit(int bit, void *addr) |
| { |
| /* |
| * ext4_test_bit on architecture like powerpc |
| * needs unsigned long aligned address |
| */ |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| return ext4_test_bit(bit, addr); |
| } |
| |
| static inline void mb_set_bit(int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_set_bit(bit, addr); |
| } |
| |
| static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_set_bit_atomic(lock, bit, addr); |
| } |
| |
| static inline void mb_clear_bit(int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_clear_bit(bit, addr); |
| } |
| |
| static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_clear_bit_atomic(lock, bit, addr); |
| } |
| |
| static inline int mb_find_next_zero_bit(void *addr, int max, int start) |
| { |
| int fix = 0; |
| addr = mb_correct_addr_and_bit(&fix, addr); |
| max += fix; |
| start += fix; |
| |
| return ext4_find_next_zero_bit(addr, max, start) - fix; |
| } |
| |
| static inline int mb_find_next_bit(void *addr, int max, int start) |
| { |
| int fix = 0; |
| addr = mb_correct_addr_and_bit(&fix, addr); |
| max += fix; |
| start += fix; |
| |
| return ext4_find_next_bit(addr, max, start) - fix; |
| } |
| |
| static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) |
| { |
| char *bb; |
| |
| BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); |
| BUG_ON(max == NULL); |
| |
| if (order > e4b->bd_blkbits + 1) { |
| *max = 0; |
| return NULL; |
| } |
| |
| /* at order 0 we see each particular block */ |
| *max = 1 << (e4b->bd_blkbits + 3); |
| if (order == 0) |
| return EXT4_MB_BITMAP(e4b); |
| |
| bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; |
| *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; |
| |
| return bb; |
| } |
| |
| #ifdef DOUBLE_CHECK |
| static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| int i; |
| struct super_block *sb = e4b->bd_sb; |
| |
| if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| return; |
| BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); |
| for (i = 0; i < count; i++) { |
| if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { |
| ext4_fsblk_t blocknr; |
| blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb); |
| blocknr += first + i; |
| blocknr += |
| le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| |
| ext4_error(sb, __func__, "double-free of inode" |
| " %lu's block %llu(bit %u in group %lu)\n", |
| inode ? inode->i_ino : 0, blocknr, |
| first + i, e4b->bd_group); |
| } |
| mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); |
| } |
| } |
| |
| static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) |
| { |
| int i; |
| |
| if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| return; |
| BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| for (i = 0; i < count; i++) { |
| BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); |
| mb_set_bit(first + i, e4b->bd_info->bb_bitmap); |
| } |
| } |
| |
| static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| { |
| if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { |
| unsigned char *b1, *b2; |
| int i; |
| b1 = (unsigned char *) e4b->bd_info->bb_bitmap; |
| b2 = (unsigned char *) bitmap; |
| for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { |
| if (b1[i] != b2[i]) { |
| printk("corruption in group %lu at byte %u(%u):" |
| " %x in copy != %x on disk/prealloc\n", |
| e4b->bd_group, i, i * 8, b1[i], b2[i]); |
| BUG(); |
| } |
| } |
| } |
| } |
| |
| #else |
| static inline void mb_free_blocks_double(struct inode *inode, |
| struct ext4_buddy *e4b, int first, int count) |
| { |
| return; |
| } |
| static inline void mb_mark_used_double(struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| return; |
| } |
| static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| { |
| return; |
| } |
| #endif |
| |
| #ifdef AGGRESSIVE_CHECK |
| |
| #define MB_CHECK_ASSERT(assert) \ |
| do { \ |
| if (!(assert)) { \ |
| printk(KERN_EMERG \ |
| "Assertion failure in %s() at %s:%d: \"%s\"\n", \ |
| function, file, line, # assert); \ |
| BUG(); \ |
| } \ |
| } while (0) |
| |
| static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, |
| const char *function, int line) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| int order = e4b->bd_blkbits + 1; |
| int max; |
| int max2; |
| int i; |
| int j; |
| int k; |
| int count; |
| struct ext4_group_info *grp; |
| int fragments = 0; |
| int fstart; |
| struct list_head *cur; |
| void *buddy; |
| void *buddy2; |
| |
| if (!test_opt(sb, MBALLOC)) |
| return 0; |
| |
| { |
| static int mb_check_counter; |
| if (mb_check_counter++ % 100 != 0) |
| return 0; |
| } |
| |
| while (order > 1) { |
| buddy = mb_find_buddy(e4b, order, &max); |
| MB_CHECK_ASSERT(buddy); |
| buddy2 = mb_find_buddy(e4b, order - 1, &max2); |
| MB_CHECK_ASSERT(buddy2); |
| MB_CHECK_ASSERT(buddy != buddy2); |
| MB_CHECK_ASSERT(max * 2 == max2); |
| |
| count = 0; |
| for (i = 0; i < max; i++) { |
| |
| if (mb_test_bit(i, buddy)) { |
| /* only single bit in buddy2 may be 1 */ |
| if (!mb_test_bit(i << 1, buddy2)) { |
| MB_CHECK_ASSERT( |
| mb_test_bit((i<<1)+1, buddy2)); |
| } else if (!mb_test_bit((i << 1) + 1, buddy2)) { |
| MB_CHECK_ASSERT( |
| mb_test_bit(i << 1, buddy2)); |
| } |
| continue; |
| } |
| |
| /* both bits in buddy2 must be 0 */ |
| MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); |
| MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); |
| |
| for (j = 0; j < (1 << order); j++) { |
| k = (i * (1 << order)) + j; |
| MB_CHECK_ASSERT( |
| !mb_test_bit(k, EXT4_MB_BITMAP(e4b))); |
| } |
| count++; |
| } |
| MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); |
| order--; |
| } |
| |
| fstart = -1; |
| buddy = mb_find_buddy(e4b, 0, &max); |
| for (i = 0; i < max; i++) { |
| if (!mb_test_bit(i, buddy)) { |
| MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); |
| if (fstart == -1) { |
| fragments++; |
| fstart = i; |
| } |
| continue; |
| } |
| fstart = -1; |
| /* check used bits only */ |
| for (j = 0; j < e4b->bd_blkbits + 1; j++) { |
| buddy2 = mb_find_buddy(e4b, j, &max2); |
| k = i >> j; |
| MB_CHECK_ASSERT(k < max2); |
| MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); |
| } |
| } |
| MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); |
| MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); |
| |
| grp = ext4_get_group_info(sb, e4b->bd_group); |
| buddy = mb_find_buddy(e4b, 0, &max); |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| ext4_group_t groupnr; |
| struct ext4_prealloc_space *pa; |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); |
| MB_CHECK_ASSERT(groupnr == e4b->bd_group); |
| for (i = 0; i < pa->pa_len; i++) |
| MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); |
| } |
| return 0; |
| } |
| #undef MB_CHECK_ASSERT |
| #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ |
| __FILE__, __func__, __LINE__) |
| #else |
| #define mb_check_buddy(e4b) |
| #endif |
| |
| /* FIXME!! need more doc */ |
| static void ext4_mb_mark_free_simple(struct super_block *sb, |
| void *buddy, unsigned first, int len, |
| struct ext4_group_info *grp) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned short min; |
| unsigned short max; |
| unsigned short chunk; |
| unsigned short border; |
| |
| BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb)); |
| |
| border = 2 << sb->s_blocksize_bits; |
| |
| while (len > 0) { |
| /* find how many blocks can be covered since this position */ |
| max = ffs(first | border) - 1; |
| |
| /* find how many blocks of power 2 we need to mark */ |
| min = fls(len) - 1; |
| |
| if (max < min) |
| min = max; |
| chunk = 1 << min; |
| |
| /* mark multiblock chunks only */ |
| grp->bb_counters[min]++; |
| if (min > 0) |
| mb_clear_bit(first >> min, |
| buddy + sbi->s_mb_offsets[min]); |
| |
| len -= chunk; |
| first += chunk; |
| } |
| } |
| |
| static void ext4_mb_generate_buddy(struct super_block *sb, |
| void *buddy, void *bitmap, ext4_group_t group) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| unsigned short max = EXT4_BLOCKS_PER_GROUP(sb); |
| unsigned short i = 0; |
| unsigned short first; |
| unsigned short len; |
| unsigned free = 0; |
| unsigned fragments = 0; |
| unsigned long long period = get_cycles(); |
| |
| /* initialize buddy from bitmap which is aggregation |
| * of on-disk bitmap and preallocations */ |
| i = mb_find_next_zero_bit(bitmap, max, 0); |
| grp->bb_first_free = i; |
| while (i < max) { |
| fragments++; |
| first = i; |
| i = mb_find_next_bit(bitmap, max, i); |
| len = i - first; |
| free += len; |
| if (len > 1) |
| ext4_mb_mark_free_simple(sb, buddy, first, len, grp); |
| else |
| grp->bb_counters[0]++; |
| if (i < max) |
| i = mb_find_next_zero_bit(bitmap, max, i); |
| } |
| grp->bb_fragments = fragments; |
| |
| if (free != grp->bb_free) { |
| ext4_error(sb, __func__, |
| "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n", |
| group, free, grp->bb_free); |
| /* |
| * If we intent to continue, we consider group descritor |
| * corrupt and update bb_free using bitmap value |
| */ |
| grp->bb_free = free; |
| } |
| |
| clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); |
| |
| period = get_cycles() - period; |
| spin_lock(&EXT4_SB(sb)->s_bal_lock); |
| EXT4_SB(sb)->s_mb_buddies_generated++; |
| EXT4_SB(sb)->s_mb_generation_time += period; |
| spin_unlock(&EXT4_SB(sb)->s_bal_lock); |
| } |
| |
| /* The buddy information is attached the buddy cache inode |
| * for convenience. The information regarding each group |
| * is loaded via ext4_mb_load_buddy. The information involve |
| * block bitmap and buddy information. The information are |
| * stored in the inode as |
| * |
| * { page } |
| * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]... |
| * |
| * |
| * one block each for bitmap and buddy information. |
| * So for each group we take up 2 blocks. A page can |
| * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks. |
| * So it can have information regarding groups_per_page which |
| * is blocks_per_page/2 |
| */ |
| |
| static int ext4_mb_init_cache(struct page *page, char *incore) |
| { |
| int blocksize; |
| int blocks_per_page; |
| int groups_per_page; |
| int err = 0; |
| int i; |
| ext4_group_t first_group; |
| int first_block; |
| struct super_block *sb; |
| struct buffer_head *bhs; |
| struct buffer_head **bh; |
| struct inode *inode; |
| char *data; |
| char *bitmap; |
| |
| mb_debug("init page %lu\n", page->index); |
| |
| inode = page->mapping->host; |
| sb = inode->i_sb; |
| blocksize = 1 << inode->i_blkbits; |
| blocks_per_page = PAGE_CACHE_SIZE / blocksize; |
| |
| groups_per_page = blocks_per_page >> 1; |
| if (groups_per_page == 0) |
| groups_per_page = 1; |
| |
| /* allocate buffer_heads to read bitmaps */ |
| if (groups_per_page > 1) { |
| err = -ENOMEM; |
| i = sizeof(struct buffer_head *) * groups_per_page; |
| bh = kzalloc(i, GFP_NOFS); |
| if (bh == NULL) |
| goto out; |
| } else |
| bh = &bhs; |
| |
| first_group = page->index * blocks_per_page / 2; |
| |
| /* read all groups the page covers into the cache */ |
| for (i = 0; i < groups_per_page; i++) { |
| struct ext4_group_desc *desc; |
| |
| if (first_group + i >= EXT4_SB(sb)->s_groups_count) |
| break; |
| |
| err = -EIO; |
| desc = ext4_get_group_desc(sb, first_group + i, NULL); |
| if (desc == NULL) |
| goto out; |
| |
| err = -ENOMEM; |
| bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc)); |
| if (bh[i] == NULL) |
| goto out; |
| |
| if (bh_uptodate_or_lock(bh[i])) |
| continue; |
| |
| if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| ext4_init_block_bitmap(sb, bh[i], |
| first_group + i, desc); |
| set_buffer_uptodate(bh[i]); |
| unlock_buffer(bh[i]); |
| continue; |
| } |
| get_bh(bh[i]); |
| bh[i]->b_end_io = end_buffer_read_sync; |
| submit_bh(READ, bh[i]); |
| mb_debug("read bitmap for group %lu\n", first_group + i); |
| } |
| |
| /* wait for I/O completion */ |
| for (i = 0; i < groups_per_page && bh[i]; i++) |
| wait_on_buffer(bh[i]); |
| |
| err = -EIO; |
| for (i = 0; i < groups_per_page && bh[i]; i++) |
| if (!buffer_uptodate(bh[i])) |
| goto out; |
| |
| first_block = page->index * blocks_per_page; |
| for (i = 0; i < blocks_per_page; i++) { |
| int group; |
| struct ext4_group_info *grinfo; |
| |
| group = (first_block + i) >> 1; |
| if (group >= EXT4_SB(sb)->s_groups_count) |
| break; |
| |
| /* |
| * data carry information regarding this |
| * particular group in the format specified |
| * above |
| * |
| */ |
| data = page_address(page) + (i * blocksize); |
| bitmap = bh[group - first_group]->b_data; |
| |
| /* |
| * We place the buddy block and bitmap block |
| * close together |
| */ |
| if ((first_block + i) & 1) { |
| /* this is block of buddy */ |
| BUG_ON(incore == NULL); |
| mb_debug("put buddy for group %u in page %lu/%x\n", |
| group, page->index, i * blocksize); |
| memset(data, 0xff, blocksize); |
| grinfo = ext4_get_group_info(sb, group); |
| grinfo->bb_fragments = 0; |
| memset(grinfo->bb_counters, 0, |
| sizeof(unsigned short)*(sb->s_blocksize_bits+2)); |
| /* |
| * incore got set to the group block bitmap below |
| */ |
| ext4_mb_generate_buddy(sb, data, incore, group); |
| incore = NULL; |
| } else { |
| /* this is block of bitmap */ |
| BUG_ON(incore != NULL); |
| mb_debug("put bitmap for group %u in page %lu/%x\n", |
| group, page->index, i * blocksize); |
| |
| /* see comments in ext4_mb_put_pa() */ |
| ext4_lock_group(sb, group); |
| memcpy(data, bitmap, blocksize); |
| |
| /* mark all preallocated blks used in in-core bitmap */ |
| ext4_mb_generate_from_pa(sb, data, group); |
| ext4_unlock_group(sb, group); |
| |
| /* set incore so that the buddy information can be |
| * generated using this |
| */ |
| incore = data; |
| } |
| } |
| SetPageUptodate(page); |
| |
| out: |
| if (bh) { |
| for (i = 0; i < groups_per_page && bh[i]; i++) |
| brelse(bh[i]); |
| if (bh != &bhs) |
| kfree(bh); |
| } |
| return err; |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct inode *inode = sbi->s_buddy_cache; |
| int blocks_per_page; |
| int block; |
| int pnum; |
| int poff; |
| struct page *page; |
| |
| mb_debug("load group %lu\n", group); |
| |
| blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; |
| |
| e4b->bd_blkbits = sb->s_blocksize_bits; |
| e4b->bd_info = ext4_get_group_info(sb, group); |
| e4b->bd_sb = sb; |
| e4b->bd_group = group; |
| e4b->bd_buddy_page = NULL; |
| e4b->bd_bitmap_page = NULL; |
| |
| /* |
| * the buddy cache inode stores the block bitmap |
| * and buddy information in consecutive blocks. |
| * So for each group we need two blocks. |
| */ |
| block = group * 2; |
| pnum = block / blocks_per_page; |
| poff = block % blocks_per_page; |
| |
| /* we could use find_or_create_page(), but it locks page |
| * what we'd like to avoid in fast path ... */ |
| page = find_get_page(inode->i_mapping, pnum); |
| if (page == NULL || !PageUptodate(page)) { |
| if (page) |
| page_cache_release(page); |
| page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); |
| if (page) { |
| BUG_ON(page->mapping != inode->i_mapping); |
| if (!PageUptodate(page)) { |
| ext4_mb_init_cache(page, NULL); |
| mb_cmp_bitmaps(e4b, page_address(page) + |
| (poff * sb->s_blocksize)); |
| } |
| unlock_page(page); |
| } |
| } |
| if (page == NULL || !PageUptodate(page)) |
| goto err; |
| e4b->bd_bitmap_page = page; |
| e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); |
| mark_page_accessed(page); |
| |
| block++; |
| pnum = block / blocks_per_page; |
| poff = block % blocks_per_page; |
| |
| page = find_get_page(inode->i_mapping, pnum); |
| if (page == NULL || !PageUptodate(page)) { |
| if (page) |
| page_cache_release(page); |
| page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); |
| if (page) { |
| BUG_ON(page->mapping != inode->i_mapping); |
| if (!PageUptodate(page)) |
| ext4_mb_init_cache(page, e4b->bd_bitmap); |
| |
| unlock_page(page); |
| } |
| } |
| if (page == NULL || !PageUptodate(page)) |
| goto err; |
| e4b->bd_buddy_page = page; |
| e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize); |
| mark_page_accessed(page); |
| |
| BUG_ON(e4b->bd_bitmap_page == NULL); |
| BUG_ON(e4b->bd_buddy_page == NULL); |
| |
| return 0; |
| |
| err: |
| if (e4b->bd_bitmap_page) |
| page_cache_release(e4b->bd_bitmap_page); |
| if (e4b->bd_buddy_page) |
| page_cache_release(e4b->bd_buddy_page); |
| e4b->bd_buddy = NULL; |
| e4b->bd_bitmap = NULL; |
| return -EIO; |
| } |
| |
| static void ext4_mb_release_desc(struct ext4_buddy *e4b) |
| { |
| if (e4b->bd_bitmap_page) |
| page_cache_release(e4b->bd_bitmap_page); |
| if (e4b->bd_buddy_page) |
| page_cache_release(e4b->bd_buddy_page); |
| } |
| |
| |
| static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) |
| { |
| int order = 1; |
| void *bb; |
| |
| BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); |
| BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); |
| |
| bb = EXT4_MB_BUDDY(e4b); |
| while (order <= e4b->bd_blkbits + 1) { |
| block = block >> 1; |
| if (!mb_test_bit(block, bb)) { |
| /* this block is part of buddy of order 'order' */ |
| return order; |
| } |
| bb += 1 << (e4b->bd_blkbits - order); |
| order++; |
| } |
| return 0; |
| } |
| |
| static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len) |
| { |
| __u32 *addr; |
| |
| len = cur + len; |
| while (cur < len) { |
| if ((cur & 31) == 0 && (len - cur) >= 32) { |
| /* fast path: clear whole word at once */ |
| addr = bm + (cur >> 3); |
| *addr = 0; |
| cur += 32; |
| continue; |
| } |
| mb_clear_bit_atomic(lock, cur, bm); |
| cur++; |
| } |
| } |
| |
| static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len) |
| { |
| __u32 *addr; |
| |
| len = cur + len; |
| while (cur < len) { |
| if ((cur & 31) == 0 && (len - cur) >= 32) { |
| /* fast path: set whole word at once */ |
| addr = bm + (cur >> 3); |
| *addr = 0xffffffff; |
| cur += 32; |
| continue; |
| } |
| mb_set_bit_atomic(lock, cur, bm); |
| cur++; |
| } |
| } |
| |
| static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| int block = 0; |
| int max = 0; |
| int order; |
| void *buddy; |
| void *buddy2; |
| struct super_block *sb = e4b->bd_sb; |
| |
| BUG_ON(first + count > (sb->s_blocksize << 3)); |
| BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); |
| mb_check_buddy(e4b); |
| mb_free_blocks_double(inode, e4b, first, count); |
| |
| e4b->bd_info->bb_free += count; |
| if (first < e4b->bd_info->bb_first_free) |
| e4b->bd_info->bb_first_free = first; |
| |
| /* let's maintain fragments counter */ |
| if (first != 0) |
| block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b)); |
| if (first + count < EXT4_SB(sb)->s_mb_maxs[0]) |
| max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b)); |
| if (block && max) |
| e4b->bd_info->bb_fragments--; |
| else if (!block && !max) |
| e4b->bd_info->bb_fragments++; |
| |
| /* let's maintain buddy itself */ |
| while (count-- > 0) { |
| block = first++; |
| order = 0; |
| |
| if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) { |
| ext4_fsblk_t blocknr; |
| blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb); |
| blocknr += block; |
| blocknr += |
| le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| |
| ext4_error(sb, __func__, "double-free of inode" |
| " %lu's block %llu(bit %u in group %lu)\n", |
| inode ? inode->i_ino : 0, blocknr, block, |
| e4b->bd_group); |
| } |
| mb_clear_bit(block, EXT4_MB_BITMAP(e4b)); |
| e4b->bd_info->bb_counters[order]++; |
| |
| /* start of the buddy */ |
| buddy = mb_find_buddy(e4b, order, &max); |
| |
| do { |
| block &= ~1UL; |
| if (mb_test_bit(block, buddy) || |
| mb_test_bit(block + 1, buddy)) |
| break; |
| |
| /* both the buddies are free, try to coalesce them */ |
| buddy2 = mb_find_buddy(e4b, order + 1, &max); |
| |
| if (!buddy2) |
| break; |
| |
| if (order > 0) { |
| /* for special purposes, we don't set |
| * free bits in bitmap */ |
| mb_set_bit(block, buddy); |
| mb_set_bit(block + 1, buddy); |
| } |
| e4b->bd_info->bb_counters[order]--; |
| e4b->bd_info->bb_counters[order]--; |
| |
| block = block >> 1; |
| order++; |
| e4b->bd_info->bb_counters[order]++; |
| |
| mb_clear_bit(block, buddy2); |
| buddy = buddy2; |
| } while (1); |
| } |
| mb_check_buddy(e4b); |
| |
| return 0; |
| } |
| |
| static int mb_find_extent(struct ext4_buddy *e4b, int order, int block, |
| int needed, struct ext4_free_extent *ex) |
| { |
| int next = block; |
| int max; |
| int ord; |
| void *buddy; |
| |
| BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| BUG_ON(ex == NULL); |
| |
| buddy = mb_find_buddy(e4b, order, &max); |
| BUG_ON(buddy == NULL); |
| BUG_ON(block >= max); |
| if (mb_test_bit(block, buddy)) { |
| ex->fe_len = 0; |
| ex->fe_start = 0; |
| ex->fe_group = 0; |
| return 0; |
| } |
| |
| /* FIXME dorp order completely ? */ |
| if (likely(order == 0)) { |
| /* find actual order */ |
| order = mb_find_order_for_block(e4b, block); |
| block = block >> order; |
| } |
| |
| ex->fe_len = 1 << order; |
| ex->fe_start = block << order; |
| ex->fe_group = e4b->bd_group; |
| |
| /* calc difference from given start */ |
| next = next - ex->fe_start; |
| ex->fe_len -= next; |
| ex->fe_start += next; |
| |
| while (needed > ex->fe_len && |
| (buddy = mb_find_buddy(e4b, order, &max))) { |
| |
| if (block + 1 >= max) |
| break; |
| |
| next = (block + 1) * (1 << order); |
| if (mb_test_bit(next, EXT4_MB_BITMAP(e4b))) |
| break; |
| |
| ord = mb_find_order_for_block(e4b, next); |
| |
| order = ord; |
| block = next >> order; |
| ex->fe_len += 1 << order; |
| } |
| |
| BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))); |
| return ex->fe_len; |
| } |
| |
| static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) |
| { |
| int ord; |
| int mlen = 0; |
| int max = 0; |
| int cur; |
| int start = ex->fe_start; |
| int len = ex->fe_len; |
| unsigned ret = 0; |
| int len0 = len; |
| void *buddy; |
| |
| BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); |
| BUG_ON(e4b->bd_group != ex->fe_group); |
| BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| mb_check_buddy(e4b); |
| mb_mark_used_double(e4b, start, len); |
| |
| e4b->bd_info->bb_free -= len; |
| if (e4b->bd_info->bb_first_free == start) |
| e4b->bd_info->bb_first_free += len; |
| |
| /* let's maintain fragments counter */ |
| if (start != 0) |
| mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b)); |
| if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) |
| max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b)); |
| if (mlen && max) |
| e4b->bd_info->bb_fragments++; |
| else if (!mlen && !max) |
| e4b->bd_info->bb_fragments--; |
| |
| /* let's maintain buddy itself */ |
| while (len) { |
| ord = mb_find_order_for_block(e4b, start); |
| |
| if (((start >> ord) << ord) == start && len >= (1 << ord)) { |
| /* the whole chunk may be allocated at once! */ |
| mlen = 1 << ord; |
| buddy = mb_find_buddy(e4b, ord, &max); |
| BUG_ON((start >> ord) >= max); |
| mb_set_bit(start >> ord, buddy); |
| e4b->bd_info->bb_counters[ord]--; |
| start += mlen; |
| len -= mlen; |
| BUG_ON(len < 0); |
| continue; |
| } |
| |
| /* store for history */ |
| if (ret == 0) |
| ret = len | (ord << 16); |
| |
| /* we have to split large buddy */ |
| BUG_ON(ord <= 0); |
| buddy = mb_find_buddy(e4b, ord, &max); |
| mb_set_bit(start >> ord, buddy); |
| e4b->bd_info->bb_counters[ord]--; |
| |
| ord--; |
| cur = (start >> ord) & ~1U; |
| buddy = mb_find_buddy(e4b, ord, &max); |
| mb_clear_bit(cur, buddy); |
| mb_clear_bit(cur + 1, buddy); |
| e4b->bd_info->bb_counters[ord]++; |
| e4b->bd_info->bb_counters[ord]++; |
| } |
| |
| mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group), |
| EXT4_MB_BITMAP(e4b), ex->fe_start, len0); |
| mb_check_buddy(e4b); |
| |
| return ret; |
| } |
| |
| /* |
| * Must be called under group lock! |
| */ |
| static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| int ret; |
| |
| BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); |
| BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| |
| ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); |
| ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; |
| ret = mb_mark_used(e4b, &ac->ac_b_ex); |
| |
| /* preallocation can change ac_b_ex, thus we store actually |
| * allocated blocks for history */ |
| ac->ac_f_ex = ac->ac_b_ex; |
| |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_tail = ret & 0xffff; |
| ac->ac_buddy = ret >> 16; |
| |
| /* XXXXXXX: SUCH A HORRIBLE **CK */ |
| /*FIXME!! Why ? */ |
| ac->ac_bitmap_page = e4b->bd_bitmap_page; |
| get_page(ac->ac_bitmap_page); |
| ac->ac_buddy_page = e4b->bd_buddy_page; |
| get_page(ac->ac_buddy_page); |
| |
| /* store last allocated for subsequent stream allocation */ |
| if ((ac->ac_flags & EXT4_MB_HINT_DATA)) { |
| spin_lock(&sbi->s_md_lock); |
| sbi->s_mb_last_group = ac->ac_f_ex.fe_group; |
| sbi->s_mb_last_start = ac->ac_f_ex.fe_start; |
| spin_unlock(&sbi->s_md_lock); |
| } |
| } |
| |
| /* |
| * regular allocator, for general purposes allocation |
| */ |
| |
| static void ext4_mb_check_limits(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b, |
| int finish_group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_free_extent *bex = &ac->ac_b_ex; |
| struct ext4_free_extent *gex = &ac->ac_g_ex; |
| struct ext4_free_extent ex; |
| int max; |
| |
| /* |
| * We don't want to scan for a whole year |
| */ |
| if (ac->ac_found > sbi->s_mb_max_to_scan && |
| !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| ac->ac_status = AC_STATUS_BREAK; |
| return; |
| } |
| |
| /* |
| * Haven't found good chunk so far, let's continue |
| */ |
| if (bex->fe_len < gex->fe_len) |
| return; |
| |
| if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) |
| && bex->fe_group == e4b->bd_group) { |
| /* recheck chunk's availability - we don't know |
| * when it was found (within this lock-unlock |
| * period or not) */ |
| max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex); |
| if (max >= gex->fe_len) { |
| ext4_mb_use_best_found(ac, e4b); |
| return; |
| } |
| } |
| } |
| |
| /* |
| * The routine checks whether found extent is good enough. If it is, |
| * then the extent gets marked used and flag is set to the context |
| * to stop scanning. Otherwise, the extent is compared with the |
| * previous found extent and if new one is better, then it's stored |
| * in the context. Later, the best found extent will be used, if |
| * mballoc can't find good enough extent. |
| * |
| * FIXME: real allocation policy is to be designed yet! |
| */ |
| static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, |
| struct ext4_free_extent *ex, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_free_extent *bex = &ac->ac_b_ex; |
| struct ext4_free_extent *gex = &ac->ac_g_ex; |
| |
| BUG_ON(ex->fe_len <= 0); |
| BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); |
| |
| ac->ac_found++; |
| |
| /* |
| * The special case - take what you catch first |
| */ |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| *bex = *ex; |
| ext4_mb_use_best_found(ac, e4b); |
| return; |
| } |
| |
| /* |
| * Let's check whether the chuck is good enough |
| */ |
| if (ex->fe_len == gex->fe_len) { |
| *bex = *ex; |
| ext4_mb_use_best_found(ac, e4b); |
| return; |
| } |
| |
| /* |
| * If this is first found extent, just store it in the context |
| */ |
| if (bex->fe_len == 0) { |
| *bex = *ex; |
| return; |
| } |
| |
| /* |
| * If new found extent is better, store it in the context |
| */ |
| if (bex->fe_len < gex->fe_len) { |
| /* if the request isn't satisfied, any found extent |
| * larger than previous best one is better */ |
| if (ex->fe_len > bex->fe_len) |
| *bex = *ex; |
| } else if (ex->fe_len > gex->fe_len) { |
| /* if the request is satisfied, then we try to find |
| * an extent that still satisfy the request, but is |
| * smaller than previous one */ |
| if (ex->fe_len < bex->fe_len) |
| *bex = *ex; |
| } |
| |
| ext4_mb_check_limits(ac, e4b, 0); |
| } |
| |
| static int ext4_mb_try_best_found(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_free_extent ex = ac->ac_b_ex; |
| ext4_group_t group = ex.fe_group; |
| int max; |
| int err; |
| |
| BUG_ON(ex.fe_len <= 0); |
| err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| if (err) |
| return err; |
| |
| ext4_lock_group(ac->ac_sb, group); |
| max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex); |
| |
| if (max > 0) { |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| |
| ext4_unlock_group(ac->ac_sb, group); |
| ext4_mb_release_desc(e4b); |
| |
| return 0; |
| } |
| |
| static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| ext4_group_t group = ac->ac_g_ex.fe_group; |
| int max; |
| int err; |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_super_block *es = sbi->s_es; |
| struct ext4_free_extent ex; |
| |
| if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL)) |
| return 0; |
| |
| err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| if (err) |
| return err; |
| |
| ext4_lock_group(ac->ac_sb, group); |
| max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start, |
| ac->ac_g_ex.fe_len, &ex); |
| |
| if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) { |
| ext4_fsblk_t start; |
| |
| start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) + |
| ex.fe_start + le32_to_cpu(es->s_first_data_block); |
| /* use do_div to get remainder (would be 64-bit modulo) */ |
| if (do_div(start, sbi->s_stripe) == 0) { |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| } else if (max >= ac->ac_g_ex.fe_len) { |
| BUG_ON(ex.fe_len <= 0); |
| BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { |
| /* Sometimes, caller may want to merge even small |
| * number of blocks to an existing extent */ |
| BUG_ON(ex.fe_len <= 0); |
| BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| ext4_unlock_group(ac->ac_sb, group); |
| ext4_mb_release_desc(e4b); |
| |
| return 0; |
| } |
| |
| /* |
| * The routine scans buddy structures (not bitmap!) from given order |
| * to max order and tries to find big enough chunk to satisfy the req |
| */ |
| static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_group_info *grp = e4b->bd_info; |
| void *buddy; |
| int i; |
| int k; |
| int max; |
| |
| BUG_ON(ac->ac_2order <= 0); |
| for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) { |
| if (grp->bb_counters[i] == 0) |
| continue; |
| |
| buddy = mb_find_buddy(e4b, i, &max); |
| BUG_ON(buddy == NULL); |
| |
| k = mb_find_next_zero_bit(buddy, max, 0); |
| BUG_ON(k >= max); |
| |
| ac->ac_found++; |
| |
| ac->ac_b_ex.fe_len = 1 << i; |
| ac->ac_b_ex.fe_start = k << i; |
| ac->ac_b_ex.fe_group = e4b->bd_group; |
| |
| ext4_mb_use_best_found(ac, e4b); |
| |
| BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len); |
| |
| if (EXT4_SB(sb)->s_mb_stats) |
| atomic_inc(&EXT4_SB(sb)->s_bal_2orders); |
| |
| break; |
| } |
| } |
| |
| /* |
| * The routine scans the group and measures all found extents. |
| * In order to optimize scanning, caller must pass number of |
| * free blocks in the group, so the routine can know upper limit. |
| */ |
| static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| void *bitmap = EXT4_MB_BITMAP(e4b); |
| struct ext4_free_extent ex; |
| int i; |
| int free; |
| |
| free = e4b->bd_info->bb_free; |
| BUG_ON(free <= 0); |
| |
| i = e4b->bd_info->bb_first_free; |
| |
| while (free && ac->ac_status == AC_STATUS_CONTINUE) { |
| i = mb_find_next_zero_bit(bitmap, |
| EXT4_BLOCKS_PER_GROUP(sb), i); |
| if (i >= EXT4_BLOCKS_PER_GROUP(sb)) { |
| /* |
| * IF we have corrupt bitmap, we won't find any |
| * free blocks even though group info says we |
| * we have free blocks |
| */ |
| ext4_error(sb, __func__, "%d free blocks as per " |
| "group info. But bitmap says 0\n", |
| free); |
| break; |
| } |
| |
| mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex); |
| BUG_ON(ex.fe_len <= 0); |
| if (free < ex.fe_len) { |
| ext4_error(sb, __func__, "%d free blocks as per " |
| "group info. But got %d blocks\n", |
| free, ex.fe_len); |
| /* |
| * The number of free blocks differs. This mostly |
| * indicate that the bitmap is corrupt. So exit |
| * without claiming the space. |
| */ |
| break; |
| } |
| |
| ext4_mb_measure_extent(ac, &ex, e4b); |
| |
| i += ex.fe_len; |
| free -= ex.fe_len; |
| } |
| |
| ext4_mb_check_limits(ac, e4b, 1); |
| } |
| |
| /* |
| * This is a special case for storages like raid5 |
| * we try to find stripe-aligned chunks for stripe-size requests |
| * XXX should do so at least for multiples of stripe size as well |
| */ |
| static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| void *bitmap = EXT4_MB_BITMAP(e4b); |
| struct ext4_free_extent ex; |
| ext4_fsblk_t first_group_block; |
| ext4_fsblk_t a; |
| ext4_grpblk_t i; |
| int max; |
| |
| BUG_ON(sbi->s_stripe == 0); |
| |
| /* find first stripe-aligned block in group */ |
| first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb) |
| + le32_to_cpu(sbi->s_es->s_first_data_block); |
| a = first_group_block + sbi->s_stripe - 1; |
| do_div(a, sbi->s_stripe); |
| i = (a * sbi->s_stripe) - first_group_block; |
| |
| while (i < EXT4_BLOCKS_PER_GROUP(sb)) { |
| if (!mb_test_bit(i, bitmap)) { |
| max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex); |
| if (max >= sbi->s_stripe) { |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| break; |
| } |
| } |
| i += sbi->s_stripe; |
| } |
| } |
| |
| static int ext4_mb_good_group(struct ext4_allocation_context *ac, |
| ext4_group_t group, int cr) |
| { |
| unsigned free, fragments; |
| unsigned i, bits; |
| struct ext4_group_desc *desc; |
| struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
| |
| BUG_ON(cr < 0 || cr >= 4); |
| BUG_ON(EXT4_MB_GRP_NEED_INIT(grp)); |
| |
| free = grp->bb_free; |
| fragments = grp->bb_fragments; |
| if (free == 0) |
| return 0; |
| if (fragments == 0) |
| return 0; |
| |
| switch (cr) { |
| case 0: |
| BUG_ON(ac->ac_2order == 0); |
| /* If this group is uninitialized, skip it initially */ |
| desc = ext4_get_group_desc(ac->ac_sb, group, NULL); |
| if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) |
| return 0; |
| |
| bits = ac->ac_sb->s_blocksize_bits + 1; |
| for (i = ac->ac_2order; i <= bits; i++) |
| if (grp->bb_counters[i] > 0) |
| return 1; |
| break; |
| case 1: |
| if ((free / fragments) >= ac->ac_g_ex.fe_len) |
| return 1; |
| break; |
| case 2: |
| if (free >= ac->ac_g_ex.fe_len) |
| return 1; |
| break; |
| case 3: |
| return 1; |
| default: |
| BUG(); |
| } |
| |
| return 0; |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_regular_allocator(struct ext4_allocation_context *ac) |
| { |
| ext4_group_t group; |
| ext4_group_t i; |
| int cr; |
| int err = 0; |
| int bsbits; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| struct ext4_buddy e4b; |
| loff_t size, isize; |
| |
| sb = ac->ac_sb; |
| sbi = EXT4_SB(sb); |
| BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| |
| /* first, try the goal */ |
| err = ext4_mb_find_by_goal(ac, &e4b); |
| if (err || ac->ac_status == AC_STATUS_FOUND) |
| goto out; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| goto out; |
| |
| /* |
| * ac->ac2_order is set only if the fe_len is a power of 2 |
| * if ac2_order is set we also set criteria to 0 so that we |
| * try exact allocation using buddy. |
| */ |
| i = fls(ac->ac_g_ex.fe_len); |
| ac->ac_2order = 0; |
| /* |
| * We search using buddy data only if the order of the request |
| * is greater than equal to the sbi_s_mb_order2_reqs |
| * You can tune it via /proc/fs/ext4/<partition>/order2_req |
| */ |
| if (i >= sbi->s_mb_order2_reqs) { |
| /* |
| * This should tell if fe_len is exactly power of 2 |
| */ |
| if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0) |
| ac->ac_2order = i - 1; |
| } |
| |
| bsbits = ac->ac_sb->s_blocksize_bits; |
| /* if stream allocation is enabled, use global goal */ |
| size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| isize = i_size_read(ac->ac_inode) >> bsbits; |
| if (size < isize) |
| size = isize; |
| |
| if (size < sbi->s_mb_stream_request && |
| (ac->ac_flags & EXT4_MB_HINT_DATA)) { |
| /* TBD: may be hot point */ |
| spin_lock(&sbi->s_md_lock); |
| ac->ac_g_ex.fe_group = sbi->s_mb_last_group; |
| ac->ac_g_ex.fe_start = sbi->s_mb_last_start; |
| spin_unlock(&sbi->s_md_lock); |
| } |
| |
| /* searching for the right group start from the goal value specified */ |
| group = ac->ac_g_ex.fe_group; |
| |
| /* Let's just scan groups to find more-less suitable blocks */ |
| cr = ac->ac_2order ? 0 : 1; |
| /* |
| * cr == 0 try to get exact allocation, |
| * cr == 3 try to get anything |
| */ |
| repeat: |
| for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) { |
| ac->ac_criteria = cr; |
| for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) { |
| struct ext4_group_info *grp; |
| struct ext4_group_desc *desc; |
| |
| if (group == EXT4_SB(sb)->s_groups_count) |
| group = 0; |
| |
| /* quick check to skip empty groups */ |
| grp = ext4_get_group_info(ac->ac_sb, group); |
| if (grp->bb_free == 0) |
| continue; |
| |
| /* |
| * if the group is already init we check whether it is |
| * a good group and if not we don't load the buddy |
| */ |
| if (EXT4_MB_GRP_NEED_INIT(grp)) { |
| /* |
| * we need full data about the group |
| * to make a good selection |
| */ |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) |
| goto out; |
| ext4_mb_release_desc(&e4b); |
| } |
| |
| /* |
| * If the particular group doesn't satisfy our |
| * criteria we continue with the next group |
| */ |
| if (!ext4_mb_good_group(ac, group, cr)) |
| continue; |
| |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) |
| goto out; |
| |
| ext4_lock_group(sb, group); |
| if (!ext4_mb_good_group(ac, group, cr)) { |
| /* someone did allocation from this group */ |
| ext4_unlock_group(sb, group); |
| ext4_mb_release_desc(&e4b); |
| continue; |
| } |
| |
| ac->ac_groups_scanned++; |
| desc = ext4_get_group_desc(sb, group, NULL); |
| if (cr == 0 || (desc->bg_flags & |
| cpu_to_le16(EXT4_BG_BLOCK_UNINIT) && |
| ac->ac_2order != 0)) |
| ext4_mb_simple_scan_group(ac, &e4b); |
| else if (cr == 1 && |
| ac->ac_g_ex.fe_len == sbi->s_stripe) |
| ext4_mb_scan_aligned(ac, &e4b); |
| else |
| ext4_mb_complex_scan_group(ac, &e4b); |
| |
| ext4_unlock_group(sb, group); |
| ext4_mb_release_desc(&e4b); |
| |
| if (ac->ac_status != AC_STATUS_CONTINUE) |
| break; |
| } |
| } |
| |
| if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && |
| !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| /* |
| * We've been searching too long. Let's try to allocate |
| * the best chunk we've found so far |
| */ |
| |
| ext4_mb_try_best_found(ac, &e4b); |
| if (ac->ac_status != AC_STATUS_FOUND) { |
| /* |
| * Someone more lucky has already allocated it. |
| * The only thing we can do is just take first |
| * found block(s) |
| printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n"); |
| */ |
| ac->ac_b_ex.fe_group = 0; |
| ac->ac_b_ex.fe_start = 0; |
| ac->ac_b_ex.fe_len = 0; |
| ac->ac_status = AC_STATUS_CONTINUE; |
| ac->ac_flags |= EXT4_MB_HINT_FIRST; |
| cr = 3; |
| atomic_inc(&sbi->s_mb_lost_chunks); |
| goto repeat; |
| } |
| } |
| out: |
| return err; |
| } |
| |
| #ifdef EXT4_MB_HISTORY |
| struct ext4_mb_proc_session { |
| struct ext4_mb_history *history; |
| struct super_block *sb; |
| int start; |
| int max; |
| }; |
| |
| static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s, |
| struct ext4_mb_history *hs, |
| int first) |
| { |
| if (hs == s->history + s->max) |
| hs = s->history; |
| if (!first && hs == s->history + s->start) |
| return NULL; |
| while (hs->orig.fe_len == 0) { |
| hs++; |
| if (hs == s->history + s->max) |
| hs = s->history; |
| if (hs == s->history + s->start) |
| return NULL; |
| } |
| return hs; |
| } |
| |
| static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct ext4_mb_proc_session *s = seq->private; |
| struct ext4_mb_history *hs; |
| int l = *pos; |
| |
| if (l == 0) |
| return SEQ_START_TOKEN; |
| hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1); |
| if (!hs) |
| return NULL; |
| while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL); |
| return hs; |
| } |
| |
| static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v, |
| loff_t *pos) |
| { |
| struct ext4_mb_proc_session *s = seq->private; |
| struct ext4_mb_history *hs = v; |
| |
| ++*pos; |
| if (v == SEQ_START_TOKEN) |
| return ext4_mb_history_skip_empty(s, s->history + s->start, 1); |
| else |
| return ext4_mb_history_skip_empty(s, ++hs, 0); |
| } |
| |
| static int ext4_mb_seq_history_show(struct seq_file *seq, void *v) |
| { |
| char buf[25], buf2[25], buf3[25], *fmt; |
| struct ext4_mb_history *hs = v; |
| |
| if (v == SEQ_START_TOKEN) { |
| seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s " |
| "%-5s %-2s %-5s %-5s %-5s %-6s\n", |
| "pid", "inode", "original", "goal", "result", "found", |
| "grps", "cr", "flags", "merge", "tail", "broken"); |
| return 0; |
| } |
| |
| if (hs->op == EXT4_MB_HISTORY_ALLOC) { |
| fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u " |
| "%-5u %-5s %-5u %-6u\n"; |
| sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group, |
| hs->result.fe_start, hs->result.fe_len, |
| hs->result.fe_logical); |
| sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group, |
| hs->orig.fe_start, hs->orig.fe_len, |
| hs->orig.fe_logical); |
| sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group, |
| hs->goal.fe_start, hs->goal.fe_len, |
| hs->goal.fe_logical); |
| seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2, |
| hs->found, hs->groups, hs->cr, hs->flags, |
| hs->merged ? "M" : "", hs->tail, |
| hs->buddy ? 1 << hs->buddy : 0); |
| } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) { |
| fmt = "%-5u %-8u %-23s %-23s %-23s\n"; |
| sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group, |
| hs->result.fe_start, hs->result.fe_len, |
| hs->result.fe_logical); |
| sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group, |
| hs->orig.fe_start, hs->orig.fe_len, |
| hs->orig.fe_logical); |
| seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2); |
| } else if (hs->op == EXT4_MB_HISTORY_DISCARD) { |
| sprintf(buf2, "%lu/%d/%u", hs->result.fe_group, |
| hs->result.fe_start, hs->result.fe_len); |
| seq_printf(seq, "%-5u %-8u %-23s discard\n", |
| hs->pid, hs->ino, buf2); |
| } else if (hs->op == EXT4_MB_HISTORY_FREE) { |
| sprintf(buf2, "%lu/%d/%u", hs->result.fe_group, |
| hs->result.fe_start, hs->result.fe_len); |
| seq_printf(seq, "%-5u %-8u %-23s free\n", |
| hs->pid, hs->ino, buf2); |
| } |
| return 0; |
| } |
| |
| static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| static struct seq_operations ext4_mb_seq_history_ops = { |
| .start = ext4_mb_seq_history_start, |
| .next = ext4_mb_seq_history_next, |
| .stop = ext4_mb_seq_history_stop, |
| .show = ext4_mb_seq_history_show, |
| }; |
| |
| static int ext4_mb_seq_history_open(struct inode *inode, struct file *file) |
| { |
| struct super_block *sb = PDE(inode)->data; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_mb_proc_session *s; |
| int rc; |
| int size; |
| |
| s = kmalloc(sizeof(*s), GFP_KERNEL); |
| if (s == NULL) |
| return -ENOMEM; |
| s->sb = sb; |
| size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max; |
| s->history = kmalloc(size, GFP_KERNEL); |
| if (s->history == NULL) { |
| kfree(s); |
| return -ENOMEM; |
| } |
| |
| spin_lock(&sbi->s_mb_history_lock); |
| memcpy(s->history, sbi->s_mb_history, size); |
| s->max = sbi->s_mb_history_max; |
| s->start = sbi->s_mb_history_cur % s->max; |
| spin_unlock(&sbi->s_mb_history_lock); |
| |
| rc = seq_open(file, &ext4_mb_seq_history_ops); |
| if (rc == 0) { |
| struct seq_file *m = (struct seq_file *)file->private_data; |
| m->private = s; |
| } else { |
| kfree(s->history); |
| kfree(s); |
| } |
| return rc; |
| |
| } |
| |
| static int ext4_mb_seq_history_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *seq = (struct seq_file *)file->private_data; |
| struct ext4_mb_proc_session *s = seq->private; |
| kfree(s->history); |
| kfree(s); |
| return seq_release(inode, file); |
| } |
| |
| static ssize_t ext4_mb_seq_history_write(struct file *file, |
| const char __user *buffer, |
| size_t count, loff_t *ppos) |
| { |
| struct seq_file *seq = (struct seq_file *)file->private_data; |
| struct ext4_mb_proc_session *s = seq->private; |
| struct super_block *sb = s->sb; |
| char str[32]; |
| int value; |
| |
| if (count >= sizeof(str)) { |
| printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n", |
| "mb_history", (int)sizeof(str)); |
| return -EOVERFLOW; |
| } |
| |
| if (copy_from_user(str, buffer, count)) |
| return -EFAULT; |
| |
| value = simple_strtol(str, NULL, 0); |
| if (value < 0) |
| return -ERANGE; |
| EXT4_SB(sb)->s_mb_history_filter = value; |
| |
| return count; |
| } |
| |
| static struct file_operations ext4_mb_seq_history_fops = { |
| .owner = THIS_MODULE, |
| .open = ext4_mb_seq_history_open, |
| .read = seq_read, |
| .write = ext4_mb_seq_history_write, |
| .llseek = seq_lseek, |
| .release = ext4_mb_seq_history_release, |
| }; |
| |
| static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct super_block *sb = seq->private; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_group_t group; |
| |
| if (*pos < 0 || *pos >= sbi->s_groups_count) |
| return NULL; |
| |
| group = *pos + 1; |
| return (void *) group; |
| } |
| |
| static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct super_block *sb = seq->private; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_group_t group; |
| |
| ++*pos; |
| if (*pos < 0 || *pos >= sbi->s_groups_count) |
| return NULL; |
| group = *pos + 1; |
| return (void *) group;; |
| } |
| |
| static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) |
| { |
| struct super_block *sb = seq->private; |
| long group = (long) v; |
| int i; |
| int err; |
| struct ext4_buddy e4b; |
| struct sg { |
| struct ext4_group_info info; |
| unsigned short counters[16]; |
| } sg; |
| |
| group--; |
| if (group == 0) |
| seq_printf(seq, "#%-5s: %-5s %-5s %-5s " |
| "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s " |
| "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n", |
| "group", "free", "frags", "first", |
| "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6", |
| "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13"); |
| |
| i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + |
| sizeof(struct ext4_group_info); |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) { |
| seq_printf(seq, "#%-5lu: I/O error\n", group); |
| return 0; |
| } |
| ext4_lock_group(sb, group); |
| memcpy(&sg, ext4_get_group_info(sb, group), i); |
| ext4_unlock_group(sb, group); |
| ext4_mb_release_desc(&e4b); |
| |
| seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free, |
| sg.info.bb_fragments, sg.info.bb_first_free); |
| for (i = 0; i <= 13; i++) |
| seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ? |
| sg.info.bb_counters[i] : 0); |
| seq_printf(seq, " ]\n"); |
| |
| return 0; |
| } |
| |
| static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| static struct seq_operations ext4_mb_seq_groups_ops = { |
| .start = ext4_mb_seq_groups_start, |
| .next = ext4_mb_seq_groups_next, |
| .stop = ext4_mb_seq_groups_stop, |
| .show = ext4_mb_seq_groups_show, |
| }; |
| |
| static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file) |
| { |
| struct super_block *sb = PDE(inode)->data; |
| int rc; |
| |
| rc = seq_open(file, &ext4_mb_seq_groups_ops); |
| if (rc == 0) { |
| struct seq_file *m = (struct seq_file *)file->private_data; |
| m->private = sb; |
| } |
| return rc; |
| |
| } |
| |
| static struct file_operations ext4_mb_seq_groups_fops = { |
| .owner = THIS_MODULE, |
| .open = ext4_mb_seq_groups_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| static void ext4_mb_history_release(struct super_block *sb) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| remove_proc_entry("mb_groups", sbi->s_mb_proc); |
| remove_proc_entry("mb_history", sbi->s_mb_proc); |
| |
| kfree(sbi->s_mb_history); |
| } |
| |
| static void ext4_mb_history_init(struct super_block *sb) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int i; |
| |
| if (sbi->s_mb_proc != NULL) { |
| proc_create_data("mb_history", S_IRUGO, sbi->s_mb_proc, |
| &ext4_mb_seq_history_fops, sb); |
| proc_create_data("mb_groups", S_IRUGO, sbi->s_mb_proc, |
| &ext4_mb_seq_groups_fops, sb); |
| } |
| |
| sbi->s_mb_history_max = 1000; |
| sbi->s_mb_history_cur = 0; |
| spin_lock_init(&sbi->s_mb_history_lock); |
| i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history); |
| sbi->s_mb_history = kmalloc(i, GFP_KERNEL); |
| if (likely(sbi->s_mb_history != NULL)) |
| memset(sbi->s_mb_history, 0, i); |
| /* if we can't allocate history, then we simple won't use it */ |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_store_history(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_mb_history h; |
| |
| if (unlikely(sbi->s_mb_history == NULL)) |
| return; |
| |
| if (!(ac->ac_op & sbi->s_mb_history_filter)) |
| return; |
| |
| h.op = ac->ac_op; |
| h.pid = current->pid; |
| h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0; |
| h.orig = ac->ac_o_ex; |
| h.result = ac->ac_b_ex; |
| h.flags = ac->ac_flags; |
| h.found = ac->ac_found; |
| h.groups = ac->ac_groups_scanned; |
| h.cr = ac->ac_criteria; |
| h.tail = ac->ac_tail; |
| h.buddy = ac->ac_buddy; |
| h.merged = 0; |
| if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) { |
| if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
| ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
| h.merged = 1; |
| h.goal = ac->ac_g_ex; |
| h.result = ac->ac_f_ex; |
| } |
| |
| spin_lock(&sbi->s_mb_history_lock); |
| memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h)); |
| if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max) |
| sbi->s_mb_history_cur = 0; |
| spin_unlock(&sbi->s_mb_history_lock); |
| } |
| |
| #else |
| #define ext4_mb_history_release(sb) |
| #define ext4_mb_history_init(sb) |
| #endif |
| |
| static int ext4_mb_init_backend(struct super_block *sb) |
| { |
| ext4_group_t i; |
| int j, len, metalen; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int num_meta_group_infos = |
| (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| EXT4_DESC_PER_BLOCK_BITS(sb); |
| struct ext4_group_info **meta_group_info; |
| |
| /* An 8TB filesystem with 64-bit pointers requires a 4096 byte |
| * kmalloc. A 128kb malloc should suffice for a 256TB filesystem. |
| * So a two level scheme suffices for now. */ |
| sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) * |
| num_meta_group_infos, GFP_KERNEL); |
| if (sbi->s_group_info == NULL) { |
| printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n"); |
| return -ENOMEM; |
| } |
| sbi->s_buddy_cache = new_inode(sb); |
| if (sbi->s_buddy_cache == NULL) { |
| printk(KERN_ERR "EXT4-fs: can't get new inode\n"); |
| goto err_freesgi; |
| } |
| EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; |
| |
| metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb); |
| for (i = 0; i < num_meta_group_infos; i++) { |
| if ((i + 1) == num_meta_group_infos) |
| metalen = sizeof(*meta_group_info) * |
| (sbi->s_groups_count - |
| (i << EXT4_DESC_PER_BLOCK_BITS(sb))); |
| meta_group_info = kmalloc(metalen, GFP_KERNEL); |
| if (meta_group_info == NULL) { |
| printk(KERN_ERR "EXT4-fs: can't allocate mem for a " |
| "buddy group\n"); |
| goto err_freemeta; |
| } |
| sbi->s_group_info[i] = meta_group_info; |
| } |
| |
| /* |
| * calculate needed size. if change bb_counters size, |
| * don't forget about ext4_mb_generate_buddy() |
| */ |
| len = sizeof(struct ext4_group_info); |
| len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2); |
| for (i = 0; i < sbi->s_groups_count; i++) { |
| struct ext4_group_desc *desc; |
| |
| meta_group_info = |
| sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)]; |
| j = i & (EXT4_DESC_PER_BLOCK(sb) - 1); |
| |
| meta_group_info[j] = kzalloc(len, GFP_KERNEL); |
| if (meta_group_info[j] == NULL) { |
| printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n"); |
| goto err_freebuddy; |
| } |
| desc = ext4_get_group_desc(sb, i, NULL); |
| if (desc == NULL) { |
| printk(KERN_ERR |
| "EXT4-fs: can't read descriptor %lu\n", i); |
| i++; |
| goto err_freebuddy; |
| } |
| memset(meta_group_info[j], 0, len); |
| set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, |
| &(meta_group_info[j]->bb_state)); |
| |
| /* |
| * initialize bb_free to be able to skip |
| * empty groups without initialization |
| */ |
| if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| meta_group_info[j]->bb_free = |
| ext4_free_blocks_after_init(sb, i, desc); |
| } else { |
| meta_group_info[j]->bb_free = |
| le16_to_cpu(desc->bg_free_blocks_count); |
| } |
| |
| INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list); |
| |
| #ifdef DOUBLE_CHECK |
| { |
| struct buffer_head *bh; |
| meta_group_info[j]->bb_bitmap = |
| kmalloc(sb->s_blocksize, GFP_KERNEL); |
| BUG_ON(meta_group_info[j]->bb_bitmap == NULL); |
| bh = read_block_bitmap(sb, i); |
| BUG_ON(bh == NULL); |
| memcpy(meta_group_info[j]->bb_bitmap, bh->b_data, |
| sb->s_blocksize); |
| put_bh(bh); |
| } |
| #endif |
| |
| } |
| |
| return 0; |
| |
| err_freebuddy: |
| while (i-- > 0) |
| kfree(ext4_get_group_info(sb, i)); |
| i = num_meta_group_infos; |
| err_freemeta: |
| while (i-- > 0) |
| kfree(sbi->s_group_info[i]); |
| iput(sbi->s_buddy_cache); |
| err_freesgi: |
| kfree(sbi->s_group_info); |
| return -ENOMEM; |
| } |
| |
| int ext4_mb_init(struct super_block *sb, int needs_recovery) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned i; |
| unsigned offset; |
| unsigned max; |
| |
| if (!test_opt(sb, MBALLOC)) |
| return 0; |
| |
| i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short); |
| |
| sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); |
| if (sbi->s_mb_offsets == NULL) { |
| clear_opt(sbi->s_mount_opt, MBALLOC); |
| return -ENOMEM; |
| } |
| sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); |
| if (sbi->s_mb_maxs == NULL) { |
| clear_opt(sbi->s_mount_opt, MBALLOC); |
| kfree(sbi->s_mb_maxs); |
| return -ENOMEM; |
| } |
| |
| /* order 0 is regular bitmap */ |
| sbi->s_mb_maxs[0] = sb->s_blocksize << 3; |
| sbi->s_mb_offsets[0] = 0; |
| |
| i = 1; |
| offset = 0; |
| max = sb->s_blocksize << 2; |
| do { |
| sbi->s_mb_offsets[i] = offset; |
| sbi->s_mb_maxs[i] = max; |
| offset += 1 << (sb->s_blocksize_bits - i); |
| max = max >> 1; |
| i++; |
| } while (i <= sb->s_blocksize_bits + 1); |
| |
| /* init file for buddy data */ |
| i = ext4_mb_init_backend(sb); |
| if (i) { |
| clear_opt(sbi->s_mount_opt, MBALLOC); |
| kfree(sbi->s_mb_offsets); |
| kfree(sbi->s_mb_maxs); |
| return i; |
| } |
| |
| spin_lock_init(&sbi->s_md_lock); |
| INIT_LIST_HEAD(&sbi->s_active_transaction); |
| INIT_LIST_HEAD(&sbi->s_closed_transaction); |
| INIT_LIST_HEAD(&sbi->s_committed_transaction); |
| spin_lock_init(&sbi->s_bal_lock); |
| |
| sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; |
| sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; |
| sbi->s_mb_stats = MB_DEFAULT_STATS; |
| sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; |
| sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; |
| sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT; |
| sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC; |
| |
| i = sizeof(struct ext4_locality_group) * NR_CPUS; |
| sbi->s_locality_groups = kmalloc(i, GFP_KERNEL); |
| if (sbi->s_locality_groups == NULL) { |
| clear_opt(sbi->s_mount_opt, MBALLOC); |
| kfree(sbi->s_mb_offsets); |
| kfree(sbi->s_mb_maxs); |
| return -ENOMEM; |
| } |
| for (i = 0; i < NR_CPUS; i++) { |
| struct ext4_locality_group *lg; |
| lg = &sbi->s_locality_groups[i]; |
| mutex_init(&lg->lg_mutex); |
| INIT_LIST_HEAD(&lg->lg_prealloc_list); |
| spin_lock_init(&lg->lg_prealloc_lock); |
| } |
| |
| ext4_mb_init_per_dev_proc(sb); |
| ext4_mb_history_init(sb); |
| |
| printk("EXT4-fs: mballoc enabled\n"); |
| return 0; |
| } |
| |
| /* need to called with ext4 group lock (ext4_lock_group) */ |
| static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) |
| { |
| struct ext4_prealloc_space *pa; |
| struct list_head *cur, *tmp; |
| int count = 0; |
| |
| list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| list_del(&pa->pa_group_list); |
| count++; |
| kfree(pa); |
| } |
| if (count) |
| mb_debug("mballoc: %u PAs left\n", count); |
| |
| } |
| |
| int ext4_mb_release(struct super_block *sb) |
| { |
| ext4_group_t i; |
| int num_meta_group_infos; |
| struct ext4_group_info *grinfo; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| if (!test_opt(sb, MBALLOC)) |
| return 0; |
| |
| /* release freed, non-committed blocks */ |
| spin_lock(&sbi->s_md_lock); |
| list_splice_init(&sbi->s_closed_transaction, |
| &sbi->s_committed_transaction); |
| list_splice_init(&sbi->s_active_transaction, |
| &sbi->s_committed_transaction); |
| spin_unlock(&sbi->s_md_lock); |
| ext4_mb_free_committed_blocks(sb); |
| |
| if (sbi->s_group_info) { |
| for (i = 0; i < sbi->s_groups_count; i++) { |
| grinfo = ext4_get_group_info(sb, i); |
| #ifdef DOUBLE_CHECK |
| kfree(grinfo->bb_bitmap); |
| #endif |
| ext4_lock_group(sb, i); |
| ext4_mb_cleanup_pa(grinfo); |
| ext4_unlock_group(sb, i); |
| kfree(grinfo); |
| } |
| num_meta_group_infos = (sbi->s_groups_count + |
| EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| EXT4_DESC_PER_BLOCK_BITS(sb); |
| for (i = 0; i < num_meta_group_infos; i++) |
| kfree(sbi->s_group_info[i]); |
| kfree(sbi->s_group_info); |
| } |
| kfree(sbi->s_mb_offsets); |
| kfree(sbi->s_mb_maxs); |
| if (sbi->s_buddy_cache) |
| iput(sbi->s_buddy_cache); |
| if (sbi->s_mb_stats) { |
| printk(KERN_INFO |
| "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n", |
| atomic_read(&sbi->s_bal_allocated), |
| atomic_read(&sbi->s_bal_reqs), |
| atomic_read(&sbi->s_bal_success)); |
| printk(KERN_INFO |
| "EXT4-fs: mballoc: %u extents scanned, %u goal hits, " |
| "%u 2^N hits, %u breaks, %u lost\n", |
| atomic_read(&sbi->s_bal_ex_scanned), |
| atomic_read(&sbi->s_bal_goals), |
| atomic_read(&sbi->s_bal_2orders), |
| atomic_read(&sbi->s_bal_breaks), |
| atomic_read(&sbi->s_mb_lost_chunks)); |
| printk(KERN_INFO |
| "EXT4-fs: mballoc: %lu generated and it took %Lu\n", |
| sbi->s_mb_buddies_generated++, |
| sbi->s_mb_generation_time); |
| printk(KERN_INFO |
| "EXT4-fs: mballoc: %u preallocated, %u discarded\n", |
| atomic_read(&sbi->s_mb_preallocated), |
| atomic_read(&sbi->s_mb_discarded)); |
| } |
| |
| kfree(sbi->s_locality_groups); |
| |
| ext4_mb_history_release(sb); |
| ext4_mb_destroy_per_dev_proc(sb); |
| |
| return 0; |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_free_committed_blocks(struct super_block *sb) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int err; |
| int i; |
| int count = 0; |
| int count2 = 0; |
| struct ext4_free_metadata *md; |
| struct ext4_buddy e4b; |
| |
| if (list_empty(&sbi->s_committed_transaction)) |
| return; |
| |
| /* there is committed blocks to be freed yet */ |
| do { |
| /* get next array of blocks */ |
| md = NULL; |
| spin_lock(&sbi->s_md_lock); |
| if (!list_empty(&sbi->s_committed_transaction)) { |
| md = list_entry(sbi->s_committed_transaction.next, |
| struct ext4_free_metadata, list); |
| list_del(&md->list); |
| } |
| spin_unlock(&sbi->s_md_lock); |
| |
| if (md == NULL) |
| break; |
| |
| mb_debug("gonna free %u blocks in group %lu (0x%p):", |
| md->num, md->group, md); |
| |
| err = ext4_mb_load_buddy(sb, md->group, &e4b); |
| /* we expect to find existing buddy because it's pinned */ |
| BUG_ON(err != 0); |
| |
| /* there are blocks to put in buddy to make them really free */ |
| count += md->num; |
| count2++; |
| ext4_lock_group(sb, md->group); |
| for (i = 0; i < md->num; i++) { |
| mb_debug(" %u", md->blocks[i]); |
| err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1); |
| BUG_ON(err != 0); |
| } |
| mb_debug("\n"); |
| ext4_unlock_group(sb, md->group); |
| |
| /* balance refcounts from ext4_mb_free_metadata() */ |
| page_cache_release(e4b.bd_buddy_page); |
| page_cache_release(e4b.bd_bitmap_page); |
| |
| kfree(md); |
| ext4_mb_release_desc(&e4b); |
| |
| } while (md); |
| |
| mb_debug("freed %u blocks in %u structures\n", count, count2); |
| } |
| |
| #define EXT4_MB_STATS_NAME "stats" |
| #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan" |
| #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan" |
| #define EXT4_MB_ORDER2_REQ "order2_req" |
| #define EXT4_MB_STREAM_REQ "stream_req" |
| #define EXT4_MB_GROUP_PREALLOC "group_prealloc" |
| |
| |
| |
| #define MB_PROC_VALUE_READ(name) \ |
| static int ext4_mb_read_##name(char *page, char **start, \ |
| off_t off, int count, int *eof, void *data) \ |
| { \ |
| struct ext4_sb_info *sbi = data; \ |
| int len; \ |
| *eof = 1; \ |
| if (off != 0) \ |
| return 0; \ |
| len = sprintf(page, "%ld\n", sbi->s_mb_##name); \ |
| *start = page; \ |
| return len; \ |
| } |
| |
| #define MB_PROC_VALUE_WRITE(name) \ |
| static int ext4_mb_write_##name(struct file *file, \ |
| const char __user *buf, unsigned long cnt, void *data) \ |
| { \ |
| struct ext4_sb_info *sbi = data; \ |
| char str[32]; \ |
| long value; \ |
| if (cnt >= sizeof(str)) \ |
| return -EINVAL; \ |
| if (copy_from_user(str, buf, cnt)) \ |
| return -EFAULT; \ |
| value = simple_strtol(str, NULL, 0); \ |
| if (value <= 0) \ |
| return -ERANGE; \ |
| sbi->s_mb_##name = value; \ |
| return cnt; \ |
| } |
| |
| MB_PROC_VALUE_READ(stats); |
| MB_PROC_VALUE_WRITE(stats); |
| MB_PROC_VALUE_READ(max_to_scan); |
| MB_PROC_VALUE_WRITE(max_to_scan); |
| MB_PROC_VALUE_READ(min_to_scan); |
| MB_PROC_VALUE_WRITE(min_to_scan); |
| MB_PROC_VALUE_READ(order2_reqs); |
| MB_PROC_VALUE_WRITE(order2_reqs); |
| MB_PROC_VALUE_READ(stream_request); |
| MB_PROC_VALUE_WRITE(stream_request); |
| MB_PROC_VALUE_READ(group_prealloc); |
| MB_PROC_VALUE_WRITE(group_prealloc); |
| |
| #define MB_PROC_HANDLER(name, var) \ |
| do { \ |
| proc = create_proc_entry(name, mode, sbi->s_mb_proc); \ |
| if (proc == NULL) { \ |
| printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \ |
| goto err_out; \ |
| } \ |
| proc->data = sbi; \ |
| proc->read_proc = ext4_mb_read_##var ; \ |
| proc->write_proc = ext4_mb_write_##var; \ |
| } while (0) |
| |
| static int ext4_mb_init_per_dev_proc(struct super_block *sb) |
| { |
| mode_t mode = S_IFREG | S_IRUGO | S_IWUSR; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct proc_dir_entry *proc; |
| char devname[64]; |
| |
| bdevname(sb->s_bdev, devname); |
| sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4); |
| |
| MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats); |
| MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan); |
| MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan); |
| MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs); |
| MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request); |
| MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc); |
| |
| return 0; |
| |
| err_out: |
| printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname); |
| remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc); |
| remove_proc_entry(devname, proc_root_ext4); |
| sbi->s_mb_proc = NULL; |
| |
| return -ENOMEM; |
| } |
| |
| static int ext4_mb_destroy_per_dev_proc(struct super_block *sb) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| char devname[64]; |
| |
| if (sbi->s_mb_proc == NULL) |
| return -EINVAL; |
| |
| bdevname(sb->s_bdev, devname); |
| remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc); |
| remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc); |
| remove_proc_entry(devname, proc_root_ext4); |
| |
| return 0; |
| } |
| |
| int __init init_ext4_mballoc(void) |
| { |
| ext4_pspace_cachep = |
| kmem_cache_create("ext4_prealloc_space", |
| sizeof(struct ext4_prealloc_space), |
| 0, SLAB_RECLAIM_ACCOUNT, NULL); |
| if (ext4_pspace_cachep == NULL) |
| return -ENOMEM; |
| |
| ext4_ac_cachep = |
| kmem_cache_create("ext4_alloc_context", |
| sizeof(struct ext4_allocation_context), |
| 0, SLAB_RECLAIM_ACCOUNT, NULL); |
| if (ext4_ac_cachep == NULL) { |
| kmem_cache_destroy(ext4_pspace_cachep); |
| return -ENOMEM; |
| } |
| #ifdef CONFIG_PROC_FS |
| proc_root_ext4 = proc_mkdir("fs/ext4", NULL); |
| if (proc_root_ext4 == NULL) |
| printk(KERN_ERR "EXT4-fs: Unable to create fs/ext4\n"); |
| #endif |
| return 0; |
| } |
| |
| void exit_ext4_mballoc(void) |
| { |
| /* XXX: synchronize_rcu(); */ |
| kmem_cache_destroy(ext4_pspace_cachep); |
| kmem_cache_destroy(ext4_ac_cachep); |
| #ifdef CONFIG_PROC_FS |
| remove_proc_entry("fs/ext4", NULL); |
| #endif |
| } |
| |
| |
| /* |
| * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps |
| * Returns 0 if success or error code |
| */ |
| static noinline_for_stack int |
| ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, |
| handle_t *handle) |
| { |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_super_block *es; |
| struct ext4_group_desc *gdp; |
| struct buffer_head *gdp_bh; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| ext4_fsblk_t block; |
| int err, len; |
| |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(ac->ac_b_ex.fe_len <= 0); |
| |
| sb = ac->ac_sb; |
| sbi = EXT4_SB(sb); |
| es = sbi->s_es; |
| |
| |
| err = -EIO; |
| bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group); |
| if (!bitmap_bh) |
| goto out_err; |
| |
| err = ext4_journal_get_write_access(handle, bitmap_bh); |
| if (err) |
| goto out_err; |
| |
| err = -EIO; |
| gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh); |
| if (!gdp) |
| goto out_err; |
| |
| ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group, |
| gdp->bg_free_blocks_count); |
| |
| err = ext4_journal_get_write_access(handle, gdp_bh); |
| if (err) |
| goto out_err; |
| |
| block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb) |
| + ac->ac_b_ex.fe_start |
| + le32_to_cpu(es->s_first_data_block); |
| |
| len = ac->ac_b_ex.fe_len; |
| if (in_range(ext4_block_bitmap(sb, gdp), block, len) || |
| in_range(ext4_inode_bitmap(sb, gdp), block, len) || |
| in_range(block, ext4_inode_table(sb, gdp), |
| EXT4_SB(sb)->s_itb_per_group) || |
| in_range(block + len - 1, ext4_inode_table(sb, gdp), |
| EXT4_SB(sb)->s_itb_per_group)) { |
| ext4_error(sb, __func__, |
| "Allocating block in system zone - block = %llu", |
| block); |
| /* File system mounted not to panic on error |
| * Fix the bitmap and repeat the block allocation |
| * We leak some of the blocks here. |
| */ |
| mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), |
| bitmap_bh->b_data, ac->ac_b_ex.fe_start, |
| ac->ac_b_ex.fe_len); |
| err = ext4_journal_dirty_metadata(handle, bitmap_bh); |
| if (!err) |
| err = -EAGAIN; |
| goto out_err; |
| } |
| #ifdef AGGRESSIVE_CHECK |
| { |
| int i; |
| for (i = 0; i < ac->ac_b_ex.fe_len; i++) { |
| BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i, |
| bitmap_bh->b_data)); |
| } |
| } |
| #endif |
| mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data, |
| ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len); |
| |
| spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); |
| if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
| gdp->bg_free_blocks_count = |
| cpu_to_le16(ext4_free_blocks_after_init(sb, |
| ac->ac_b_ex.fe_group, |
| gdp)); |
| } |
| le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len); |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); |
| spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); |
| percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len); |
| |
| err = ext4_journal_dirty_metadata(handle, bitmap_bh); |
| if (err) |
| goto out_err; |
| err = ext4_journal_dirty_metadata(handle, gdp_bh); |
| |
| out_err: |
| sb->s_dirt = 1; |
| brelse(bitmap_bh); |
| return err; |
| } |
| |
| /* |
| * here we normalize request for locality group |
| * Group request are normalized to s_strip size if we set the same via mount |
| * option. If not we set it to s_mb_group_prealloc which can be configured via |
| * /proc/fs/ext4/<partition>/group_prealloc |
| * |
| * XXX: should we try to preallocate more than the group has now? |
| */ |
| static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_locality_group *lg = ac->ac_lg; |
| |
| BUG_ON(lg == NULL); |
| if (EXT4_SB(sb)->s_stripe) |
| ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe; |
| else |
| ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; |
| mb_debug("#%u: goal %u blocks for locality group\n", |
| current->pid, ac->ac_g_ex.fe_len); |
| } |
| |
| /* |
| * Normalization means making request better in terms of |
| * size and alignment |
| */ |
| static noinline_for_stack void |
| ext4_mb_normalize_request(struct ext4_allocation_context *ac, |
| struct ext4_allocation_request *ar) |
| { |
| int bsbits, max; |
| ext4_lblk_t end; |
| loff_t size, orig_size, start_off; |
| ext4_lblk_t start, orig_start; |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| struct ext4_prealloc_space *pa; |
| |
| /* do normalize only data requests, metadata requests |
| do not need preallocation */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return; |
| |
| /* sometime caller may want exact blocks */ |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| return; |
| |
| /* caller may indicate that preallocation isn't |
| * required (it's a tail, for example) */ |
| if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) |
| return; |
| |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { |
| ext4_mb_normalize_group_request(ac); |
| return ; |
| } |
| |
| bsbits = ac->ac_sb->s_blocksize_bits; |
| |
| /* first, let's learn actual file size |
| * given current request is allocated */ |
| size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| size = size << bsbits; |
| if (size < i_size_read(ac->ac_inode)) |
| size = i_size_read(ac->ac_inode); |
| |
| /* max size of free chunks */ |
| max = 2 << bsbits; |
| |
| #define NRL_CHECK_SIZE(req, size, max, chunk_size) \ |
| (req <= (size) || max <= (chunk_size)) |
| |
| /* first, try to predict filesize */ |
| /* XXX: should this table be tunable? */ |
| start_off = 0; |
| if (size <= 16 * 1024) { |
| size = 16 * 1024; |
| } else if (size <= 32 * 1024) { |
| size = 32 * 1024; |
| } else if (size <= 64 * 1024) { |
| size = 64 * 1024; |
| } else if (size <= 128 * 1024) { |
| size = 128 * 1024; |
| } else if (size <= 256 * 1024) { |
| size = 256 * 1024; |
| } else if (size <= 512 * 1024) { |
| size = 512 * 1024; |
| } else if (size <= 1024 * 1024) { |
| size = 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (21 - bsbits)) << 21; |
| size = 2 * 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (22 - bsbits)) << 22; |
| size = 4 * 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, |
| (8<<20)>>bsbits, max, 8 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (23 - bsbits)) << 23; |
| size = 8 * 1024 * 1024; |
| } else { |
| start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits; |
| size = ac->ac_o_ex.fe_len << bsbits; |
| } |
| orig_size = size = size >> bsbits; |
| orig_start = start = start_off >> bsbits; |
| |
| /* don't cover already allocated blocks in selected range */ |
| if (ar->pleft && start <= ar->lleft) { |
| size -= ar->lleft + 1 - start; |
| start = ar->lleft + 1; |
| } |
| if (ar->pright && start + size - 1 >= ar->lright) |
| size -= start + size - ar->lright; |
| |
| end = start + size; |
| |
| /* check we don't cross already preallocated blocks */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
| unsigned long pa_end; |
| |
| if (pa->pa_deleted) |
| continue; |
| spin_lock(&pa->pa_lock); |
| if (pa->pa_deleted) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| |
| pa_end = pa->pa_lstart + pa->pa_len; |
| |
| /* PA must not overlap original request */ |
| BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || |
| ac->ac_o_ex.fe_logical < pa->pa_lstart)); |
| |
| /* skip PA normalized request doesn't overlap with */ |
| if (pa->pa_lstart >= end) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| if (pa_end <= start) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| BUG_ON(pa->pa_lstart <= start && pa_end >= end); |
| |
| if (pa_end <= ac->ac_o_ex.fe_logical) { |
| BUG_ON(pa_end < start); |
| start = pa_end; |
| } |
| |
| if (pa->pa_lstart > ac->ac_o_ex.fe_logical) { |
| BUG_ON(pa->pa_lstart > end); |
| end = pa->pa_lstart; |
| } |
| spin_unlock(&pa->pa_lock); |
| } |
| rcu_read_unlock(); |
| size = end - start; |
| |
| /* XXX: extra loop to check we really don't overlap preallocations */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
| unsigned long pa_end; |
| spin_lock(&pa->pa_lock); |
| if (pa->pa_deleted == 0) { |
| pa_end = pa->pa_lstart + pa->pa_len; |
| BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); |
| } |
| spin_unlock(&pa->pa_lock); |
| } |
| rcu_read_unlock(); |
| |
| if (start + size <= ac->ac_o_ex.fe_logical && |
| start > ac->ac_o_ex.fe_logical) { |
| printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n", |
| (unsigned long) start, (unsigned long) size, |
| (unsigned long) ac->ac_o_ex.fe_logical); |
| } |
| BUG_ON(start + size <= ac->ac_o_ex.fe_logical && |
| start > ac->ac_o_ex.fe_logical); |
| BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| |
| /* now prepare goal request */ |
| |
| /* XXX: is it better to align blocks WRT to logical |
| * placement or satisfy big request as is */ |
| ac->ac_g_ex.fe_logical = start; |
| ac->ac_g_ex.fe_len = size; |
| |
| /* define goal start in order to merge */ |
| if (ar->pright && (ar->lright == (start + size))) { |
| /* merge to the right */ |
| ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, |
| &ac->ac_f_ex.fe_group, |
| &ac->ac_f_ex.fe_start); |
| ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| } |
| if (ar->pleft && (ar->lleft + 1 == start)) { |
| /* merge to the left */ |
| ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, |
| &ac->ac_f_ex.fe_group, |
| &ac->ac_f_ex.fe_start); |
| ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| } |
| |
| mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size, |
| (unsigned) orig_size, (unsigned) start); |
| } |
| |
| static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| |
| if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) { |
| atomic_inc(&sbi->s_bal_reqs); |
| atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); |
| if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len) |
| atomic_inc(&sbi->s_bal_success); |
| atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); |
| if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
| ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
| atomic_inc(&sbi->s_bal_goals); |
| if (ac->ac_found > sbi->s_mb_max_to_scan) |
| atomic_inc(&sbi->s_bal_breaks); |
| } |
| |
| ext4_mb_store_history(ac); |
| } |
| |
| /* |
| * use blocks preallocated to inode |
| */ |
| static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, |
| struct ext4_prealloc_space *pa) |
| { |
| ext4_fsblk_t start; |
| ext4_fsblk_t end; |
| int len; |
| |
| /* found preallocated blocks, use them */ |
| start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); |
| end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len); |
| len = end - start; |
| ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, |
| &ac->ac_b_ex.fe_start); |
| ac->ac_b_ex.fe_len = len; |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_pa = pa; |
| |
| BUG_ON(start < pa->pa_pstart); |
| BUG_ON(start + len > pa->pa_pstart + pa->pa_len); |
| BUG_ON(pa->pa_free < len); |
| pa->pa_free -= len; |
| |
| mb_debug("use %llu/%u from inode pa %p\n", start, len, pa); |
| } |
| |
| /* |
| * use blocks preallocated to locality group |
| */ |
| static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, |
| struct ext4_prealloc_space *pa) |
| { |
| unsigned int len = ac->ac_o_ex.fe_len; |
| ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, |
| &ac->ac_b_ex.fe_group, |
| &ac->ac_b_ex.fe_start); |
| ac->ac_b_ex.fe_len = len; |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_pa = pa; |
| |
| /* we don't correct pa_pstart or pa_plen here to avoid |
| * possible race when the group is being loaded concurrently |
| * instead we correct pa later, after blocks are marked |
| * in on-disk bitmap -- see ext4_mb_release_context() |
| * Other CPUs are prevented from allocating from this pa by lg_mutex |
| */ |
| mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa); |
| } |
| |
| /* |
| * search goal blocks in preallocated space |
| */ |
| static noinline_for_stack int |
| ext4_mb_use_preallocated(struct ext4_allocation_context *ac) |
| { |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| struct ext4_locality_group *lg; |
| struct ext4_prealloc_space *pa; |
| |
| /* only data can be preallocated */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return 0; |
| |
| /* first, try per-file preallocation */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { |
| |
| /* all fields in this condition don't change, |
| * so we can skip locking for them */ |
| if (ac->ac_o_ex.fe_logical < pa->pa_lstart || |
| ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len) |
| continue; |
| |
| /* found preallocated blocks, use them */ |
| spin_lock(&pa->pa_lock); |
| if (pa->pa_deleted == 0 && pa->pa_free) { |
| atomic_inc(&pa->pa_count); |
| ext4_mb_use_inode_pa(ac, pa); |
| spin_unlock(&pa->pa_lock); |
| ac->ac_criteria = 10; |
| rcu_read_unlock(); |
| return 1; |
| } |
| spin_unlock(&pa->pa_lock); |
| } |
| rcu_read_unlock(); |
| |
| /* can we use group allocation? */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) |
| return 0; |
| |
| /* inode may have no locality group for some reason */ |
| lg = ac->ac_lg; |
| if (lg == NULL) |
| return 0; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(pa, &lg->lg_prealloc_list, pa_inode_list) { |
| spin_lock(&pa->pa_lock); |
| if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) { |
| atomic_inc(&pa->pa_count); |
| ext4_mb_use_group_pa(ac, pa); |
| spin_unlock(&pa->pa_lock); |
| ac->ac_criteria = 20; |
| rcu_read_unlock(); |
| return 1; |
| } |
| spin_unlock(&pa->pa_lock); |
| } |
| rcu_read_unlock(); |
| |
| return 0; |
| } |
| |
| /* |
| * the function goes through all preallocation in this group and marks them |
| * used in in-core bitmap. buddy must be generated from this bitmap |
| * Need to be called with ext4 group lock (ext4_lock_group) |
| */ |
| static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
| ext4_group_t group) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| struct ext4_prealloc_space *pa; |
| struct list_head *cur; |
| ext4_group_t groupnr; |
| ext4_grpblk_t start; |
| int preallocated = 0; |
| int count = 0; |
| int len; |
| |
| /* all form of preallocation discards first load group, |
| * so the only competing code is preallocation use. |
| * we don't need any locking here |
| * notice we do NOT ignore preallocations with pa_deleted |
| * otherwise we could leave used blocks available for |
| * allocation in buddy when concurrent ext4_mb_put_pa() |
| * is dropping preallocation |
| */ |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| spin_lock(&pa->pa_lock); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| &groupnr, &start); |
| len = pa->pa_len; |
| spin_unlock(&pa->pa_lock); |
| if (unlikely(len == 0)) |
| continue; |
| BUG_ON(groupnr != group); |
| mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group), |
| bitmap, start, len); |
| preallocated += len; |
| count++; |
| } |
| mb_debug("prellocated %u for group %lu\n", preallocated, group); |
| } |
| |
| static void ext4_mb_pa_callback(struct rcu_head *head) |
| { |
| struct ext4_prealloc_space *pa; |
| pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); |
| kmem_cache_free(ext4_pspace_cachep, pa); |
| } |
| |
| /* |
| * drops a reference to preallocated space descriptor |
| * if this was the last reference and the space is consumed |
| */ |
| static void ext4_mb_put_pa(struct ext4_allocation_context *ac, |
| struct super_block *sb, struct ext4_prealloc_space *pa) |
| { |
| unsigned long grp; |
| |
| if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) |
| return; |
| |
| /* in this short window concurrent discard can set pa_deleted */ |
| spin_lock(&pa->pa_lock); |
| if (pa->pa_deleted == 1) { |
| spin_unlock(&pa->pa_lock); |
| return; |
| } |
| |
| pa->pa_deleted = 1; |
| spin_unlock(&pa->pa_lock); |
| |
| /* -1 is to protect from crossing allocation group */ |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL); |
| |
| /* |
| * possible race: |
| * |
| * P1 (buddy init) P2 (regular allocation) |
| * find block B in PA |
| * copy on-disk bitmap to buddy |
| * mark B in on-disk bitmap |
| * drop PA from group |
| * mark all PAs in buddy |
| * |
| * thus, P1 initializes buddy with B available. to prevent this |
| * we make "copy" and "mark all PAs" atomic and serialize "drop PA" |
| * against that pair |
| */ |
| ext4_lock_group(sb, grp); |
| list_del(&pa->pa_group_list); |
| ext4_unlock_group(sb, grp); |
| |
| spin_lock(pa->pa_obj_lock); |
| list_del_rcu(&pa->pa_inode_list); |
| spin_unlock(pa->pa_obj_lock); |
| |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } |
| |
| /* |
| * creates new preallocated space for given inode |
| */ |
| static noinline_for_stack int |
| ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_prealloc_space *pa; |
| struct ext4_group_info *grp; |
| struct ext4_inode_info *ei; |
| |
| /* preallocate only when found space is larger then requested */ |
| BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| |
| pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); |
| if (pa == NULL) |
| return -ENOMEM; |
| |
| if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { |
| int winl; |
| int wins; |
| int win; |
| int offs; |
| |
| /* we can't allocate as much as normalizer wants. |
| * so, found space must get proper lstart |
| * to cover original request */ |
| BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); |
| BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); |
| |
| /* we're limited by original request in that |
| * logical block must be covered any way |
| * winl is window we can move our chunk within */ |
| winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical; |
| |
| /* also, we should cover whole original request */ |
| wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len; |
| |
| /* the smallest one defines real window */ |
| win = min(winl, wins); |
| |
| offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len; |
| if (offs && offs < win) |
| win = offs; |
| |
| ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win; |
| BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); |
| BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); |
| } |
| |
| /* preallocation can change ac_b_ex, thus we store actually |
| * allocated blocks for history */ |
| ac->ac_f_ex = ac->ac_b_ex; |
| |
| pa->pa_lstart = ac->ac_b_ex.fe_logical; |
| pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| pa->pa_len = ac->ac_b_ex.fe_len; |
| pa->pa_free = pa->pa_len; |
| atomic_set(&pa->pa_count, 1); |
| spin_lock_init(&pa->pa_lock); |
| pa->pa_deleted = 0; |
| pa->pa_linear = 0; |
| |
| mb_debug("new inode pa %p: %llu/%u for %u\n", pa, |
| pa->pa_pstart, pa->pa_len, pa->pa_lstart); |
| |
| ext4_mb_use_inode_pa(ac, pa); |
| atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
| |
| ei = EXT4_I(ac->ac_inode); |
| grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| |
| pa->pa_obj_lock = &ei->i_prealloc_lock; |
| pa->pa_inode = ac->ac_inode; |
| |
| ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
| list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
| |
| spin_lock(pa->pa_obj_lock); |
| list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list); |
| spin_unlock(pa->pa_obj_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * creates new preallocated space for locality group inodes belongs to |
| */ |
| static noinline_for_stack int |
| ext4_mb_new_group_pa(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_locality_group *lg; |
| struct ext4_prealloc_space *pa; |
| struct ext4_group_info *grp; |
| |
| /* preallocate only when found space is larger then requested */ |
| BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| |
| BUG_ON(ext4_pspace_cachep == NULL); |
| pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); |
| if (pa == NULL) |
| return -ENOMEM; |
| |
| /* preallocation can change ac_b_ex, thus we store actually |
| * allocated blocks for history */ |
| ac->ac_f_ex = ac->ac_b_ex; |
| |
| pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| pa->pa_lstart = pa->pa_pstart; |
| pa->pa_len = ac->ac_b_ex.fe_len; |
| pa->pa_free = pa->pa_len; |
| atomic_set(&pa->pa_count, 1); |
| spin_lock_init(&pa->pa_lock); |
| pa->pa_deleted = 0; |
| pa->pa_linear = 1; |
| |
| mb_debug("new group pa %p: %llu/%u for %u\n", pa, |
| pa->pa_pstart, pa->pa_len, pa->pa_lstart); |
| |
| ext4_mb_use_group_pa(ac, pa); |
| atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
| |
| grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| lg = ac->ac_lg; |
| BUG_ON(lg == NULL); |
| |
| pa->pa_obj_lock = &lg->lg_prealloc_lock; |
| pa->pa_inode = NULL; |
| |
| ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
| list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
| |
| spin_lock(pa->pa_obj_lock); |
| list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list); |
| spin_unlock(pa->pa_obj_lock); |
| |
| return 0; |
| } |
| |
| static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) |
| { |
| int err; |
| |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| err = ext4_mb_new_group_pa(ac); |
| else |
| err = ext4_mb_new_inode_pa(ac); |
| return err; |
| } |
| |
| /* |
| * finds all unused blocks in on-disk bitmap, frees them in |
| * in-core bitmap and buddy. |
| * @pa must be unlinked from inode and group lists, so that |
| * nobody else can find/use it. |
| * the caller MUST hold group/inode locks. |
| * TODO: optimize the case when there are no in-core structures yet |
| */ |
| static noinline_for_stack int |
| ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, |
| struct ext4_prealloc_space *pa, |
| struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned long end; |
| unsigned long next; |
| ext4_group_t group; |
| ext4_grpblk_t bit; |
| sector_t start; |
| int err = 0; |
| int free = 0; |
| |
| BUG_ON(pa->pa_deleted == 0); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
| end = bit + pa->pa_len; |
| |
| if (ac) { |
| ac->ac_sb = sb; |
| ac->ac_inode = pa->pa_inode; |
| ac->ac_op = EXT4_MB_HISTORY_DISCARD; |
| } |
| |
| while (bit < end) { |
| bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); |
| if (bit >= end) |
| break; |
| next = mb_find_next_bit(bitmap_bh->b_data, end, bit); |
| if (next > end) |
| next = end; |
| start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit + |
| le32_to_cpu(sbi->s_es->s_first_data_block); |
| mb_debug(" free preallocated %u/%u in group %u\n", |
| (unsigned) start, (unsigned) next - bit, |
| (unsigned) group); |
| free += next - bit; |
| |
| if (ac) { |
| ac->ac_b_ex.fe_group = group; |
| ac->ac_b_ex.fe_start = bit; |
| ac->ac_b_ex.fe_len = next - bit; |
| ac->ac_b_ex.fe_logical = 0; |
| ext4_mb_store_history(ac); |
| } |
| |
| mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); |
| bit = next + 1; |
| } |
| if (free != pa->pa_free) { |
| printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n", |
| pa, (unsigned long) pa->pa_lstart, |
| (unsigned long) pa->pa_pstart, |
| (unsigned long) pa->pa_len); |
| ext4_error(sb, __func__, "free %u, pa_free %u\n", |
| free, pa->pa_free); |
| /* |
| * pa is already deleted so we use the value obtained |
| * from the bitmap and continue. |
| */ |
| } |
| atomic_add(free, &sbi->s_mb_discarded); |
| |
| return err; |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_release_group_pa(struct ext4_buddy *e4b, |
| struct ext4_prealloc_space *pa, |
| struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| ext4_group_t group; |
| ext4_grpblk_t bit; |
| |
| if (ac) |
| ac->ac_op = EXT4_MB_HISTORY_DISCARD; |
| |
| BUG_ON(pa->pa_deleted == 0); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
| mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); |
| atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); |
| |
| if (ac) { |
| ac->ac_sb = sb; |
| ac->ac_inode = NULL; |
| ac->ac_b_ex.fe_group = group; |
| ac->ac_b_ex.fe_start = bit; |
| ac->ac_b_ex.fe_len = pa->pa_len; |
| ac->ac_b_ex.fe_logical = 0; |
| ext4_mb_store_history(ac); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * releases all preallocations in given group |
| * |
| * first, we need to decide discard policy: |
| * - when do we discard |
| * 1) ENOSPC |
| * - how many do we discard |
| * 1) how many requested |
| */ |
| static noinline_for_stack int |
| ext4_mb_discard_group_preallocations(struct super_block *sb, |
| ext4_group_t group, int needed) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_prealloc_space *pa, *tmp; |
| struct ext4_allocation_context *ac; |
| struct list_head list; |
| struct ext4_buddy e4b; |
| int err; |
| int busy = 0; |
| int free = 0; |
| |
| mb_debug("discard preallocation for group %lu\n", group); |
| |
| if (list_empty(&grp->bb_prealloc_list)) |
| return 0; |
| |
| bitmap_bh = read_block_bitmap(sb, group); |
| if (bitmap_bh == NULL) { |
| /* error handling here */ |
| ext4_mb_release_desc(&e4b); |
| BUG_ON(bitmap_bh == NULL); |
| } |
| |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| BUG_ON(err != 0); /* error handling here */ |
| |
| if (needed == 0) |
| needed = EXT4_BLOCKS_PER_GROUP(sb) + 1; |
| |
| grp = ext4_get_group_info(sb, group); |
| INIT_LIST_HEAD(&list); |
| |
| ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); |
| repeat: |
| ext4_lock_group(sb, group); |
| list_for_each_entry_safe(pa, tmp, |
| &grp->bb_prealloc_list, pa_group_list) { |
| spin_lock(&pa->pa_lock); |
| if (atomic_read(&pa->pa_count)) { |
| spin_unlock(&pa->pa_lock); |
| busy = 1; |
| continue; |
| } |
| if (pa->pa_deleted) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| |
| /* seems this one can be freed ... */ |
| pa->pa_deleted = 1; |
| |
| /* we can trust pa_free ... */ |
| free += pa->pa_free; |
| |
| spin_unlock(&pa->pa_lock); |
| |
| list_del(&pa->pa_group_list); |
| list_add(&pa->u.pa_tmp_list, &list); |
| } |
| |
| /* if we still need more blocks and some PAs were used, try again */ |
| if (free < needed && busy) { |
| busy = 0; |
| ext4_unlock_group(sb, group); |
| /* |
| * Yield the CPU here so that we don't get soft lockup |
| * in non preempt case. |
| */ |
| yield(); |
| goto repeat; |
| } |
| |
| /* found anything to free? */ |
| if (list_empty(&list)) { |
| BUG_ON(free != 0); |
| goto out; |
| } |
| |
| /* now free all selected PAs */ |
| list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| |
| /* remove from object (inode or locality group) */ |
| spin_lock(pa->pa_obj_lock); |
| list_del_rcu(&pa->pa_inode_list); |
| spin_unlock(pa->pa_obj_lock); |
| |
| if (pa->pa_linear) |
| ext4_mb_release_group_pa(&e4b, pa, ac); |
| else |
| ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac); |
| |
| list_del(&pa->u.pa_tmp_list); |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } |
| |
| out: |
| ext4_unlock_group(sb, group); |
| if (ac) |
| kmem_cache_free(ext4_ac_cachep, ac); |
| ext4_mb_release_desc(&e4b); |
| put_bh(bitmap_bh); |
| return free; |
| } |
| |
| /* |
| * releases all non-used preallocated blocks for given inode |
| * |
| * It's important to discard preallocations under i_data_sem |
| * We don't want another block to be served from the prealloc |
| * space when we are discarding the inode prealloc space. |
| * |
| * FIXME!! Make sure it is valid at all the call sites |
| */ |
| void ext4_mb_discard_inode_preallocations(struct inode *inode) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct super_block *sb = inode->i_sb; |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_prealloc_space *pa, *tmp; |
| struct ext4_allocation_context *ac; |
| ext4_group_t group = 0; |
| struct list_head list; |
| struct ext4_buddy e4b; |
| int err; |
| |
| if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) { |
| /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/ |
| return; |
| } |
| |
| mb_debug("discard preallocation for inode %lu\n", inode->i_ino); |
| |
| INIT_LIST_HEAD(&list); |
| |
| ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); |
| repeat: |
| /* first, collect all pa's in the inode */ |
| spin_lock(&ei->i_prealloc_lock); |
| while (!list_empty(&ei->i_prealloc_list)) { |
| pa = list_entry(ei->i_prealloc_list.next, |
| struct ext4_prealloc_space, pa_inode_list); |
| BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); |
| spin_lock(&pa->pa_lock); |
| if (atomic_read(&pa->pa_count)) { |
| /* this shouldn't happen often - nobody should |
| * use preallocation while we're discarding it */ |
| spin_unlock(&pa->pa_lock); |
| spin_unlock(&ei->i_prealloc_lock); |
| printk(KERN_ERR "uh-oh! used pa while discarding\n"); |
| WARN_ON(1); |
| schedule_timeout_uninterruptible(HZ); |
| goto repeat; |
| |
| } |
| if (pa->pa_deleted == 0) { |
| pa->pa_deleted = 1; |
| spin_unlock(&pa->pa_lock); |
| list_del_rcu(&pa->pa_inode_list); |
| list_add(&pa->u.pa_tmp_list, &list); |
| continue; |
| } |
| |
| /* someone is deleting pa right now */ |
| spin_unlock(&pa->pa_lock); |
| spin_unlock(&ei->i_prealloc_lock); |
| |
| /* we have to wait here because pa_deleted |
| * doesn't mean pa is already unlinked from |
| * the list. as we might be called from |
| * ->clear_inode() the inode will get freed |
| * and concurrent thread which is unlinking |
| * pa from inode's list may access already |
| * freed memory, bad-bad-bad */ |
| |
| /* XXX: if this happens too often, we can |
| * add a flag to force wait only in case |
| * of ->clear_inode(), but not in case of |
| * regular truncate */ |
| schedule_timeout_uninterruptible(HZ); |
| goto repeat; |
| } |
| spin_unlock(&ei->i_prealloc_lock); |
| |
| list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| BUG_ON(pa->pa_linear != 0); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); |
| |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| BUG_ON(err != 0); /* error handling here */ |
| |
| bitmap_bh = read_block_bitmap(sb, group); |
| if (bitmap_bh == NULL) { |
| /* error handling here */ |
| ext4_mb_release_desc(&e4b); |
| BUG_ON(bitmap_bh == NULL); |
| } |
| |
| ext4_lock_group(sb, group); |
| list_del(&pa->pa_group_list); |
| ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac); |
| ext4_unlock_group(sb, group); |
| |
| ext4_mb_release_desc(&e4b); |
| put_bh(bitmap_bh); |
| |
| list_del(&pa->u.pa_tmp_list); |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } |
| if (ac) |
| kmem_cache_free(ext4_ac_cachep, ac); |
| } |
| |
| /* |
| * finds all preallocated spaces and return blocks being freed to them |
| * if preallocated space becomes full (no block is used from the space) |
| * then the function frees space in buddy |
| * XXX: at the moment, truncate (which is the only way to free blocks) |
| * discards all preallocations |
| */ |
| static void ext4_mb_return_to_preallocation(struct inode *inode, |
| struct ext4_buddy *e4b, |
| sector_t block, int count) |
| { |
| BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list)); |
| } |
| #ifdef MB_DEBUG |
| static void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| ext4_group_t i; |
| |
| printk(KERN_ERR "EXT4-fs: Can't allocate:" |
| " Allocation context details:\n"); |
| printk(KERN_ERR "EXT4-fs: status %d flags %d\n", |
| ac->ac_status, ac->ac_flags); |
| printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, " |
| "best %lu/%lu/%lu@%lu cr %d\n", |
| (unsigned long)ac->ac_o_ex.fe_group, |
| (unsigned long)ac->ac_o_ex.fe_start, |
| (unsigned long)ac->ac_o_ex.fe_len, |
| (unsigned long)ac->ac_o_ex.fe_logical, |
| (unsigned long)ac->ac_g_ex.fe_group, |
| (unsigned long)ac->ac_g_ex.fe_start, |
| (unsigned long)ac->ac_g_ex.fe_len, |
| (unsigned long)ac->ac_g_ex.fe_logical, |
| (unsigned long)ac->ac_b_ex.fe_group, |
| (unsigned long)ac->ac_b_ex.fe_start, |
| (unsigned long)ac->ac_b_ex.fe_len, |
| (unsigned long)ac->ac_b_ex.fe_logical, |
| (int)ac->ac_criteria); |
| printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned, |
| ac->ac_found); |
| printk(KERN_ERR "EXT4-fs: groups: \n"); |
| for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, i); |
| struct ext4_prealloc_space *pa; |
| ext4_grpblk_t start; |
| struct list_head *cur; |
| ext4_lock_group(sb, i); |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, |
| pa_group_list); |
| spin_lock(&pa->pa_lock); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| NULL, &start); |
| spin_unlock(&pa->pa_lock); |
| printk(KERN_ERR "PA:%lu:%d:%u \n", i, |
| start, pa->pa_len); |
| } |
| ext4_unlock_group(sb, i); |
| |
| if (grp->bb_free == 0) |
| continue; |
| printk(KERN_ERR "%lu: %d/%d \n", |
| i, grp->bb_free, grp->bb_fragments); |
| } |
| printk(KERN_ERR "\n"); |
| } |
| #else |
| static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| { |
| return; |
| } |
| #endif |
| |
| /* |
| * We use locality group preallocation for small size file. The size of the |
| * file is determined by the current size or the resulting size after |
| * allocation which ever is larger |
| * |
| * One can tune this size via /proc/fs/ext4/<partition>/stream_req |
| */ |
| static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| int bsbits = ac->ac_sb->s_blocksize_bits; |
| loff_t size, isize; |
| |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return; |
| |
| size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| isize = i_size_read(ac->ac_inode) >> bsbits; |
| size = max(size, isize); |
| |
| /* don't use group allocation for large files */ |
| if (size >= sbi->s_mb_stream_request) |
| return; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| return; |
| |
| BUG_ON(ac->ac_lg != NULL); |
| /* |
| * locality group prealloc space are per cpu. The reason for having |
| * per cpu locality group is to reduce the contention between block |
| * request from multiple CPUs. |
| */ |
| ac->ac_lg = &sbi->s_locality_groups[get_cpu()]; |
| put_cpu(); |
| |
| /* we're going to use group allocation */ |
| ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; |
| |
| /* serialize all allocations in the group */ |
| mutex_lock(&ac->ac_lg->lg_mutex); |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_initialize_context(struct ext4_allocation_context *ac, |
| struct ext4_allocation_request *ar) |
| { |
| struct super_block *sb = ar->inode->i_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_super_block *es = sbi->s_es; |
| ext4_group_t group; |
| unsigned long len; |
| unsigned long goal; |
| ext4_grpblk_t block; |
| |
| /* we can't allocate > group size */ |
| len = ar->len; |
| |
| /* just a dirty hack to filter too big requests */ |
| if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10) |
| len = EXT4_BLOCKS_PER_GROUP(sb) - 10; |
| |
| /* start searching from the goal */ |
| goal = ar->goal; |
| if (goal < le32_to_cpu(es->s_first_data_block) || |
| goal >= ext4_blocks_count(es)) |
| goal = le32_to_cpu(es->s_first_data_block); |
| ext4_get_group_no_and_offset(sb, goal, &group, &block); |
| |
| /* set up allocation goals */ |
| ac->ac_b_ex.fe_logical = ar->logical; |
| ac->ac_b_ex.fe_group = 0; |
| ac->ac_b_ex.fe_start = 0; |
| ac->ac_b_ex.fe_len = 0; |
| ac->ac_status = AC_STATUS_CONTINUE; |
| ac->ac_groups_scanned = 0; |
| ac->ac_ex_scanned = 0; |
| ac->ac_found = 0; |
| ac->ac_sb = sb; |
| ac->ac_inode = ar->inode; |
| ac->ac_o_ex.fe_logical = ar->logical; |
| ac->ac_o_ex.fe_group = group; |
| ac->ac_o_ex.fe_start = block; |
| ac->ac_o_ex.fe_len = len; |
| ac->ac_g_ex.fe_logical = ar->logical; |
| ac->ac_g_ex.fe_group = group; |
| ac->ac_g_ex.fe_start = block; |
| ac->ac_g_ex.fe_len = len; |
| ac->ac_f_ex.fe_len = 0; |
| ac->ac_flags = ar->flags; |
| ac->ac_2order = 0; |
| ac->ac_criteria = 0; |
| ac->ac_pa = NULL; |
| ac->ac_bitmap_page = NULL; |
| ac->ac_buddy_page = NULL; |
| ac->ac_lg = NULL; |
| |
| /* we have to define context: we'll we work with a file or |
| * locality group. this is a policy, actually */ |
| ext4_mb_group_or_file(ac); |
| |
| mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, " |
| "left: %u/%u, right %u/%u to %swritable\n", |
| (unsigned) ar->len, (unsigned) ar->logical, |
| (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, |
| (unsigned) ar->lleft, (unsigned) ar->pleft, |
| (unsigned) ar->lright, (unsigned) ar->pright, |
| atomic_read(&ar->inode->i_writecount) ? "" : "non-"); |
| return 0; |
| |
| } |
| |
| /* |
| * release all resource we used in allocation |
| */ |
| static int ext4_mb_release_context(struct ext4_allocation_context *ac) |
| { |
| if (ac->ac_pa) { |
| if (ac->ac_pa->pa_linear) { |
| /* see comment in ext4_mb_use_group_pa() */ |
| spin_lock(&ac->ac_pa->pa_lock); |
| ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len; |
| ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len; |
| ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len; |
| ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len; |
| spin_unlock(&ac->ac_pa->pa_lock); |
| } |
| ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa); |
| } |
| if (ac->ac_bitmap_page) |
| page_cache_release(ac->ac_bitmap_page); |
| if (ac->ac_buddy_page) |
| page_cache_release(ac->ac_buddy_page); |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| mutex_unlock(&ac->ac_lg->lg_mutex); |
| ext4_mb_collect_stats(ac); |
| return 0; |
| } |
| |
| static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) |
| { |
| ext4_group_t i; |
| int ret; |
| int freed = 0; |
| |
| for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) { |
| ret = ext4_mb_discard_group_preallocations(sb, i, needed); |
| freed += ret; |
| needed -= ret; |
| } |
| |
| return freed; |
| } |
| |
| /* |
| * Main entry point into mballoc to allocate blocks |
| * it tries to use preallocation first, then falls back |
| * to usual allocation |
| */ |
| ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, |
| struct ext4_allocation_request *ar, int *errp) |
| { |
| struct ext4_allocation_context *ac = NULL; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| ext4_fsblk_t block = 0; |
| int freed; |
| int inquota; |
| |
| sb = ar->inode->i_sb; |
| sbi = EXT4_SB(sb); |
| |
| if (!test_opt(sb, MBALLOC)) { |
| block = ext4_new_blocks_old(handle, ar->inode, ar->goal, |
| &(ar->len), errp); |
| return block; |
| } |
| |
| while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) { |
| ar->flags |= EXT4_MB_HINT_NOPREALLOC; |
| ar->len--; |
| } |
| if (ar->len == 0) { |
| *errp = -EDQUOT; |
| return 0; |
| } |
| inquota = ar->len; |
| |
| ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); |
| if (!ac) { |
| *errp = -ENOMEM; |
| return 0; |
| } |
| |
| ext4_mb_poll_new_transaction(sb, handle); |
| |
| *errp = ext4_mb_initialize_context(ac, ar); |
| if (*errp) { |
| ar->len = 0; |
| goto out; |
| } |
| |
| ac->ac_op = EXT4_MB_HISTORY_PREALLOC; |
| if (!ext4_mb_use_preallocated(ac)) { |
| |
| ac->ac_op = EXT4_MB_HISTORY_ALLOC; |
| ext4_mb_normalize_request(ac, ar); |
| repeat: |
| /* allocate space in core */ |
| ext4_mb_regular_allocator(ac); |
| |
| /* as we've just preallocated more space than |
| * user requested orinally, we store allocated |
| * space in a special descriptor */ |
| if (ac->ac_status == AC_STATUS_FOUND && |
| ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) |
| ext4_mb_new_preallocation(ac); |
| } |
| |
| if (likely(ac->ac_status == AC_STATUS_FOUND)) { |
| *errp = ext4_mb_mark_diskspace_used(ac, handle); |
| if (*errp == -EAGAIN) { |
| ac->ac_b_ex.fe_group = 0; |
| ac->ac_b_ex.fe_start = 0; |
| ac->ac_b_ex.fe_len = 0; |
| ac->ac_status = AC_STATUS_CONTINUE; |
| goto repeat; |
| } else if (*errp) { |
| ac->ac_b_ex.fe_len = 0; |
| ar->len = 0; |
| ext4_mb_show_ac(ac); |
| } else { |
| block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| ar->len = ac->ac_b_ex.fe_len; |
| } |
| } else { |
| freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); |
| if (freed) |
| goto repeat; |
| *errp = -ENOSPC; |
| ac->ac_b_ex.fe_len = 0; |
| ar->len = 0; |
| ext4_mb_show_ac(ac); |
| } |
| |
| ext4_mb_release_context(ac); |
| |
| out: |
| if (ar->len < inquota) |
| DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len); |
| |
| kmem_cache_free(ext4_ac_cachep, ac); |
| return block; |
| } |
| static void ext4_mb_poll_new_transaction(struct super_block *sb, |
| handle_t *handle) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| if (sbi->s_last_transaction == handle->h_transaction->t_tid) |
| return; |
| |
| /* new transaction! time to close last one and free blocks for |
| * committed transaction. we know that only transaction can be |
| * active, so previos transaction can be being logged and we |
| * know that transaction before previous is known to be already |
| * logged. this means that now we may free blocks freed in all |
| * transactions before previous one. hope I'm clear enough ... */ |
| |
| spin_lock(&sbi->s_md_lock); |
| if (sbi->s_last_transaction != handle->h_transaction->t_tid) { |
| mb_debug("new transaction %lu, old %lu\n", |
| (unsigned long) handle->h_transaction->t_tid, |
| (unsigned long) sbi->s_last_transaction); |
| list_splice_init(&sbi->s_closed_transaction, |
| &sbi->s_committed_transaction); |
| list_splice_init(&sbi->s_active_transaction, |
| &sbi->s_closed_transaction); |
| sbi->s_last_transaction = handle->h_transaction->t_tid; |
| } |
| spin_unlock(&sbi->s_md_lock); |
| |
| ext4_mb_free_committed_blocks(sb); |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, |
| ext4_group_t group, ext4_grpblk_t block, int count) |
| { |
| struct ext4_group_info *db = e4b->bd_info; |
| struct super_block *sb = e4b->bd_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_free_metadata *md; |
| int i; |
| |
| BUG_ON(e4b->bd_bitmap_page == NULL); |
| BUG_ON(e4b->bd_buddy_page == NULL); |
| |
| ext4_lock_group(sb, group); |
| for (i = 0; i < count; i++) { |
| md = db->bb_md_cur; |
| if (md && db->bb_tid != handle->h_transaction->t_tid) { |
| db->bb_md_cur = NULL; |
| md = NULL; |
| } |
| |
| if (md == NULL) { |
| ext4_unlock_group(sb, group); |
| md = kmalloc(sizeof(*md), GFP_NOFS); |
| if (md == NULL) |
| return -ENOMEM; |
| md->num = 0; |
| md->group = group; |
| |
| ext4_lock_group(sb, group); |
| if (db->bb_md_cur == NULL) { |
| spin_lock(&sbi->s_md_lock); |
| list_add(&md->list, &sbi->s_active_transaction); |
| spin_unlock(&sbi->s_md_lock); |
| /* protect buddy cache from being freed, |
| * otherwise we'll refresh it from |
| * on-disk bitmap and lose not-yet-available |
| * blocks */ |
| page_cache_get(e4b->bd_buddy_page); |
| page_cache_get(e4b->bd_bitmap_page); |
| db->bb_md_cur = md; |
| db->bb_tid = handle->h_transaction->t_tid; |
| mb_debug("new md 0x%p for group %lu\n", |
| md, md->group); |
| } else { |
| kfree(md); |
| md = db->bb_md_cur; |
| } |
| } |
| |
| BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS); |
| md->blocks[md->num] = block + i; |
| md->num++; |
| if (md->num == EXT4_BB_MAX_BLOCKS) { |
| /* no more space, put full container on a sb's list */ |
| db->bb_md_cur = NULL; |
| } |
| } |
| ext4_unlock_group(sb, group); |
| return 0; |
| } |
| |
| /* |
| * Main entry point into mballoc to free blocks |
| */ |
| void ext4_mb_free_blocks(handle_t *handle, struct inode *inode, |
| unsigned long block, unsigned long count, |
| int metadata, unsigned long *freed) |
| { |
| struct buffer_head *bitmap_bh = NULL; |
| struct super_block *sb = inode->i_sb; |
| struct ext4_allocation_context *ac = NULL; |
| struct ext4_group_desc *gdp; |
| struct ext4_super_block *es; |
| unsigned long overflow; |
| ext4_grpblk_t bit; |
| struct buffer_head *gd_bh; |
| ext4_group_t block_group; |
| struct ext4_sb_info *sbi; |
| struct ext4_buddy e4b; |
| int err = 0; |
| int ret; |
| |
| *freed = 0; |
| |
| ext4_mb_poll_new_transaction(sb, handle); |
| |
| sbi = EXT4_SB(sb); |
| es = EXT4_SB(sb)->s_es; |
| if (block < le32_to_cpu(es->s_first_data_block) || |
| block + count < block || |
| block + count > ext4_blocks_count(es)) { |
| ext4_error(sb, __func__, |
| "Freeing blocks not in datazone - " |
| "block = %lu, count = %lu", block, count); |
| goto error_return; |
| } |
| |
| ext4_debug("freeing block %lu\n", block); |
| |
| ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); |
| if (ac) { |
| ac->ac_op = EXT4_MB_HISTORY_FREE; |
| ac->ac_inode = inode; |
| ac->ac_sb = sb; |
| } |
| |
| do_more: |
| overflow = 0; |
| ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
| |
| /* |
| * Check to see if we are freeing blocks across a group |
| * boundary. |
| */ |
| if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { |
| overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb); |
| count -= overflow; |
| } |
| bitmap_bh = read_block_bitmap(sb, block_group); |
| if (!bitmap_bh) |
| goto error_return; |
| gdp = ext4_get_group_desc(sb, block_group, &gd_bh); |
| if (!gdp) |
| goto error_return; |
| |
| if (in_range(ext4_block_bitmap(sb, gdp), block, count) || |
| in_range(ext4_inode_bitmap(sb, gdp), block, count) || |
| in_range(block, ext4_inode_table(sb, gdp), |
| EXT4_SB(sb)->s_itb_per_group) || |
| in_range(block + count - 1, ext4_inode_table(sb, gdp), |
| EXT4_SB(sb)->s_itb_per_group)) { |
| |
| ext4_error(sb, __func__, |
| "Freeing blocks in system zone - " |
| "Block = %lu, count = %lu", block, count); |
| /* err = 0. ext4_std_error should be a no op */ |
| goto error_return; |
| } |
| |
| BUFFER_TRACE(bitmap_bh, "getting write access"); |
| err = ext4_journal_get_write_access(handle, bitmap_bh); |
| if (err) |
| goto error_return; |
| |
| /* |
| * We are about to modify some metadata. Call the journal APIs |
| * to unshare ->b_data if a currently-committing transaction is |
| * using it |
| */ |
| BUFFER_TRACE(gd_bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, gd_bh); |
| if (err) |
| goto error_return; |
| |
| err = ext4_mb_load_buddy(sb, block_group, &e4b); |
| if (err) |
| goto error_return; |
| |
| #ifdef AGGRESSIVE_CHECK |
| { |
| int i; |
| for (i = 0; i < count; i++) |
| BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data)); |
| } |
| #endif |
| mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data, |
| bit, count); |
| |
| /* We dirtied the bitmap block */ |
| BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); |
| err = ext4_journal_dirty_metadata(handle, bitmap_bh); |
| |
| if (ac) { |
| ac->ac_b_ex.fe_group = block_group; |
| ac->ac_b_ex.fe_start = bit; |
| ac->ac_b_ex.fe_len = count; |
| ext4_mb_store_history(ac); |
| } |
| |
| if (metadata) { |
| /* blocks being freed are metadata. these blocks shouldn't |
| * be used until this transaction is committed */ |
| ext4_mb_free_metadata(handle, &e4b, block_group, bit, count); |
| } else { |
| ext4_lock_group(sb, block_group); |
| err = mb_free_blocks(inode, &e4b, bit, count); |
| ext4_mb_return_to_preallocation(inode, &e4b, block, count); |
| ext4_unlock_group(sb, block_group); |
| BUG_ON(err != 0); |
| } |
| |
| spin_lock(sb_bgl_lock(sbi, block_group)); |
| le16_add_cpu(&gdp->bg_free_blocks_count, count); |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); |
| spin_unlock(sb_bgl_lock(sbi, block_group)); |
| percpu_counter_add(&sbi->s_freeblocks_counter, count); |
| |
| ext4_mb_release_desc(&e4b); |
| |
| *freed += count; |
| |
| /* And the group descriptor block */ |
| BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); |
| ret = ext4_journal_dirty_metadata(handle, gd_bh); |
| if (!err) |
| err = ret; |
| |
| if (overflow && !err) { |
| block += count; |
| count = overflow; |
| put_bh(bitmap_bh); |
| goto do_more; |
| } |
| sb->s_dirt = 1; |
| error_return: |
| brelse(bitmap_bh); |
| ext4_std_error(sb, err); |
| if (ac) |
| kmem_cache_free(ext4_ac_cachep, ac); |
| return; |
| } |
