blob: cd0c7ed0677200d09ce1445def04452a2f178978 [file] [log] [blame]
/*
* Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
* Written by Alex Tomas <alex@clusterfs.com>
*
* Architecture independence:
* Copyright (c) 2005, Bull S.A.
* Written by Pierre Peiffer <pierre.peiffer@bull.net>
*
* 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-
*/
/*
* Extents support for EXT4
*
* TODO:
* - ext4*_error() should be used in some situations
* - analyze all BUG()/BUG_ON(), use -EIO where appropriate
* - smart tree reduction
*/
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/jbd2.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/falloc.h>
#include <asm/uaccess.h>
#include <linux/fiemap.h>
#include "ext4_jbd2.h"
#include <trace/events/ext4.h>
/*
* used by extent splitting.
*/
#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
due to ENOSPC */
#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
static __le32 ext4_extent_block_csum(struct inode *inode,
struct ext4_extent_header *eh)
{
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
__u32 csum;
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
EXT4_EXTENT_TAIL_OFFSET(eh));
return cpu_to_le32(csum);
}
static int ext4_extent_block_csum_verify(struct inode *inode,
struct ext4_extent_header *eh)
{
struct ext4_extent_tail *et;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return 1;
et = find_ext4_extent_tail(eh);
if (et->et_checksum != ext4_extent_block_csum(inode, eh))
return 0;
return 1;
}
static void ext4_extent_block_csum_set(struct inode *inode,
struct ext4_extent_header *eh)
{
struct ext4_extent_tail *et;
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return;
et = find_ext4_extent_tail(eh);
et->et_checksum = ext4_extent_block_csum(inode, eh);
}
static int ext4_split_extent(handle_t *handle,
struct inode *inode,
struct ext4_ext_path *path,
struct ext4_map_blocks *map,
int split_flag,
int flags);
static int ext4_split_extent_at(handle_t *handle,
struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t split,
int split_flag,
int flags);
static int ext4_ext_truncate_extend_restart(handle_t *handle,
struct inode *inode,
int needed)
{
int err;
if (!ext4_handle_valid(handle))
return 0;
if (handle->h_buffer_credits > needed)
return 0;
err = ext4_journal_extend(handle, needed);
if (err <= 0)
return err;
err = ext4_truncate_restart_trans(handle, inode, needed);
if (err == 0)
err = -EAGAIN;
return err;
}
/*
* could return:
* - EROFS
* - ENOMEM
*/
static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
{
if (path->p_bh) {
/* path points to block */
return ext4_journal_get_write_access(handle, path->p_bh);
}
/* path points to leaf/index in inode body */
/* we use in-core data, no need to protect them */
return 0;
}
/*
* could return:
* - EROFS
* - ENOMEM
* - EIO
*/
#define ext4_ext_dirty(handle, inode, path) \
__ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
static int __ext4_ext_dirty(const char *where, unsigned int line,
handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
{
int err;
if (path->p_bh) {
ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
/* path points to block */
err = __ext4_handle_dirty_metadata(where, line, handle,
inode, path->p_bh);
} else {
/* path points to leaf/index in inode body */
err = ext4_mark_inode_dirty(handle, inode);
}
return err;
}
static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t block)
{
if (path) {
int depth = path->p_depth;
struct ext4_extent *ex;
/*
* Try to predict block placement assuming that we are
* filling in a file which will eventually be
* non-sparse --- i.e., in the case of libbfd writing
* an ELF object sections out-of-order but in a way
* the eventually results in a contiguous object or
* executable file, or some database extending a table
* space file. However, this is actually somewhat
* non-ideal if we are writing a sparse file such as
* qemu or KVM writing a raw image file that is going
* to stay fairly sparse, since it will end up
* fragmenting the file system's free space. Maybe we
* should have some hueristics or some way to allow
* userspace to pass a hint to file system,
* especially if the latter case turns out to be
* common.
*/
ex = path[depth].p_ext;
if (ex) {
ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
if (block > ext_block)
return ext_pblk + (block - ext_block);
else
return ext_pblk - (ext_block - block);
}
/* it looks like index is empty;
* try to find starting block from index itself */
if (path[depth].p_bh)
return path[depth].p_bh->b_blocknr;
}
/* OK. use inode's group */
return ext4_inode_to_goal_block(inode);
}
/*
* Allocation for a meta data block
*/
static ext4_fsblk_t
ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path,
struct ext4_extent *ex, int *err, unsigned int flags)
{
ext4_fsblk_t goal, newblock;
goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
NULL, err);
return newblock;
}
static inline int ext4_ext_space_block(struct inode *inode, int check)
{
int size;
size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
/ sizeof(struct ext4_extent);
#ifdef AGGRESSIVE_TEST
if (!check && size > 6)
size = 6;
#endif
return size;
}
static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
{
int size;
size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
/ sizeof(struct ext4_extent_idx);
#ifdef AGGRESSIVE_TEST
if (!check && size > 5)
size = 5;
#endif
return size;
}
static inline int ext4_ext_space_root(struct inode *inode, int check)
{
int size;
size = sizeof(EXT4_I(inode)->i_data);
size -= sizeof(struct ext4_extent_header);
size /= sizeof(struct ext4_extent);
#ifdef AGGRESSIVE_TEST
if (!check && size > 3)
size = 3;
#endif
return size;
}
static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
{
int size;
size = sizeof(EXT4_I(inode)->i_data);
size -= sizeof(struct ext4_extent_header);
size /= sizeof(struct ext4_extent_idx);
#ifdef AGGRESSIVE_TEST
if (!check && size > 4)
size = 4;
#endif
return size;
}
/*
* Calculate the number of metadata blocks needed
* to allocate @blocks
* Worse case is one block per extent
*/
int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
{
struct ext4_inode_info *ei = EXT4_I(inode);
int idxs;
idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
/ sizeof(struct ext4_extent_idx));
/*
* If the new delayed allocation block is contiguous with the
* previous da block, it can share index blocks with the
* previous block, so we only need to allocate a new index
* block every idxs leaf blocks. At ldxs**2 blocks, we need
* an additional index block, and at ldxs**3 blocks, yet
* another index blocks.
*/
if (ei->i_da_metadata_calc_len &&
ei->i_da_metadata_calc_last_lblock+1 == lblock) {
int num = 0;
if ((ei->i_da_metadata_calc_len % idxs) == 0)
num++;
if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
num++;
if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
num++;
ei->i_da_metadata_calc_len = 0;
} else
ei->i_da_metadata_calc_len++;
ei->i_da_metadata_calc_last_lblock++;
return num;
}
/*
* In the worst case we need a new set of index blocks at
* every level of the inode's extent tree.
*/
ei->i_da_metadata_calc_len = 1;
ei->i_da_metadata_calc_last_lblock = lblock;
return ext_depth(inode) + 1;
}
static int
ext4_ext_max_entries(struct inode *inode, int depth)
{
int max;
if (depth == ext_depth(inode)) {
if (depth == 0)
max = ext4_ext_space_root(inode, 1);
else
max = ext4_ext_space_root_idx(inode, 1);
} else {
if (depth == 0)
max = ext4_ext_space_block(inode, 1);
else
max = ext4_ext_space_block_idx(inode, 1);
}
return max;
}
static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
{
ext4_fsblk_t block = ext4_ext_pblock(ext);
int len = ext4_ext_get_actual_len(ext);
if (len == 0)
return 0;
return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
}
static int ext4_valid_extent_idx(struct inode *inode,
struct ext4_extent_idx *ext_idx)
{
ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
}
static int ext4_valid_extent_entries(struct inode *inode,
struct ext4_extent_header *eh,
int depth)
{
unsigned short entries;
if (eh->eh_entries == 0)
return 1;
entries = le16_to_cpu(eh->eh_entries);
if (depth == 0) {
/* leaf entries */
struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
while (entries) {
if (!ext4_valid_extent(inode, ext))
return 0;
ext++;
entries--;
}
} else {
struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
while (entries) {
if (!ext4_valid_extent_idx(inode, ext_idx))
return 0;
ext_idx++;
entries--;
}
}
return 1;
}
static int __ext4_ext_check(const char *function, unsigned int line,
struct inode *inode, struct ext4_extent_header *eh,
int depth)
{
const char *error_msg;
int max = 0;
if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
error_msg = "invalid magic";
goto corrupted;
}
if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
error_msg = "unexpected eh_depth";
goto corrupted;
}
if (unlikely(eh->eh_max == 0)) {
error_msg = "invalid eh_max";
goto corrupted;
}
max = ext4_ext_max_entries(inode, depth);
if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
error_msg = "too large eh_max";
goto corrupted;
}
if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
error_msg = "invalid eh_entries";
goto corrupted;
}
if (!ext4_valid_extent_entries(inode, eh, depth)) {
error_msg = "invalid extent entries";
goto corrupted;
}
/* Verify checksum on non-root extent tree nodes */
if (ext_depth(inode) != depth &&
!ext4_extent_block_csum_verify(inode, eh)) {
error_msg = "extent tree corrupted";
goto corrupted;
}
return 0;
corrupted:
ext4_error_inode(inode, function, line, 0,
"bad header/extent: %s - magic %x, "
"entries %u, max %u(%u), depth %u(%u)",
error_msg, le16_to_cpu(eh->eh_magic),
le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
max, le16_to_cpu(eh->eh_depth), depth);
return -EIO;
}
#define ext4_ext_check(inode, eh, depth) \
__ext4_ext_check(__func__, __LINE__, inode, eh, depth)
int ext4_ext_check_inode(struct inode *inode)
{
return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
}
static int __ext4_ext_check_block(const char *function, unsigned int line,
struct inode *inode,
struct ext4_extent_header *eh,
int depth,
struct buffer_head *bh)
{
int ret;
if (buffer_verified(bh))
return 0;
ret = ext4_ext_check(inode, eh, depth);
if (ret)
return ret;
set_buffer_verified(bh);
return ret;
}
#define ext4_ext_check_block(inode, eh, depth, bh) \
__ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
#ifdef EXT_DEBUG
static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
{
int k, l = path->p_depth;
ext_debug("path:");
for (k = 0; k <= l; k++, path++) {
if (path->p_idx) {
ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
ext4_idx_pblock(path->p_idx));
} else if (path->p_ext) {
ext_debug(" %d:[%d]%d:%llu ",
le32_to_cpu(path->p_ext->ee_block),
ext4_ext_is_uninitialized(path->p_ext),
ext4_ext_get_actual_len(path->p_ext),
ext4_ext_pblock(path->p_ext));
} else
ext_debug(" []");
}
ext_debug("\n");
}
static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
{
int depth = ext_depth(inode);
struct ext4_extent_header *eh;
struct ext4_extent *ex;
int i;
if (!path)
return;
eh = path[depth].p_hdr;
ex = EXT_FIRST_EXTENT(eh);
ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
ext4_ext_is_uninitialized(ex),
ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
}
ext_debug("\n");
}
static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
ext4_fsblk_t newblock, int level)
{
int depth = ext_depth(inode);
struct ext4_extent *ex;
if (depth != level) {
struct ext4_extent_idx *idx;
idx = path[level].p_idx;
while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
ext_debug("%d: move %d:%llu in new index %llu\n", level,
le32_to_cpu(idx->ei_block),
ext4_idx_pblock(idx),
newblock);
idx++;
}
return;
}
ex = path[depth].p_ext;
while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
le32_to_cpu(ex->ee_block),
ext4_ext_pblock(ex),
ext4_ext_is_uninitialized(ex),
ext4_ext_get_actual_len(ex),
newblock);
ex++;
}
}
#else
#define ext4_ext_show_path(inode, path)
#define ext4_ext_show_leaf(inode, path)
#define ext4_ext_show_move(inode, path, newblock, level)
#endif
void ext4_ext_drop_refs(struct ext4_ext_path *path)
{
int depth = path->p_depth;
int i;
for (i = 0; i <= depth; i++, path++)
if (path->p_bh) {
brelse(path->p_bh);
path->p_bh = NULL;
}
}
/*
* ext4_ext_binsearch_idx:
* binary search for the closest index of the given block
* the header must be checked before calling this
*/
static void
ext4_ext_binsearch_idx(struct inode *inode,
struct ext4_ext_path *path, ext4_lblk_t block)
{
struct ext4_extent_header *eh = path->p_hdr;
struct ext4_extent_idx *r, *l, *m;
ext_debug("binsearch for %u(idx): ", block);
l = EXT_FIRST_INDEX(eh) + 1;
r = EXT_LAST_INDEX(eh);
while (l <= r) {
m = l + (r - l) / 2;
if (block < le32_to_cpu(m->ei_block))
r = m - 1;
else
l = m + 1;
ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
m, le32_to_cpu(m->ei_block),
r, le32_to_cpu(r->ei_block));
}
path->p_idx = l - 1;
ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
ext4_idx_pblock(path->p_idx));
#ifdef CHECK_BINSEARCH
{
struct ext4_extent_idx *chix, *ix;
int k;
chix = ix = EXT_FIRST_INDEX(eh);
for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
if (k != 0 &&
le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
printk(KERN_DEBUG "k=%d, ix=0x%p, "
"first=0x%p\n", k,
ix, EXT_FIRST_INDEX(eh));
printk(KERN_DEBUG "%u <= %u\n",
le32_to_cpu(ix->ei_block),
le32_to_cpu(ix[-1].ei_block));
}
BUG_ON(k && le32_to_cpu(ix->ei_block)
<= le32_to_cpu(ix[-1].ei_block));
if (block < le32_to_cpu(ix->ei_block))
break;
chix = ix;
}
BUG_ON(chix != path->p_idx);
}
#endif
}
/*
* ext4_ext_binsearch:
* binary search for closest extent of the given block
* the header must be checked before calling this
*/
static void
ext4_ext_binsearch(struct inode *inode,
struct ext4_ext_path *path, ext4_lblk_t block)
{
struct ext4_extent_header *eh = path->p_hdr;
struct ext4_extent *r, *l, *m;
if (eh->eh_entries == 0) {
/*
* this leaf is empty:
* we get such a leaf in split/add case
*/
return;
}
ext_debug("binsearch for %u: ", block);
l = EXT_FIRST_EXTENT(eh) + 1;
r = EXT_LAST_EXTENT(eh);
while (l <= r) {
m = l + (r - l) / 2;
if (block < le32_to_cpu(m->ee_block))
r = m - 1;
else
l = m + 1;
ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
m, le32_to_cpu(m->ee_block),
r, le32_to_cpu(r->ee_block));
}
path->p_ext = l - 1;
ext_debug(" -> %d:%llu:[%d]%d ",
le32_to_cpu(path->p_ext->ee_block),
ext4_ext_pblock(path->p_ext),
ext4_ext_is_uninitialized(path->p_ext),
ext4_ext_get_actual_len(path->p_ext));
#ifdef CHECK_BINSEARCH
{
struct ext4_extent *chex, *ex;
int k;
chex = ex = EXT_FIRST_EXTENT(eh);
for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
BUG_ON(k && le32_to_cpu(ex->ee_block)
<= le32_to_cpu(ex[-1].ee_block));
if (block < le32_to_cpu(ex->ee_block))
break;
chex = ex;
}
BUG_ON(chex != path->p_ext);
}
#endif
}
int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
{
struct ext4_extent_header *eh;
eh = ext_inode_hdr(inode);
eh->eh_depth = 0;
eh->eh_entries = 0;
eh->eh_magic = EXT4_EXT_MAGIC;
eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
ext4_mark_inode_dirty(handle, inode);
ext4_ext_invalidate_cache(inode);
return 0;
}
struct ext4_ext_path *
ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
struct ext4_ext_path *path)
{
struct ext4_extent_header *eh;
struct buffer_head *bh;
short int depth, i, ppos = 0, alloc = 0;
eh = ext_inode_hdr(inode);
depth = ext_depth(inode);
/* account possible depth increase */
if (!path) {
path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
GFP_NOFS);
if (!path)
return ERR_PTR(-ENOMEM);
alloc = 1;
}
path[0].p_hdr = eh;
path[0].p_bh = NULL;
i = depth;
/* walk through the tree */
while (i) {
ext_debug("depth %d: num %d, max %d\n",
ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
ext4_ext_binsearch_idx(inode, path + ppos, block);
path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
path[ppos].p_depth = i;
path[ppos].p_ext = NULL;
bh = sb_getblk(inode->i_sb, path[ppos].p_block);
if (unlikely(!bh))
goto err;
if (!bh_uptodate_or_lock(bh)) {
trace_ext4_ext_load_extent(inode, block,
path[ppos].p_block);
if (bh_submit_read(bh) < 0) {
put_bh(bh);
goto err;
}
}
eh = ext_block_hdr(bh);
ppos++;
if (unlikely(ppos > depth)) {
put_bh(bh);
EXT4_ERROR_INODE(inode,
"ppos %d > depth %d", ppos, depth);
goto err;
}
path[ppos].p_bh = bh;
path[ppos].p_hdr = eh;
i--;
if (ext4_ext_check_block(inode, eh, i, bh))
goto err;
}
path[ppos].p_depth = i;
path[ppos].p_ext = NULL;
path[ppos].p_idx = NULL;
/* find extent */
ext4_ext_binsearch(inode, path + ppos, block);
/* if not an empty leaf */
if (path[ppos].p_ext)
path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
ext4_ext_show_path(inode, path);
return path;
err:
ext4_ext_drop_refs(path);
if (alloc)
kfree(path);
return ERR_PTR(-EIO);
}
/*
* ext4_ext_insert_index:
* insert new index [@logical;@ptr] into the block at @curp;
* check where to insert: before @curp or after @curp
*/
static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
struct ext4_ext_path *curp,
int logical, ext4_fsblk_t ptr)
{
struct ext4_extent_idx *ix;
int len, err;
err = ext4_ext_get_access(handle, inode, curp);
if (err)
return err;
if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
EXT4_ERROR_INODE(inode,
"logical %d == ei_block %d!",
logical, le32_to_cpu(curp->p_idx->ei_block));
return -EIO;
}
if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
>= le16_to_cpu(curp->p_hdr->eh_max))) {
EXT4_ERROR_INODE(inode,
"eh_entries %d >= eh_max %d!",
le16_to_cpu(curp->p_hdr->eh_entries),
le16_to_cpu(curp->p_hdr->eh_max));
return -EIO;
}
if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
/* insert after */
ext_debug("insert new index %d after: %llu\n", logical, ptr);
ix = curp->p_idx + 1;
} else {
/* insert before */
ext_debug("insert new index %d before: %llu\n", logical, ptr);
ix = curp->p_idx;
}
len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
BUG_ON(len < 0);
if (len > 0) {
ext_debug("insert new index %d: "
"move %d indices from 0x%p to 0x%p\n",
logical, len, ix, ix + 1);
memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
}
if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
return -EIO;
}
ix->ei_block = cpu_to_le32(logical);
ext4_idx_store_pblock(ix, ptr);
le16_add_cpu(&curp->p_hdr->eh_entries, 1);
if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
return -EIO;
}
err = ext4_ext_dirty(handle, inode, curp);
ext4_std_error(inode->i_sb, err);
return err;
}
/*
* ext4_ext_split:
* inserts new subtree into the path, using free index entry
* at depth @at:
* - allocates all needed blocks (new leaf and all intermediate index blocks)
* - makes decision where to split
* - moves remaining extents and index entries (right to the split point)
* into the newly allocated blocks
* - initializes subtree
*/
static int ext4_ext_split(handle_t *handle, struct inode *inode,
unsigned int flags,
struct ext4_ext_path *path,
struct ext4_extent *newext, int at)
{
struct buffer_head *bh = NULL;
int depth = ext_depth(inode);
struct ext4_extent_header *neh;
struct ext4_extent_idx *fidx;
int i = at, k, m, a;
ext4_fsblk_t newblock, oldblock;
__le32 border;
ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
int err = 0;
/* make decision: where to split? */
/* FIXME: now decision is simplest: at current extent */
/* if current leaf will be split, then we should use
* border from split point */
if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
return -EIO;
}
if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
border = path[depth].p_ext[1].ee_block;
ext_debug("leaf will be split."
" next leaf starts at %d\n",
le32_to_cpu(border));
} else {
border = newext->ee_block;
ext_debug("leaf will be added."
" next leaf starts at %d\n",
le32_to_cpu(border));
}
/*
* If error occurs, then we break processing
* and mark filesystem read-only. index won't
* be inserted and tree will be in consistent
* state. Next mount will repair buffers too.
*/
/*
* Get array to track all allocated blocks.
* We need this to handle errors and free blocks
* upon them.
*/
ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
if (!ablocks)
return -ENOMEM;
/* allocate all needed blocks */
ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
for (a = 0; a < depth - at; a++) {
newblock = ext4_ext_new_meta_block(handle, inode, path,
newext, &err, flags);
if (newblock == 0)
goto cleanup;
ablocks[a] = newblock;
}
/* initialize new leaf */
newblock = ablocks[--a];
if (unlikely(newblock == 0)) {
EXT4_ERROR_INODE(inode, "newblock == 0!");
err = -EIO;
goto cleanup;
}
bh = sb_getblk(inode->i_sb, newblock);
if (!bh) {
err = -EIO;
goto cleanup;
}
lock_buffer(bh);
err = ext4_journal_get_create_access(handle, bh);
if (err)
goto cleanup;
neh = ext_block_hdr(bh);
neh->eh_entries = 0;
neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
neh->eh_magic = EXT4_EXT_MAGIC;
neh->eh_depth = 0;
/* move remainder of path[depth] to the new leaf */
if (unlikely(path[depth].p_hdr->eh_entries !=
path[depth].p_hdr->eh_max)) {
EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
path[depth].p_hdr->eh_entries,
path[depth].p_hdr->eh_max);
err = -EIO;
goto cleanup;
}
/* start copy from next extent */
m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
ext4_ext_show_move(inode, path, newblock, depth);
if (m) {
struct ext4_extent *ex;
ex = EXT_FIRST_EXTENT(neh);
memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
le16_add_cpu(&neh->eh_entries, m);
}
ext4_extent_block_csum_set(inode, neh);
set_buffer_uptodate(bh);
unlock_buffer(bh);
err = ext4_handle_dirty_metadata(handle, inode, bh);
if (err)
goto cleanup;
brelse(bh);
bh = NULL;
/* correct old leaf */
if (m) {
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
goto cleanup;
le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
err = ext4_ext_dirty(handle, inode, path + depth);
if (err)
goto cleanup;
}
/* create intermediate indexes */
k = depth - at - 1;
if (unlikely(k < 0)) {
EXT4_ERROR_INODE(inode, "k %d < 0!", k);
err = -EIO;
goto cleanup;
}
if (k)
ext_debug("create %d intermediate indices\n", k);
/* insert new index into current index block */
/* current depth stored in i var */
i = depth - 1;
while (k--) {
oldblock = newblock;
newblock = ablocks[--a];
bh = sb_getblk(inode->i_sb, newblock);
if (!bh) {
err = -EIO;
goto cleanup;
}
lock_buffer(bh);
err = ext4_journal_get_create_access(handle, bh);
if (err)
goto cleanup;
neh = ext_block_hdr(bh);
neh->eh_entries = cpu_to_le16(1);
neh->eh_magic = EXT4_EXT_MAGIC;
neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
neh->eh_depth = cpu_to_le16(depth - i);
fidx = EXT_FIRST_INDEX(neh);
fidx->ei_block = border;
ext4_idx_store_pblock(fidx, oldblock);
ext_debug("int.index at %d (block %llu): %u -> %llu\n",
i, newblock, le32_to_cpu(border), oldblock);
/* move remainder of path[i] to the new index block */
if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
EXT_LAST_INDEX(path[i].p_hdr))) {
EXT4_ERROR_INODE(inode,
"EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
le32_to_cpu(path[i].p_ext->ee_block));
err = -EIO;
goto cleanup;
}
/* start copy indexes */
m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
EXT_MAX_INDEX(path[i].p_hdr));
ext4_ext_show_move(inode, path, newblock, i);
if (m) {
memmove(++fidx, path[i].p_idx,
sizeof(struct ext4_extent_idx) * m);
le16_add_cpu(&neh->eh_entries, m);
}
ext4_extent_block_csum_set(inode, neh);
set_buffer_uptodate(bh);
unlock_buffer(bh);
err = ext4_handle_dirty_metadata(handle, inode, bh);
if (err)
goto cleanup;
brelse(bh);
bh = NULL;
/* correct old index */
if (m) {
err = ext4_ext_get_access(handle, inode, path + i);
if (err)
goto cleanup;
le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
err = ext4_ext_dirty(handle, inode, path + i);
if (err)
goto cleanup;
}
i--;
}
/* insert new index */
err = ext4_ext_insert_index(handle, inode, path + at,
le32_to_cpu(border), newblock);
cleanup:
if (bh) {
if (buffer_locked(bh))
unlock_buffer(bh);
brelse(bh);
}
if (err) {
/* free all allocated blocks in error case */
for (i = 0; i < depth; i++) {
if (!ablocks[i])
continue;
ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
EXT4_FREE_BLOCKS_METADATA);
}
}
kfree(ablocks);
return err;
}
/*
* ext4_ext_grow_indepth:
* implements tree growing procedure:
* - allocates new block
* - moves top-level data (index block or leaf) into the new block
* - initializes new top-level, creating index that points to the
* just created block
*/
static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
unsigned int flags,
struct ext4_extent *newext)
{
struct ext4_extent_header *neh;
struct buffer_head *bh;
ext4_fsblk_t newblock;
int err = 0;
newblock = ext4_ext_new_meta_block(handle, inode, NULL,
newext, &err, flags);
if (newblock == 0)
return err;
bh = sb_getblk(inode->i_sb, newblock);
if (!bh) {
err = -EIO;
ext4_std_error(inode->i_sb, err);
return err;
}
lock_buffer(bh);
err = ext4_journal_get_create_access(handle, bh);
if (err) {
unlock_buffer(bh);
goto out;
}
/* move top-level index/leaf into new block */
memmove(bh->b_data, EXT4_I(inode)->i_data,
sizeof(EXT4_I(inode)->i_data));
/* set size of new block */
neh = ext_block_hdr(bh);
/* old root could have indexes or leaves
* so calculate e_max right way */
if (ext_depth(inode))
neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
else
neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
neh->eh_magic = EXT4_EXT_MAGIC;
ext4_extent_block_csum_set(inode, neh);
set_buffer_uptodate(bh);
unlock_buffer(bh);
err = ext4_handle_dirty_metadata(handle, inode, bh);
if (err)
goto out;
/* Update top-level index: num,max,pointer */
neh = ext_inode_hdr(inode);
neh->eh_entries = cpu_to_le16(1);
ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
if (neh->eh_depth == 0) {
/* Root extent block becomes index block */
neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
EXT_FIRST_INDEX(neh)->ei_block =
EXT_FIRST_EXTENT(neh)->ee_block;
}
ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
neh->eh_depth = cpu_to_le16(le16_to_cpu(neh->eh_depth) + 1);
ext4_mark_inode_dirty(handle, inode);
out:
brelse(bh);
return err;
}
/*
* ext4_ext_create_new_leaf:
* finds empty index and adds new leaf.
* if no free index is found, then it requests in-depth growing.
*/
static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
unsigned int flags,
struct ext4_ext_path *path,
struct ext4_extent *newext)
{
struct ext4_ext_path *curp;
int depth, i, err = 0;
repeat:
i = depth = ext_depth(inode);
/* walk up to the tree and look for free index entry */
curp = path + depth;
while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
i--;
curp--;
}
/* we use already allocated block for index block,
* so subsequent data blocks should be contiguous */
if (EXT_HAS_FREE_INDEX(curp)) {
/* if we found index with free entry, then use that
* entry: create all needed subtree and add new leaf */
err = ext4_ext_split(handle, inode, flags, path, newext, i);
if (err)
goto out;
/* refill path */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block),
path);
if (IS_ERR(path))
err = PTR_ERR(path);
} else {
/* tree is full, time to grow in depth */
err = ext4_ext_grow_indepth(handle, inode, flags, newext);
if (err)
goto out;
/* refill path */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block),
path);
if (IS_ERR(path)) {
err = PTR_ERR(path);
goto out;
}
/*
* only first (depth 0 -> 1) produces free space;
* in all other cases we have to split the grown tree
*/
depth = ext_depth(inode);
if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
/* now we need to split */
goto repeat;
}
}
out:
return err;
}
/*
* search the closest allocated block to the left for *logical
* and returns it at @logical + it's physical address at @phys
* if *logical is the smallest allocated block, the function
* returns 0 at @phys
* return value contains 0 (success) or error code
*/
static int ext4_ext_search_left(struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t *logical, ext4_fsblk_t *phys)
{
struct ext4_extent_idx *ix;
struct ext4_extent *ex;
int depth, ee_len;
if (unlikely(path == NULL)) {
EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
return -EIO;
}
depth = path->p_depth;
*phys = 0;
if (depth == 0 && path->p_ext == NULL)
return 0;
/* usually extent in the path covers blocks smaller
* then *logical, but it can be that extent is the
* first one in the file */
ex = path[depth].p_ext;
ee_len = ext4_ext_get_actual_len(ex);
if (*logical < le32_to_cpu(ex->ee_block)) {
if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
EXT4_ERROR_INODE(inode,
"EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
*logical, le32_to_cpu(ex->ee_block));
return -EIO;
}
while (--depth >= 0) {
ix = path[depth].p_idx;
if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
EXT4_ERROR_INODE(inode,
"ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
depth);
return -EIO;
}
}
return 0;
}
if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
EXT4_ERROR_INODE(inode,
"logical %d < ee_block %d + ee_len %d!",
*logical, le32_to_cpu(ex->ee_block), ee_len);
return -EIO;
}
*logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
*phys = ext4_ext_pblock(ex) + ee_len - 1;
return 0;
}
/*
* search the closest allocated block to the right for *logical
* and returns it at @logical + it's physical address at @phys
* if *logical is the largest allocated block, the function
* returns 0 at @phys
* return value contains 0 (success) or error code
*/
static int ext4_ext_search_right(struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t *logical, ext4_fsblk_t *phys,
struct ext4_extent **ret_ex)
{
struct buffer_head *bh = NULL;
struct ext4_extent_header *eh;
struct ext4_extent_idx *ix;
struct ext4_extent *ex;
ext4_fsblk_t block;
int depth; /* Note, NOT eh_depth; depth from top of tree */
int ee_len;
if (unlikely(path == NULL)) {
EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
return -EIO;
}
depth = path->p_depth;
*phys = 0;
if (depth == 0 && path->p_ext == NULL)
return 0;
/* usually extent in the path covers blocks smaller
* then *logical, but it can be that extent is the
* first one in the file */
ex = path[depth].p_ext;
ee_len = ext4_ext_get_actual_len(ex);
if (*logical < le32_to_cpu(ex->ee_block)) {
if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
EXT4_ERROR_INODE(inode,
"first_extent(path[%d].p_hdr) != ex",
depth);
return -EIO;
}
while (--depth >= 0) {
ix = path[depth].p_idx;
if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
EXT4_ERROR_INODE(inode,
"ix != EXT_FIRST_INDEX *logical %d!",
*logical);
return -EIO;
}
}
goto found_extent;
}
if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
EXT4_ERROR_INODE(inode,
"logical %d < ee_block %d + ee_len %d!",
*logical, le32_to_cpu(ex->ee_block), ee_len);
return -EIO;
}
if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
/* next allocated block in this leaf */
ex++;
goto found_extent;
}
/* go up and search for index to the right */
while (--depth >= 0) {
ix = path[depth].p_idx;
if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
goto got_index;
}
/* we've gone up to the root and found no index to the right */
return 0;
got_index:
/* we've found index to the right, let's
* follow it and find the closest allocated
* block to the right */
ix++;
block = ext4_idx_pblock(ix);
while (++depth < path->p_depth) {
bh = sb_bread(inode->i_sb, block);
if (bh == NULL)
return -EIO;
eh = ext_block_hdr(bh);
/* subtract from p_depth to get proper eh_depth */
if (ext4_ext_check_block(inode, eh,
path->p_depth - depth, bh)) {
put_bh(bh);
return -EIO;
}
ix = EXT_FIRST_INDEX(eh);
block = ext4_idx_pblock(ix);
put_bh(bh);
}
bh = sb_bread(inode->i_sb, block);
if (bh == NULL)
return -EIO;
eh = ext_block_hdr(bh);
if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
put_bh(bh);
return -EIO;
}
ex = EXT_FIRST_EXTENT(eh);
found_extent:
*logical = le32_to_cpu(ex->ee_block);
*phys = ext4_ext_pblock(ex);
*ret_ex = ex;
if (bh)
put_bh(bh);
return 0;
}
/*
* ext4_ext_next_allocated_block:
* returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
* NOTE: it considers block number from index entry as
* allocated block. Thus, index entries have to be consistent
* with leaves.
*/
static ext4_lblk_t
ext4_ext_next_allocated_block(struct ext4_ext_path *path)
{
int depth;
BUG_ON(path == NULL);
depth = path->p_depth;
if (depth == 0 && path->p_ext == NULL)
return EXT_MAX_BLOCKS;
while (depth >= 0) {
if (depth == path->p_depth) {
/* leaf */
if (path[depth].p_ext &&
path[depth].p_ext !=
EXT_LAST_EXTENT(path[depth].p_hdr))
return le32_to_cpu(path[depth].p_ext[1].ee_block);
} else {
/* index */
if (path[depth].p_idx !=
EXT_LAST_INDEX(path[depth].p_hdr))
return le32_to_cpu(path[depth].p_idx[1].ei_block);
}
depth--;
}
return EXT_MAX_BLOCKS;
}
/*
* ext4_ext_next_leaf_block:
* returns first allocated block from next leaf or EXT_MAX_BLOCKS
*/
static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
{
int depth;
BUG_ON(path == NULL);
depth = path->p_depth;
/* zero-tree has no leaf blocks at all */
if (depth == 0)
return EXT_MAX_BLOCKS;
/* go to index block */
depth--;
while (depth >= 0) {
if (path[depth].p_idx !=
EXT_LAST_INDEX(path[depth].p_hdr))
return (ext4_lblk_t)
le32_to_cpu(path[depth].p_idx[1].ei_block);
depth--;
}
return EXT_MAX_BLOCKS;
}
/*
* ext4_ext_correct_indexes:
* if leaf gets modified and modified extent is first in the leaf,
* then we have to correct all indexes above.
* TODO: do we need to correct tree in all cases?
*/
static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
{
struct ext4_extent_header *eh;
int depth = ext_depth(inode);
struct ext4_extent *ex;
__le32 border;
int k, err = 0;
eh = path[depth].p_hdr;
ex = path[depth].p_ext;
if (unlikely(ex == NULL || eh == NULL)) {
EXT4_ERROR_INODE(inode,
"ex %p == NULL or eh %p == NULL", ex, eh);
return -EIO;
}
if (depth == 0) {
/* there is no tree at all */
return 0;
}
if (ex != EXT_FIRST_EXTENT(eh)) {
/* we correct tree if first leaf got modified only */
return 0;
}
/*
* TODO: we need correction if border is smaller than current one
*/
k = depth - 1;
border = path[depth].p_ext->ee_block;
err = ext4_ext_get_access(handle, inode, path + k);
if (err)
return err;
path[k].p_idx->ei_block = border;
err = ext4_ext_dirty(handle, inode, path + k);
if (err)
return err;
while (k--) {
/* change all left-side indexes */
if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
break;
err = ext4_ext_get_access(handle, inode, path + k);
if (err)
break;
path[k].p_idx->ei_block = border;
err = ext4_ext_dirty(handle, inode, path + k);
if (err)
break;
}
return err;
}
int
ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
struct ext4_extent *ex2)
{
unsigned short ext1_ee_len, ext2_ee_len, max_len;
/*
* Make sure that either both extents are uninitialized, or
* both are _not_.
*/
if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
return 0;
if (ext4_ext_is_uninitialized(ex1))
max_len = EXT_UNINIT_MAX_LEN;
else
max_len = EXT_INIT_MAX_LEN;
ext1_ee_len = ext4_ext_get_actual_len(ex1);
ext2_ee_len = ext4_ext_get_actual_len(ex2);
if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
le32_to_cpu(ex2->ee_block))
return 0;
/*
* To allow future support for preallocated extents to be added
* as an RO_COMPAT feature, refuse to merge to extents if
* this can result in the top bit of ee_len being set.
*/
if (ext1_ee_len + ext2_ee_len > max_len)
return 0;
#ifdef AGGRESSIVE_TEST
if (ext1_ee_len >= 4)
return 0;
#endif
if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
return 1;
return 0;
}
/*
* This function tries to merge the "ex" extent to the next extent in the tree.
* It always tries to merge towards right. If you want to merge towards
* left, pass "ex - 1" as argument instead of "ex".
* Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
* 1 if they got merged.
*/
static int ext4_ext_try_to_merge_right(struct inode *inode,
struct ext4_ext_path *path,
struct ext4_extent *ex)
{
struct ext4_extent_header *eh;
unsigned int depth, len;
int merge_done = 0;
int uninitialized = 0;
depth = ext_depth(inode);
BUG_ON(path[depth].p_hdr == NULL);
eh = path[depth].p_hdr;
while (ex < EXT_LAST_EXTENT(eh)) {
if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
break;
/* merge with next extent! */
if (ext4_ext_is_uninitialized(ex))
uninitialized = 1;
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(ex + 1));
if (uninitialized)
ext4_ext_mark_uninitialized(ex);
if (ex + 1 < EXT_LAST_EXTENT(eh)) {
len = (EXT_LAST_EXTENT(eh) - ex - 1)
* sizeof(struct ext4_extent);
memmove(ex + 1, ex + 2, len);
}
le16_add_cpu(&eh->eh_entries, -1);
merge_done = 1;
WARN_ON(eh->eh_entries == 0);
if (!eh->eh_entries)
EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
}
return merge_done;
}
/*
* This function tries to merge the @ex extent to neighbours in the tree.
* return 1 if merge left else 0.
*/
static int ext4_ext_try_to_merge(struct inode *inode,
struct ext4_ext_path *path,
struct ext4_extent *ex) {
struct ext4_extent_header *eh;
unsigned int depth;
int merge_done = 0;
int ret = 0;
depth = ext_depth(inode);
BUG_ON(path[depth].p_hdr == NULL);
eh = path[depth].p_hdr;
if (ex > EXT_FIRST_EXTENT(eh))
merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
if (!merge_done)
ret = ext4_ext_try_to_merge_right(inode, path, ex);
return ret;
}
/*
* check if a portion of the "newext" extent overlaps with an
* existing extent.
*
* If there is an overlap discovered, it updates the length of the newext
* such that there will be no overlap, and then returns 1.
* If there is no overlap found, it returns 0.
*/
static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
struct inode *inode,
struct ext4_extent *newext,
struct ext4_ext_path *path)
{
ext4_lblk_t b1, b2;
unsigned int depth, len1;
unsigned int ret = 0;
b1 = le32_to_cpu(newext->ee_block);
len1 = ext4_ext_get_actual_len(newext);
depth = ext_depth(inode);
if (!path[depth].p_ext)
goto out;
b2 = le32_to_cpu(path[depth].p_ext->ee_block);
b2 &= ~(sbi->s_cluster_ratio - 1);
/*
* get the next allocated block if the extent in the path
* is before the requested block(s)
*/
if (b2 < b1) {
b2 = ext4_ext_next_allocated_block(path);
if (b2 == EXT_MAX_BLOCKS)
goto out;
b2 &= ~(sbi->s_cluster_ratio - 1);
}
/* check for wrap through zero on extent logical start block*/
if (b1 + len1 < b1) {
len1 = EXT_MAX_BLOCKS - b1;
newext->ee_len = cpu_to_le16(len1);
ret = 1;
}
/* check for overlap */
if (b1 + len1 > b2) {
newext->ee_len = cpu_to_le16(b2 - b1);
ret = 1;
}
out:
return ret;
}
/*
* ext4_ext_insert_extent:
* tries to merge requsted extent into the existing extent or
* inserts requested extent as new one into the tree,
* creating new leaf in the no-space case.
*/
int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path,
struct ext4_extent *newext, int flag)
{
struct ext4_extent_header *eh;
struct ext4_extent *ex, *fex;
struct ext4_extent *nearex; /* nearest extent */
struct ext4_ext_path *npath = NULL;
int depth, len, err;
ext4_lblk_t next;
unsigned uninitialized = 0;
int flags = 0;
if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
return -EIO;
}
depth = ext_depth(inode);
ex = path[depth].p_ext;
if (unlikely(path[depth].p_hdr == NULL)) {
EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
return -EIO;
}
/* try to insert block into found extent and return */
if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
&& ext4_can_extents_be_merged(inode, ex, newext)) {
ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
ext4_ext_is_uninitialized(newext),
ext4_ext_get_actual_len(newext),
le32_to_cpu(ex->ee_block),
ext4_ext_is_uninitialized(ex),
ext4_ext_get_actual_len(ex),
ext4_ext_pblock(ex));
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
return err;
/*
* ext4_can_extents_be_merged should have checked that either
* both extents are uninitialized, or both aren't. Thus we
* need to check only one of them here.
*/
if (ext4_ext_is_uninitialized(ex))
uninitialized = 1;
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(newext));
if (uninitialized)
ext4_ext_mark_uninitialized(ex);
eh = path[depth].p_hdr;
nearex = ex;
goto merge;
}
depth = ext_depth(inode);
eh = path[depth].p_hdr;
if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
goto has_space;
/* probably next leaf has space for us? */
fex = EXT_LAST_EXTENT(eh);
next = EXT_MAX_BLOCKS;
if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
next = ext4_ext_next_leaf_block(path);
if (next != EXT_MAX_BLOCKS) {
ext_debug("next leaf block - %u\n", next);
BUG_ON(npath != NULL);
npath = ext4_ext_find_extent(inode, next, NULL);
if (IS_ERR(npath))
return PTR_ERR(npath);
BUG_ON(npath->p_depth != path->p_depth);
eh = npath[depth].p_hdr;
if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
ext_debug("next leaf isn't full(%d)\n",
le16_to_cpu(eh->eh_entries));
path = npath;
goto has_space;
}
ext_debug("next leaf has no free space(%d,%d)\n",
le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
}
/*
* There is no free space in the found leaf.
* We're gonna add a new leaf in the tree.
*/
if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
flags = EXT4_MB_USE_ROOT_BLOCKS;
err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
if (err)
goto cleanup;
depth = ext_depth(inode);
eh = path[depth].p_hdr;
has_space:
nearex = path[depth].p_ext;
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
goto cleanup;
if (!nearex) {
/* there is no extent in this leaf, create first one */
ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
le32_to_cpu(newext->ee_block),
ext4_ext_pblock(newext),
ext4_ext_is_uninitialized(newext),
ext4_ext_get_actual_len(newext));
nearex = EXT_FIRST_EXTENT(eh);
} else {
if (le32_to_cpu(newext->ee_block)
> le32_to_cpu(nearex->ee_block)) {
/* Insert after */
ext_debug("insert %u:%llu:[%d]%d before: "
"nearest %p\n",
le32_to_cpu(newext->ee_block),
ext4_ext_pblock(newext),
ext4_ext_is_uninitialized(newext),
ext4_ext_get_actual_len(newext),
nearex);
nearex++;
} else {
/* Insert before */
BUG_ON(newext->ee_block == nearex->ee_block);
ext_debug("insert %u:%llu:[%d]%d after: "
"nearest %p\n",
le32_to_cpu(newext->ee_block),
ext4_ext_pblock(newext),
ext4_ext_is_uninitialized(newext),
ext4_ext_get_actual_len(newext),
nearex);
}
len = EXT_LAST_EXTENT(eh) - nearex + 1;
if (len > 0) {
ext_debug("insert %u:%llu:[%d]%d: "
"move %d extents from 0x%p to 0x%p\n",
le32_to_cpu(newext->ee_block),
ext4_ext_pblock(newext),
ext4_ext_is_uninitialized(newext),
ext4_ext_get_actual_len(newext),
len, nearex, nearex + 1);
memmove(nearex + 1, nearex,
len * sizeof(struct ext4_extent));
}
}
le16_add_cpu(&eh->eh_entries, 1);
path[depth].p_ext = nearex;
nearex->ee_block = newext->ee_block;
ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
nearex->ee_len = newext->ee_len;
merge:
/* try to merge extents */
if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
ext4_ext_try_to_merge(inode, path, nearex);
/* time to correct all indexes above */
err = ext4_ext_correct_indexes(handle, inode, path);
if (err)
goto cleanup;
err = ext4_ext_dirty(handle, inode, path + depth);
cleanup:
if (npath) {
ext4_ext_drop_refs(npath);
kfree(npath);
}
ext4_ext_invalidate_cache(inode);
return err;
}
static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
ext4_lblk_t num, ext_prepare_callback func,
void *cbdata)
{
struct ext4_ext_path *path = NULL;
struct ext4_ext_cache cbex;
struct ext4_extent *ex;
ext4_lblk_t next, start = 0, end = 0;
ext4_lblk_t last = block + num;
int depth, exists, err = 0;
BUG_ON(func == NULL);
BUG_ON(inode == NULL);
while (block < last && block != EXT_MAX_BLOCKS) {
num = last - block;
/* find extent for this block */
down_read(&EXT4_I(inode)->i_data_sem);
path = ext4_ext_find_extent(inode, block, path);
up_read(&EXT4_I(inode)->i_data_sem);
if (IS_ERR(path)) {
err = PTR_ERR(path);
path = NULL;
break;
}
depth = ext_depth(inode);
if (unlikely(path[depth].p_hdr == NULL)) {
EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
err = -EIO;
break;
}
ex = path[depth].p_ext;
next = ext4_ext_next_allocated_block(path);
exists = 0;
if (!ex) {
/* there is no extent yet, so try to allocate
* all requested space */
start = block;
end = block + num;
} else if (le32_to_cpu(ex->ee_block) > block) {
/* need to allocate space before found extent */
start = block;
end = le32_to_cpu(ex->ee_block);
if (block + num < end)
end = block + num;
} else if (block >= le32_to_cpu(ex->ee_block)
+ ext4_ext_get_actual_len(ex)) {
/* need to allocate space after found extent */
start = block;
end = block + num;
if (end >= next)
end = next;
} else if (block >= le32_to_cpu(ex->ee_block)) {
/*
* some part of requested space is covered
* by found extent
*/
start = block;
end = le32_to_cpu(ex->ee_block)
+ ext4_ext_get_actual_len(ex);
if (block + num < end)
end = block + num;
exists = 1;
} else {
BUG();
}
BUG_ON(end <= start);
if (!exists) {
cbex.ec_block = start;
cbex.ec_len = end - start;
cbex.ec_start = 0;
} else {
cbex.ec_block = le32_to_cpu(ex->ee_block);
cbex.ec_len = ext4_ext_get_actual_len(ex);
cbex.ec_start = ext4_ext_pblock(ex);
}
if (unlikely(cbex.ec_len == 0)) {
EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
err = -EIO;
break;
}
err = func(inode, next, &cbex, ex, cbdata);
ext4_ext_drop_refs(path);
if (err < 0)
break;
if (err == EXT_REPEAT)
continue;
else if (err == EXT_BREAK) {
err = 0;
break;
}
if (ext_depth(inode) != depth) {
/* depth was changed. we have to realloc path */
kfree(path);
path = NULL;
}
block = cbex.ec_block + cbex.ec_len;
}
if (path) {
ext4_ext_drop_refs(path);
kfree(path);
}
return err;
}
static void
ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
__u32 len, ext4_fsblk_t start)
{
struct ext4_ext_cache *cex;
BUG_ON(len == 0);
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
trace_ext4_ext_put_in_cache(inode, block, len, start);
cex = &EXT4_I(inode)->i_cached_extent;
cex->ec_block = block;
cex->ec_len = len;
cex->ec_start = start;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
/*
* ext4_ext_put_gap_in_cache:
* calculate boundaries of the gap that the requested block fits into
* and cache this gap
*/
static void
ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
ext4_lblk_t block)
{
int depth = ext_depth(inode);
unsigned long len;
ext4_lblk_t lblock;
struct ext4_extent *ex;
ex = path[depth].p_ext;
if (ex == NULL) {
/* there is no extent yet, so gap is [0;-] */
lblock = 0;
len = EXT_MAX_BLOCKS;
ext_debug("cache gap(whole file):");
} else if (block < le32_to_cpu(ex->ee_block)) {
lblock = block;
len = le32_to_cpu(ex->ee_block) - block;
ext_debug("cache gap(before): %u [%u:%u]",
block,
le32_to_cpu(ex->ee_block),
ext4_ext_get_actual_len(ex));
} else if (block >= le32_to_cpu(ex->ee_block)
+ ext4_ext_get_actual_len(ex)) {
ext4_lblk_t next;
lblock = le32_to_cpu(ex->ee_block)
+ ext4_ext_get_actual_len(ex);
next = ext4_ext_next_allocated_block(path);
ext_debug("cache gap(after): [%u:%u] %u",
le32_to_cpu(ex->ee_block),
ext4_ext_get_actual_len(ex),
block);
BUG_ON(next == lblock);
len = next - lblock;
} else {
lblock = len = 0;
BUG();
}
ext_debug(" -> %u:%lu\n", lblock, len);
ext4_ext_put_in_cache(inode, lblock, len, 0);
}
/*
* ext4_ext_check_cache()
* Checks to see if the given block is in the cache.
* If it is, the cached extent is stored in the given
* cache extent pointer. If the cached extent is a hole,
* this routine should be used instead of
* ext4_ext_in_cache if the calling function needs to
* know the size of the hole.
*
* @inode: The files inode
* @block: The block to look for in the cache
* @ex: Pointer where the cached extent will be stored
* if it contains block
*
* Return 0 if cache is invalid; 1 if the cache is valid
*/
static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
struct ext4_ext_cache *ex){
struct ext4_ext_cache *cex;
struct ext4_sb_info *sbi;
int ret = 0;
/*
* We borrow i_block_reservation_lock to protect i_cached_extent
*/
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
sbi = EXT4_SB(inode->i_sb);
/* has cache valid data? */
if (cex->ec_len == 0)
goto errout;
if (in_range(block, cex->ec_block, cex->ec_len)) {
memcpy(ex, cex, sizeof(struct ext4_ext_cache));
ext_debug("%u cached by %u:%u:%llu\n",
block,
cex->ec_block, cex->ec_len, cex->ec_start);
ret = 1;
}
errout:
trace_ext4_ext_in_cache(inode, block, ret);
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return ret;
}
/*
* ext4_ext_in_cache()
* Checks to see if the given block is in the cache.
* If it is, the cached extent is stored in the given
* extent pointer.
*
* @inode: The files inode
* @block: The block to look for in the cache
* @ex: Pointer where the cached extent will be stored
* if it contains block
*
* Return 0 if cache is invalid; 1 if the cache is valid
*/
static int
ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
struct ext4_extent *ex)
{
struct ext4_ext_cache cex;
int ret = 0;
if (ext4_ext_check_cache(inode, block, &cex)) {
ex->ee_block = cpu_to_le32(cex.ec_block);
ext4_ext_store_pblock(ex, cex.ec_start);
ex->ee_len = cpu_to_le16(cex.ec_len);
ret = 1;
}
return ret;
}
/*
* ext4_ext_rm_idx:
* removes index from the index block.
*/
static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
{
int err;
ext4_fsblk_t leaf;
/* free index block */
path--;
leaf = ext4_idx_pblock(path->p_idx);
if (unlikely(path->p_hdr->eh_entries == 0)) {
EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
return -EIO;
}
err = ext4_ext_get_access(handle, inode, path);
if (err)
return err;
if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
len *= sizeof(struct ext4_extent_idx);
memmove(path->p_idx, path->p_idx + 1, len);
}
le16_add_cpu(&path->p_hdr->eh_entries, -1);
err = ext4_ext_dirty(handle, inode, path);
if (err)
return err;
ext_debug("index is empty, remove it, free block %llu\n", leaf);
trace_ext4_ext_rm_idx(inode, leaf);
ext4_free_blocks(handle, inode, NULL, leaf, 1,
EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
return err;
}
/*
* ext4_ext_calc_credits_for_single_extent:
* This routine returns max. credits that needed to insert an extent
* to the extent tree.
* When pass the actual path, the caller should calculate credits
* under i_data_sem.
*/
int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
struct ext4_ext_path *path)
{
if (path) {
int depth = ext_depth(inode);
int ret = 0;
/* probably there is space in leaf? */
if (le16_to_cpu(path[depth].p_hdr->eh_entries)
< le16_to_cpu(path[depth].p_hdr->eh_max)) {
/*
* There are some space in the leaf tree, no
* need to account for leaf block credit
*
* bitmaps and block group descriptor blocks
* and other metadata blocks still need to be
* accounted.
*/
/* 1 bitmap, 1 block group descriptor */
ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
return ret;
}
}
return ext4_chunk_trans_blocks(inode, nrblocks);
}
/*
* How many index/leaf blocks need to change/allocate to modify nrblocks?
*
* if nrblocks are fit in a single extent (chunk flag is 1), then
* in the worse case, each tree level index/leaf need to be changed
* if the tree split due to insert a new extent, then the old tree
* index/leaf need to be updated too
*
* If the nrblocks are discontiguous, they could cause
* the whole tree split more than once, but this is really rare.
*/
int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
{
int index;
int depth = ext_depth(inode);
if (chunk)
index = depth * 2;
else
index = depth * 3;
return index;
}
static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
struct ext4_extent *ex,
ext4_fsblk_t *partial_cluster,
ext4_lblk_t from, ext4_lblk_t to)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
unsigned short ee_len = ext4_ext_get_actual_len(ex);
ext4_fsblk_t pblk;
int flags = EXT4_FREE_BLOCKS_FORGET;
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
flags |= EXT4_FREE_BLOCKS_METADATA;
/*
* For bigalloc file systems, we never free a partial cluster
* at the beginning of the extent. Instead, we make a note
* that we tried freeing the cluster, and check to see if we
* need to free it on a subsequent call to ext4_remove_blocks,
* or at the end of the ext4_truncate() operation.
*/
flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
/*
* If we have a partial cluster, and it's different from the
* cluster of the last block, we need to explicitly free the
* partial cluster here.
*/
pblk = ext4_ext_pblock(ex) + ee_len - 1;
if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, *partial_cluster),
sbi->s_cluster_ratio, flags);
*partial_cluster = 0;
}
#ifdef EXTENTS_STATS
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
spin_lock(&sbi->s_ext_stats_lock);
sbi->s_ext_blocks += ee_len;
sbi->s_ext_extents++;
if (ee_len < sbi->s_ext_min)
sbi->s_ext_min = ee_len;
if (ee_len > sbi->s_ext_max)
sbi->s_ext_max = ee_len;
if (ext_depth(inode) > sbi->s_depth_max)
sbi->s_depth_max = ext_depth(inode);
spin_unlock(&sbi->s_ext_stats_lock);
}
#endif
if (from >= le32_to_cpu(ex->ee_block)
&& to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
/* tail removal */
ext4_lblk_t num;
num = le32_to_cpu(ex->ee_block) + ee_len - from;
pblk = ext4_ext_pblock(ex) + ee_len - num;
ext_debug("free last %u blocks starting %llu\n", num, pblk);
ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
/*
* If the block range to be freed didn't start at the
* beginning of a cluster, and we removed the entire
* extent, save the partial cluster here, since we
* might need to delete if we determine that the
* truncate operation has removed all of the blocks in
* the cluster.
*/
if (pblk & (sbi->s_cluster_ratio - 1) &&
(ee_len == num))
*partial_cluster = EXT4_B2C(sbi, pblk);
else
*partial_cluster = 0;
} else if (from == le32_to_cpu(ex->ee_block)
&& to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
/* head removal */
ext4_lblk_t num;
ext4_fsblk_t start;
num = to - from;
start = ext4_ext_pblock(ex);
ext_debug("free first %u blocks starting %llu\n", num, start);
ext4_free_blocks(handle, inode, NULL, start, num, flags);
} else {
printk(KERN_INFO "strange request: removal(2) "
"%u-%u from %u:%u\n",
from, to, le32_to_cpu(ex->ee_block), ee_len);
}
return 0;
}
/*
* ext4_ext_rm_leaf() Removes the extents associated with the
* blocks appearing between "start" and "end", and splits the extents
* if "start" and "end" appear in the same extent
*
* @handle: The journal handle
* @inode: The files inode
* @path: The path to the leaf
* @start: The first block to remove
* @end: The last block to remove
*/
static int
ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
ext4_lblk_t start, ext4_lblk_t end)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int err = 0, correct_index = 0;
int depth = ext_depth(inode), credits;
struct ext4_extent_header *eh;
ext4_lblk_t a, b;
unsigned num;
ext4_lblk_t ex_ee_block;
unsigned short ex_ee_len;
unsigned uninitialized = 0;
struct ext4_extent *ex;
/* the header must be checked already in ext4_ext_remove_space() */
ext_debug("truncate since %u in leaf to %u\n", start, end);
if (!path[depth].p_hdr)
path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
eh = path[depth].p_hdr;
if (unlikely(path[depth].p_hdr == NULL)) {
EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
return -EIO;
}
/* find where to start removing */
ex = EXT_LAST_EXTENT(eh);
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
while (ex >= EXT_FIRST_EXTENT(eh) &&
ex_ee_block + ex_ee_len > start) {
if (ext4_ext_is_uninitialized(ex))
uninitialized = 1;
else
uninitialized = 0;
ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
uninitialized, ex_ee_len);
path[depth].p_ext = ex;
a = ex_ee_block > start ? ex_ee_block : start;
b = ex_ee_block+ex_ee_len - 1 < end ?
ex_ee_block+ex_ee_len - 1 : end;
ext_debug(" border %u:%u\n", a, b);
/* If this extent is beyond the end of the hole, skip it */
if (end < ex_ee_block) {
ex--;
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
continue;
} else if (b != ex_ee_block + ex_ee_len - 1) {
EXT4_ERROR_INODE(inode,
"can not handle truncate %u:%u "
"on extent %u:%u",
start, end, ex_ee_block,
ex_ee_block + ex_ee_len - 1);
err = -EIO;
goto out;
} else if (a != ex_ee_block) {
/* remove tail of the extent */
num = a - ex_ee_block;
} else {
/* remove whole extent: excellent! */
num = 0;
}
/*
* 3 for leaf, sb, and inode plus 2 (bmap and group
* descriptor) for each block group; assume two block
* groups plus ex_ee_len/blocks_per_block_group for
* the worst case
*/
credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
if (ex == EXT_FIRST_EXTENT(eh)) {
correct_index = 1;
credits += (ext_depth(inode)) + 1;
}
credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
err = ext4_ext_truncate_extend_restart(handle, inode, credits);
if (err)
goto out;
err = ext4_ext_get_access(handle, inode, path + depth);
if (err)
goto out;
err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
a, b);
if (err)
goto out;
if (num == 0)
/* this extent is removed; mark slot entirely unused */
ext4_ext_store_pblock(ex, 0);
ex->ee_len = cpu_to_le16(num);
/*
* Do not mark uninitialized if all the blocks in the
* extent have been removed.
*/
if (uninitialized && num)
ext4_ext_mark_uninitialized(ex);
/*
* If the extent was completely released,
* we need to remove it from the leaf
*/
if (num == 0) {
if (end != EXT_MAX_BLOCKS - 1) {
/*
* For hole punching, we need to scoot all the
* extents up when an extent is removed so that
* we dont have blank extents in the middle
*/
memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
sizeof(struct ext4_extent));
/* Now get rid of the one at the end */
memset(EXT_LAST_EXTENT(eh), 0,
sizeof(struct ext4_extent));
}
le16_add_cpu(&eh->eh_entries, -1);
} else
*partial_cluster = 0;
err = ext4_ext_dirty(handle, inode, path + depth);
if (err)
goto out;
ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
ext4_ext_pblock(ex));
ex--;
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
}
if (correct_index && eh->eh_entries)
err = ext4_ext_correct_indexes(handle, inode, path);
/*
* If there is still a entry in the leaf node, check to see if
* it references the partial cluster. This is the only place
* where it could; if it doesn't, we can free the cluster.
*/
if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
(EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
*partial_cluster)) {
int flags = EXT4_FREE_BLOCKS_FORGET;
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
flags |= EXT4_FREE_BLOCKS_METADATA;
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, *partial_cluster),
sbi->s_cluster_ratio, flags);
*partial_cluster = 0;
}
/* if this leaf is free, then we should
* remove it from index block above */
if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
err = ext4_ext_rm_idx(handle, inode, path + depth);
out:
return err;
}
/*
* ext4_ext_more_to_rm:
* returns 1 if current index has to be freed (even partial)
*/
static int
ext4_ext_more_to_rm(struct ext4_ext_path *path)
{
BUG_ON(path->p_idx == NULL);
if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
return 0;
/*
* if truncate on deeper level happened, it wasn't partial,
* so we have to consider current index for truncation
*/
if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
return 0;
return 1;
}
static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
ext4_lblk_t end)
{
struct super_block *sb = inode->i_sb;
int depth = ext_depth(inode);
struct ext4_ext_path *path = NULL;
ext4_fsblk_t partial_cluster = 0;
handle_t *handle;
int i = 0, err;
ext_debug("truncate since %u to %u\n", start, end);
/* probably first extent we're gonna free will be last in block */
handle = ext4_journal_start(inode, depth + 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
again:
ext4_ext_invalidate_cache(inode);
trace_ext4_ext_remove_space(inode, start, depth);
/*
* Check if we are removing extents inside the extent tree. If that
* is the case, we are going to punch a hole inside the extent tree
* so we have to check whether we need to split the extent covering
* the last block to remove so we can easily remove the part of it
* in ext4_ext_rm_leaf().
*/
if (end < EXT_MAX_BLOCKS - 1) {
struct ext4_extent *ex;
ext4_lblk_t ee_block;
/* find extent for this block */
path = ext4_ext_find_extent(inode, end, NULL);
if (IS_ERR(path)) {
ext4_journal_stop(handle);
return PTR_ERR(path);
}
depth = ext_depth(inode);
ex = path[depth].p_ext;
if (!ex) {
ext4_ext_drop_refs(path);
kfree(path);
path = NULL;
goto cont;
}
ee_block = le32_to_cpu(ex->ee_block);
/*
* See if the last block is inside the extent, if so split
* the extent at 'end' block so we can easily remove the
* tail of the first part of the split extent in
* ext4_ext_rm_leaf().
*/
if (end >= ee_block &&
end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
int split_flag = 0;
if (ext4_ext_is_uninitialized(ex))
split_flag = EXT4_EXT_MARK_UNINIT1 |
EXT4_EXT_MARK_UNINIT2;
/*
* Split the extent in two so that 'end' is the last
* block in the first new extent
*/
err = ext4_split_extent_at(handle, inode, path,
end + 1, split_flag,
EXT4_GET_BLOCKS_PRE_IO |
EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
if (err < 0)
goto out;
}
}
cont:
/*
* We start scanning from right side, freeing all the blocks
* after i_size and walking into the tree depth-wise.
*/
depth = ext_depth(inode);
if (path) {
int k = i = depth;
while (--k > 0)
path[k].p_block =
le16_to_cpu(path[k].p_hdr->eh_entries)+1;
} else {
path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
GFP_NOFS);
if (path == NULL) {
ext4_journal_stop(handle);
return -ENOMEM;
}
path[0].p_depth = depth;
path[0].p_hdr = ext_inode_hdr(inode);
if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
err = -EIO;
goto out;
}
}
err = 0;
while (i >= 0 && err == 0) {
if (i == depth) {
/* this is leaf block */
err = ext4_ext_rm_leaf(handle, inode, path,
&partial_cluster, start,
end);
/* root level has p_bh == NULL, brelse() eats this */
brelse(path[i].p_bh);
path[i].p_bh = NULL;
i--;
continue;
}
/* this is index block */
if (!path[i].p_hdr) {
ext_debug("initialize header\n");
path[i].p_hdr = ext_block_hdr(path[i].p_bh);
}
if (!path[i].p_idx) {
/* this level hasn't been touched yet */
path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
ext_debug("init index ptr: hdr 0x%p, num %d\n",
path[i].p_hdr,
le16_to_cpu(path[i].p_hdr->eh_entries));
} else {
/* we were already here, see at next index */
path[i].p_idx--;
}
ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
i, EXT_FIRST_INDEX(path[i].p_hdr),
path[i].p_idx);
if (ext4_ext_more_to_rm(path + i)) {
struct buffer_head *bh;
/* go to the next level */
ext_debug("move to level %d (block %llu)\n",
i + 1, ext4_idx_pblock(path[i].p_idx));
memset(path + i + 1, 0, sizeof(*path));
bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
if (!bh) {
/* should we reset i_size? */
err = -EIO;
break;
}
if (WARN_ON(i + 1 > depth)) {
err = -EIO;
break;
}
if (ext4_ext_check_block(inode, ext_block_hdr(bh),
depth - i - 1, bh)) {
err = -EIO;
break;
}
path[i + 1].p_bh = bh;
/* save actual number of indexes since this
* number is changed at the next iteration */
path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
i++;
} else {
/* we finished processing this index, go up */
if (path[i].p_hdr->eh_entries == 0 && i > 0) {
/* index is empty, remove it;
* handle must be already prepared by the
* truncatei_leaf() */
err = ext4_ext_rm_idx(handle, inode, path + i);
}
/* root level has p_bh == NULL, brelse() eats this */
brelse(path[i].p_bh);
path[i].p_bh = NULL;
i--;
ext_debug("return to level %d\n", i);
}
}
trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
path->p_hdr->eh_entries);
/* If we still have something in the partial cluster and we have removed
* even the first extent, then we should free the blocks in the partial
* cluster as well. */
if (partial_cluster && path->p_hdr->eh_entries == 0) {
int flags = EXT4_FREE_BLOCKS_FORGET;
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
flags |=