| /* |
| * JFFS2 -- Journalling Flash File System, Version 2. |
| * |
| * Copyright (C) 2001-2003 Red Hat, Inc. |
| * |
| * Created by David Woodhouse <dwmw2@redhat.com> |
| * |
| * For licensing information, see the file 'LICENCE' in this directory. |
| * |
| * $Id: build.c,v 1.52 2003/10/09 00:38:38 dwmw2 Exp $ |
| * |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include "nodelist.h" |
| |
| int jffs2_build_inode_pass1(struct jffs2_sb_info *, struct jffs2_inode_cache *); |
| int jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *, struct jffs2_inode_cache *); |
| |
| static inline struct jffs2_inode_cache * |
| first_inode_chain(int *i, struct jffs2_sb_info *c) |
| { |
| for (; *i < INOCACHE_HASHSIZE; (*i)++) { |
| if (c->inocache_list[*i]) |
| return c->inocache_list[*i]; |
| } |
| return NULL; |
| } |
| |
| static inline struct jffs2_inode_cache * |
| next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c) |
| { |
| /* More in this chain? */ |
| if (ic->next) |
| return ic->next; |
| (*i)++; |
| return first_inode_chain(i, c); |
| } |
| |
| #define for_each_inode(i, c, ic) \ |
| for (i = 0, ic = first_inode_chain(&i, (c)); \ |
| ic; \ |
| ic = next_inode(&i, ic, (c))) |
| |
| /* Scan plan: |
| - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go |
| - Scan directory tree from top down, setting nlink in inocaches |
| - Scan inocaches for inodes with nlink==0 |
| */ |
| static int jffs2_build_filesystem(struct jffs2_sb_info *c) |
| { |
| int ret; |
| int i; |
| struct jffs2_inode_cache *ic; |
| |
| /* First, scan the medium and build all the inode caches with |
| lists of physical nodes */ |
| |
| c->flags |= JFFS2_SB_FLAG_MOUNTING; |
| ret = jffs2_scan_medium(c); |
| c->flags &= ~JFFS2_SB_FLAG_MOUNTING; |
| |
| if (ret) |
| return ret; |
| |
| D1(printk(KERN_DEBUG "Scanned flash completely\n")); |
| D1(jffs2_dump_block_lists(c)); |
| |
| /* Now scan the directory tree, increasing nlink according to every dirent found. */ |
| for_each_inode(i, c, ic) { |
| D1(printk(KERN_DEBUG "Pass 1: ino #%u\n", ic->ino)); |
| ret = jffs2_build_inode_pass1(c, ic); |
| if (ret) { |
| D1(printk(KERN_WARNING "Eep. jffs2_build_inode_pass1 for ino %d returned %d\n", ic->ino, ret)); |
| return ret; |
| } |
| cond_resched(); |
| } |
| D1(printk(KERN_DEBUG "Pass 1 complete\n")); |
| D1(jffs2_dump_block_lists(c)); |
| |
| /* Next, scan for inodes with nlink == 0 and remove them. If |
| they were directories, then decrement the nlink of their |
| children too, and repeat the scan. As that's going to be |
| a fairly uncommon occurrence, it's not so evil to do it this |
| way. Recursion bad. */ |
| do { |
| D1(printk(KERN_DEBUG "Pass 2 (re)starting\n")); |
| ret = 0; |
| for_each_inode(i, c, ic) { |
| D1(printk(KERN_DEBUG "Pass 2: ino #%u, nlink %d, ic %p, nodes %p\n", ic->ino, ic->nlink, ic, ic->nodes)); |
| if (ic->nlink) |
| continue; |
| |
| /* XXX: Can get high latency here. Move the cond_resched() from the end of the loop? */ |
| |
| ret = jffs2_build_remove_unlinked_inode(c, ic); |
| if (ret) |
| break; |
| /* -EAGAIN means the inode's nlink was zero, so we deleted it, |
| and furthermore that it had children and their nlink has now |
| gone to zero too. So we have to restart the scan. */ |
| } |
| D1(jffs2_dump_block_lists(c)); |
| |
| cond_resched(); |
| |
| } while(ret == -EAGAIN); |
| |
| D1(printk(KERN_DEBUG "Pass 2 complete\n")); |
| |
| /* Finally, we can scan again and free the dirent nodes and scan_info structs */ |
| for_each_inode(i, c, ic) { |
| struct jffs2_full_dirent *fd; |
| D1(printk(KERN_DEBUG "Pass 3: ino #%u, ic %p, nodes %p\n", ic->ino, ic, ic->nodes)); |
| |
| while(ic->scan_dents) { |
| fd = ic->scan_dents; |
| ic->scan_dents = fd->next; |
| jffs2_free_full_dirent(fd); |
| } |
| ic->scan_dents = NULL; |
| cond_resched(); |
| } |
| D1(printk(KERN_DEBUG "Pass 3 complete\n")); |
| D1(jffs2_dump_block_lists(c)); |
| |
| /* Rotate the lists by some number to ensure wear levelling */ |
| jffs2_rotate_lists(c); |
| |
| return ret; |
| } |
| |
| int jffs2_build_inode_pass1(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic) |
| { |
| struct jffs2_full_dirent *fd; |
| |
| D1(printk(KERN_DEBUG "jffs2_build_inode building inode #%u\n", ic->ino)); |
| |
| if (ic->ino > c->highest_ino) |
| c->highest_ino = ic->ino; |
| |
| /* For each child, increase nlink */ |
| for(fd=ic->scan_dents; fd; fd = fd->next) { |
| struct jffs2_inode_cache *child_ic; |
| if (!fd->ino) |
| continue; |
| |
| /* XXX: Can get high latency here with huge directories */ |
| |
| child_ic = jffs2_get_ino_cache(c, fd->ino); |
| if (!child_ic) { |
| printk(KERN_NOTICE "Eep. Child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n", |
| fd->name, fd->ino, ic->ino); |
| continue; |
| } |
| |
| if (child_ic->nlink++ && fd->type == DT_DIR) { |
| printk(KERN_NOTICE "Child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n", fd->name, fd->ino, ic->ino); |
| if (fd->ino == 1 && ic->ino == 1) { |
| printk(KERN_NOTICE "This is mostly harmless, and probably caused by creating a JFFS2 image\n"); |
| printk(KERN_NOTICE "using a buggy version of mkfs.jffs2. Use at least v1.17.\n"); |
| } |
| /* What do we do about it? */ |
| } |
| D1(printk(KERN_DEBUG "Increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino)); |
| /* Can't free them. We might need them in pass 2 */ |
| } |
| return 0; |
| } |
| |
| int jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic) |
| { |
| struct jffs2_raw_node_ref *raw; |
| struct jffs2_full_dirent *fd; |
| int ret = 0; |
| |
| D1(printk(KERN_DEBUG "JFFS2: Removing ino #%u with nlink == zero.\n", ic->ino)); |
| |
| for (raw = ic->nodes; raw != (void *)ic; raw = raw->next_in_ino) { |
| D1(printk(KERN_DEBUG "obsoleting node at 0x%08x\n", ref_offset(raw))); |
| jffs2_mark_node_obsolete(c, raw); |
| } |
| |
| if (ic->scan_dents) { |
| int whinged = 0; |
| D1(printk(KERN_DEBUG "Inode #%u was a directory which may have children...\n", ic->ino)); |
| |
| while(ic->scan_dents) { |
| struct jffs2_inode_cache *child_ic; |
| |
| fd = ic->scan_dents; |
| ic->scan_dents = fd->next; |
| |
| if (!fd->ino) { |
| /* It's a deletion dirent. Ignore it */ |
| D1(printk(KERN_DEBUG "Child \"%s\" is a deletion dirent, skipping...\n", fd->name)); |
| jffs2_free_full_dirent(fd); |
| continue; |
| } |
| if (!whinged) { |
| whinged = 1; |
| printk(KERN_NOTICE "Inode #%u was a directory with children - removing those too...\n", ic->ino); |
| } |
| |
| D1(printk(KERN_DEBUG "Removing child \"%s\", ino #%u\n", |
| fd->name, fd->ino)); |
| |
| child_ic = jffs2_get_ino_cache(c, fd->ino); |
| if (!child_ic) { |
| printk(KERN_NOTICE "Cannot remove child \"%s\", ino #%u, because it doesn't exist\n", fd->name, fd->ino); |
| jffs2_free_full_dirent(fd); |
| continue; |
| } |
| jffs2_free_full_dirent(fd); |
| child_ic->nlink--; |
| } |
| ret = -EAGAIN; |
| } |
| |
| /* |
| We don't delete the inocache from the hash list and free it yet. |
| The erase code will do that, when all the nodes are completely gone. |
| */ |
| |
| return ret; |
| } |
| |
| static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c) |
| { |
| uint32_t size; |
| |
| /* Deletion should almost _always_ be allowed. We're fairly |
| buggered once we stop allowing people to delete stuff |
| because there's not enough free space... */ |
| c->resv_blocks_deletion = 2; |
| |
| /* Be conservative about how much space we need before we allow writes. |
| On top of that which is required for deletia, require an extra 2% |
| of the medium to be available, for overhead caused by nodes being |
| split across blocks, etc. */ |
| |
| size = c->flash_size / 50; /* 2% of flash size */ |
| size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */ |
| size += c->sector_size - 1; /* ... and round up */ |
| |
| c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size); |
| |
| /* When do we let the GC thread run in the background */ |
| |
| c->resv_blocks_gctrigger = c->resv_blocks_write + 1; |
| |
| /* When do we allow garbage collection to merge nodes to make |
| long-term progress at the expense of short-term space exhaustion? */ |
| c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1; |
| |
| /* When do we allow garbage collection to eat from bad blocks rather |
| than actually making progress? */ |
| c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2; |
| |
| /* If there's less than this amount of dirty space, don't bother |
| trying to GC to make more space. It'll be a fruitless task */ |
| c->nospc_dirty_size = c->sector_size + (c->flash_size / 100); |
| |
| D1(printk(KERN_DEBUG "JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n", |
| c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks)); |
| D1(printk(KERN_DEBUG "Blocks required to allow deletion: %d (%d KiB)\n", |
| c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024)); |
| D1(printk(KERN_DEBUG "Blocks required to allow writes: %d (%d KiB)\n", |
| c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024)); |
| D1(printk(KERN_DEBUG "Blocks required to quiesce GC thread: %d (%d KiB)\n", |
| c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024)); |
| D1(printk(KERN_DEBUG "Blocks required to allow GC merges: %d (%d KiB)\n", |
| c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024)); |
| D1(printk(KERN_DEBUG "Blocks required to GC bad blocks: %d (%d KiB)\n", |
| c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024)); |
| D1(printk(KERN_DEBUG "Amount of dirty space required to GC: %d bytes\n", |
| c->nospc_dirty_size)); |
| } |
| |
| int jffs2_do_mount_fs(struct jffs2_sb_info *c) |
| { |
| int i; |
| |
| c->free_size = c->flash_size; |
| c->nr_blocks = c->flash_size / c->sector_size; |
| c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL); |
| if (!c->blocks) |
| return -ENOMEM; |
| for (i=0; i<c->nr_blocks; i++) { |
| INIT_LIST_HEAD(&c->blocks[i].list); |
| c->blocks[i].offset = i * c->sector_size; |
| c->blocks[i].free_size = c->sector_size; |
| c->blocks[i].dirty_size = 0; |
| c->blocks[i].wasted_size = 0; |
| c->blocks[i].unchecked_size = 0; |
| c->blocks[i].used_size = 0; |
| c->blocks[i].first_node = NULL; |
| c->blocks[i].last_node = NULL; |
| } |
| |
| init_MUTEX(&c->alloc_sem); |
| init_MUTEX(&c->erase_free_sem); |
| init_waitqueue_head(&c->erase_wait); |
| init_waitqueue_head(&c->inocache_wq); |
| spin_lock_init(&c->erase_completion_lock); |
| spin_lock_init(&c->inocache_lock); |
| |
| INIT_LIST_HEAD(&c->clean_list); |
| INIT_LIST_HEAD(&c->very_dirty_list); |
| INIT_LIST_HEAD(&c->dirty_list); |
| INIT_LIST_HEAD(&c->erasable_list); |
| INIT_LIST_HEAD(&c->erasing_list); |
| INIT_LIST_HEAD(&c->erase_pending_list); |
| INIT_LIST_HEAD(&c->erasable_pending_wbuf_list); |
| INIT_LIST_HEAD(&c->erase_complete_list); |
| INIT_LIST_HEAD(&c->free_list); |
| INIT_LIST_HEAD(&c->bad_list); |
| INIT_LIST_HEAD(&c->bad_used_list); |
| c->highest_ino = 1; |
| |
| if (jffs2_build_filesystem(c)) { |
| D1(printk(KERN_DEBUG "build_fs failed\n")); |
| jffs2_free_ino_caches(c); |
| jffs2_free_raw_node_refs(c); |
| kfree(c->blocks); |
| return -EIO; |
| } |
| |
| jffs2_calc_trigger_levels(c); |
| |
| return 0; |
| } |