From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- fs/jffs2/build.c | 371 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 371 insertions(+) create mode 100644 fs/jffs2/build.c (limited to 'fs/jffs2/build.c') diff --git a/fs/jffs2/build.c b/fs/jffs2/build.c new file mode 100644 index 00000000000..a01dd5fdbb9 --- /dev/null +++ b/fs/jffs2/build.c @@ -0,0 +1,371 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright (C) 2001-2003 Red Hat, Inc. + * + * Created by David Woodhouse + * + * For licensing information, see the file 'LICENCE' in this directory. + * + * $Id: build.c,v 1.69 2004/12/16 20:22:18 dmarlin Exp $ + * + */ + +#include +#include +#include +#include +#include +#include "nodelist.h" + +static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *, struct jffs2_inode_cache *, struct jffs2_full_dirent **); + +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))) + + +static inline void 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 directory inode #%u\n", 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); + jffs2_mark_node_obsolete(c, fd->raw); + 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 */ + } +} + +/* 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; + struct jffs2_full_dirent *fd; + struct jffs2_full_dirent *dead_fds = NULL; + + /* 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); + if (ret) + goto exit; + + D1(printk(KERN_DEBUG "Scanned flash completely\n")); + D2(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)); + + D1(BUG_ON(ic->ino > c->highest_ino)); + + if (ic->scan_dents) { + jffs2_build_inode_pass1(c, ic); + cond_resched(); + } + } + c->flags &= ~JFFS2_SB_FLAG_MOUNTING; + + D1(printk(KERN_DEBUG "Pass 1 complete\n")); + + /* 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. */ + D1(printk(KERN_DEBUG "Pass 2 starting\n")); + + 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; + + jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); + cond_resched(); + } + + D1(printk(KERN_DEBUG "Pass 2a starting\n")); + + while (dead_fds) { + fd = dead_fds; + dead_fds = fd->next; + + ic = jffs2_get_ino_cache(c, fd->ino); + D1(printk(KERN_DEBUG "Removing dead_fd ino #%u (\"%s\"), ic at %p\n", fd->ino, fd->name, ic)); + + if (ic) + jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); + jffs2_free_full_dirent(fd); + } + + D1(printk(KERN_DEBUG "Pass 2 complete\n")); + + /* Finally, we can scan again and free the dirent structs */ + for_each_inode(i, c, ic) { + 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")); + D2(jffs2_dump_block_lists(c)); + + /* Rotate the lists by some number to ensure wear levelling */ + jffs2_rotate_lists(c); + + ret = 0; + +exit: + if (ret) { + for_each_inode(i, c, ic) { + while(ic->scan_dents) { + fd = ic->scan_dents; + ic->scan_dents = fd->next; + jffs2_free_full_dirent(fd); + } + } + } + + return ret; +} + +static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, struct jffs2_full_dirent **dead_fds) +{ + struct jffs2_raw_node_ref *raw; + struct jffs2_full_dirent *fd; + + D1(printk(KERN_DEBUG "JFFS2: Removing ino #%u with nlink == zero.\n", ic->ino)); + + raw = ic->nodes; + while (raw != (void *)ic) { + struct jffs2_raw_node_ref *next = raw->next_in_ino; + D1(printk(KERN_DEBUG "obsoleting node at 0x%08x\n", ref_offset(raw))); + jffs2_mark_node_obsolete(c, raw); + raw = next; + } + + 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; + } + + /* Reduce nlink of the child. If it's now zero, stick it on the + dead_fds list to be cleaned up later. Else just free the fd */ + + child_ic->nlink--; + + if (!child_ic->nlink) { + D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got zero nlink. Adding to dead_fds list.\n", + fd->ino, fd->name)); + fd->next = *dead_fds; + *dead_fds = fd; + } else { + D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got nlink %d. Ignoring.\n", + fd->ino, fd->name, child_ic->nlink)); + jffs2_free_full_dirent(fd); + } + } + } + + /* + 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. + */ +} + +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; + if (c->mtd->flags & MTD_NO_VIRTBLOCKS) + c->blocks = vmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks); + else + c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL); + if (!c->blocks) + return -ENOMEM; + for (i=0; inr_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; + c->blocks[i].bad_count = 0; + } + + 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); + if (c->mtd->flags & MTD_NO_VIRTBLOCKS) { + vfree(c->blocks); + } else { + kfree(c->blocks); + } + return -EIO; + } + + jffs2_calc_trigger_levels(c); + + return 0; +} -- cgit v1.2.3