/* 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;
dbg_fsbuild("build FS data structures\n");
/* First, scan the medium and build all the inode caches with
lists of physical nodes */
c->flags |= JFFS2_SB_FLAG_SCANNING;
ret = jffs2_scan_medium(c);
c->flags &= ~JFFS2_SB_FLAG_SCANNING;
if (ret)
goto exit;
dbg_fsbuild("scanned flash completely\n");
jffs2_dbg_dump_block_lists_nolock(c);
dbg_fsbuild("pass 1 starting\n");
c->flags |= JFFS2_SB_FLAG_BUILDING;
/* Now scan the directory tree, increasing nlink according to every dirent found. */
for_each_inode(i, c, ic) {
if (ic->scan_dents) {
jffs2_build_inode_pass1(c, ic);
cond_resched();
}
}
dbg_fsbuild("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. */
dbg_fsbuild("pass 2 starting\n");
for_each_inode(i, c, ic) {
if (ic->pino_nlink)
continue;
jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
cond_resched();
}
dbg_fsbuild("pass 2a starting\n");
while (dead_fds) {
fd = dead_fds;
dead_fds = fd->next;
ic = jffs2_get_ino_cache(c, fd->ino);
if (ic)
jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
jffs2_free_full_dirent(fd);
}
dbg_fsbuild("pass 2a complete\n");
dbg_fsbuild("freeing temporary data structures\n");
/* Finally, we can scan again and free the dirent structs */
for_each_inode(i, c, ic) {
while(ic->scan_dents) {
fd = ic->scan_dents;
ic->scan_dents = fd->next;
jffs2_free_full_dirent(fd);
}
ic->scan_dents = NULL;
cond_resched();
}
jffs2_build_xattr_subsystem(c);
c->flags &= ~JFFS2_SB_FLAG_BUILDING;
dbg_fsbuild("FS build complete\n");
/* 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);
}
}
jffs2_clear_xattr_subsystem(c);
}
return ret;
}
int jffs2_scan_medium(struct jffs2_sb_info *c)
{
int i, ret;
__u32 empty_blocks = 0;
if (!c->blocks) {
printk(KERN_WARNING "EEEK! c->blocks is NULL!\n");
return -EINVAL;
}
for (i=0; i<c->nr_blocks; i++) {
struct jffs2_eraseblock *jeb = &c->blocks[i];
if (c->flags & (1 << 7))
ret = 1;
else
ret = jffs2_scan_eraseblock(c, jeb);
if (ret < 0)
return ret;
ACCT_PARANOIA_CHECK(jeb);
/* Now decide which list to put it on */
if (ret == 1) {
/*
* Empty block. Since we can't be sure it
* was entirely erased, we just queue it for erase
* again. It will be marked as such when the erase
* is complete. Meanwhile we still count it as empty
* for later checks.
*/
list_add(&jeb->list, &c->erase_pending_list);
empty_blocks++;
c->nr_erasing_blocks++;
} else if (jeb->used_size == PAD(sizeof(struct jffs2_unknown_node)) && !jeb->first_node->next_in_ino) {
/* Only a CLEANMARKER node is valid */
if (!jeb->dirty_size) {
/* It's actually free */
list_add(&jeb->list, &c->free_list);
c->nr_free_blocks++;
} else {
/* Dirt */
D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
list_add(&jeb->list, &c->erase_pending_list);
c->nr_erasing_blocks++;
}
} else if (jeb->used_size > c->sector_size - (2*sizeof(struct jffs2_raw_inode))) {
/* Full (or almost full) of clean data. Clean list */
list_add(&jeb->list, &c->clean_list);
} else if (jeb->used_size) {
/* Some data, but not full. Dirty list. */
/* Except that we want to remember the block with most free space,
and stick it in the 'nextblock' position to start writing to it.
Later when we do snapshots, this must be the most recent block,
not the one with most free space.
*/
if (jeb->free_size > 2*sizeof(struct jffs2_raw_inode) &&
(!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
/* Better candidate for the next writes to go to */
if (c->nextblock)
list_add(&c->nextblock->list, &c->dirty_list);
c->nextblock = jeb;
} else {
list_add(&jeb->list, &c->dirty_list);
}
} else {
/* Nothing valid - not even a clean marker. Needs erasing. */
/* For now we just put it on the erasing list. We'll start the erases later */
printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset);
list_add(&jeb->list, &c->erase_pending_list);
c->nr_erasing_blocks++;
}
}
/* Rotate the lists by some number to ensure wear levelling */
jffs2_rotate_lists(c);
if (c->nr_erasing_blocks) {
if (!c->used_size && empty_blocks != c->nr_blocks) {
printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
return -EIO;
}
jffs2_erase_pending_trigger(c);
}
return 0;
}