diff options
| author | Jeff Layton <jlayton@redhat.com> | 2007-05-08 00:32:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:16 -0700 |
| commit | 1a1c9bb433af252767ee90d6394d287afa30cf8b (patch) | |
| tree | 586225fc9f3ca52d60d59400a3c7d4e90ca0667e /fs | |
| parent | 866b04fccbf125cd39f2bdbcfeaa611d39a061a8 (diff) | |
inode numbering: change libfs sb creation routines to avoid collisions with their root inodes
This patch makes it so that simple_fill_super and get_sb_pseudo assign their
root inodes to be number 1. It also fixes up a couple of callers of
simple_fill_super that were passing in files arrays that had an index at
number 1, and adds a warning for any caller that sends in such an array.
It would have been nice to have made it so that it wasn't possible to make
such a collision, but some callers need to be able to control what inode
number their entries get, so I think this is the best that can be done.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/binfmt_misc.c | 4 | ||||
| -rw-r--r-- | fs/libfs.c | 23 |
2 files changed, 25 insertions, 2 deletions
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index e6f57990b12..18657f001b4 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -727,8 +727,8 @@ static const struct super_operations s_ops = { static int bm_fill_super(struct super_block * sb, void * data, int silent) { static struct tree_descr bm_files[] = { - [1] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO}, - [2] = {"register", &bm_register_operations, S_IWUSR}, + [2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO}, + [3] = {"register", &bm_register_operations, S_IWUSR}, /* last one */ {""} }; int err = simple_fill_super(sb, 0x42494e4d, bm_files); diff --git a/fs/libfs.c b/fs/libfs.c index d93842d3c0a..1247ee90253 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -220,6 +220,12 @@ int get_sb_pseudo(struct file_system_type *fs_type, char *name, root = new_inode(s); if (!root) goto Enomem; + /* + * since this is the first inode, make it number 1. New inodes created + * after this must take care not to collide with it (by passing + * max_reserved of 1 to iunique). + */ + root->i_ino = 1; root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; root->i_uid = root->i_gid = 0; root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; @@ -360,6 +366,11 @@ int simple_commit_write(struct file *file, struct page *page, return 0; } +/* + * the inodes created here are not hashed. If you use iunique to generate + * unique inode values later for this filesystem, then you must take care + * to pass it an appropriate max_reserved value to avoid collisions. + */ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) { struct inode *inode; @@ -376,6 +387,11 @@ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files inode = new_inode(s); if (!inode) return -ENOMEM; + /* + * because the root inode is 1, the files array must not contain an + * entry at index 1 + */ + inode->i_ino = 1; inode->i_mode = S_IFDIR | 0755; inode->i_uid = inode->i_gid = 0; inode->i_blocks = 0; @@ -391,6 +407,13 @@ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files for (i = 0; !files->name || files->name[0]; i++, files++) { if (!files->name) continue; + + /* warn if it tries to conflict with the root inode */ + if (unlikely(i == 1)) + printk(KERN_WARNING "%s: %s passed in a files array" + "with an index of 1!\n", __func__, + s->s_type->name); + dentry = d_alloc_name(root, files->name); if (!dentry) goto out; |