diff options
author | Josef Bacik <josef@redhat.com> | 2010-11-19 19:59:15 (GMT) |
---|---|---|
committer | Chris Mason <chris.mason@oracle.com> | 2010-11-27 18:37:51 (GMT) |
commit | 450ba0ea06b6ed3612d27f2b7127a9de4160f285 (patch) | |
tree | 2276ddbcb65d7656416cdce69432a5858b35c413 /fs/btrfs/super.c | |
parent | 975f84fee2e8a77ee5f41bfe7c5682bf29366b10 (diff) | |
download | linux-fsl-qoriq-450ba0ea06b6ed3612d27f2b7127a9de4160f285.tar.xz |
Btrfs: setup blank root and fs_info for mount time
There is a problem with how we use sget, it searches through the list of supers
attached to the fs_type looking for a super with the same fs_devices as what
we're trying to mount. This depends on sb->s_fs_info being filled, but we don't
fill that in until we get to btrfs_fill_super, so we could hit supers on the
fs_type super list that have a null s_fs_info. In order to fix that we need to
go ahead and setup a blank root with a blank fs_info to hold fs_devices, that
way our test will work out right and then we can set s_fs_info in
btrfs_set_super, and then open_ctree will simply use our pre-allocated root and
fs_info when setting everything up. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/super.c')
-rw-r--r-- | fs/btrfs/super.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 141fb31..47bf67c 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -563,7 +563,7 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) static int btrfs_test_super(struct super_block *s, void *data) { - struct btrfs_fs_devices *test_fs_devices = data; + struct btrfs_root *test_root = data; struct btrfs_root *root = btrfs_sb(s); /* @@ -572,9 +572,17 @@ static int btrfs_test_super(struct super_block *s, void *data) */ if (!atomic_read(&s->s_active)) return 0; - return root->fs_info->fs_devices == test_fs_devices; + return root->fs_info->fs_devices == test_root->fs_info->fs_devices; } +static int btrfs_set_super(struct super_block *s, void *data) +{ + s->s_fs_info = data; + + return set_anon_super(s, data); +} + + /* * Find a superblock for the given device / mount point. * @@ -588,6 +596,8 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, struct super_block *s; struct dentry *root; struct btrfs_fs_devices *fs_devices = NULL; + struct btrfs_root *tree_root = NULL; + struct btrfs_fs_info *fs_info = NULL; fmode_t mode = FMODE_READ; char *subvol_name = NULL; u64 subvol_objectid = 0; @@ -615,8 +625,24 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, goto error_close_devices; } + /* + * Setup a dummy root and fs_info for test/set super. This is because + * we don't actually fill this stuff out until open_ctree, but we need + * it for searching for existing supers, so this lets us do that and + * then open_ctree will properly initialize everything later. + */ + fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); + tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); + if (!fs_info || !tree_root) { + error = -ENOMEM; + goto error_close_devices; + } + fs_info->tree_root = tree_root; + fs_info->fs_devices = fs_devices; + tree_root->fs_info = fs_info; + bdev = fs_devices->latest_bdev; - s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); + s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root); if (IS_ERR(s)) goto error_s; @@ -685,6 +711,8 @@ error_s: error = PTR_ERR(s); error_close_devices: btrfs_close_devices(fs_devices); + kfree(fs_info); + kfree(tree_root); error_free_subvol_name: kfree(subvol_name); return error; |