diff options
| author | Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> | 2018-10-30 15:06:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-31 08:54:13 -0700 |
| commit | 54640c7502e5ed41fbf4eedd499e85f9acc9698f (patch) | |
| tree | 0745ae35891531719808bf29bdcecf0bf8cf1119 /fs/hfs/catalog.c | |
| parent | d92915c35bfaf763d78bf1d5ac7f183420e3bd99 (diff) | |
hfs: prevent btree data loss on ENOSPC
Inserting a new record in a btree may require splitting several of its
nodes. If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost. This could mean lost inodes or
extents.
Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.
There is no need to reserve space before deleting a catalog record, as we
do for hfsplus. This difference is because hfs index nodes have fixed
length keys.
Link: http://lkml.kernel.org/r/ab5fc8a7d5ffccfd5f27b1cf2cb4ceb6c110da74.1536269131.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/hfs/catalog.c')
| -rw-r--r-- | fs/hfs/catalog.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/hfs/catalog.c b/fs/hfs/catalog.c index 8a66405b0f8b..d365bf0b8c77 100644 --- a/fs/hfs/catalog.c +++ b/fs/hfs/catalog.c @@ -97,6 +97,14 @@ int hfs_cat_create(u32 cnid, struct inode *dir, const struct qstr *str, struct i if (err) return err; + /* + * Fail early and avoid ENOSPC during the btree operations. We may + * have to split the root node at most once. + */ + err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth); + if (err) + goto err2; + hfs_cat_build_key(sb, fd.search_key, cnid, NULL); entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ? HFS_CDR_THD : HFS_CDR_FTH, @@ -295,6 +303,14 @@ int hfs_cat_move(u32 cnid, struct inode *src_dir, const struct qstr *src_name, return err; dst_fd = src_fd; + /* + * Fail early and avoid ENOSPC during the btree operations. We may + * have to split the root node at most once. + */ + err = hfs_bmap_reserve(src_fd.tree, 2 * src_fd.tree->depth); + if (err) + goto out; + /* find the old dir entry and read the data */ hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name); err = hfs_brec_find(&src_fd); |