hfsplus: prevent btree data loss on ENOSPC
Inserting or deleting a 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,
extents or xattrs.
Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.
The patch can be tested with xfstests generic/027.
Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.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>
diff --git a/fs/hfsplus/attributes.c b/fs/hfsplus/attributes.c
index 2bab6b3..e6d5544 100644
--- a/fs/hfsplus/attributes.c
+++ b/fs/hfsplus/attributes.c
@@ -217,6 +217,11 @@
if (err)
goto failed_init_create_attr;
+ /* Fail early and avoid ENOSPC during the btree operation */
+ err = hfs_bmap_reserve(fd.tree, fd.tree->depth + 1);
+ if (err)
+ goto failed_create_attr;
+
if (name) {
err = hfsplus_attr_build_key(sb, fd.search_key,
inode->i_ino, name);
@@ -313,6 +318,11 @@
if (err)
return err;
+ /* Fail early and avoid ENOSPC during the btree operation */
+ err = hfs_bmap_reserve(fd.tree, fd.tree->depth);
+ if (err)
+ goto out;
+
if (name) {
err = hfsplus_attr_build_key(sb, fd.search_key,
inode->i_ino, name);