ext4: return ENOMEM if sb_getblk() fails

commit 860d21e2c585f7ee8a4ecc06f474fdc33c9474f4 upstream.

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So ENOMEM is more appropriate than EIO.  In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
[bwh: Backported to 3.2:
 - Adjust context
 - Drop change to inline.c
 - Call to ext4_ext_check() from ext4_ext_find_extent() is conditional]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

1 files changed, 14 insertions, 11 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index fbb92e6434e9..aaa01ccf3e10 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -636,6 +636,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 	struct ext4_extent_header *eh;
 	struct buffer_head *bh;
 	short int depth, i, ppos = 0, alloc = 0;
+	int ret;
 
 	eh = ext_inode_hdr(inode);
 	depth = ext_depth(inode);
@@ -665,12 +666,15 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 		path[ppos].p_ext = NULL;
 
 		bh = sb_getblk(inode->i_sb, path[ppos].p_block);
-		if (unlikely(!bh))
+		if (unlikely(!bh)) {
+			ret = -ENOMEM;
 			goto err;
+		}
 		if (!bh_uptodate_or_lock(bh)) {
 			trace_ext4_ext_load_extent(inode, block,
 						path[ppos].p_block);
-			if (bh_submit_read(bh) < 0) {
+			ret = bh_submit_read(bh);
+			if (ret < 0) {
 				put_bh(bh);
 				goto err;
 			}
@@ -683,13 +687,15 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 			put_bh(bh);
 			EXT4_ERROR_INODE(inode,
 					 "ppos %d > depth %d", ppos, depth);
+			ret = -EIO;
 			goto err;
 		}
 		path[ppos].p_bh = bh;
 		path[ppos].p_hdr = eh;
 		i--;
 
-		if (need_to_validate && ext4_ext_check(inode, eh, i))
+		ret = need_to_validate ? ext4_ext_check(inode, eh, i) : 0;
+		if (ret < 0)
 			goto err;
 	}
 
@@ -711,7 +717,7 @@ err:
 	ext4_ext_drop_refs(path);
 	if (alloc)
 		kfree(path);
-	return ERR_PTR(-EIO);
+	return ERR_PTR(ret);
 }
 
 /*
@@ -866,7 +872,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	}
 	bh = sb_getblk(inode->i_sb, newblock);
 	if (!bh) {
-		err = -EIO;
+		err = -ENOMEM;
 		goto cleanup;
 	}
 	lock_buffer(bh);
@@ -938,7 +944,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		newblock = ablocks[--a];
 		bh = sb_getblk(inode->i_sb, newblock);
 		if (!bh) {
-			err = -EIO;
+			err = -ENOMEM;
 			goto cleanup;
 		}
 		lock_buffer(bh);
@@ -1049,11 +1055,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 		return err;
 
 	bh = sb_getblk(inode->i_sb, newblock);
-	if (!bh) {
-		err = -EIO;
-		ext4_std_error(inode->i_sb, err);
-		return err;
-	}
+	if (!bh)
+		return -ENOMEM;
 	lock_buffer(bh);
 
 	err = ext4_journal_get_create_access(handle, bh);