commit 32f123a3f34283f9c6446de87861696f0502b02e upstream.
udf_getblk() has a single call site. Fold it there.
Signed-off-by: Jan Kara <jack@xxxxxxx>
[acsjakub: backport-adjusting changes]
udf_getblk() has changed between 6.1 and the backported commit namely
in commit 541e047b14c8 ("udf: Use udf_map_block() in udf_getblk()")
Backport using the form of udf_getblk present in 6.1., that means use
udf_get_block() instead of udf_map_block() and use dummy in buffer_new()
and buffer_mapped().
Closes: https://syzkaller.appspot.com/bug?extid=a38e34ca637c224f4a79
Signed-off-by: Jakub Acs <acsjakub@xxxxxxxxx>
---
While doing the backport I have noticed potential side effect of the
upstream commit (present in the mainline):
If we take the if-branch of 'if (map.oflags & UDF_BLK_NEW)', we will
return the bh without the 'if (bh_read(bh, 0) >= 0)' check. Prior to
the folding, the check wouldn't be skipped, was this intentional by the
upstream commit?
---
fs/udf/inode.c | 46 +++++++++++++++++++++-------------------------
1 file changed, 21 insertions(+), 25 deletions(-)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index d7d6ccd0af06..626450101412 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -369,29 +369,6 @@ static int udf_get_block(struct inode *inode, sector_t block,
return err;
}
-static struct buffer_head *udf_getblk(struct inode *inode, udf_pblk_t block,
- int create, int *err)
-{
- struct buffer_head *bh;
- struct buffer_head dummy;
-
- dummy.b_state = 0;
- dummy.b_blocknr = -1000;
- *err = udf_get_block(inode, block, &dummy, create);
- if (!*err && buffer_mapped(&dummy)) {
- bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
- if (buffer_new(&dummy)) {
- lock_buffer(bh);
- memset(bh->b_data, 0x00, inode->i_sb->s_blocksize);
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- mark_buffer_dirty_inode(bh, inode);
- }
- return bh;
- }
-
- return NULL;
-}
/* Extend the file with new blocks totaling 'new_block_bytes',
* return the number of extents added
@@ -1108,10 +1085,29 @@ struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
int create, int *err)
{
struct buffer_head *bh = NULL;
+ struct buffer_head dummy;
- bh = udf_getblk(inode, block, create, err);
- if (!bh)
+ dummy.b_state = 0;
+ dummy.b_blocknr = -1000;
+
+ *err = udf_get_block(inode, block, &dummy, create);
+ if (*err || !buffer_mapped(&dummy))
+ return NULL
+
+ bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
+ if (!bh) {
+ *err = -ENOMEM;
return NULL;
+ }
+
+ if (buffer_new(&dummy)) {
+ lock_buffer(bh);
+ memset(bh->b_data, 0x00, inode->i_sb->s_blocksize);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ mark_buffer_dirty_inode(bh, inode);
+ return bh;
+ }
if (bh_read(bh, 0) >= 0)
return bh;
base-commit: e4d90d63d385228b1e0bcf31cc15539bbbc28f7f
--
2.40.1
