commit 32f123a3f34283f9c6446de87861696f0502b02e upstream.
udf_getblk() has a single call site. Fold it there.
Signed-off-by: Jan Kara jack@suse.cz
[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@amazon.de --- 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