[PATCH 3.16 181/233] excessive checks in ufs_write_failed() and ufs_evict_inode()

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:42:52 EST


3.16.48-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit babef37dccbaa49249a22bae9150686815d7be71 upstream.

As it is, short copy in write() to append-only file will fail
to truncate the excessive allocated blocks. As the matter of
fact, all checks in ufs_truncate_blocks() are either redundant
or wrong for that caller. As for the only other caller
(ufs_evict_inode()), we only need the file type checks there.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16:
- No functions need to be renamed
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -894,7 +894,10 @@ void ufs_evict_inode(struct inode * inod
ufs_update_inode(inode, IS_SYNC(inode));
old_i_size = inode->i_size;
inode->i_size = 0;
- if (inode->i_blocks && ufs_truncate(inode, old_i_size))
+ if (inode->i_blocks &&
+ (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)) &&
+ ufs_truncate(inode, old_i_size))
ufs_warning(inode->i_sb, __func__, "ufs_truncate failed\n");
unlock_ufs(inode->i_sb);
}
--- a/fs/ufs/truncate.c
+++ b/fs/ufs/truncate.c
@@ -451,12 +451,6 @@ int ufs_truncate(struct inode *inode, lo
inode->i_ino, (unsigned long long)i_size_read(inode),
(unsigned long long)old_i_size);

- if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
- S_ISLNK(inode->i_mode)))
- return -EINVAL;
- if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
- return -EPERM;
-
err = ufs_alloc_lastblock(inode);

if (err) {