[PATCH AUTOSEL 5.8 119/132] cifs: handle -EINTR in cifs_setattr

Sasha Levin
2020-10-27T00:00:30Z

From: Ronnie Sahlberg <lsahlber@redhat.com>

[ Upstream commit c6cc4c5a72505a0ecefc9b413f16bec512f38078 ]

RHBZ: 1848178

Some calls that set attributes, like utimensat(), are not supposed to return
-EINTR and thus do not have handlers for this in glibc which causes us
to leak -EINTR to the applications which are also unprepared to handle it.

For example tar will break if utimensat() return -EINTR and abort unpacking
the archive. Other applications may break too.

To handle this we add checks, and retry, for -EINTR in cifs_setattr()

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/inode.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 7708175062eba..8c0b7f40714ba 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2885,13 +2885,18 @@ cifs_setattr(struct dentry *direntry, struct iattr *attrs)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
struct cifs_tcon *pTcon = cifs_sb_master_tcon(cifs_sb);
+ int rc, retries = 0;

- if (pTcon->unix_ext)
- return cifs_setattr_unix(direntry, attrs);
-
- return cifs_setattr_nounix(direntry, attrs);
+ do {
+ if (pTcon->unix_ext)
+ rc = cifs_setattr_unix(direntry, attrs);
+ else
+ rc = cifs_setattr_nounix(direntry, attrs);
+ retries++;
+ } while (is_retryable_error(rc) && retries < 2);

/* BB: add cifs_setattr_legacy for really old servers */
+ return rc;
}

#if 0
--
2.25.1