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| author | David Howells <dhowells@redhat.com> | 2024-04-02 11:11:35 +0200 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2024-04-02 16:29:55 +0200 |
| commit | e9e62243a3e2322cf639f653a0b0a88a76446ce7 (patch) | |
| tree | 024278ce7501e2550652340ddb3f7daa1bbb766e /fs/smb/client/fscache.h | |
| parent | smb: client: fix UAF in smb2_reconnect_server() (diff) | |
| download | linux-e9e62243a3e2322cf639f653a0b0a88a76446ce7.tar.xz linux-e9e62243a3e2322cf639f653a0b0a88a76446ce7.zip | |
cifs: Fix caching to try to do open O_WRONLY as rdwr on server
When we're engaged in local caching of a cifs filesystem, we cannot perform
caching of a partially written cache granule unless we can read the rest of
the granule. This can result in unexpected access errors being reported to
the user.
Fix this by the following: if a file is opened O_WRONLY locally, but the
mount was given the "-o fsc" flag, try first opening the remote file with
GENERIC_READ|GENERIC_WRITE and if that returns -EACCES, try dropping the
GENERIC_READ and doing the open again. If that last succeeds, invalidate
the cache for that file as for O_DIRECT.
Fixes: 70431bfd825d ("cifs: Support fscache indexing rewrite")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb/client/fscache.h')
| -rw-r--r-- | fs/smb/client/fscache.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/smb/client/fscache.h b/fs/smb/client/fscache.h index a3d73720914f..1f2ea9f5cc9a 100644 --- a/fs/smb/client/fscache.h +++ b/fs/smb/client/fscache.h @@ -109,6 +109,11 @@ static inline void cifs_readahead_to_fscache(struct inode *inode, __cifs_readahead_to_fscache(inode, pos, len); } +static inline bool cifs_fscache_enabled(struct inode *inode) +{ + return fscache_cookie_enabled(cifs_inode_cookie(inode)); +} + #else /* CONFIG_CIFS_FSCACHE */ static inline void cifs_fscache_fill_coherency(struct inode *inode, @@ -124,6 +129,7 @@ static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {} static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {} static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; } static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {} +static inline bool cifs_fscache_enabled(struct inode *inode) { return false; } static inline int cifs_fscache_query_occupancy(struct inode *inode, pgoff_t first, unsigned int nr_pages, |