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path: root/fs/cifs/smb2misc.c
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2014-04-16cifs: Wait for writebacks to complete before attempting write.Sachin Prabhu
Problem reported in Red Hat bz 1040329 for strict writes where we cache only when we hold oplock and write direct to the server when we don't. When we receive an oplock break, we first change the oplock value for the inode in cifsInodeInfo->oplock to indicate that we no longer hold the oplock before we enqueue a task to flush changes to the backing device. Once we have completed flushing the changes, we return the oplock to the server. There are 2 ways here where we can have data corruption 1) While we flush changes to the backing device as part of the oplock break, we can have processes write to the file. These writes check for the oplock, find none and attempt to write directly to the server. These direct writes made while we are flushing from cache could be overwritten by data being flushed from the cache causing data corruption. 2) While a thread runs in cifs_strict_writev, the machine could receive and process an oplock break after the thread has checked the oplock and found that it allows us to cache and before we have made changes to the cache. In that case, we end up with a dirty page in cache when we shouldn't have any. This will be flushed later and will overwrite all subsequent writes to the part of the file represented by this page. Before making any writes to the server, we need to confirm that we are not in the process of flushing data to the server and if we are, we should wait until the process is complete before we attempt the write. We should also wait for existing writes to complete before we process an oplock break request which changes oplock values. We add a version specific downgrade_oplock() operation to allow for differences in the oplock values set for the different smb versions. Cc: stable@vger.kernel.org Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-10CIFS: Respect epoch value from create lease context v2Pavel Shilovsky
that force a client to purge cache pages when a server requests it. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-10CIFS: Store lease state itself rather than a mapped oplock valuePavel Shilovsky
and separate smb20_operations struct. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08CIFS: Replace clientCanCache* bools with an integerPavel Shilovsky
that prepare the code to handle different types of SMB2 leases. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08CIFS: Fix missing lease breakPavel Shilovsky
If a server sends a lease break to a connection that doesn't have opens with a lease key specified in the server response, we can't find an open file to send an ack. Fix this by walking through all connections we have. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08CIFS: Fix a memory leak when a lease break comesPavel Shilovsky
This happens when we receive a lease break from a server, then find an appropriate lease key in opened files and schedule the oplock_break slow work. lw pointer isn't freed in this case. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08CIFS: Implement follow_link for SMB2Pavel Shilovsky
that allows to access files through symlink created on a server. Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-26SMB2 FSCTL and IOCTL worker functionSteve French
This worker function is needed to send SMB2 fsctl (and ioctl) requests including: validating negotiation info (secure negotiate) querying the servers network interfaces copy offload (refcopy) Followon patches for the above three will use this. This patch also does general validation of the response. In the future, as David Disseldorp notes, for the copychunk ioctl case, we will want to enhance the response processing to allow returning the chunk request limits to the caller (even though the server returns an error, in that case we would return data that the caller could use - see 2.2.32.1). See MS-SMB2 Section 2.2.31 for more details on format of fsctl. Acked-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-05[CIFS] cifs: Rename cERROR and cFYI to cifs_dbgJoe Perches
It's not obvious from reading the macro names that these macros are for debugging. Convert the names to a single more typical kernel style cifs_dbg macro. cERROR(1, ...) -> cifs_dbg(VFS, ...) cFYI(1, ...) -> cifs_dbg(FYI, ...) cFYI(DBG2, ...) -> cifs_dbg(NOISY, ...) Move the terminating format newline from the macro to the call site. Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the "CIFS VFS: " prefix for VFS messages. Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y) $ size fs/cifs/cifs.ko* text data bss dec hex filename 265245 2525 132 267902 4167e fs/cifs/cifs.ko.new 268359 2525 132 271016 422a8 fs/cifs/cifs.ko.old Other miscellaneous changes around these conversions: o Miscellaneous typo fixes o Add terminating \n's to almost all formats and remove them from the macros to be more kernel style like. A few formats previously had defective \n's o Remove unnecessary OOM messages as kmalloc() calls dump_stack o Coalesce formats to make grep easier, added missing spaces when coalescing formats o Use %s, __func__ instead of embedded function name o Removed unnecessary "cifs: " prefixes o Convert kzalloc with multiply to kcalloc o Remove unused cifswarn macro Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-25Trivial endian fixesSteve French
Some trivial endian fixes for the SMB2 code. One warning remains which I asked Pavel to look at. Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-25CIFS: Fix fast lease break after open problemPavel Shilovsky
Now we walk though cifsFileInfo's list for every incoming lease break and look for an equivalent there. That approach misses lease breaks that come just after an open response - we don't have time to populate new cifsFileInfo structure to the list. Fix this by adding new list of pending opens and look for a lease there if we didn't find it in the list of cifsFileInfo structures. Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-09-25CIFS: Add SMB2.1 lease break supportPavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-09-25CIFS: Add oplock break support for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-25CIFS: Add readdir support for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-25CIFS: Add SMB2 support for cifs_iovec_readPavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-08-20CIFS: Fix log messages in packet checking for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Query SMB2 inode infoPavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add SMB2 support for is_path_accessiblePavel Shilovsky
that needs for a successful mount through SMB2 protocol. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add session setup/logoff capability for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add capability to send SMB2 negotiate messagePavel Shilovsky
and add negotiate request type to let set_credits know that we are only on negotiate stage and no need to make a decision about disabling echos and oplocks. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Make demultiplex_thread work with SMB2 codePavel Shilovsky
Now we can process SMB2 messages: check message, get message id and wakeup awaiting routines. Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>