litmus-rt.git/fs/cifs/dir.c, branch 2010.2

cifs: overhaul cifs_revalidate and rename to cifs_revalidate_dentry

2010-03-06T04:37:05+00:00

cifs_revalidate is renamed to cifs_revalidate_dentry as a later patch
will add a by-filehandle variant.

Add a new "invalid_mapping" flag to the cifsInodeInfo that indicates
that the pagecache is considered invalid. Add a new routine to check
inode attributes whenever they're updated and set that flag if the inode
has changed on the server.

cifs_revalidate_dentry is then changed to just update the attrcache if
needed and then to zap the pagecache if it's not valid.

There are some other behavior changes in here as well. Open files are
now allowed to have their caches invalidated. I see no reason why we'd
want to keep stale data around just because a file is open. Also,
cifs_revalidate_cache uses the server_eof for revalidating the file
size since that should more closely match the size of the file on the
server.

Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

vfs: Implement proper O_SYNC semantics

2009-12-10T14:02:50+00:00

While Linux provided an O_SYNC flag basically since day 1, it took until
Linux 2.4.0-test12pre2 to actually get it implemented for filesystems,
since that day we had generic_osync_around with only minor changes and the
great "For now, when the user asks for O_SYNC, we'll actually give
O_DSYNC" comment.  This patch intends to actually give us real O_SYNC
semantics in addition to the O_DSYNC semantics.  After Jan's O_SYNC
patches which are required before this patch it's actually surprisingly
simple, we just need to figure out when to set the datasync flag to
vfs_fsync_range and when not.

This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's
numerical value to keep binary compatibility, and adds a new real O_SYNC
flag.  To guarantee backwards compatiblity it is defined as expanding to
both the O_DSYNC and the new additional binary flag (__O_SYNC) to make
sure we are backwards-compatible when compiled against the new headers.

This also means that all places that don't care about the differences can
just check O_DSYNC and get the right behaviour for O_SYNC, too - only
places that actuall care need to check __O_SYNC in addition.  Drivers and
network filesystems have been updated in a fail safe way to always do the
full sync magic if O_DSYNC is set.  The few places setting O_SYNC for
lower layers are kept that way for now to stay failsafe.

We enforce that O_DSYNC is set when __O_SYNC is set early in the open path
to make sure we always get these sane options.

Note that parisc really screwed up their headers as they already define a
O_DSYNC that has always been a no-op.  We try to repair it by using it for
the new O_DSYNC and redefinining O_SYNC to send both the traditional
O_SYNC numerical value _and_ the O_DSYNC one.

Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Grant Grundler 
Cc: "David S. Miller" 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Cc: Al Viro 
Cc: Andreas Dilger 
Acked-by: Trond Myklebust 
Acked-by: Kyle McMartin 
Acked-by: Ulrich Drepper 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Jan Kara

[CIFS] Fix sparse warning

2009-11-25T00:11:31+00:00

Also update CHANGES file

Signed-off-by: Steve French

[CIFS] Duplicate data on appending to some Samba servers

2009-11-24T22:52:13+00:00

SMB writes are sent with a starting offset and length. When the server
supports the newer SMB trans2 posix open (rather than using the SMB
NTCreateX) a file can be opened with SMB_O_APPEND flag, and for that
case Samba server assumes that the offset sent in SMBWriteX is unneeded
since the write should go to the end of the file - which can cause
problems if the write was cached (since the beginning part of a
page could be written twice by the client mm).  Jeff suggested that
masking the flag on posix open on the client is easiest for the time
being. Note that recent Samba server also had an unrelated problem with
SMB NTCreateX and append (see samba bugzilla bug number 6898) which
should not affect current Linux clients (unless cifs Unix Extensions
are disabled).

The cifs client did not send the O_APPEND flag on posix open
before 2.6.29 so the fix is unneeded on early kernels.

In the future, for the non-cached case (O_DIRECT, and forcedirectio mounts)
it would be possible and useful to send O_APPEND on posix open (for Windows
case: FILE_APPEND_DATA but not FILE_WRITE_DATA on SMB NTCreateX) but for
cached writes although the vfs sets the offset to end of file it
may fragment a write across pages - so we can't send O_APPEND on
open (could result in sending part of a page twice).

CC: Stable 
Reviewed-by: Shirish Pargaonkar 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

[CIFS] fix oops in cifs_lookup during net boot

2009-11-24T22:17:59+00:00

Fixes bugzilla.kernel.org bug number 14641

Lookup called during network boot (network root filesystem
for diskless workstation) has case where nd is null in
lookup.  This patch fixes that in cifs_lookup.

(Shirish noted that 2.6.30 and 2.6.31 stable need the same check)

Signed-off-by: Shirish Pargaonkar 
Acked-by: Jeff Layton 
Tested-by:  Vladimir Stavrinov 
CC: Stable 
Signed-off-by: Steve French

cifs: eliminate cifs_init_private

2009-09-24T19:35:18+00:00

...it does the same thing as cifs_fill_fileinfo, but doesn't handle the
flist ordering correctly. Also rename cifs_fill_fileinfo to a more
descriptive name and have it take an open flags arg instead of just a
write_only flag. That makes the logic in the callers a little simpler.

Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

cifs: convert oplock breaks to use slow_work facility (try #4)

2009-09-24T18:33:18+00:00

This is the fourth respin of the patch to convert oplock breaks to
use the slow_work facility.

A customer of ours was testing a backport of one of the earlier
patchsets, and hit a "Busy inodes after umount..." problem. An oplock
break job had raced with a umount, and the superblock got torn down and
its memory reused. When the oplock break job tried to dereference the
inode->i_sb, the kernel oopsed.

This patchset has the oplock break job hold an inode and vfsmount
reference until the oplock break completes.  With this, there should be
no need to take a tcon reference (the vfsmount implicitly holds one
already).

Currently, when an oplock break comes in there's a chance that the
oplock break job won't occur if the allocation of the oplock_q_entry
fails. There are also some rather nasty races in the allocation and
handling these structs.

Rather than allocating oplock queue entries when an oplock break comes
in, add a few extra fields to the cifsFileInfo struct. Get rid of the
dedicated cifs_oplock_thread as well and queue the oplock break job to
the slow_work thread pool.

This approach also has the advantage that the oplock break jobs can
potentially run in parallel rather than be serialized like they are
today.

Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

cifs: have cifsFileInfo hold an extra inode reference

2009-09-15T19:45:25+00:00

It's possible that this struct will outlive the filp to which it is
attached. If it does and it needs to do some work on the inode, then
it'll need a reference.

Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

cifs: fix oplock request handling in posix codepath

2009-09-15T19:45:03+00:00

cifs_posix_open takes a "poplock" argument that's intended to be used in
the actual posix open call to set the "Flags" field. It ignores this
value however and declares an "oplock" parameter on the stack that it
passes uninitialized to the CIFSPOSIXOpen function. Not only does this
mean that the oplock request flags are bogus, but the result that's
expected to be in that variable is unchanged.

Fix this, and also clean up the type of the oplock parameter used. Since
it's expected to be __u32, we should use that everywhere and not
implicitly cast it from a signed type.

Signed-off-by: Jeff Layton 
Signed-off-by: Steve French

cifs: Replace wrtPending with a real reference count

2009-09-01T22:35:01+00:00

Currently, cifs_close() tries to wait until all I/O is complete and then
frees the file private data.  If I/O does not completely in a reasonable
amount of time it frees the structure anyway, leaving a potential use-
after-free situation.

This patch changes the wrtPending counter to a complete reference count and
lets the last user free the structure.

Signed-off-by: Dave Kleikamp 
Reviewed-by: Jeff Layton 
Tested-by: Shirish Pargaonkar 
Signed-off-by: Steve French