...ensure that we undo things in the reverse order from the way they
were done. In truth, the ordering doesn't matter for a lot of these,
but it's still better to do it that way to be sure.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Take the #ifdef junk out of the code, and turn it into a noop macro
when CONFIG_CIFS_DFS_UPCALL isn't defined.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
It's the essential step before respecting MaxMpxCount value during
negotiating because we will keep only one extra slot for sending
echo requests. If there is no response during two echo intervals -
reconnect the tcp session.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Some servers sets this value less than 50 that was hardcoded and
we lost the connection if when we exceed this limit. Fix this by
respecting this value - not sending more than the server allows.
Cc: stable@kernel.org
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <stevef@smf-gateway.(none)>
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue: (21 commits)
leases: fix write-open/read-lease race
nfs: drop unnecessary locking in llseek
ext4: replace cut'n'pasted llseek code with generic_file_llseek_size
vfs: add generic_file_llseek_size
vfs: do (nearly) lockless generic_file_llseek
direct-io: merge direct_io_walker into __blockdev_direct_IO
direct-io: inline the complete submission path
direct-io: separate map_bh from dio
direct-io: use a slab cache for struct dio
direct-io: rearrange fields in dio/dio_submit to avoid holes
direct-io: fix a wrong comment
direct-io: separate fields only used in the submission path from struct dio
vfs: fix spinning prevention in prune_icache_sb
vfs: add a comment to inode_permission()
vfs: pass all mask flags check_acl and posix_acl_permission
vfs: add hex format for MAY_* flag values
vfs: indicate that the permission functions take all the MAY_* flags
compat: sync compat_stats with statfs.
vfs: add "device" tag to /proc/self/mountstats
cleanup: vfs: small comment fix for block_invalidatepage
...
Fix up trivial conflict in fs/gfs2/file.c (llseek changes)
The i_mutex lock use of generic _file_llseek hurts. Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.
Under high utilization this can cause llseek to scale very poorly on larger
systems.
This patch does some rethinking of the llseek locking model:
First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.
Let's look at the different seek variants:
SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.
For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now. The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.
=> Don't need a lock.
SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.
Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET. On non atomic 32bit it's the same
as SEEK_SET.
=> Don't need a lock, but need to use i_size_read()
SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.
=> So still need a lock, but can use a f_lock.
This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add support to print nostrictsync and noperm mount options in
/proc/mounts for shares mounted with these options.
(cleanup merge conflict in Sachin's original patch)
Suggested-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
that let us do local lock checks before requesting to the server.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Thus spake Jeff Layton:
"Making that a module parm would allow you to set that parameter at boot
time without needing to add special startup scripts. IMO, all of the
procfile "switches" under /proc/fs/cifs should be module parms
instead."
This patch doesn't alter the default behavior (Oplocks are enabled by
default).
To disable oplocks when loading the module, use
modprobe cifs enable_oplocks=0
(any of '0' or 'n' or 'N' conventions can be used).
To disable oplocks at runtime using the new interface, use
echo 0 > /sys/module/cifs/parameters/enable_oplocks
The older /proc/fs/cifs/OplockEnabled interface will be deprecated
after two releases. A subsequent patch will add an warning message
about this deprecation.
Changes since v2:
- make enable_oplocks a 'bool'
Changes since v1:
- eliminate the use of extra variable by renaming the old one to
enable_oplocks and make it an 'int' type.
Reported-by: Alexander Swen <alex@swen.nu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
It should be 'CONFIG_CIFS_NFSD_EXPORT'. No-one noticed because that
symbol depends on BROKEN.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Steve French <smfrench@gmail.com>
Commit d39454ffe4 adds a strictcache mount
option. This patch allows the display of this mount option in
/proc/mounts when listing shares mounted with the strictcache mount
option.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
move it to the beginning of the loop.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The loop around lookup_one_len doesn't handle the case where it might
return a negative dentry, which can cause an oops on the next pass
through the loop. Check for that and break out of the loop with an
error of -ENOENT if there is one.
Fixes the panic reported here:
https://bugzilla.redhat.com/show_bug.cgi?id=727927
Reported-by: TR Bentley <home@trarbentley.net>
Reported-by: Iain Arnell <iarnell@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Currently, we take a sb->s_active reference and a cifsFileInfo reference
when an oplock break workqueue job is queued. This is unnecessary and
more complicated than it needs to be. Also as Al points out,
deactivate_super has non-trivial locking implications so it's best to
avoid that if we can.
Instead, just cancel any pending oplock breaks for this filehandle
synchronously in cifsFileInfo_put after taking it off the lists.
That should ensure that this job doesn't outlive the structures it
depends on.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This converts everybody to handle SEEK_HOLE/SEEK_DATA properly. In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done. For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add missing ->i_mutex, convert to lookup_one_len() instead of
(broken) open-coded analog, cope with getting something like
a//b as relative pathname. Simplify the hell out of it, while
we are there...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
...as that makes for a cumbersome interface. Make it take a regular
smb_vol pointer and rely on the caller to zero it out if needed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
... instead of just failing with -EINVAL
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
if cifs_get_root() fails, we end up with ->mount() returning NULL,
which is not what callers expect. Moreover, in case of superblock
reuse we end up leaking a superblock reference...
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
have ->s_fs_info set by the set() callback passed to sget()
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
all callers of cifs_umount() proceed to do the same thing; pull it into
cifs_umount() itself.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
instead of calling it manually in case if cifs_read_super() fails
to set ->s_root, just call it from ->kill_sb(). cifs_put_super()
is gone now *and* we have cifs_sb shutdown and destruction done
after the superblock is gone from ->s_instances.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... to the point prior to sget(). Now we have cifs_sb set up early
enough.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) superblock argument is unused
b) it always returns 0
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
no need to wait until cifs_read_super() and we need it done
by the time cifs_mount() will be called.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pull mountdata allocation up, so that it won't stand in the way when
we lift cifs_mount() to location before sget().
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
cifs_sb and nls end up leaked...
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
To close sget() races we'll need to be able to set cifs_sb up before
we get the superblock, so we'll want to be able to do cifs_mount()
earlier. Fortunately, it's easy to do - setting ->s_maxbytes can
be done in cifs_read_super(), ditto for ->s_time_gran and as for
putting MS_POSIXACL into ->s_flags, we can mirror it in ->mnt_cifs_flags
until cifs_read_super() is called. Kill unused 'devname' argument,
while we are at it...
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
if cifs_sb allocation fails, we still need to drop nls we'd stashed
into volume_info - the one we would've copied to cifs_sb if we could
allocate the latter.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
if we get to out_super with ->s_root already set (e.g. with
cifs_get_root() failure), we'll end up with cifs_put_super()
called and ->mountdata freed twice. We'll also get cifs_sb
freed twice and cifs_sb->local_nls dropped twice. The problem
is, we can get to out_super both with and without ->s_root,
which makes ->put_super() a bad place for such work.
Switch to ->kill_sb(), have all that work done there after
kill_anon_super(). Unlike ->put_super(), ->kill_sb() is
called by deactivate_locked_super() whether we have ->s_root
or not.
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add rwpidforward mount option that switches on a mode when we forward
pid of a process who opened a file to any read and write operation.
This can prevent applications like WINE from failing on read or write
operation on a previously locked file region from the same netfd from
another process if we use mandatory brlock style.
It is actual for WINE because during a run of WINE program two processes
work on the same netfd - share the same file struct between several VFS
fds:
1) WINE-server does open and lock;
2) WINE-application does read and write.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Add cifs_match_super to use in sget to share superblock between mounts
that have the same //server/sharename, credentials and mount options.
It helps us to improve performance on work with future SMB2.1 leases.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Now we point superblock to a server share root and set a root dentry
appropriately. This let us share superblock between mounts like
//server/sharename/foo/bar and //server/sharename/foo further.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fix double kfree() calls on the same pointers and cleanup mount code.
Reviewed-and-Tested-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Reorganize code to get mount option at first and when get a superblock.
This lets us use shared superblock model further for equal mounts.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fix to earlier "Simplify invalidate part (try #6)" patch
That patch caused problems with connectathon test 5.
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Change idmap key name from cifs.cifs_idmap to cifs.idmap.
Removed unused structure wksidarr and function match_sid().
Handle errors correctly in function init_cifs().
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Previously mount options were copied and updated in the cifs_sb_info
struct only when CONFIG_CIFS_DFS_UPCALL was enabled. Making this
information generally available allows us to remove a number of ifdefs,
extra function params, and temporary variables.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Sean Finney <seanius@seanius.net>
Signed-off-by: Steve French <sfrench@us.ibm.com>
A relatively minor nit, but also clarified the "consensus" from the
preceding comments that it is in fact better to try for the kstrdup
early and cleanup while cleaning up is still a simple thing to do.
Reviewed-By: Steve French <smfrench@gmail.com>
Signed-off-by: Sean Finney <seanius@seanius.net>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Simplify many places when we call cifs_revalidate/invalidate to make
it do what it exactly needs.
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Recently introduced strictcache mode brought a new code that can be
efficiently used by directio part. That's let us add vectored operations
and break unnecessary cifs_user_read and cifs_user_write.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Define (global) data structures to store ids, uids and gids, to which a
SID maps. There are two separate trees, one for SID/uid and another one
for SID/gid.
A new type of key, cifs_idmap_key_type, is used.
Keys are instantiated and searched using credential of the root by
overriding and restoring the credentials of the caller requesting the key.
Id mapping functions are invoked under config option of cifs acl.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Remove config flag CIFS_EXPERIMENTAL.
Do export operations under new config flag CIFS_NFSD_EXPORT
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The CIFSSMBNotify worker is unused, pending changes to allow it to be called
via inotify, so move it into its own experimental config option so it does
not get built in, until the necessary VFS support is fixed. It used to
be used in dnotify, but according to Jeff, inotify needs minor changes
before we can reenable this.
CC: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
ino is unused in function cifs_root_iget().
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This is more or less the same patch as before, but with some merge
conflicts fixed up.
If a process has a dirty page mapped into its page tables, then it has
the ability to change it while the client is trying to write the data
out to the server. If that happens after the signature has been
calculated then that signature will then be wrong, and the server will
likely reset the TCP connection.
This patch adds a page_mkwrite handler for CIFS that simply takes the
page lock. Because the page lock is held over the life of writepage and
writepages, this prevents the page from becoming writeable until
the write call has completed.
With this, we can also remove the "sign_zero_copy" module option and
always inline the pages when writing.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Commit 522440ed made cifs set backing_dev_info on the mapping attached
to new inodes. This change caused a fairly significant read performance
regression, as cifs started doing page-sized reads exclusively.
By virtue of the fact that they're allocated as part of cifs_sb_info by
kzalloc, the ra_pages on cifs BDIs get set to 0, which prevents any
readahead. This forces the normal read codepaths to use readpage instead
of readpages causing a four-fold increase in the number of read calls
with the default rsize.
Fix it by setting ra_pages in the BDI to the same value as that in the
default_backing_dev_info.
Fixes https://bugzilla.kernel.org/show_bug.cgi?id=31662
Cc: stable@kernel.org
Reported-and-Tested-by: Till <till2.schaefer@uni-dortmund.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We artificially limited the user name to 32 bytes, but modern servers handle
larger. Set the maximum length to a reasonable 256, and make the user name
string dynamically allocated rather than a fixed size in session structure.
Also clean up old checkpatch warning.
Signed-off-by: Steve French <sfrench@us.ibm.com>
This flag currently only affects whether we allow "zero-copy" writes
with signing enabled. Typically we map pages in the pagecache directly
into the write request. If signing is enabled however and the contents
of the page change after the signature is calculated but before the
write is sent then the signature will be wrong. Servers typically
respond to this by closing down the socket.
Still, this can provide a performance benefit so the "Experimental" flag
was overloaded to allow this. That's really not a good place for this
option however since it's not clear what that flag does.
Move that flag instead to a new module parameter that better describes
its purpose. That's also better since it can be set at module insertion
time by configuring modprobe.d.
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
If we don't have Exclusive oplock we write a data to the server.
Also set invalidate_mapping flag on the inode if we wrote something
to the server. Add cifs_iovec_write to let the client write iovec
buffers through CIFSSMBWrite2.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Read from the cache if we have at least Level II oplock - otherwise
read from the server. Add cifs_user_readv to let the client read into
iovec buffers.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Invalidate inode mapping if we don't have at least Level II oplock.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Invalidate inode mapping if we don't have at least Level II oplock in
cifs_strict_fsync. Also remove filemap_write_and_wait call from cifs_fsync
because it is previously called from vfs_fsync_range. Add file operations'
structures for strict cache mode.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
If the server isn't responding to echoes, we don't want to leave tasks
hung waiting for it to reply. At that point, we'll want to reconnect
so that soft mounts can return an error to userspace quickly.
If the client hasn't received a reply after a specified number of echo
intervals, assume that the transport is down and attempt to reconnect
the socket.
The number of echo_intervals to wait before attempting to reconnect is
tunable via a module parameter. Setting it to 0, means that the client
will never attempt to reconnect. The default is 5.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reduce false inode collisions by using the CreationTime like an
i_generation field. This way, even if the server ends up reusing
a uniqueid after a delete/create cycle, we can avoid matching
the inode incorrectly.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make connect logic more ip-protocol independent and move RFC1001 stuff into
a separate function. Also replace union addr in TCP_Server_Info structure
with sockaddr_storage.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-and-Tested-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...this string is zeroed out and nothing ever changes it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Currently, the attribute cache timeout for CIFS is hardcoded to 1 second. This
means that the client might have to issue a QPATHINFO/QFILEINFO call every 1
second to verify if something has changes, which seems too expensive. On the
other hand, if the timeout is hardcoded to a higher value, workloads that
expect strict cache coherency might see unexpected results.
Making attribute cache timeout as a tunable will allow us to make a tradeoff
between performance and cache metadata correctness depending on the
application/workload needs.
Add 'actimeo' tunable that can be used to tune the attribute cache timeout.
The default timeout is set to 1 second. Also, display actimeo option value in
/proc/mounts.
It appears to me that 'actimeo' and the proposed (but not yet merged)
'strictcache' option cannot coexist, so care must be taken that we reset the
other option if one of them is set.
Changes since last post:
- fix option parsing and handle possible values correcly
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
All the callers already have a pointer to struct cifsInodeInfo. Use it.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Radix trees are ideal when you want to track a bunch of pointers and
can't embed a tracking structure within the target of those pointers.
The tradeoff is an increase in memory, particularly if the tree is
sparse.
In CIFS, we use the tlink_tree to track tcon_link structs. A tcon_link
can never be in more than one tlink_tree, so there's no impediment to
using a rb_tree here instead of a radix tree.
Convert the new multiuser mount code to use a rb_tree instead. This
should reduce the memory required to manage the tlink_tree.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The caller allocated it, the caller should free it.
The only issue so far is that we could change the flp pointer even on an
error return if the fl_change callback failed. But we can simply move
the flp assignment after the fl_change invocation, as the callers don't
care about the flp return value if the setlease call failed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We modified setlease to require the caller to allocate the new lease in
the case of creating a new lease, but forgot to fix up the filesystem
methods.
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: Cleanup and thus reduce smb session structure and fields used during authentication
NTLM auth and sign - Use appropriate server challenge
cifs: add kfree() on error path
NTLM auth and sign - minor error corrections and cleanup
NTLM auth and sign - Use kernel crypto apis to calculate hashes and smb signatures
NTLM auth and sign - Define crypto hash functions and create and send keys needed for key exchange
cifs: cifs_convert_address() returns zero on error
NTLM auth and sign - Allocate session key/client response dynamically
cifs: update comments - [s/GlobalSMBSesLock/cifs_file_list_lock/g]
cifs: eliminate cifsInodeInfo->write_behind_rc (try #6)
[CIFS] Fix checkpatch warnings and bump cifs version number
cifs: wait for writeback to complete in cifs_flush
cifs: convert cifsFileInfo->count to non-atomic counter
write_behind_rc is redundant and just adds complexity to the code. What
we really want to do instead is to use mapping_set_error to reset the
flags on the mapping when we find a writeback error and can't report it
to userspace yet.
For cifs_flush and cifs_fsync, we shouldn't reset the flags since errors
returned there do get reported to userspace.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (56 commits)
[CIFS] move close processing from cifs_close to cifsFileInfo_put
cifs: convert cifs_tcp_ses_lock from a rwlock to a spinlock
cifs: cancel_delayed_work() + flush_scheduled_work() -> cancel_delayed_work_sync()
Clean up two declarations of blob_len
cifs: move cifsFileInfo_put to file.c
cifs: convert GlobalSMBSeslock from a rwlock to regular spinlock
[CIFS] Fix minor checkpatch warning and update cifs version
cifs: move cifs_new_fileinfo to file.c
cifs: eliminate pfile pointer from cifsFileInfo
cifs: cifs_write argument change and cleanup
cifs: clean up cifs_reopen_file
cifs: eliminate the inode argument from cifs_new_fileinfo
cifs: eliminate oflags option from cifs_new_fileinfo
cifs: fix flags handling in cifs_posix_open
cifs: eliminate cifs_posix_open_inode_helper
cifs: handle FindFirst failure gracefully
NTLM authentication and signing - Calculate auth response per smb session
cifs: don't use vfsmount to pin superblock for oplock breaks
cifs: keep dentry reference in cifsFileInfo instead of inode reference
cifs: on multiuser mount, set ownership to current_fsuid/current_fsgid (try #7)
...
Fix up trivial conflict in fs/cifs/cifsfs.c due to added/removed header files
cifs_tcp_ses_lock is a rwlock with protects the cifs_tcp_ses_list,
server->smb_ses_list and the ses->tcon_list. It also protects a few
ref counters in server, ses and tcon. In most cases the critical section
doesn't seem to be large, in a few cases where it is slightly large, there
seem to be really no benefit from concurrent access. I briefly considered RCU
mechanism but it appears to me that there is no real need.
Replace it with a spinlock and get rid of the last rwlock in the cifs code.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Convert this lock to a regular spinlock
A rwlock_t offers little value here. It's more expensive than a regular
spinlock unless you have a fairly large section of code that runs under
the read lock and can benefit from the concurrency.
Additionally, we need to ensure that the refcounting for files isn't
racy and to do that we need to lock areas that can increment it for
write. That means that the areas that can actually use a read_lock are
very few and relatively infrequently used.
While we're at it, change the name to something easier to type, and fix
a bug in find_writable_file. cifsFileInfo_put can sleep and shouldn't be
called while holding the lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Filesystems aren't really supposed to do anything with a vfsmount. It's
considered a layering violation since vfsmounts are entirely managed at
the VFS layer.
CIFS currently keeps an active reference to a vfsmount in order to
prevent the superblock vanishing before an oplock break has completed.
What we really want to do instead is to keep sb->s_active high until the
oplock break has completed. This patch borrows the scheme that NFS uses
for handling sillyrenames.
An atomic_t is added to the cifs_sb_info. When it transitions from 0 to
1, an extra reference to the superblock is taken (by bumping the
s_active value). When it transitions from 1 to 0, that reference is
dropped and a the superblock teardown may proceed if there are no more
references to it.
Also, the vfsmount pointer is removed from cifsFileInfo and from
cifs_new_fileinfo, and some bogus forward declarations are removed from
cifsfs.h.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifsFileInfo needs a pointer to a tcon, but it doesn't currently hold a
reference to it. Change it to keep a pointer to a tcon_link instead and
hold a reference to it.
That will keep the tcon from being freed until the file is closed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This prepares the removal of the big kernel lock from the
file locking code. We still use the BKL as long as fs/lockd
uses it and ceph might sleep, but we can flip the definition
to a private spinlock as soon as that's done.
All users outside of fs/lockd get converted to use
lock_flocks() instead of lock_kernel() where appropriate.
Based on an earlier patch to use a spinlock from Matthew
Wilcox, who has attempted this a few times before, the
earliest patch from over 10 years ago turned it into
a semaphore, which ended up being slower than the BKL
and was subsequently reverted.
Someone should do some serious performance testing when
this becomes a spinlock, since this has caused problems
before. Using a spinlock should be at least as good
as the BKL in theory, but who knows...
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
The BKL is only used in put_super and fill_super that are both protected by
the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
BKL entirely.
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
At mount time, we'll always need to create a tcon that will serve as a
template for others that are associated with the mount. This tcon is
known as the "master" tcon.
In some cases, we'll need to use that tcon regardless of who's accessing
the mount. Add an accessor function for the master tcon and go ahead and
switch the appropriate places to use it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When we convert cifs to do multiple sessions per mount, we'll need more
than one tcon per superblock. At that point "cifs_sb->tcon" will make
no sense. Add a new accessor function that gets a tcon given a cifs_sb.
For now, it just returns cifs_sb->tcon. Later it'll do more.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
