...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>
* 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>
Jeff Layton
Suresh Jayaraman
Pavel Shilovsky
Jeff Layton
Christoph Hellwig
J. Bruce Fields
Linus Torvalds
Al Viro
Arnd Bergmann
Jan Blunck
Steve French
Stefan Metzmacher