Commit Graph

21194 Commits

Author SHA1 Message Date
Josef Bacik 9ecf639a96 Gfs2: fail if we try to use hole punch
Gfs2 doesn't have the ability to punch holes yet, so make sure we return
EOPNOTSUPP if we try to use hole punching through fallocate.  This support can
be added later.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:44 -05:00
Josef Bacik 23a8519b55 Btrfs: fail if we try to use hole punch
Btrfs doesn't have the ability to punch holes yet, so make sure we return
EOPNOTSUPP if we try to use hole punching through fallocate.  This support can
be added later.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:44 -05:00
Josef Bacik d6dc8462f4 Ext4: fail if we try to use hole punch
Ext4 doesn't have the ability to punch holes yet, so make sure we return
EOPNOTSUPP if we try to use hole punching through fallocate.  This support can
be added later.  Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:44 -05:00
Josef Bacik db47fef2cd Ocfs2: handle hole punching via fallocate properly
This patch just makes ocfs2 use its UNRESERVP ioctl when we get the hole punch
flag in fallocate.  I didn't test it, but it seems simple enough.  Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:43 -05:00
Josef Bacik c25d246715 XFS: handle hole punching via fallocate properly
This patch simply allows XFS to handle the hole punching flag in fallocate
properly.  I've tested this with a little program that does a bunch of random
hole punching with FL_KEEP_SIZE and without it to make sure it does the right
thing.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:43 -05:00
Josef Bacik 79124f18b3 fs: add hole punching to fallocate
Hole punching has already been implemented by XFS and OCFS2, and has the
potential to be implemented on both BTRFS and EXT4 so we need a generic way to
get to this feature.  The simplest way in my mind is to add FALLOC_FL_PUNCH_HOLE
to fallocate() since it already looks like the normal fallocate() operation.
I've tested this patch with XFS and BTRFS to make sure XFS did what it's
supposed to do and that BTRFS failed like it was supposed to.  Thank you,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:43 -05:00
Jeff Layton e1181ee657 vfs: pass struct file to do_truncate on O_TRUNC opens (try #2)
When a file is opened with O_TRUNC, the truncate processing is handled
by handle_truncate(). This function however doesn't receive any info
about the newly instantiated filp, and therefore can't pass that info
along so that the setattr can use it.

This makes NFSv4 misbehave. The client does an open and gets a valid
stateid, and then doesn't use that stateid on the subsequent truncate.
It uses the zero-stateid instead. Most servers ignore this fact and
just do the truncate anyway, but some don't like it (notably, RHEL4).

It seems more correct that since we have a fully instantiated file at
the time that handle_truncate is called, that we pass that along so
that the truncate operation can properly use it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:06:59 -05:00
Al Viro cccb5a1e69 fix signedness mess in rw_verify_area() on 64bit architectures
... and clean the unsigned-f_pos code, while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:06:58 -05:00
Randy Dunlap 208898c17a fs: fix kernel-doc for dcache::prepend_path
Fix function kernel-doc warning for prepend_path():

Warning(fs/dcache.c:1924): missing initial short description on line:

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:06:57 -05:00
Randy Dunlap 1c977540fd fs: fix kernel-doc for dcache::d_validate
Fix function parameter kernel-doc for d_validate():

Warning(fs/dcache.c:1495): No description found for parameter 'parent'
Warning(fs/dcache.c:1495): Excess function parameter 'dparent' description in 'd_validate'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:06:55 -05:00
Al Viro 66cb76666d sanitize ecryptfs ->mount()
kill ecryptfs_read_super(), reorder code allowing to use
normal d_alloc_root() instead of opencoding it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:04:37 -05:00
Al Viro d61dcce297 switch afs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:04:20 -05:00
Al Viro 32c419d95f move internal-only parts of ncpfs headers to fs/ncpfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:43 -05:00
Al Viro 0378c4051a switch ncpfs
merge dentry_operations for root and non-root

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:43 -05:00
Al Viro 98cd3fb0a2 switch 9p
here we actually *want* ->d_op for root; setting it allows to get rid
of kludge in v9fs_kill_super() since now we have proper ->d_release()
for root and don't need to call it manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:43 -05:00
Al Viro c74a1cbb3c pass default dentry_operations to mount_pseudo()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:43 -05:00
Al Viro f772c4a6a3 switch hostfs
->d_delete() doesn't matter for s_root anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:42 -05:00
Al Viro a129880daf switch affs
either d_op instance would work for root, actually...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:42 -05:00
Al Viro d463a0c4b5 switch configfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:12 -05:00
Al Viro 31a203df9c take coda-private headers out of include/linux
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:48 -05:00
Al Viro 9501e4c48e switch coda
Coda ->d_revalidate() actually checks for root, ->d_delete() is irrelevant.
So we can use the same d_op for all coda dentries

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:48 -05:00
Al Viro 43d344d772 switch hpfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:47 -05:00
Al Viro af53d29ac1 switch btrfs, close races
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:47 -05:00
Al Viro ba87167c06 switch ocfs2, close races
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:46 -05:00
Al Viro 41ced6dcf3 switch gfs2, close races
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:46 -05:00
Al Viro 1c929cfe6d switch cifs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:46 -05:00
Al Viro 8b244ff2fa switch nfs to ->s_d_op
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:45 -05:00
Al Viro 96e1391414 switch adfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:45 -05:00
Al Viro eddf790bd4 switch hfsplus
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:45 -05:00
Al Viro 518c79d28e switch hfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:45 -05:00
Al Viro c6cb412366 minixfs: kill dead code
->d_op of root stays NULL these days on minixfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:44 -05:00
Al Viro 30304aba6a switch sysv
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:44 -05:00
Al Viro c35eebe993 switch fuse
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:44 -05:00
Al Viro 94b77bd86f switch jfs to ->s_d_op, close exportfs races
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:43 -05:00
Al Viro 3d23985d6c switch fat to ->s_d_op, close exportfs races there
don't bother with lock_super() in fat_fill_super() callers, while
we are at it - there won't be any concurrency anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:43 -05:00
Al Viro 6cc9c1d2c1 fix isofs d_op handling
switch to ->s_d_op; d_obtain_alias() will DTRT now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:43 -05:00
Al Viro c8aebb0c9f per-superblock default ->d_op
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:34 -05:00
Tejun Heo 01e6acc4ea ceph: fsc->*_wq's aren't used in memory reclaim path
fsc->*_wq's aren't depended upon during memory reclaim.  Convert to
alloc_workqueue() w/o WQ_MEM_RECLAIM.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Sage Weil <sage@newdream.net>
Cc: ceph-devel@vger.kernel.org
Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:14 -08:00
Tracey Dent 582c86e690 ceph: Makefile: Remove unnessary code
Remove the if and else conditional because the code is in mainline and there
is no need in it being there.

Also, Changed Makefile to use <modules>-y instead of <modules>-objs
because -objs is deprecated and not mentioned in
 Documentation/kbuild/makefiles.txt.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:13 -08:00
Sage Weil dc69e2e9fc ceph: associate requests with opening sessions
Associate request with sessions that aren't yep open.  This makes the
debugfs mdsc request list more informative.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:13 -08:00
Sage Weil 4af25fdda6 ceph: drop redundant r_mds field
The r_mds field is redundant, since we can find the same information at
r_session->s_mds, and when r_session is NULL then r_mds is meaningless.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:13 -08:00
Sage Weil 14303d20f3 ceph: implement DIRLAYOUTHASH feature to get dir layout from MDS
This implements the DIRLAYOUTHASH protocol feature, which passes the dir
layout over the wire from the MDS.  This gives the client knowledge
of the correct hash function to use for mapping dentries among dir
fragments.

Note that if this feature is _not_ present on the client but is on the
MDS, the client may misdirect requests.  This will result in a forward
and degrade performance.  It may also result in inaccurate NFS filehandle
generation, which will prevent fh resolution when the inode is not present
in the client cache and the parent directories have been fragmented.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:13 -08:00
Sage Weil 6c0f3af72c ceph: add dir_layout to inode
Add a ceph_dir_layout to the inode, and calculate dentry hash values based
on the parent directory's specified dir_hash function.  This is needed
because the old default Linux dcache hash function is extremely week and
leads to a poor distribution of files among dir fragments.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-12 15:15:12 -08:00
Anton Altaparmakov 2818ef50c4 NTFS: writev() fix and maintenance/contact details update
Fix writev() to not keep writing the first segment over and over again
instead of moving onto subsequent segments and update the NTFS entry in
MAINTAINERS to reflect that Tuxera Inc. now supports the NTFS driver.

Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12 08:35:53 -08:00
Dave Chinner 73efe4a4dd xfs: prevent NMI timeouts in cmn_err
We currently have a global error message buffer in cmn_err that is
protected by a spin lock that disables interrupts.  Recently there
have been reports of NMI timeouts occurring when the console is
being flooded by SCSI error reports due to cmn_err() getting stuck
trying to print to the console while holding this lock (i.e. with
interrupts disabled). The NMI watchdog is seeing this CPU as
non-responding and so is triggering a panic.  While the trigger for
the reported case is SCSI errors, pretty much anything that spams
the kernel log could cause this to occur.

Realistically the only reason that we have the intemediate message
buffer is to prepend the correct kernel log level prefix to the log
message. The only reason we have the lock is to protect the global
message buffer and the only reason the message buffer is global is
to keep it off the stack. Hence if we can avoid needing a global
message buffer we avoid needing the lock, and we can do this with a
small amount of cleanup and some preprocessor tricks:

	1. clean up xfs_cmn_err() panic mask functionality to avoid
	   needing debug code in xfs_cmn_err()
	2. remove the couple of "!" message prefixes that still exist that
	   the existing cmn_err() code steps over.
	3. redefine CE_* levels directly to KERN_*
	4. redefine cmn_err() and friends to use printk() directly
	   via variable argument length macros.

By doing this, we can completely remove the cmn_err() code and the
lock that is causing the problems, and rely solely on printk()
serialisation to ensure that we don't get garbled messages.

A series of followup patches is really needed to clean up all the
cmn_err() calls and related messages properly, but that results in a
series that is not easily back portable to enterprise kernels. Hence
this initial fix is only to address the direct problem in the lowest
impact way possible.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:46:41 -06:00
Anton Blanchard 65a84a0f75 xfs: Add log level to assertion printk
I received a ppc64 bug report involving xfs but the assertion was
filtered out by the console log level. Use KERN_CRIT to ensure it
makes it out.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11 22:29:46 -06:00
Jesper Juhl 1884bd8354 xfs: fix an assignment within an ASSERT()
In fs/xfs/xfs_trans.c::xfs_trans_unreserve_and_mod_sb() at the out:
label we have this:
	ASSERT(error = 0);
I believe a comparison was intended, not an assignment. If I'm
right, the patch below fixes that up.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11 22:29:13 -06:00
Christoph Hellwig bfc60177f8 xfs: fix error handling for synchronous writes
If we get an IO error on a synchronous superblock write, we attach an
error release function to it so that when the last reference goes away
the release function is called and the buffer is invalidated and
unlocked. The buffer is left locked until the release function is
called so that other concurrent users of the buffer will be locked out
until the buffer error is fully processed.

Unfortunately, for the superblock buffer the filesyetm itself holds a
reference to the buffer which prevents the reference count from
dropping to zero and the release function being called. As a result,
once an IO error occurs on a sync write, the buffer will never be
unlocked and all future attempts to lock the buffer will hang.

To make matters worse, this problems is not unique to such buffers;
if there is a concurrent _xfs_buf_find() running, the lookup will grab
a reference to the buffer and then wait on the buffer lock, preventing
the reference count from ever falling to zero and hence unlocking the
buffer.

As such, the whole b_relse function implementation is broken because it
cannot rely on the buffer reference count falling to zero to unlock the
errored buffer. The synchronous write error path is the only path that
uses this callback - it is used to ensure that the synchronous waiter
gets the buffer error before the error state is cleared from the buffer
by the release function.

Given that the only sychronous buffer writes now go through xfs_bwrite
and the error path in question can only occur for a write of a dirty,
logged buffer, we can move most of the b_relse processing to happen
inline in xfs_buf_iodone_callbacks, just like a normal I/O completion.
In addition to that we make sure the error is not cleared in
xfs_buf_iodone_callbacks, so that xfs_bwrite can reliably check it.
Given that xfs_bwrite keeps the buffer locked until it has waited for
it and checked the error this allows to reliably propagate the error
to the caller, and make sure that the buffer is reliably unlocked.

Given that xfs_buf_iodone_callbacks was the only instance of the
b_relse callback we can remove it entirely.

Based on earlier patches by Dave Chinner and Ajeet Yadav.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11 20:28:42 -06:00
Christoph Hellwig a46db60834 xfs: add FITRIM support
Allow manual discards from userspace using the FITRIM ioctl.  This is not
intended to be run during normal workloads, as the freepsace btree walks
can cause large performance degradation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11 20:28:29 -06:00
Dave Chinner c58efdb442 xfs: ensure log covering transactions are synchronous
To ensure the log is covered and the filesystem idles correctly, we
need to ensure that dummy transactions hit the disk and do not stay
pinned in memory.  If the superblock is pinned in memory, it can't
be flushed so the log covering cannot make progress. The result is
dependent on timing - more oftent han not we continue to issues a
log covering transaction every 36s rather than idling after ~90s.

Fix this by making the log covering transaction synchronous. To
avoid additional log force from xfssyncd, make the log covering
transaction take the place of the existing log force in the xfssyncd
background sync process.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11 20:28:17 -06:00
Linus Torvalds b9d919a4ac Merge branch 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits)
  NFS fix the setting of exchange id flag
  NFS: Don't use vm_map_ram() in readdir
  NFSv4: Ensure continued open and lockowner name uniqueness
  NFS: Move cl_delegations to the nfs_server struct
  NFS: Introduce nfs_detach_delegations()
  NFS: Move cl_state_owners and related fields to the nfs_server struct
  NFS: Allow walking nfs_client.cl_superblocks list outside client.c
  pnfs: layout roc code
  pnfs: update nfs4_callback_recallany to handle layouts
  pnfs: add CB_LAYOUTRECALL handling
  pnfs: CB_LAYOUTRECALL xdr code
  pnfs: change lo refcounting to atomic_t
  pnfs: check that partial LAYOUTGET return is ignored
  pnfs: add layout to client list before sending rpc
  pnfs: serialize LAYOUTGET(openstateid)
  pnfs: layoutget rpc code cleanup
  pnfs: change how lsegs are removed from layout list
  pnfs: change layout state seqlock to a spinlock
  pnfs: add prefix to struct pnfs_layout_hdr fields
  pnfs: add prefix to struct pnfs_layout_segment fields
  ...
2011-01-11 15:11:56 -08:00
Linus Torvalds 7c955fca3e Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6:
  UDF: Close small mem leak in udf_find_entry()
  udf: Fix directory corruption after extent merging
  udf: Protect udf_file_aio_write from possible races
  udf: Remove unnecessary bkl usages
  udf: Use of s_alloc_mutex to serialize udf_relocate_blocks() execution
  udf: Replace bkl with the UDF_I(inode)->i_data_sem for protect udf_inode_info struct
  udf: Remove BKL from free space counting functions
  udf: Call udf_add_free_space() for more blocks at once in udf_free_blocks()
  udf: Remove BKL from udf_put_super() and udf_remount_fs()
  udf: Protect default inode credentials by rwlock
  udf: Protect all modifications of LVID with s_alloc_mutex
  udf: Move handling of uniqueID into a helper function and protect it by a s_alloc_mutex
  udf: Remove BKL from udf_update_inode
  udf: Convert UDF_SB(sb)->s_flags to use bitops
  fs/udf: Add printf format/argument verification
  fs/udf: Use vzalloc

(Evil merge: this also removes the BKL dependency from the Kconfig file)
2011-01-11 14:45:52 -08:00
Linus Torvalds e9688f6aca Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (44 commits)
  ext4: fix trimming starting with block 0 with small blocksize
  ext4: revert buggy trim overflow patch
  ext4: don't pass entire map to check_eofblocks_fl
  ext4: fix memory leak in ext4_free_branches
  ext4: remove ext4_mb_return_to_preallocation()
  ext4: flush the i_completed_io_list during ext4_truncate
  ext4: add error checking to calls to ext4_handle_dirty_metadata()
  ext4: fix trimming of a single group
  ext4: fix uninitialized variable in ext4_register_li_request
  ext4: dynamically allocate the jbd2_inode in ext4_inode_info as necessary
  ext4: drop i_state_flags on architectures with 64-bit longs
  ext4: reorder ext4_inode_info structure elements to remove unneeded padding
  ext4: drop ec_type from the ext4_ext_cache structure
  ext4: use ext4_lblk_t instead of sector_t for logical blocks
  ext4: replace i_delalloc_reserved_flag with EXT4_STATE_DELALLOC_RESERVED
  ext4: fix 32bit overflow in ext4_ext_find_goal()
  ext4: add more error checks to ext4_mkdir()
  ext4: ext4_ext_migrate should use NULL not 0
  ext4: Use ext4_error_file() to print the pathname to the corrupted inode
  ext4: use IS_ERR() to check for errors in ext4_error_file
  ...
2011-01-11 14:37:31 -08:00
Linus Torvalds 40c73abbb3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG
  ext3: Remove redundant unlikely()
  ext2: Remove redundant unlikely()
  ext3: speed up file creates by optimizing rec_len functions
  ext2: speed up file creates by optimizing rec_len functions
  ext3: Add more journal error check
  ext3: Add journal error check in resize.c
  quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout
  ext3: Add FITRIM handling
  ext3: Add batched discard support for ext3
  ext3: Add journal error check into ext3_rename()
  ext3: Use search_dirblock() in ext3_dx_find_entry()
  ext3: Avoid uninitialized memory references with a corrupted htree directory
  ext3: Return error code from generic_check_addressable
  ext3: Add journal error check into ext3_delete_entry()
  ext3: Add error check in ext3_mkdir()
  fs/ext3/super.c: Use printf extension %pV
  fs/ext2/super.c: Use printf extension %pV
  ext3: don't update sb journal_devnum when RO dev
2011-01-11 14:36:55 -08:00
Linus Torvalds 0945f352ce Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  fs/9p: Don't set dentry->d_op in create routines
  fs/9p: fix spelling typo
  fs/9p: TREADLINK bugfix
  net/9p: Use proper data types
  fs/9p: Simplify the .L create operation
  fs/9p: Move dotl inode operations into a seperate file
  fs/9p: fix menu presentation
  fs/9p: Fix the return error on default acl removal
  fs/9p: Remove unnecessary semicolons
2011-01-11 14:36:08 -08:00
Jan Kara 0f0a25bf51 ext4: fix trimming starting with block 0 with small blocksize
When s_first_data_block is not zero (which happens e.g. when block size is 1KB)
and trim ioctl is called to start trimming from block 0, the math in
ext4_get_group_no_and_offset() overflows. The overall result is that ioctl
returns EINVAL which is kind of unexpected and we probably don't want
userspace tools to bother with internal details of filesystem structure.
So just silently increase starting offset (and shorten length) when starting
block is below s_first_data_block.

CC: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-11 15:16:31 -05:00
J. Bruce Fields 5ce8ba25d6 nfsd4: allow restarting callbacks
If we lose the backchannel and then the client repairs the problem,
resend any callbacks.

We use a new cb_done flag to track whether there is still work to be
done for the callback or whether it can be destroyed with the rpc.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:11 -05:00
J. Bruce Fields 3ff3600e7e nfsd4: simplify nfsd4_cb_prepare
Remove handling for a nonexistant case (status && !-EAGAIN).

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:11 -05:00
J. Bruce Fields 14a24e99f4 nfsd4: give out delegations more quickly in 4.1 case
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:11 -05:00
J. Bruce Fields 229b2a0839 nfsd4: add helper function to run callbacks
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:11 -05:00
J. Bruce Fields 84f5f7ccc5 nfsd4: make sure sequence flags are set after destroy_session
If this loses any backchannel, make sure we have a chance to notice that
and set the sequence flags.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:11 -05:00
J. Bruce Fields eea4980660 nfsd4: re-probe callback on connection loss
This makes sure we set the sequence flag when necessary.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:10 -05:00
J. Bruce Fields 0d7bb71907 nfsd4: set sequence flag when backchannel is down
Implement the SEQ4_STATUS_CB_PATH_DOWN flag.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:10 -05:00
J. Bruce Fields 77a3569d6c nfsd4: keep finer-grained callback status
Distinguish between when the callback channel is known to be down, and
when it is not yet confirmed.  This will be useful in the 4.1 case.

Also, we don't seem to be using the fact that this field is atomic.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2011-01-11 15:04:10 -05:00
J. Bruce Fields dcbeaa68db nfsd4: allow backchannel recovery
Now that we have a list of connections to choose from, we can teach the
callback code to just pick a suitable connection and use that, instead
of insisting on forever using the connection that the first
create_session was sent with.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2011-01-11 15:04:10 -05:00
J. Bruce Fields 1d1bc8f207 nfsd4: support BIND_CONN_TO_SESSION
Basic xdr and processing for BIND_CONN_TO_SESSION.  This adds a
connection to the list of connections associated with a session.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:09 -05:00
J. Bruce Fields 4c6493785a nfsd4: modify session list under cl_lock
We want to traverse this from the callback code.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2011-01-11 15:04:09 -05:00
J. Bruce Fields a2c50f6916 Merge commit 'v2.6.37' into for-2.6.38-incoming
I made a slight mess of Documentation/filesystems/Locking; resolve
conflicts with upstream before fixing it up.
2011-01-11 15:02:19 -05:00
Theodore Ts'o 0a2179b169 ext4: revert buggy trim overflow patch
This reverts commit 4f531501e44: ext4: fix possible overflow in
ext4_trim_fs()

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-11 14:42:29 -05:00
Linus Torvalds 7bc4a4ce68 Merge branch 'for-linus-merged' of git://oss.sgi.com/xfs/xfs
* 'for-linus-merged' of git://oss.sgi.com/xfs/xfs: (47 commits)
  xfs: convert grant head manipulations to lockless algorithm
  xfs: introduce new locks for the log grant ticket wait queues
  xfs: convert log grant heads to atomic variables
  xfs: convert l_tail_lsn to an atomic variable.
  xfs: convert l_last_sync_lsn to an atomic variable
  xfs: make AIL tail pushing independent of the grant lock
  xfs: use wait queues directly for the log wait queues
  xfs: combine grant heads into a single 64 bit integer
  xfs: rework log grant space calculations
  xfs: fact out common grant head/log tail verification code
  xfs: convert log grant ticket queues to list heads
  xfs: use AIL bulk delete function to implement single delete
  xfs: use AIL bulk update function to implement single updates
  xfs: remove all the inodes on a buffer from the AIL in bulk
  xfs: consume iodone callback items on buffers as they are processed
  xfs: reduce the number of AIL push wakeups
  xfs: bulk AIL insertion during transaction commit
  xfs: clean up xfs_ail_delete()
  xfs: Pull EFI/EFD handling out from under the AIL lock
  xfs: fix EFI transaction cancellation.
  ...
2011-01-11 11:42:06 -08:00
Linus Torvalds 498f7f505d Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (22 commits)
  MAINTAINERS: Update Joel Becker's email address
  ocfs2: Remove unused truncate function from alloc.c
  ocfs2/cluster: dereferencing before checking in nst_seq_show()
  ocfs2: fix build for OCFS2_FS_STATS not enabled
  ocfs2/cluster: Show o2net timing statistics
  ocfs2/cluster: Track process message timing stats for each socket
  ocfs2/cluster: Track send message timing stats for each socket
  ocfs2/cluster: Use ktime instead of timeval in struct o2net_sock_container
  ocfs2/cluster: Replace timeval with ktime in struct o2net_send_tracking
  ocfs2: Add DEBUG_FS dependency
  ocfs2/dlm: Hard code the values for enums
  ocfs2/dlm: Minor cleanup
  ocfs2/dlm: Cleanup dlmdebug.c
  ocfs2: Release buffer_head in case of error in ocfs2_double_lock.
  ocfs2/cluster: Pin the local node when o2hb thread starts
  ocfs2/cluster: Show pin state for each o2hb region
  ocfs2/cluster: Pin/unpin o2hb regions
  ocfs2/cluster: Remove dropped region from o2hb quorum region bitmap
  ocfs2/cluster: Pin the remote node item in configfs
  ocfs2/dlm: make existing convertion precedent over new lock
  ...
2011-01-11 11:28:34 -08:00
Andy Adamson 357f54d6b3 NFS fix the setting of exchange id flag
Indicate support for referrals. Do not set any PNFS roles. Check the flags
returned by the server for validity. Do not use exchange flags from an old
client ID instance when recovering a client ID.

Update the EXCHID4_FLAG_XXX set to RFC 5661.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-11 14:17:09 -05:00
Aneesh Kumar K.V b8b80cf37c fs/9p: Don't set dentry->d_op in create routines
We do set dentry->d_op in lookup even in case of EOENT entries.
That implies we should have dentry->d_op already set when
create/mkdir/mknod/link/symlink routines are called

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:08 -06:00
Eric Van Hensbergen c25a61f542 fs/9p: fix spelling typo
introduced a typo somehow during a hand merge

Reported by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:08 -06:00
M. Mohan Kumar 31b6ceac49 fs/9p: TREADLINK bugfix
Remove v9fs_vfs_readlink_dotl function and use generic_readlink. Update
v9fs_vfs_follow_link_dotl function to accommodate this change

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reported-by:  Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:08 -06:00
Aneesh Kumar K.V af7542fc8a fs/9p: Simplify the .L create operation
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:07 -06:00
Aneesh Kumar K.V 53c06f4e0a fs/9p: Move dotl inode operations into a seperate file
Source Code Reorganization

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:07 -06:00
Randy Dunlap 255614c459 fs/9p: fix menu presentation
Make the 9P_FS kconfig options subordinate to the 9P_FS kconfig symbol
in the menu presentation instead of them all being at the same level.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:07 -06:00
Aneesh Kumar K.V 6f81c11574 fs/9p: Fix the return error on default acl removal
If we don't have default ACL, then trying to remove
default acl on a file should return 0.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
2011-01-11 09:58:07 -06:00
Joe Perches 009ca3897e fs/9p: Remove unnecessary semicolons
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-01-11 09:58:07 -06:00
Alex Elder 92f1c008ae Merge branch 'master' into for-linus-merged
This merge pulls the XFS master branch into the latest Linus master.
This results in a merge conflict whose best fix is not obvious.
I manually fixed the conflict, in "fs/xfs/xfs_iget.c".

Dave Chinner had done work that resulted in RCU freeing of inodes
separate from what Nick Piggin had done, and their results differed
slightly in xfs_inode_free().  The fix updates Nick's call_rcu()
with the use of VFS_I(), while incorporating needed updates to some
XFS inode fields implemented in Dave's series.  Dave's RCU callback
function has also been removed.

Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-10 21:35:55 -06:00
Linus Torvalds e54be894ea Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  driver core: Document that device_rename() is only for networking
  sysfs: remove useless test from sysfs_merge_group
  driver-core: merge private parts of class and bus
  driver core: fix whitespace in class_attr_string
2011-01-10 16:10:33 -08:00
Dave Chinner eda7798272 xfs: serialise unaligned direct IOs
When two concurrent unaligned, non-overlapping direct IOs are issued
to the same block, the direct Io layer will race to zero the block.
The result is that one of the concurrent IOs will overwrite data
written by the other IO with zeros. This is demonstrated by the
xfsqa test 240.

To avoid this problem, serialise all unaligned direct IOs to an
inode with a big hammer. We need a big hammer approach as we need to
serialise AIO as well, so we can't just block writes on locks.
Hence, the big hammer is calling xfs_ioend_wait() while holding out
other unaligned direct IOs from starting.

We don't bother trying to serialised aligned vs unaligned IOs as
they are overlapping IO and the result of concurrent overlapping IOs
is undefined - the result of either IO is a valid result so we let
them race. Hence we only penalise unaligned IO, which already has a
major overhead compared to aligned IO so this isn't a major problem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:22:40 +11:00
Dave Chinner 4d8d15812f xfs: factor common write setup code
The buffered IO and direct IO write paths share a common set of
checks and limiting code prior to issuing the write. Factor that
into a common helper function.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:23:42 +11:00
Dave Chinner 637bbc75d9 xfs: split buffered IO write path from xfs_file_aio_write
Complete the split of the different write IO paths by splitting the
buffered IO write path out of xfs_file_aio_write(). This makes the
different mechanisms of the write patchs easier to follow.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:17:30 +11:00
Dave Chinner f0d26e860b xfs: split direct IO write path from xfs_file_aio_write
The current xfs_file_aio_write code is a mess of locking shenanigans
to handle the different locking requirements of buffered and direct
IO. Start to clean this up by disentangling the direct IO path from
the mess.

This also removes the failed direct IO fallback path to buffered IO.
XFS handles all direct IO cases without needing to fall back to
buffered IO, so we can safely remove this unused path. This greatly
simplifies the logic and locking needed in the write path.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:15:36 +11:00
Dave Chinner 487f84f3f8 xfs: introduce xfs_rw_lock() helpers for locking the inode
We need to obtain the i_mutex, i_iolock and i_ilock during the read
and write paths. Add a set of wrapper functions to neatly
encapsulate the lock ordering and shared/exclusive semantics to make
the locking easier to follow and get right.

Note that this changes some of the exclusive locking serialisation in
that serialisation will occur against the i_mutex instead of the
XFS_IOLOCK_EXCL. This does not change any behaviour, and it is
arguably more efficient to use the mutex for such serialisation than
the rw_sem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-12 11:37:10 +11:00
Dave Chinner 4c5cfd1b41 xfs: factor post-write newsize updates
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:14:16 +11:00
Dave Chinner edafb6da9a xfs: factor common post-write isize handling code
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:14:06 +11:00
Dave Chinner a363f0c203 xfs: ensure sync write errors are returned
xfs_file_aio_write() only returns the error from synchronous
flushing of the data and inode if error == 0. At the point where
error is being checked, it is guaranteed to be > 0. Therefore any
errors returned by the data or fsync flush will never be returned.
Fix the checks so we overwrite the current error once and only if an
error really occurred.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11 10:13:53 +11:00
Trond Myklebust 68c404b18f Merge branch 'bugfixes' into nfs-for-2.6.38
Conflicts:
	fs/nfs/nfs2xdr.c
	fs/nfs/nfs3xdr.c
	fs/nfs/nfs4xdr.c
2011-01-10 14:48:02 -05:00
Trond Myklebust 6650239a4b NFS: Don't use vm_map_ram() in readdir
vm_map_ram() is not available on NOMMU platforms, and causes trouble
on incoherrent architectures such as ARM when we access the page data
through both the direct and the virtual mapping.

The alternative is to use the direct mapping to access page data
for the case when we are not crossing a page boundary, but to copy
the data into a linear scratch buffer when we are accessing data
that spans page boundaries.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: stable@kernel.org  [2.6.37]
2011-01-10 14:45:01 -05:00
Josh Hunt d96336b05d ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG
When I enable EXT2_XATTR_DEBUG in fs/ext2/xattr.c I get a build error stating
the following:

  CC      fs/ext2/xattr.o
fs/ext2/xattr.c: In function 'ext2_xattr_cache_insert':
fs/ext2/xattr.c:841: error: dereferencing pointer to incomplete type
fs/ext2/xattr.c:846: error: dereferencing pointer to incomplete type
make[2]: *** [fs/ext2/xattr.o] Error 1
make[1]: *** [fs/ext2] Error 2
make: *** [fs] Error 2

These lines reference ext2_xattr_cache->c_entry_count which is defined
in struct mb_cache. struct mb_cache is currently only defined in fs/mbcache.c.
Moving struct mb_cache definition to include/linux/mbcache.h to resolve the
issue.

Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:08 +01:00
Tobias Klauser 8057b96539 ext3: Remove redundant unlikely()
IS_ERR() already implies unlikely(), so it can be omitted here.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:07 +01:00
Tobias Klauser 0ed0cca7aa ext2: Remove redundant unlikely()
IS_ERR() already implies unlikely(), so it can be omitted here.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:07 +01:00
Eric Sandeen a4ae309486 ext3: speed up file creates by optimizing rec_len functions
The addition of 64k block capability in the rec_len_from_disk
and rec_len_to_disk functions added a bit of math overhead which
slows down file create workloads needlessly when the architecture
cannot even support 64k blocks, thanks to page size limits.

Similar changes already exist in the ext4 codebase.

The directory entry checking can also be optimized a bit
by sprinkling in some unlikely() conditions to move the
error handling out of line.

bonnie++ sequential file creates on a 512MB ramdisk speeds up
from about 77,000/s to about 82,000/s, about a 6% improvement.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:07 +01:00
Eric Sandeen 40a063f669 ext2: speed up file creates by optimizing rec_len functions
The addition of 64k block capability in the rec_len_from_disk
and rec_len_to_disk functions added a bit of math overhead which
slows down file create workloads needlessly when the architecture
cannot even support 64k blocks, thanks to page size limits.

The directory entry checking can also be optimized a bit
by sprinkling in some unlikely() conditions to move the
error handling out of line.

bonnie++ sequential file creates on a 512MB ramdisk speeds up
from about 2200/s to about 2500/s, about a 14% improvement.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:06 +01:00
Namhyung Kim 156e74312f ext3: Add more journal error check
Check return value of ext3_journal_get_write_acccess() and
ext3_journal_dirty_metadata().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:06 +01:00
Namhyung Kim 41dc6385bd ext3: Add journal error check in resize.c
Check return value of ext3_journal_get_write_access() and
ext3_journal_dirty_metadata().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:06 +01:00
Joe Perches 055adcbd7d quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout
Use %pV in __quota_error so a single printk can not be
interleaved with other logging messages.
Add __attribute__((format (printf, 3, 4))) so format
and arguments can be verified by compiler.
Make sure printk formats and arguments match.

Block # needed a pointer dereference.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:05 +01:00
Lukas Czerner 9c52749232 ext3: Add FITRIM handling
The ioctl takes fstrim_range structure (defined in include/linux/fs.h) as an
argument specifying a range of filesystem to trim and the minimum size of an
continguous extent to trim. After the FITRIM is done, the number of bytes
passed from the filesystem down the block stack to the device for potential
discard is stored in fstrim_range.len.  This number is a maximum discard amount
from the storage device's perspective, because FITRIM called repeatedly will
keep sending the same sectors for discard.  fstrim_range.len will report the
same potential discard bytes each time, but only sectors which had been written
to between the discards would actually be discarded by the storage device.
Further, the kernel block layer reserves the right to adjust the discard ranges
to fit raid stripe geometry, non-trim capable devices in a LVM setup, etc.
These reductions would not be reflected in fstrim_range.len.

Thus fstrim_range.len can give the user better insight on how much storage
space has potentially been released for wear-leveling, but it needs to be one
of only one criteria the userspace tools take into account when trying to
optimize calls to FITRIM.

Thanks to Greg Freemyer <greg.freemyer@gmail.com> for better commit message.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:05 +01:00
Lukas Czerner b853b96b1d ext3: Add batched discard support for ext3
Walk through allocation groups and trim all free extents. It can be
invoked through FITRIM ioctl on the file system. The main idea is to
provide a way to trim the whole file system if needed, since some SSD's
may suffer from performance loss after the whole device was filled (it
does not mean that fs is full!).

It search for free extents in allocation groups specified by Byte range
start -> start+len. When the free extent is within this range, blocks are
marked as used and then trimmed. Afterwards these blocks are marked as
free in per-group bitmap.

[JK: Fixed up error handling and trimming of a single group]

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:03:58 +01:00
Eric Sandeen d002ebf1d8 ext4: don't pass entire map to check_eofblocks_fl
Since check_eofblocks_fl() only uses the m_lblk portion of the map
structure, we may as well pass that directly, rather than passing the
entire map, which IMHO obfuscates what parameters check_eofblocks_fl()
cares about.  Not a big deal, but seems tidier and less confusing, to
me.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 13:03:35 -05:00
Theodore Ts'o 1c5b9e9065 ext4: fix memory leak in ext4_free_branches
Commit 40389687 moved a call to ext4_forget() out of
ext4_free_branches and let ext4_free_blocks() handle calling
bforget().  But that change unfortunately did not replace the call to
ext4_forget() with brelse(), which was needed to drop the in-use count
of the indirect block's buffer head, which lead to a memory leak when
deleting files that used indirect blocks.  Fix this.

Thanks to Hugh Dickins for pointing this out.

Cc: stable@kernel.org
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:51:28 -05:00
Theodore Ts'o a5196f8cdf ext4: remove ext4_mb_return_to_preallocation()
This function was never implemented, except for a BUG_ON which was
tripping when ext4 is run without a journal.  The problem is that
although the comment asserts that "truncate (which is the only way to
free block) discards all preallocations", ext4_free_blocks() is also
called in various error recovery paths when blocks have been
allocated, but for various reasons, we were not able to use those data
blocks (for example, because we ran out of memory while trying to
manipulate the extent tree, or some other similar situation).

In addition to the fact that this function isn't implemented except
for the incorrect BUG_ON, the single caller of this function,
ext4_free_blocks(), doesn't use it all if the journal is enabled.

So remove the (stub) function entirely for now.  If we decide it's
better to add it back, it's only going to be useful with a relatively
large number of code changes anyway.

Google-Bug-Id: 3236408

Cc: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:47:07 -05:00
Jiaying Zhang 3889fd57ea ext4: flush the i_completed_io_list during ext4_truncate
Ted first found the bug when running 2.6.36 kernel with dioread_nolock
mount option that xfstests #13 complained about wrong file size during fsck.
However, the bug exists in the older kernels as well although it is
somehow harder to trigger.

The problem is that ext4_end_io_work() can happen after we have truncated an
inode to a smaller size. Then when ext4_end_io_work() calls 
ext4_convert_unwritten_extents(), we may reallocate some blocks that have 
been truncated, so the inode size becomes inconsistent with the allocated
blocks. 

The following patch flushes the i_completed_io_list during truncate to reduce 
the risk that some pending end_io requests are executed later and convert 
already truncated blocks to initialized. 

Note that although the fix helps reduce the problem a lot there may still 
be a race window between vmtruncate() and ext4_end_io_work(). The fundamental
problem is that if vmtruncate() is called without either i_mutex or i_alloc_sem
held, it can race with an ongoing write request so that the io_end request is
processed later when the corresponding blocks have been truncated.

Ted and I have discussed the problem offline and we saw a few ways to fix
the race completely:

a) We guarantee that i_mutex lock and i_alloc_sem write lock are both hold 
whenever vmtruncate() is called. The i_mutex lock prevents any new write
requests from entering writeback and the i_alloc_sem prevents the race
from ext4_page_mkwrite(). Currently we hold both locks if vmtruncate()
is called from do_truncate(), which is probably the most common case.
However, there are places where we may call vmtruncate() without holding
either i_mutex or i_alloc_sem. I would like to ask for other people's
opinions on what locks are expected to be held before calling vmtruncate().
There seems a disagreement among the callers of that function.

b) We change the ext4 write path so that we change the extent tree to contain 
the newly allocated blocks and update i_size both at the same time --- when 
the write of the data blocks is completed.

c) We add some additional locking to synchronize vmtruncate() and 
ext4_end_io_work(). This approach may have performance implications so we
need to be careful.

All of the above proposals may require more substantial changes, so
we may consider to take the following patch as a bandaid.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:47:05 -05:00
Theodore Ts'o b40971426a ext4: add error checking to calls to ext4_handle_dirty_metadata()
Call ext4_std_error() in various places when we can't bail out
cleanly, so the file system can be marked as in error.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:46:59 -05:00
Jan Kara ca6e909f9b ext4: fix trimming of a single group
When ext4_trim_fs() is called to trim a part of a single group, the
logic will wrongly set last block of the interval to 'len' instead
of 'first_block + len'. Thus a shorter interval is possibly trimmed.
Fix it.

CC: Lukas Czerner <lczerner@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:30:39 -05:00
Andrew Morton 6c5a6cb998 ext4: fix uninitialized variable in ext4_register_li_request
fs/ext4/super.c: In function 'ext4_register_li_request':
fs/ext4/super.c:2936: warning: 'ret' may be used uninitialized in this function

It looks buggy to me, too.

Cc: Lukas Czerner <lczerner@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:30:17 -05:00
Theodore Ts'o 8aefcd557d ext4: dynamically allocate the jbd2_inode in ext4_inode_info as necessary
Replace the jbd2_inode structure (which is 48 bytes) with a pointer
and only allocate the jbd2_inode when it is needed --- that is, when
the file system has a journal present and the inode has been opened
for writing.  This allows us to further slim down the ext4_inode_info
structure.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:29:43 -05:00
Theodore Ts'o 353eb83c14 ext4: drop i_state_flags on architectures with 64-bit longs
We can store the dynamic inode state flags in the high bits of
EXT4_I(inode)->i_flags, and eliminate i_state_flags.  This saves 8
bytes from the size of ext4_inode_info structure, which when
multiplied by the number of the number of in the inode cache, can save
a lot of memory.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:18:25 -05:00
Theodore Ts'o 8a2005d3f8 ext4: reorder ext4_inode_info structure elements to remove unneeded padding
By reordering the elements in the ext4_inode_info structure, we can
reduce the padding needed on an x86_64 system by 16 bytes.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:13:42 -05:00
Theodore Ts'o b05e6ae58a ext4: drop ec_type from the ext4_ext_cache structure
We can encode the ec_type information by using ee_len == 0 to denote
EXT4_EXT_CACHE_NO, ee_start == 0 to denote EXT4_EXT_CACHE_GAP, and if
neither is true, then the cache type must be EXT4_EXT_CACHE_EXTENT.
This allows us to reduce the size of ext4_ext_inode by another 8
bytes.  (ec_type is 4 bytes, plus another 4 bytes of padding)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:13:26 -05:00
Theodore Ts'o 01f49d0b9d ext4: use ext4_lblk_t instead of sector_t for logical blocks
This fixes a number of places where we used sector_t instead of
ext4_lblk_t for logical blocks, which for ext4 are still 32-bit data
types.  No point wasting space in the ext4_inode_info structure, and
requiring 64-bit arithmetic on 32-bit systems, when it isn't
necessary.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:13:03 -05:00
Theodore Ts'o f232109773 ext4: replace i_delalloc_reserved_flag with EXT4_STATE_DELALLOC_RESERVED
Remove the short element i_delalloc_reserved_flag from the
ext4_inode_info structure and replace it a new bit in i_state_flags.
Since we have an ext4_inode_info for every ext4 inode cached in the
inode cache, any savings we can produce here is a very good thing from
a memory utilization perspective.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:12:36 -05:00
Kazuya Mio ad4fb9cafe ext4: fix 32bit overflow in ext4_ext_find_goal()
ext4_ext_find_goal() returns an ideal physical block number that the block
allocator tries to allocate first. However, if a required file offset is
smaller than the existing extent's one, ext4_ext_find_goal() returns
a wrong block number because it may overflow at
"block - le32_to_cpu(ex->ee_block)". This patch fixes the problem.

ext4_ext_find_goal() will also return a wrong block number in case
a file offset of the existing extent is too big. In this case,
the ideal physical block number is fixed in ext4_mb_initialize_context(),
so it's no problem.

reproduce:
# dd if=/dev/zero of=/mnt/mp1/tmp bs=127M count=1 oflag=sync
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 seek=1 oflag=sync
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0     128    67456             128 eof
/mnt/mp1/file: 2 extents found
# rm -rf /mnt/mp1/tmp
# echo $((512*4096)) > /sys/fs/ext4/loop0/mb_stream_req
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 oflag=sync conv=notrunc

result (linux-2.6.37-rc2 + ext4 patch queue):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0    33280             128 
   1     128    67456    33407    128 eof
/mnt/mp1/file: 2 extents found

result(apply this patch):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0    66560             128 
   1     128    67456    66687    128 eof
/mnt/mp1/file: 2 extents found

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:12:28 -05:00
Namhyung Kim dabd991f9d ext4: add more error checks to ext4_mkdir()
Check return value of ext4_journal_get_write_access,
ext4_journal_dirty_metadata and ext4_mark_inode_dirty. Move brelse()
under 'out_stop' to release bh properly in case of journal error.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:11:16 -05:00
Eric Paris f1dffc4c54 ext4: ext4_ext_migrate should use NULL not 0
ext4_ext_migrate() calls ext4_new_inode() and passes 0 instead of a pointer
to a struct qstr.  This patch uses NULL, to make it obvious to the caller
that this was a pointer.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:11:00 -05:00
Theodore Ts'o f7c21177af ext4: Use ext4_error_file() to print the pathname to the corrupted inode
Where the file pointer is available, use ext4_error_file() instead of
ext4_error_inode().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:10:55 -05:00
Dan Carpenter f9a62d090c ext4: use IS_ERR() to check for errors in ext4_error_file
d_path() returns an ERR_PTR and it doesn't return NULL.  This is in
ext4_error_file() and no one actually calls ext4_error_file().

Signed-off-by: Dan Carpenter <error27@gmail.com>
2011-01-10 12:10:50 -05:00
Dan Carpenter 13195184a8 ext4: test the correct variable in ext4_init_pageio()
This is a copy and paste error.  The intent was to check
"io_page_cachep".  We tested "io_page_cachep" earlier.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:10:44 -05:00
Wang Sheng-Hui 1f605b3027 ext2: remove dead code in ext2_xattr_get
Reviewed-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Wang Sheng-Hui <crosslonelyover@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:10:37 -05:00
Wang Sheng-Hui 6e9510b0e0 ext2,ext3,ext4: clarify comment for extN_xattr_set_handle
Signed-off-by: Wang Sheng-Hui <crosslonelyover@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:10:30 -05:00
Theodore Ts'o eaeef86718 ext4: clean up ext4_xattr_list()'s error code checking and return strategy
Any time you see code that tries to add error codes together, you
should want to claw your eyes out...

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:10:07 -05:00
Lukas Czerner 9325963667 ext4: remove warning message from ext4_issue_discard helper
ext4_issue_discard is supposed to be helper for calling discard, however
in case that underlying device does not support discard it prints out
the warning message and clears the DISCARD t_mount_opt flag. Since it
can be (and is) used by others, it should not do anything and let the
caller to handle the error case.

This commit removes warning message and flag setting from
ext4_issue_discard and use it just in place where it is really needed
(release_blocks_on_commit). FITRIM ioctl should not set any flags nor it
should print out warning messages, so get rid of the warning as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
2011-01-10 12:09:59 -05:00
Lukas Czerner 4f531501e4 ext4: fix possible overflow in ext4_trim_fs()
When determining last group through ext4_get_group_no_and_offset() the
result may be wrong in cases when range->start and range-len are too
big, because it may overflow when summing up those two numbers.

Fix that by checking range->len and limit its value to
ext4_blocks_count(). This commit was tested by myself with expected
result.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
2011-01-10 12:04:55 -05:00
Alexey Dobriyan 57cc7215b7 headers: kobject.h redux
Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10 08:51:44 -08:00
Linus Torvalds b65f0d673a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: unfold nilfs_dat_inode function
  nilfs2: do not pass sbi to functions which can get it from inode
  nilfs2: get rid of nilfs_mount_options structure
  nilfs2: simplify nilfs_mdt_freeze_buffer
  nilfs2: get rid of loaded flag from nilfs object
  nilfs2: fix a checkpatch error in page.c
  nilfs2: fiemap support
  nilfs2: mark buffer heads as delayed until the data is written to disk
  nilfs2: call nilfs_error inside bmap routines
  fs/nilfs2/super.c: Use printf extension %pV
  MAINTAINERS: add nilfs2 git tree entry
2011-01-10 07:50:40 -08:00
Linus Torvalds f3ea597251 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  cifs: use CreationTime like an i_generation field
  cifs: switch cifs_open and cifs_create to use CIFSSMBUnixSetFileInfo
  cifs: show "acl" in DebugData Features when it's compiled in
  cifs: move "ntlmssp" and "local_leases" options out of experimental code
  cifs: replace some hardcoded values with preprocessor constants
  cifs: remove unnecessary locking around sequence_number
  [CIFS] Fix minor merge conflict in fs/cifs/dir.c
  CIFS: Simplify cifs_open code
  CIFS: Simplify non-posix open stuff (try #2)
  CIFS: Add match_port check during looking for an existing connection (try #4)
  CIFS: Simplify ipv*_connect functions into one (try #4)
  cifs: Support NTLM2 session security during NTLMSSP authentication [try #5]
  cifs: don't overwrite dentry name in d_revalidate
2011-01-10 07:47:11 -08:00
Linus Torvalds f9f265f355 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
  dlm: sanitize work_start() in lowcomms.c
  dlm: reduce cond_resched during send
  dlm: use TCP_NODELAY
  dlm: Use cmwq for send and receive workqueues
  dlm: Handle application limited situations properly.
2011-01-10 07:46:26 -08:00
Linus Torvalds 7d44b04401 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix ioctl ABI
  fuse: allow batching of FORGET requests
  fuse: separate queue for FORGET requests
  fuse: ioctl cleanup

Fix up trivial conflict in fs/fuse/inode.c due to RCU lookup having done
the RCU-freeing of the inode in fuse_destroy_inode().
2011-01-10 07:43:54 -08:00
Randy Dunlap 39191628ed fs: fix namei.c kernel-doc notation
Fix new kernel-doc notation warnings in fs/namei.c and spell
ECHILD correctly.

  Warning(fs/namei.c:218): No description found for parameter 'flags'
  Warning(fs/namei.c:425): Excess function parameter 'Returns' description in 'nameidata_drop_rcu'
  Warning(fs/namei.c:478): Excess function parameter 'Returns' description in 'nameidata_dentry_drop_rcu'
  Warning(fs/namei.c:540): Excess function parameter 'Returns' description in 'nameidata_drop_rcu_last'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10 07:38:53 -08:00
Ryusuke Konishi 365e215ce1 nilfs2: unfold nilfs_dat_inode function
nilfs_dat_inode function was a wrapper to switch between normal dat
inode and gcdat, a clone of the dat inode for garbage collection.

This function got obsolete when the gcdat inode was removed, and now
we can access the dat inode directly from a nilfs object.  So, we will
unfold the wrapper and remove it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:38:39 +09:00
Ryusuke Konishi bcbc8c648d nilfs2: do not pass sbi to functions which can get it from inode
This removes argument for passing nilfs_sb_info structure from
nilfs_set_file_dirty and nilfs_load_inode_block functions.  We can get
a pointer to the structure from inodes.

[Stephen Rothwell <sfr@canb.auug.org.au>: fix conflict with commit
 b74c79e993]

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:37:54 +09:00
Ryusuke Konishi 06df0f9992 nilfs2: get rid of nilfs_mount_options structure
Only mount_opt member is used in the nilfs_mount_options structure,
and we can simplify it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Ryusuke Konishi a7a8447ede nilfs2: simplify nilfs_mdt_freeze_buffer
nilfs_page_get_nth_block() function used in nilfs_mdt_freeze_buffer()
always returns a valid buffer head, so its validity check can be
removed.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Ryusuke Konishi 888da23c2f nilfs2: get rid of loaded flag from nilfs object
NILFS_LOADED flag of the nilfs object is not used now, so this will
remove it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Ryusuke Konishi ae53a0a2ce nilfs2: fix a checkpatch error in page.c
Will correct the following checkpatch error:

 ERROR: trailing whitespace
 #494: FILE: page.c:494:
 + $

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Ryusuke Konishi 622daaff0a nilfs2: fiemap support
This adds fiemap to nilfs.  Two new functions, nilfs_fiemap and
nilfs_find_uncommitted_extent are added.

nilfs_fiemap() implements the fiemap inode operation, and
nilfs_find_uncommitted_extent() helps to get a range of data blocks
whose physical location has not been determined.

nilfs_fiemap() collects extent information by looping through
nilfs_bmap_lookup_contig and nilfs_find_uncommitted_extent routines.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:46 +09:00
Ryusuke Konishi 27e6c7a3ce nilfs2: mark buffer heads as delayed until the data is written to disk
Nilfs does not allocate new blocks on disk until they are actually
written to.  To implement fiemap, we need to deal with such blocks.

To allow successive fiemap patch to distinguish mapped but unallocated
regions, this marks buffer heads of those new blocks as delayed and
clears the flag after the blocks are written to disk.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:45 +09:00
Ryusuke Konishi e828949e5b nilfs2: call nilfs_error inside bmap routines
Some functions using nilfs bmap routines can wrongly return invalid
argument error (i.e. -EINVAL) that bmap returns as an internal code
for btree corruption.

This fixes the issue by catching and converting the internal EINVAL to
EIO and calling nilfs_error function inside bmap routines.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:45 +09:00
Joe Perches b004a5eb0b fs/nilfs2/super.c: Use printf extension %pV
Using %pV reduces the number of printk calls and
eliminates any possible message interleaving from
other printk calls.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10 14:05:45 +09:00
Jeff Layton 20054bd657 cifs: use CreationTime like an i_generation field
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>
2011-01-09 23:43:00 +00:00
Jeff Layton d44a9fe2c8 cifs: switch cifs_open and cifs_create to use CIFSSMBUnixSetFileInfo
We call CIFSSMBUnixSetPathInfo in these functions, but we have a
filehandle since an open was just done. Switch these functions to
use CIFSSMBUnixSetFileInfo instead.

In practice, these codepaths are only used if posix opens are broken.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:39:24 +00:00
Jeff Layton ca40b714b8 cifs: show "acl" in DebugData Features when it's compiled in
...and while we're at it, reduce the number of calls into the seq_*
functions by prepending spaces to strings.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:39:20 +00:00
Jeff Layton b4d6fcf13f cifs: move "ntlmssp" and "local_leases" options out of experimental code
I see no real need to leave these sorts of options under an
EXPERIMENTAL ifdef. Since you need a mount option to turn this code
on, that only blows out the testing matrix.

local_leases has been under the EXPERIMENTAL tag for some time, but
it's only the mount option that's under this label. Move it out
from under this tag.

The NTLMSSP code is also under EXPERIMENTAL, but it needs a mount
option to turn it on, and in the future any distro will reasonably
want this enabled. Go ahead and move it out from under the
EXPERIMENTAL tag.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:39:17 +00:00
Jeff Layton 1397f2ee4b cifs: replace some hardcoded values with preprocessor constants
A number of places that deal with RFC1001/1002 negotiations have bare
"15" or "16" values. Replace them with RFC_1001_NAME_LEN and
RFC_1001_NAME_LEN_WITH_NULL.

The patch also cleans up some checkpatch warnings for code surrounding
the changes. This should apply cleanly on top of the patch to remove
Local_System_Name.

Reported-and-Reviwed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:39:12 +00:00
Jeff Layton a0f8b4fb4c cifs: remove unnecessary locking around sequence_number
The server->sequence_number is already protected by the srv_mutex. The
GlobalMid_lock is unneeded here.

Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:38:20 +00:00
Steve French 197a1eeb7f [CIFS] Fix minor merge conflict in fs/cifs/dir.c
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-09 23:26:56 +00:00
Steve French acc6f11272 Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
	fs/cifs/dir.c
2011-01-09 23:18:16 +00:00
Tao Ma aecf586619 ocfs2: Remove unused truncate function from alloc.c
Tristan Ye has done some refactoring against our truncate
process, so some functions like ocfs2_prepare_truncate and
ocfs2_free_truncate_context are no use and we'd better
remove them.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2011-01-07 18:03:00 -08:00
Dan Carpenter cc548166b2 ocfs2/cluster: dereferencing before checking in nst_seq_show()
In the original code, we dereferenced "nst" before checking that it was
non-NULL.  I moved the check forward and pulled the code in an indent
level.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2011-01-07 18:02:03 -08:00
Randy Dunlap e70d84501b ocfs2: fix build for OCFS2_FS_STATS not enabled
When CONFIG_OCFS2_FS_STATS is not enabled:

fs/ocfs2/cluster/tcp.c:1254: error: implicit declaration of function 'o2net_update_recv_stats'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Mark Fasheh <mfasheh@suse.com>
Cc:	Joel Becker <joel.becker@oracle.com>
Cc:	ocfs2-devel@oss.oracle.com
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2011-01-07 18:02:00 -08:00
Linus Torvalds 0c21e3aaf6 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus:
  hfsplus: %L-to-%ll, macro correction, and remove unneeded braces
  hfsplus: spaces/indentation clean-up
  hfsplus: C99 comments clean-up
  hfsplus: over 80 character lines clean-up
  hfsplus: fix an artifact in ioctl flag checking
  hfsplus: flush disk caches in sync and fsync
  hfsplus: optimize fsync
  hfsplus: split up inode flags
  hfsplus: write up fsync for directories
  hfsplus: simplify fsync
  hfsplus: avoid useless work in hfsplus_sync_fs
  hfsplus: make sure sync writes out all metadata
  hfsplus: use raw bio access for partition tables
  hfsplus: use raw bio access for the volume headers
  hfsplus: always use hfsplus_sync_fs to write the volume header
  hfsplus: silence a few debug printks
  hfsplus: fix option parsing during remount

Fix up conflicts due to VFS changes in fs/hfsplus/{hfsplus_fs.h,unicode.c}
2011-01-07 17:16:27 -08:00
Linus Torvalds 72eb6a7914 Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
2011-01-07 17:02:58 -08:00
Linus Torvalds 23d69b09b7 Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
  usb: don't use flush_scheduled_work()
  speedtch: don't abuse struct delayed_work
  media/video: don't use flush_scheduled_work()
  media/video: explicitly flush request_module work
  ioc4: use static work_struct for ioc4_load_modules()
  init: don't call flush_scheduled_work() from do_initcalls()
  s390: don't use flush_scheduled_work()
  rtc: don't use flush_scheduled_work()
  mmc: update workqueue usages
  mfd: update workqueue usages
  dvb: don't use flush_scheduled_work()
  leds-wm8350: don't use flush_scheduled_work()
  mISDN: don't use flush_scheduled_work()
  macintosh/ams: don't use flush_scheduled_work()
  vmwgfx: don't use flush_scheduled_work()
  tpm: don't use flush_scheduled_work()
  sonypi: don't use flush_scheduled_work()
  hvsi: don't use flush_scheduled_work()
  xen: don't use flush_scheduled_work()
  gdrom: don't use flush_scheduled_work()
  ...

Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
2011-01-07 16:58:04 -08:00
Linus Torvalds 56b85f32d5 Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
  serial: apbuart: Fixup apbuart_console_init()
  TTY: Add tty ioctl to figure device node of the system console.
  tty: add 'active' sysfs attribute to tty0 and console device
  drivers: serial: apbuart: Handle OF failures gracefully
  Serial: Avoid unbalanced IRQ wake disable during resume
  tty: fix typos/errors in tty_driver.h comments
  pch_uart : fix warnings for 64bit compile
  8250: fix uninitialized FIFOs
  ip2: fix compiler warning on ip2main_pci_tbl
  specialix: fix compiler warning on specialix_pci_tbl
  rocket: fix compiler warning on rocket_pci_ids
  8250: add a UPIO_DWAPB32 for 32 bit accesses
  8250: use container_of() instead of casting
  serial: omap-serial: Add support for kernel debugger
  serial: fix pch_uart kconfig & build
  drivers: char: hvc: add arm JTAG DCC console support
  RS485 documentation: add 16C950 UART description
  serial: ifx6x60: fix memory leak
  serial: ifx6x60: free IRQ on error
  Serial: EG20T: add PCH_UART driver
  ...

Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
2011-01-07 14:39:20 -08:00
Linus Torvalds b4a45f5fe8 Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...
2011-01-07 08:56:33 -08:00
Jens Axboe 6c23a9681c block: add internal hd part table references
We can't use krefs since it's apparently restricted to very basic
reference counting.

This reverts commit e4a683c8.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-07 08:43:37 +01:00
Nick Piggin b3e19d924b fs: scale mntget/mntput
The problem that this patch aims to fix is vfsmount refcounting scalability.
We need to take a reference on the vfsmount for every successful path lookup,
which often go to the same mount point.

The fundamental difficulty is that a "simple" reference count can never be made
scalable, because any time a reference is dropped, we must check whether that
was the last reference. To do that requires communication with all other CPUs
that may have taken a reference count.

We can make refcounts more scalable in a couple of ways, involving keeping
distributed counters, and checking for the global-zero condition less
frequently.

- check the global sum once every interval (this will delay zero detection
  for some interval, so it's probably a showstopper for vfsmounts).

- keep a local count and only taking the global sum when local reaches 0 (this
  is difficult for vfsmounts, because we can't hold preempt off for the life of
  a reference, so a counter would need to be per-thread or tied strongly to a
  particular CPU which requires more locking).

- keep a local difference of increments and decrements, which allows us to sum
  the total difference and hence find the refcount when summing all CPUs. Then,
  keep a single integer "long" refcount for slow and long lasting references,
  and only take the global sum of local counters when the long refcount is 0.

This last scheme is what I implemented here. Attached mounts and process root
and working directory references are "long" references, and everything else is
a short reference.

This allows scalable vfsmount references during path walking over mounted
subtrees and unattached (lazy umounted) mounts with processes still running
in them.

This results in one fewer atomic op in the fastpath: mntget is now just a
per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock
and non-atomic decrement in the common case. However code is otherwise bigger
and heavier, so single threaded performance is basically a wash.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:33 +11:00
Nick Piggin c6653a838b fs: rename vfsmount counter helpers
Suggested by Andreas, mnt_ prefix is clearer namespace, follows kernel
conventions better, and is easier for tab complete. I introduced these
names so I'll admit they were not good choices.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:33 +11:00
Nick Piggin 9d55c369bb fs: implement faster dentry memcmp
The standard memcmp function on a Westmere system shows up hot in
profiles in the `git diff` workload (both parallel and single threaded),
and it is likely due to the costs associated with trapping into
microcode, and little opportunity to improve memory access (dentry
name is not likely to take up more than a cacheline).

So replace it with an open-coded byte comparison. This increases code
size by 8 bytes in the critical __d_lookup_rcu function, but the
speedup is huge, averaging 10 runs of each:

git diff st   user   sys   elapsed  CPU
before        1.15   2.57  3.82      97.1
after         1.14   2.35  3.61      96.8

git diff mt   user   sys   elapsed  CPU
before        1.27   3.85  1.46     349
after         1.26   3.54  1.43     333

Elapsed time for single threaded git diff at 95.0% confidence:
        -0.21  +/- 0.01
        -5.45% +/- 0.24%

It's -0.66% +/- 0.06% elapsed time on my Opteron, so rep cmp costs on the
fam10h seem to be relatively smaller, but there is still a win.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:32 +11:00
Nick Piggin e1bb578263 fs: prefetch inode data in dcache lookup
This makes single threaded git diff -1.25% +/- 0.05% elapsed time on my
2s12c24t Westmere system, and -0.86% +/- 0.05% on my 2s8c Barcelona, by
prefetching the important first cacheline of the inode in while we do the
actual name compare and other operations on the dentry.

There was no measurable slowdown in the single file stat case, or the creat
case (where negative dentries would be common).

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:32 +11:00
Nick Piggin 4b936885ab fs: improve scalability of pseudo filesystems
Regardless of how much we possibly try to scale dcache, there is likely
always going to be some fundamental contention when adding or removing children
under the same parent. Pseudo filesystems do not seem need to have connected
dentries because by definition they are disconnected.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:32 +11:00
Nick Piggin 873feea09e fs: dcache per-inode inode alias locking
dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:31 +11:00
Nick Piggin ceb5bdc2d2 fs: dcache per-bucket dcache hash locking
We can turn the dcache hash locking from a global dcache_hash_lock into
per-bucket locking.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:31 +11:00
Nick Piggin 880566e17c xfs: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:30 +11:00
Nick Piggin 258a5aa8df btrfs: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:30 +11:00
Nick Piggin 73598611ad ext2,3,4: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:30 +11:00
Nick Piggin 1e1743ebe3 fs: provide simple rcu-walk generic_check_acl implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.

This could easily be extended to put acls under RCU and check them
under seqlock, if need be. But this implementation is enough to show
the rcu-walk aware permissions code for path lookups is working, and
will handle cases where there are no ACLs or ACLs in just the final
element.

This patch implicity converts tmpfs to rcu-aware permission check.
Subsequent patches onvert ext*, xfs, and, btrfs. Each of these uses
acl/permission code in a different way, so convert them all to provide
templates and proof of concept.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:29 +11:00
Nick Piggin b74c79e993 fs: provide rcu-walk aware permission i_ops
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:29 +11:00
Nick Piggin 34286d6662 fs: rcu-walk aware d_revalidate method
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:29 +11:00
Nick Piggin 44a7d7a878 fs: cache optimise dentry and inode for rcu-walk
Put dentry and inode fields into top of data structure.  This allows RCU path
traversal to perform an RCU dentry lookup in a path walk by touching only the
first 56 bytes of the dentry.

We also fit in 8 bytes of inline name in the first 64 bytes, so for short
names, only 64 bytes needs to be touched to perform the lookup. We should
get rid of the hash->prev pointer from the first 64 bytes, and fit 16 bytes
of name in there, which will take care of 81% rather than 32% of the kernel
tree.

inode is also rearranged so that RCU lookup will only touch a single cacheline
in the inode, plus one in the i_ops structure.

This is important for directory component lookups in RCU path walking. In the
kernel source, directory names average is around 6 chars, so this works.

When we reach the last element of the lookup, we need to lock it and take its
refcount which requires another cacheline access.

Align dentry and inode operations structs, so members will be at predictable
offsets and we can group common operations into head of structure.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin fb045adb99 fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin 5f57cbcc02 fs: dcache remove d_mounted
Rather than keep a d_mounted count in the dentry, set a dentry flag instead.
The flag can be cleared by checking the hash table to see if there are any
mounts left, which is not time critical because it is performed at detach time.

The mounted state of a dentry is only used to speculatively take a look in the
mount hash table if it is set -- before following the mount, vfsmount lock is
taken and mount re-checked without races.

This saves 4 bytes on 32-bit, nothing on 64-bit but it does provide a hole I
might use later (and some configs have larger than 32-bit spinlocks which might
make use of the hole).

Autofs4 conversion and changelog by Ian Kent <raven@themaw.net>:
In autofs4, when expring direct (or offset) mounts we need to ensure that we
block user path walks into the autofs mount, which is covered by another mount.
To do this we clear the mounted status so that follows stop before walking into
the mount and are essentially blocked until the expire is completed. The
automount daemon still finds the correct dentry for the umount due to the
follow mount logic in fs/autofs4/root.c:autofs4_follow_link(), which is set as
an inode operation for direct and offset mounts only and is called following
the lookup that stopped at the covered mount.

At the end of the expire the covering mount probably has gone away so the
mounted status need not be restored. But we need to check this and only restore
the mounted status if the expire failed.

XXX: autofs may not work right if we have other mounts go over the top of it?

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin c28cc36469 fs: fs_struct use seqlock
Use a seqlock in the fs_struct to enable us to take an atomic copy of the
complete cwd and root paths. Use this in the RCU lookup path to avoid a
thread-shared spinlock in RCU lookup operations.

Multi-threaded apps may now perform path lookups with scalability matching
multi-process apps. Operations such as stat(2) become very scalable for
multi-threaded workload.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:27 +11:00
Nick Piggin 31e6b01f41 fs: rcu-walk for path lookup
Perform common cases of path lookups without any stores or locking in the
ancestor dentry elements. This is called rcu-walk, as opposed to the current
algorithm which is a refcount based walk, or ref-walk.

This results in far fewer atomic operations on every path element,
significantly improving path lookup performance. It also avoids cacheline
bouncing on common dentries, significantly improving scalability.

The overall design is like this:
* LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk.
* Take the RCU lock for the entire path walk, starting with the acquiring
  of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are
  not required for dentry persistence.
* synchronize_rcu is called when unregistering a filesystem, so we can
  access d_ops and i_ops during rcu-walk.
* Similarly take the vfsmount lock for the entire path walk. So now mnt
  refcounts are not required for persistence. Also we are free to perform mount
  lookups, and to assume dentry mount points and mount roots are stable up and
  down the path.
* Have a per-dentry seqlock to protect the dentry name, parent, and inode,
  so we can load this tuple atomically, and also check whether any of its
  members have changed.
* Dentry lookups (based on parent, candidate string tuple) recheck the parent
  sequence after the child is found in case anything changed in the parent
  during the path walk.
* inode is also RCU protected so we can load d_inode and use the inode for
  limited things.
* i_mode, i_uid, i_gid can be tested for exec permissions during path walk.
* i_op can be loaded.

When we reach the destination dentry, we lock it, recheck lookup sequence,
and increment its refcount and mountpoint refcount. RCU and vfsmount locks
are dropped. This is termed "dropping rcu-walk". If the dentry refcount does
not match, we can not drop rcu-walk gracefully at the current point in the
lokup, so instead return -ECHILD (for want of a better errno). This signals the
path walking code to re-do the entire lookup with a ref-walk.

Aside from the final dentry, there are other situations that may be encounted
where we cannot continue rcu-walk. In that case, we drop rcu-walk (ie. take
a reference on the last good dentry) and continue with a ref-walk. Again, if
we can drop rcu-walk gracefully, we return -ECHILD and do the whole lookup
using ref-walk. But it is very important that we can continue with ref-walk
for most cases, particularly to avoid the overhead of double lookups, and to
gain the scalability advantages on common path elements (like cwd and root).

The cases where rcu-walk cannot continue are:
* NULL dentry (ie. any uncached path element)
* parent with d_inode->i_op->permission or ACLs
* dentries with d_revalidate
* Following links

In future patches, permission checks and d_revalidate become rcu-walk aware. It
may be possible eventually to make following links rcu-walk aware.

Uncached path elements will always require dropping to ref-walk mode, at the
very least because i_mutex needs to be grabbed, and objects allocated.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:27 +11:00
Nick Piggin ff0c7d15f9 fs: avoid inode RCU freeing for pseudo fs
Pseudo filesystems that don't put inode on RCU list or reachable by
rcu-walk dentries do not need to RCU free their inodes.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
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>
2011-01-07 17:50:26 +11:00
Nick Piggin 77812a1ef1 fs: consolidate dentry kill sequence
The tricky locking for disposing of a dentry is duplicated 3 times in the
dcache (dput, pruning a dentry from the LRU, and pruning its ancestors).
Consolidate them all into a single function dentry_kill.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:25 +11:00
Nick Piggin ec33679d78 fs: use RCU in shrink_dentry_list to reduce lock nesting
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:25 +11:00
Nick Piggin be182bff72 fs: reduce dcache_inode_lock width in lru scanning
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:25 +11:00
Nick Piggin 89e6054836 fs: dcache reduce prune_one_dentry locking
prune_one_dentry can avoid quite a bit of locking in the common case where
ancestors have an elevated refcount. Alternatively, we could have gone the
other way and made fewer trylocks in the case where d_count goes to zero, but
is probably less common.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:25 +11:00
Nick Piggin a734eb458a fs: dcache reduce d_parent locking
Use RCU to simplify locking in dget_parent.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin dc0474be3e fs: dcache rationalise dget variants
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin 357f8e658b fs: dcache reduce dcache_inode_lock
dcache_inode_lock can be avoided in d_delete() and d_materialise_unique()
in cases where it is not required.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin 89ad485f01 fs: dcache reduce locking in d_alloc
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin 61f3dee4af fs: dcache reduce dput locking
It is possible to run dput without taking data structure locks up-front. In
many cases where we don't kill the dentry anyway, these locks are not required.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:23 +11:00
Nick Piggin 58db63d086 fs: dcache avoid starvation in dcache multi-step operations
Long lived dcache "multi-step" operations which retry on rename seq can
be starved with a lot of rename activity. If they fail after the 1st pass,
take the rename_lock for writing to avoid further starvation.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:23 +11:00
Nick Piggin b5c84bf6f6 fs: dcache remove dcache_lock
dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:23 +11:00
Nick Piggin 949854d024 fs: Use rename lock and RCU for multi-step operations
The remaining usages for dcache_lock is to allow atomic, multi-step read-side
operations over the directory tree by excluding modifications to the tree.
Also, to walk in the leaf->root direction in the tree where we don't have
a natural d_lock ordering.

This could be accomplished by taking every d_lock, but this would mean a
huge number of locks and actually gets very tricky.

Solve this instead by using the rename seqlock for multi-step read-side
operations, retry in case of a rename so we don't walk up the wrong parent.
Concurrent dentry insertions are not serialised against.  Concurrent deletes
are tricky when walking up the directory: our parent might have been deleted
when dropping locks so also need to check and retry for that.

We can also use the rename lock in cases where livelock is a worry (and it
is introduced in subsequent patch).

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:22 +11:00
Nick Piggin 9abca36087 fs: increase d_name lock coverage
Cover d_name with d_lock in more cases, where there may be concurrent
modification to it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:22 +11:00
Nick Piggin b23fb0a603 fs: scale inode alias list
Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:22 +11:00
Nick Piggin 2fd6b7f507 fs: dcache scale subdirs
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).

Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Nick Piggin da5029563a fs: dcache scale d_unhashed
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Nick Piggin b7ab39f631 fs: dcache scale dentry refcount
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Nick Piggin 2304450783 fs: dcache scale lru
Add a new lock, dcache_lru_lock, to protect the dcache LRU list from concurrent
modification. d_lru is also protected by d_lock, which allows LRU lists to be
accessed without the lru lock, using RCU in future patches.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:20 +11:00
Nick Piggin 789680d1ee fs: dcache scale hash
Add a new lock, dcache_hash_lock, to protect the dcache hash table from
concurrent modification. d_hash is also protected by d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:20 +11:00
Nick Piggin ec2447c278 hostfs: simplify locking
Remove dcache_lock locking from hostfs filesystem, and move it into dcache
helpers. All that is required is a coherent path name. Protection from
concurrent modification of the namespace after path name generation is not
provided in current code, because dcache_lock is dropped before the path is
used.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:20 +11:00
Nick Piggin b1e6a015a5 fs: change d_hash for rcu-walk
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:20 +11:00