Commit Graph

71 Commits

Author SHA1 Message Date
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Darrick J. Wong 1d1d1a7672 mm: only enforce stable page writes if the backing device requires it
Create a helper function to check if a backing device requires stable
page writes and, if so, performs the necessary wait.  Then, make it so
that all points in the memory manager that handle making pages writable
use the helper function.  This should provide stable page write support
to most filesystems, while eliminating unnecessary waiting for devices
that don't require the feature.

Before this patchset, all filesystems would block, regardless of whether
or not it was necessary.  ext3 would wait, but still generate occasional
checksum errors.  The network filesystems were left to do their own
thing, so they'd wait too.

After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it.  ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait.  Network filesystems haven't been touched, so either they
provide their own stable page guarantees or they don't block at all.
The blocking behavior is back to what it was before 3.0 if you don't
have a disk requiring stable page writes.

Here's the result of using dbench to test latency on ext2:

3.8.0-rc3:
 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 WriteX        109347     0.028    59.817
 ReadX         347180     0.004     3.391
 Flush          15514    29.828   287.283

Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms

3.8.0-rc3 + patches:
 WriteX        105556     0.029     4.273
 ReadX         335004     0.005     4.112
 Flush          14982    30.540   298.634

Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms

As you can see, the maximum write latency drops considerably with this
patch enabled.  The other filesystems (ext3/ext4/xfs/btrfs) behave
similarly, but see the cover letter for those results.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:19 -08:00
Steven Whitehouse 350a9b0a72 GFS2: Split gfs2_trans_add_bh() into two
There is little common content in gfs2_trans_add_bh() between the data
and meta classes by the time that the functions which it calls are
taken into account. The intent here is to split this into two
separate functions. Stage one is to introduce gfs2_trans_add_data()
and gfs2_trans_add_meta() and update the callers accordingly.

Later patches will then pull in the content of gfs2_trans_add_bh()
and its dependent functions in order to clean up the code in this
area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-01-29 10:28:04 +00:00
Andrew Morton 965c8e59cf lseek: the "whence" argument is called "whence"
But the kernel decided to call it "origin" instead.  Fix most of the
sites.

Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:12 -08:00
Steven Whitehouse 9dbe9610b9 GFS2: Add Orlov allocator
Just like ext3, this works on the root directory and any directory
with the +T flag set. Also, just like ext3, any subdirectory created
in one of the just mentioned cases will be allocated to a random
resource group (GFS2 equivalent of a block group).

If you are creating a set of directories, each of which will contain a
job running on a different node, then by setting +T on the parent
directory before creating the subdirectories, each will land up in a
different resource group, and thus resource group contention between
nodes will be kept to a minimum.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 13:33:17 +00:00
Benjamin Marzinski 3d1626889a GFS2: Don't call file_accessed() with a shared glock
file_accessed() was being called by gfs2_mmap() with a shared glock. If it
needed to update the atime, it was crashing because it dirtied the inode in
gfs2_dirty_inode() without holding an exclusive lock. gfs2_dirty_inode()
checked if the caller was already holding a glock, but it didn't make sure that
the glock was in the exclusive state. Now, instead of calling file_accessed()
while holding the shared lock in gfs2_mmap(), file_accessed() is called after
grabbing and releasing the glock to update the inode.  If file_accessed() needs
to update the atime, it will grab an exclusive lock in gfs2_dirty_inode().

gfs2_dirty_inode() now also checks to make sure that if the calling process has
already locked the glock, it has an exclusive lock.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:42:49 +00:00
Andrew Price 73738a77f4 GFS2: Clean up some unused assignments
Cleans up two cases where variables were assigned values but then never
used again.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07 09:41:07 +00:00
Konstantin Khlebnikov 0b173bc4da mm: kill vma flag VM_CAN_NONLINEAR
Move actual pte filling for non-linear file mappings into the new special
vma operation: ->remap_pages().

Filesystems must implement this method to get non-linear mapping support,
if it uses filemap_fault() then generic_file_remap_pages() can be used.

Now device drivers can implement this method and obtain nonlinear vma support.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>	#arch/tile
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:17 +09:00
Steven Whitehouse 71f890f7f7 GFS2: Remove rs_requested field from reservations
The rs_requested field is left over from the original allocation
code, however this should have been a parameter passed to the
various functions from gfs2_inplace_reserve() and not a member of the
reservation structure as the value is not required after the
initial allocation.

This also helps simplify the code since we no longer need to set
the rs_requested to zero. Also the gfs2_inplace_release()
function can also be simplified since the reservation structure
will always be defined when it is called, and the only remaining
task is to unlock the rgrp if required. It can also now be
called unconditionally too, resulting in a further simplification.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24 10:46:54 +01:00
Steven Whitehouse da1dfb6af8 GFS2: Make write size hinting code common
This collects up the write size hinting code which is used by the
block reservation subsystem into a single function. At the same
time this also corrects the rounding for this calculation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-13 10:30:00 +01:00
Linus Torvalds a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00
Jan Kara 39263d5e71 gfs2: Convert to new freezing mechanism
We update gfs2_page_mkwrite() to use new freeze protection and the transaction
code to use freeze protection while the transaction is running. That is needed
to stop iput() of unlinked file from modifying the filesystem. The rest is
handled by the generic code.

CC: cluster-devel@redhat.com
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:45:50 +04:00
Jan Kara a63e9b2e76 gfs2: Push file_update_time() into gfs2_page_mkwrite()
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: cluster-devel@redhat.com
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 01:02:46 +04:00
Bob Peterson 15e1c96022 GFS2: Eliminate 64-bit divides
This patch removes the 64-bit divides introduced in the previous patch
in favor of shifting, so that it will compile properly on 32-bit machines.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-07-20 19:15:09 +01:00
Bob Peterson 8e2e004735 GFS2: Reduce file fragmentation
This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-07-19 14:51:08 +01:00
Steven Whitehouse 23d0bb834e GFS2: Add "top dir" flag support
This patch adds support for the "top dir" flag. Currently this is unused
but a subsequent patch is planned which will add support for the
Orlov allocation policy when allocating subdirectories in a parent
with this flag set.

In order to ensure backward compatible behaviour, mkfs.gfs2 does
not currently tag the root directory with this flag, it must always be
set manually.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06 11:27:36 +01:00
Bob Peterson 5407e24229 GFS2: Fold quota data into the reservations struct
This patch moves the ancillary quota data structures into the
block reservations structure. This saves GFS2 some time and
effort in allocating and deallocating the qadata structure.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06 11:20:22 +01:00
Bob Peterson 0a305e4960 GFS2: Extend the life of the reservations
This patch lengthens the lifespan of the reservations structure for
inodes. Before, they were allocated and deallocated for every write
operation. With this patch, they are allocated when the first write
occurs, and deallocated when the last process closes the file.
It's more efficient to do it this way because it saves GFS2 a lot of
unnecessary allocates and frees. It also gives us more flexibility
for the future: (1) we can now fold the qadata structure back into
the structure and save those alloc/frees, (2) we can use this for
multi-block reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06 11:17:59 +01:00
Bob Peterson df3fd117f9 GFS2: Rename function gfs2_close to gfs2_release
This patch renames function gfs2_close to gfs2_release.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:27 +01:00
Al Viro 2f99c36986 get rid of pointless includes of ext2_fs.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-31 16:03:15 -04:00
Benjamin Marzinski 58a7d5fb8e GFS2: call gfs2_write_alloc_required for each chunk
gfs2_fallocate was calling gfs2_write_alloc_required() once at the start of
the function. This caused problems since gfs2_write_alloc_required used a
long unsigned int for the len, but gfs2_fallocate could allocate a much
larger amount.  This patch will move the call into the loop where the
chunks are actually allocated and zeroed out. This will keep the allocation
size under the limit, and also allow gfs2_fallocate to quickly skip over
sections of the file that are already completely allocated.

fallcate_chunk was also not correctly setting the file size.  It was using the
len veriable to find the last block written to, but by the time it was setting
the size, the len variable had already been decremented to 0.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-03-09 15:29:10 +00:00
Steven Whitehouse 66fc061bda GFS2: FITRIM ioctl support
The FITRIM ioctl provides an alternative way to send discard requests to
the underlying device. Using the discard mount option results in every
freed block generating a discard request to the block device. This can
be slow, since many block devices can only process discard requests of
larger sizes, and also such operations can be time consuming.

Rather than using the discard mount option, FITRIM allows a sweep of the
filesystem on an occasional basis, and also to optionally avoid sending
down discard requests for smaller regions.

In GFS2 FITRIM will work at resource group granularity. There is a flag
for each resource group which keeps track of which resource groups have
been trimmed. This flag is reset whenever a deallocation occurs in the
resource group, and set whenever a successful FITRIM of that resource
group has taken place. This helps to reduce repeated discard requests
for the same block ranges, again improving performance.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 17:10:21 +00:00
Linus Torvalds 1619ed8f60 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: local functions should be static
  GFS2: We only need one ACL getting function
  GFS2: Fix multi-block allocation
  GFS2: decouple quota allocations from block allocations
  GFS2: split function rgblk_search
  GFS2: Fix up "off by one" in the previous patch
  GFS2: move toward a generic multi-block allocator
  GFS2: O_(D)SYNC support for fallocate
  GFS2: remove vestigial al_alloced
  GFS2: combine gfs2_alloc_block and gfs2_alloc_di
  GFS2: Add non-try locks back to get_local_rgrp
  GFS2: f_ra is always valid in dir readahead function
  GFS2: Fix very unlikley memory leak in ACL xattr code
  GFS2: More automated code analysis fixes
  GFS2: Add readahead to sequential directory traversal
  GFS2: Fix up REQ flags
2012-01-08 13:07:54 -08:00
Al Viro 2a79f17e4a vfs: mnt_drop_write_file()
new helper (wrapper around mnt_drop_write()) to be used in pair with
mnt_want_write_file().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:40 -05:00
Al Viro a561be7100 switch a bunch of places to mnt_want_write_file()
it's both faster (in case when file has been opened for write) and cleaner.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:35 -05:00
Bob Peterson 564e12b115 GFS2: decouple quota allocations from block allocations
This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-22 10:25:21 +00:00
Steven Whitehouse 4442f2e03e GFS2: O_(D)SYNC support for fallocate
Add sync of metadata after fallocate for O_SYNC files to ensure that we
meet expectations for everything being on disk in this case.
Unfortunately, the offset and len parameters are modified during the
course of the fallocate function, so I've had to add a couple of new
variables to call generic_write_sync() at the end.

I know that potentially this will sync data as well within the range,
but I think that is a fairly harmless side-effect overall, since we
would not normally expect there to be any dirty data within the range in
question.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
2011-11-21 10:01:25 +00:00
Steven Whitehouse 87654896ca GFS2: More automated code analysis fixes
A potentially uninitialised variable, some unreachable code,
and the main part of this, fixing the error path in the
unlink function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-08 14:04:20 +00:00
Bob Peterson dfe4d34b39 GFS2: Add readahead to sequential directory traversal
This patch adds read-ahead capability to GFS2's
directory hash table management.  It greatly improves
performance for some directory operations.  For example:
In one of my file systems that has 1000 directories, each
of which has 1000 files, time to execute a recursive
ls (time ls -fR /mnt/gfs2 > /dev/null) was reduced
from 2m2.814s on a stock kernel to 0m45.938s.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-08 09:52:12 +00:00
Linus Torvalds f362f98e7c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue: (21 commits)
  leases: fix write-open/read-lease race
  nfs: drop unnecessary locking in llseek
  ext4: replace cut'n'pasted llseek code with generic_file_llseek_size
  vfs: add generic_file_llseek_size
  vfs: do (nearly) lockless generic_file_llseek
  direct-io: merge direct_io_walker into __blockdev_direct_IO
  direct-io: inline the complete submission path
  direct-io: separate map_bh from dio
  direct-io: use a slab cache for struct dio
  direct-io: rearrange fields in dio/dio_submit to avoid holes
  direct-io: fix a wrong comment
  direct-io: separate fields only used in the submission path from struct dio
  vfs: fix spinning prevention in prune_icache_sb
  vfs: add a comment to inode_permission()
  vfs: pass all mask flags check_acl and posix_acl_permission
  vfs: add hex format for MAY_* flag values
  vfs: indicate that the permission functions take all the MAY_* flags
  compat: sync compat_stats with statfs.
  vfs: add "device" tag to /proc/self/mountstats
  cleanup: vfs: small comment fix for block_invalidatepage
  ...

Fix up trivial conflict in fs/gfs2/file.c (llseek changes)
2011-10-28 10:49:34 -07:00
Andi Kleen ef3d0fd27e vfs: do (nearly) lockless generic_file_llseek
The i_mutex lock use of generic _file_llseek hurts.  Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.

Under high utilization this can cause llseek to scale very poorly on larger
systems.

This patch does some rethinking of the llseek locking model:

First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.

Let's look at the different seek variants:

SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.

For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now.  The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.

=> Don't need a lock.

SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.

Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET.  On non atomic 32bit it's the same
as SEEK_SET.

=> Don't need a lock, but need to use i_size_read()

SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.

=> So still need a lock, but can use a f_lock.

This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-10-28 14:58:58 +02:00
Benjamin Marzinski 64dd153c83 GFS2: rewrite fallocate code to write blocks directly
GFS2's fallocate code currently goes through the page cache. Since it's only
writing to the end of the file or to holes in it, it doesn't need to, and it
was causing issues on low memory environments. This patch pulls in some of
Steve's block allocation work, and uses it to simply allocate the blocks for
the file, and zero them out at allocation time.  It provides a slight
performance increase, and it dramatically simplifies the code.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:49 +01:00
Steven Whitehouse 13d921e371 GFS2: Clean up ->page_mkwrite
This patch brings gfs2's ->page_mkwrite uptodate with respect to the
expectations set by the VM. Also added is a check to wait if the fs
is frozen, before we attempt to get a glock. This will only work on
the node which initiates the freeze, but thats ok since the transaction
lock will still provide the expected barrier on other nodes.

The major change here is that we return a locked page now, except when
we don't return a page at all (error cases). This removes the race
which required rechecking the page after it was returned.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Nick Piggin <npiggin@kernel.dk>
2011-10-21 12:39:44 +01:00
Steven Whitehouse b5b24d7aeb GFS2: Fix AIL flush issue during fsync
Unfortunately, it is not enough to just ignore locked buffers during
the AIL flush from fsync. We need to be able to ignore all buffers
which are locked, dirty or pinned at this stage as they might have
been added subsequent to the log flush earlier in the fsync function.

In addition, this means that we no longer need to rely on i_mutex to
keep out writes during fsync, so we can, as a side-effect, remove
that protection too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tested-By: Abhijith Das <adas@redhat.com>
2011-10-21 12:39:41 +01:00
Steven Whitehouse 54335b1fca GFS2: Cache the most recently used resource group in the inode
This means that after the initial allocation for any inode, the
last used resource group is cached in the inode for future use.
This drastically reduces the number of lookups of resource
groups in the common case, and this the contention on that
data structure.

The allocation algorithm is the same as previously, except that we
always check to see if the goal block is within the cached rgrp
first before going to the rbtree to look one up.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:34 +01:00
Steven Whitehouse 9453615a1a GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added
We need to take the inode's glock whenever the inode's size
is referenced, otherwise it might not be uptodate. Even
though generic_file_llseek_unlocked() doesn't implement
SEEK_DATA, SEEK_HOLE directly, it does reference the inode's
size in those cases, so we need to add them to the list
of origins which need the glock.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
2011-10-21 12:39:29 +01:00
Steven Whitehouse ab9bbda020 GFS2: Use ->dirty_inode()
The aim of this patch is to use the newly enhanced ->dirty_inode()
super block operation to deal with atime updates, rather than
piggy backing that code into ->write_inode() as is currently
done.

The net result is a simplification of the code in various places
and a reduction of the number of gfs2_dinode_out() calls since
this is now implied by ->dirty_inode().

Some of the mark_inode_dirty() calls have been moved under glocks
in order to take advantage of then being able to avoid locking in
->dirty_inode() when we already have suitable locks.

One consequence is that generic_write_end() now correctly deals
with file size updates, so that we do not need a separate check
for that afterwards. This also, indirectly, means that fdatasync
should work correctly on GFS2 - the current code always syncs the
metadata whether it needs to or not.

Has survived testing with postmark (with and without atime) and
also fsx.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:26 +01:00
Steven Whitehouse f18185291d GFS2: Fix bug trap and journaled data fsync
Journaled data requires that a complete flush of all dirty data for
the file is done, in order that the ail flush which comes after
will succeed.

Also the recently enhanced bug trap can trigger falsely in case
an ail flush from fsync races with a page read. This updates the
bug trap such that it will ignore buffers which are locked and
only trigger on dirty and/or pinned buffers when the ail flush
is run from fsync. The original bug trap is retained when ail
flush is run from ->go_sync()

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:25 +01:00
Steven Whitehouse 2f0264d592 GFS2: Split data write & wait in fsync
Now that the data writing is part of fsync proper, we can split
the waiting part out and do it later on. This reduces the
number of waits that we do during fsync on average.

There is also no need to take the i_mutex unless we are flushing
metadata to disk, so we can move that to within the metadata
flushing code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:18 +01:00
Linus Torvalds bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Josef Bacik 02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
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>
2011-07-20 20:47:59 -04:00
Al Viro 10556cb21a ->permission() sanitizing: don't pass flags to ->permission()
not used by the instances anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:24 -04:00
Steven Whitehouse 9964afbb79 GFS2: Add S_NOSEC support
This adds S_NOSEC support to GFS2. We set/reset the flag either when
a user calls setattr or when we have just regained the glock
from another node. The flag is only set if there are no xattrs
on the inode and there is no suid bit set.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2011-07-15 09:32:35 +01:00
Benjamin Marzinski 6905d9e4dd GFS2: make sure fallocate bytes is a multiple of blksize
The GFS2 fallocate code chooses a target size to for allocating chunks of
space.  Whenever it can't find any resource groups with enough space free, it
halves its target. Since this target is in bytes, eventually it will no longer
be a multiple of blksize.  As long as there is more space available in the
resource group than the target, this isn't a problem, since gfs2 will use the
actual space available, which is always a multiple of blksize.  However,
when gfs couldn't fallocate a bigger chunk than the target, it was using the
non-blksize aligned number. This caused a BUG in later code that required
blksize aligned offsets.  GFS2 now ensures that bytes is always a multiple of
blksize

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-03 11:47:42 +01:00
Steven Whitehouse dba898b02d GFS2: Clean up fsync()
This patch is designed to clean up GFS2's fsync
implementation and ensure that it really does get everything on
disk. Since ->write_inode() has been updated, we can call that
via the vfs library function sync_inode_metadata() and the only
remaining thing that has to be done is to ensure that we get
any revoke records in the log after the inode has been written back.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20 09:00:41 +01:00
Benjamin Marzinski 0ee532062f GFS2: directly write blocks past i_size
GFS2 was relying on the writepage code to write out the zeroed data for
fallocate.  However, with FALLOC_FL_KEEP_SIZE set, this may be past i_size.
If it is, it will be ignored.  To work around this, gfs2 now calls
write_dirty_buffer directly on the buffer_heads when FALLOC_FL_KEEP_SIZE
is set, and it's writing past i_size.

This version is just a cleanup of my last version

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-18 15:22:52 +01:00
Serge E. Hallyn 2e14967075 userns: rename is_owner_or_cap to inode_owner_or_capable
And give it a kernel-doc comment.

[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:47:13 -07:00
Benjamin Marzinski e4a7b7b0c9 GFS2: fix block allocation check for fallocate
GFS2 fallocate wasn't properly checking if a blocks were already allocated.
In write_empty_blocks(), if a page didn't have buffer_heads attached, GFS2
was always treating it as if there were no blocks allocated for that page.
GFS2 now calls gfs2_block_map() to check if the blocks are allocated before
writing them out.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-11 09:26:48 +00:00
Steven Whitehouse 0a33443b38 GFS2: Remove potential race in flock code
This patch ensures that we always wait for glock demotion when
dropping flocks on a file in order to prevent any race
conditions associated with further flock calls or closing
the file.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-09 11:14:32 +00:00