Commit graph

235 commits

Author SHA1 Message Date
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
5d37e9e6de fs: Skip atime update on frozen filesystem
It is unexpected to block reading of frozen filesystem because of atime update.
Also handling blocking on frozen filesystem because of atime update would make
locking more complex than it already is. So just skip atime update when
filesystem is frozen like we skip it when filesystem is remounted read-only.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:45:38 +04:00
Jan Kara
eb04c28288 fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
Most of places where we want freeze protection coincides with the places where
we also have remount-ro protection. So make mnt_want_write() and
mnt_drop_write() (and their _file alternative) prevent freezing as well.
For the few cases that are really interested only in remount-ro protection
provide new function variants.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:40:38 +04:00
Linus Torvalds
e2aed8dfa5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull large btrfs update from Chris Mason:
 "This pull request is very large, and the two main features in here
  have been under testing/devel for quite a while.

  We have subvolume quotas from the strato developers.  This enables
  full tracking of how many blocks are allocated to each subvolume (and
  all snapshots) and you can set limits on a per-subvolume basis.  You
  can also create quota groups and toss multiple subvolumes into a big
  group.  It's everything you need to be a web hosting company and give
  each user their own subvolume.

  The userland side of the quotas is being refreshed, they'll send out
  details on where to grab it soon.

  Next is the kernel side of btrfs send/receive from Alexander Block.
  This leverages the same infrastructure as the quota code to figure out
  relationships between blocks and their owners.  It can then compute
  the difference between two snapshots and sends the diffs in a neutral
  format into userland.

  The basic model:

        create a snapshot
        send that snapshot as the initial backup
        make changes
        create a second snapshot
        send the incremental as a backup
        delete the first snapshot
        (use the second snapshot for the next incremental)

  The receive portion is all in userland, and in the 'next' branch of my
  btrfs-progs repo.

  There's still some work to do in terms of optimizing the send side
  from kernel to userland.  The really important part is figuring out
  how two snapshots are different, and this is where we are
  concentrating right now.  The initial send of a dataset is a little
  slower than tar, but the incremental sends are dramatically faster
  than what rsync can do.

  On top of all of that, we have a nice queue of fixes, cleanups and
  optimizations."

Fix up trivial modify/del conflict in fs/btrfs/ioctl.c

Also fix up semantic conflict in fs/btrfs/send.c: the interface to
dentry_open() changed in commit 765927b2d5 ("switch dentry_open() to
struct path, make it grab references itself"), and since it now grabs
whatever references it needs, we should no longer do the mntget() on the
mnt (and we need to dput() the dentry reference we took).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (65 commits)
  Btrfs: uninit variable fixes in send/receive
  Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive
  Btrfs: add btrfs_compare_trees function
  Btrfs: introduce subvol uuids and times
  Btrfs: make iref_to_path non static
  Btrfs: add a barrier before a waitqueue_active check
  Btrfs: call the ordered free operation without any locks held
  Btrfs: Check INCOMPAT flags on remount and add helper function
  Btrfs: add helper for tree enumeration
  btrfs: allow cross-subvolume file clone
  Btrfs: improve multi-thread buffer read
  Btrfs: make btrfs's allocation smoothly with preallocation
  Btrfs: lock the transition from dirty to writeback for an eb
  Btrfs: fix potential race in extent buffer freeing
  Btrfs: don't return true in releasepage unless we actually freed the eb
  Btrfs: suppress printk() if all device I/O stats are zero
  Btrfs: remove unwanted printk() for btrfs device I/O stats
  Btrfs: rewrite BTRFS_SETGET_FUNCS
  Btrfs: zero unused bytes in inode item
  Btrfs: kill free_space pointer from inode structure
  ...

Conflicts:
	fs/btrfs/ioctl.c
2012-07-26 14:48:55 -07:00
Alexander Block
2bc5565286 Btrfs: don't update atime on RO subvolumes
Before the update_time inode operation was indroduced, it was
not possible to prevent updates of atime on RO subvolumes. VFS
was only able to check for RO on the mount, but did not know
anything about btrfs subvolumes.

btrfs_update_time does now check if the root is RO and skip
updating of times.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-07-23 15:41:38 -04:00
Al Viro
b3d9b7a3c7 vfs: switch i_dentry/d_alias to hlist
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:32:55 +04:00
Linus Torvalds
1193755ac6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs changes from Al Viro.
 "A lot of misc stuff.  The obvious groups:
   * Miklos' atomic_open series; kills the damn abuse of
     ->d_revalidate() by NFS, which was the major stumbling block for
     all work in that area.
   * ripping security_file_mmap() and dealing with deadlocks in the
     area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
     general.
   * ->encode_fh() switched to saner API; insane fake dentry in
     mm/cleancache.c gone.
   * assorted annotations in fs (endianness, __user)
   * parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
   * ->update_time() work from Josef.
   * other bits and pieces all over the place.

  Normally it would've been in two or three pull requests, but
  signal.git stuff had eaten a lot of time during this cycle ;-/"

Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
  nfs: don't open in ->d_revalidate
  vfs: retry last component if opening stale dentry
  vfs: nameidata_to_filp(): don't throw away file on error
  vfs: nameidata_to_filp(): inline __dentry_open()
  vfs: do_dentry_open(): don't put filp
  vfs: split __dentry_open()
  vfs: do_last() common post lookup
  vfs: do_last(): add audit_inode before open
  vfs: do_last(): only return EISDIR for O_CREAT
  vfs: do_last(): check LOOKUP_DIRECTORY
  vfs: do_last(): make ENOENT exit RCU safe
  vfs: make follow_link check RCU safe
  vfs: do_last(): use inode variable
  vfs: do_last(): inline walk_component()
  vfs: do_last(): make exit RCU safe
  vfs: split do_lookup()
  Btrfs: move over to use ->update_time
  fs: introduce inode operation ->update_time
  reiserfs: get rid of resierfs_sync_super
  reiserfs: mark the superblock as dirty a bit later
  ...
2012-06-01 10:34:35 -07:00
Josef Bacik
c3b2da3148 fs: introduce inode operation ->update_time
Btrfs has to make sure we have space to allocate new blocks in order to modify
the inode, so updating time can fail.  We've gotten around this by having our
own file_update_time but this is kind of a pain, and Christoph has indicated he
would like to make xfs do something different with atime updates.  So introduce
->update_time, where we will deal with i_version an a/m/c time updates and
indicate which changes need to be made.  The normal version just does what it
has always done, updates the time and marks the inode dirty, and then
filesystems can choose to do something different.

I've gone through all of the users of file_update_time and made them check for
errors with the exception of the fault code since it's complicated and I wasn't
quite sure what to do there, also Jan is going to be pushing the file time
updates into page_mkwrite for those who have it so that should satisfy btrfs and
make it not a big deal to check the file_update_time() return code in the
generic fault path. Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-01 12:07:25 -04:00
Trond Myklebust
1d59d61f60 NFS: Ensure that setattr and getattr wait for O_DIRECT write completion
Use the same mechanism as the block devices are using, but move the
helper functions from fs/direct-io.c into fs/inode.c to remove the
dependency on CONFIG_BLOCK.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 11:41:36 -07:00
Cong Wang
3ed37648e1 fs: move file_remove_suid() to fs/inode.c
file_remove_suid() is a generic function operates on struct file,
it almost has no relations with file mapping, so move it to fs/inode.c.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-30 21:04:52 -04:00
Randy Dunlap
185553b224 fs: fix inode.c kernel-doc warnings
Fix kernel-doc warnings in fs/inode.c:

Warning(fs/inode.c:1493): No description found for parameter 'path'
Warning(fs/inode.c:1493): Excess function parameter 'mnt' description in 'touch_atime'
Warning(fs/inode.c:1493): Excess function parameter 'dentry' description in 'touch_atime'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29 23:28:36 -04:00
Linus Torvalds
90324cc1b1 avoid iput() from flusher thread
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Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback tree from Wu Fengguang:
 "Mainly from Jan Kara to avoid iput() in the flusher threads."

* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Avoid iput() from flusher thread
  vfs: Rename end_writeback() to clear_inode()
  vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
  writeback: Refactor writeback_single_inode()
  writeback: Remove wb->list_lock from writeback_single_inode()
  writeback: Separate inode requeueing after writeback
  writeback: Move I_DIRTY_PAGES handling
  writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
  writeback: Move clearing of I_SYNC into inode_sync_complete()
  writeback: initialize global_dirty_limit
  fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
  mm: page-writeback.c: local functions should not be exposed globally
2012-05-28 09:54:45 -07:00
Linus Torvalds
28f3d71761 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull more networking updates from David Miller:
 "Ok, everything from here on out will be bug fixes."

1) One final sync of wireless and bluetooth stuff from John Linville.
   These changes have all been in his tree for more than a week, and
   therefore have had the necessary -next exposure.  John was just away
   on a trip and didn't have a change to send the pull request until a
   day or two ago.

2) Put back some defines in user exposed header file areas that were
   removed during the tokenring purge.  From Stephen Hemminger and Paul
   Gortmaker.

3) A bug fix for UDP hash table allocation got lost in the pile due to
   one of those "you got it..  no I've got it.." situations.  :-)

   From Tim Bird.

4) SKB coalescing in TCP needs to have stricter checks, otherwise we'll
   try to coalesce overlapping frags and crash.  Fix from Eric Dumazet.

5) RCU routing table lookups can race with free_fib_info(), causing
   crashes when we deref the device pointers in the route.  Fix by
   releasing the net device in the RCU callback.  From Yanmin Zhang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (293 commits)
  tcp: take care of overlaps in tcp_try_coalesce()
  ipv4: fix the rcu race between free_fib_info and ip_route_output_slow
  mm: add a low limit to alloc_large_system_hash
  ipx: restore token ring define to include/linux/ipx.h
  if: restore token ring ARP type to header
  xen: do not disable netfront in dom0
  phy/micrel: Fix ID of KSZ9021
  mISDN: Add X-Tensions USB ISDN TA XC-525
  gianfar:don't add FCB length to hard_header_len
  Bluetooth: Report proper error number in disconnection
  Bluetooth: Create flags for bt_sk()
  Bluetooth: report the right security level in getsockopt
  Bluetooth: Lock the L2CAP channel when sending
  Bluetooth: Restore locking semantics when looking up L2CAP channels
  Bluetooth: Fix a redundant and problematic incoming MTU check
  Bluetooth: Add support for Foxconn/Hon Hai AR5BBU22 0489:E03C
  Bluetooth: Fix EIR data generation for mgmt_device_found
  Bluetooth: Fix Inquiry with RSSI event mask
  Bluetooth: improve readability of l2cap_seq_list code
  Bluetooth: Fix skb length calculation
  ...
2012-05-24 11:54:29 -07:00
Tim Bird
31fe62b958 mm: add a low limit to alloc_large_system_hash
UDP stack needs a minimum hash size value for proper operation and also
uses alloc_large_system_hash() for proper NUMA distribution of its hash
tables and automatic sizing depending on available system memory.

On some low memory situations, udp_table_init() must ignore the
alloc_large_system_hash() result and reallocs a bigger memory area.

As we cannot easily free old hash table, we leak it and kmemleak can
issue a warning.

This patch adds a low limit parameter to alloc_large_system_hash() to
solve this problem.

We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table
allocation.

Reported-by: Mark Asselstine <mark.asselstine@windriver.com>
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 00:28:21 -04:00
Jan Kara
169ebd9013 writeback: Avoid iput() from flusher thread
Doing iput() from flusher thread (writeback_sb_inodes()) can create problems
because iput() can do a lot of work - for example truncate the inode if it's
the last iput on unlinked file. Some filesystems depend on flusher thread
progressing (e.g. because they need to flush delay allocated blocks to reduce
allocation uncertainty) and so flusher thread doing truncate creates
interesting dependencies and possibilities for deadlocks.

We get rid of iput() in flusher thread by using the fact that I_SYNC inode
flag effectively pins the inode in memory. So if we take care to either hold
i_lock or have I_SYNC set, we can get away without taking inode reference
in writeback_sb_inodes().

As a side effect of these changes, we also fix possible use-after-free in
wb_writeback() because inode_wait_for_writeback() call could try to reacquire
i_lock on the inode that was already free.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:41 +08:00
Jan Kara
dbd5768f87 vfs: Rename end_writeback() to clear_inode()
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:41 +08:00
Jan Kara
7994e6f725 vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
Currently, I_SYNC can never be set when evict_inode() (and thus
end_writeback()) is called because flusher thread holds inode reference while
inode is under writeback. As a result inode_sync_wait() in those places
currently does nothing. However that is going to change and unveils problems
with calling inode_sync_wait() from end_writeback(). Several filesystems call
end_writeback() after they have deleted the inode (btrfs, gfs2, ...) and other
filesystems (ext3, ext4, reiserfs, ...) can deadlock when waiting for I_SYNC
because they call end_writeback() from within a transaction.

To avoid these issues, we move inode_sync_wait() into evict_inode() before
calling ->evict_inode(). That way we preserve the current property that
->evict_inode() and writeback never run in parallel and all filesystems are
safe.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:40 +08:00
Eric W. Biederman
92361636e0 userns: Store uid and gid types in vfs structures with kuid_t and kgid_t types
The conversion of all of the users is not done yet there are too many to change
in one go and leave the code reviewable. For now I change just the header and
a few trivial users and rely on CONFIG_UIDGID_STRICT_TYPE_CHECKS not being set
to ensure that the code will still compile during the transition.

Helper functions i_uid_read, i_uid_write, i_gid_read, i_gid_write are added
so that in most cases filesystems can avoid the complexities of multiple user
namespaces and can concentrate on moving their raw numeric values into and
out of the vfs data structures.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03 03:29:32 -07:00
Eric W. Biederman
1a48e2ac03 userns: Replace the hard to write inode_userns with inode_capable.
This represents a change in strategy of how to handle user namespaces.
Instead of tagging everything explicitly with a user namespace and bulking
up all of the comparisons of uids and gids in the kernel,  all uids and gids
in use will have a mapping to a flat kuid and kgid spaces respectively.  This
allows much more of the existing logic to be preserved and in general
allows for faster code.

In this new and improved world we allow someone to utiliize capabilities
over an inode if the inodes owner mapps into the capabilities holders user
namespace and the user has capabilities in their user namespace.  Which
is simple and efficient.

Moving the fs uid comparisons to be comparisons in a flat kuid space
follows in later patches, something that is only significant if you
are using user namespaces.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07 17:02:46 -07:00
Al Viro
e59cc473cc trim includes in inode.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:51 -04:00
Al Viro
68ac1234fb switch touch_atime to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:41 -04:00
Al Viro
9bcb4b733c vfs: turn generic_drop_inode() into static inline
Once upon a time it used to be much bigger, but these days there's
no point whatsoever keeping it in fs/inode.c, especially since
it's not even needed as initializer for ->drop_inode() - it's the
default and leaving ->drop_inode NULL will do just as well.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:33 -04:00
Al Viro
310fa7a367 restore smp_mb() in unlock_new_inode()
wait_on_inode() doesn't have ->i_lock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-10 17:07:28 -05:00
Tyler Hicks
978d6d8c45 vfs: Correctly set the dir i_mutex lockdep class
9a7aa12f39 introduced additional logic around setting the i_mutex
lockdep class for directory inodes. The idea was that some filesystems
may want their own special lockdep class for different directory
inodes and calling unlock_new_inode() should not clobber one of
those special classes.

I believe that the added conditional, around the *negated* return value
of lockdep_match_class(), caused directory inodes to be placed in the
wrong lockdep class.

inode_init_always() sets the i_mutex lockdep class with i_mutex_key for
all inodes. If the filesystem did not change the class during inode
initialization, then the conditional mentioned above was false and the
directory inode was incorrectly left in the non-directory lockdep class.
If the filesystem did set a special lockdep class, then the conditional
mentioned above was true and that class was clobbered with
i_mutex_dir_key.

This patch removes the negation from the conditional so that the i_mutex
lockdep class is properly set for directory inodes. Special classes are
preserved and directory inodes with unmodified classes are set with
i_mutex_dir_key.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-10 16:05:38 -05:00
Dimitri Sivanich
074b85175a vfs: fix panic in __d_lookup() with high dentry hashtable counts
When the number of dentry cache hash table entries gets too high
(2147483648 entries), as happens by default on a 16TB system, use of a
signed integer in the dcache_init() initialization loop prevents the
dentry_hashtable from getting initialized, causing a panic in
__d_lookup().  Fix this in dcache_init() and similar areas.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-13 20:45:38 -05:00
Miklos Szeredi
424a5334a5 vfs: remove printk from set_nlink()
Don't log a message for set_nlink(0).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-17 16:39:47 -05:00
Konstantin Khlebnikov
5f8aefd44e mm: account reaped page cache on inode cache pruning
Inode cache pruning indirectly reclaims page-cache by invalidating mapping
pages.  Let's account them into reclaim-state to notice this progress in
memory reclaimer.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 16:30:42 -08:00
Miklos Szeredi
7ada4db886 vfs: count unlinked inodes
Add a new counter to the superblock that keeps track of unlinked but
not yet deleted inodes.

Do not WARN_ON if set_nlink is called with zero count, just do a
ratelimited printk.  This happens on xfs and probably other
filesystems after an unclean shutdown when the filesystem reads inodes
which already have zero i_nlink.  Reported by Christoph Hellwig.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06 23:20:12 -05:00
Al Viro
62bb109170 switch inode_init_owner() to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:55:11 -05:00
Al Viro
6b520e0565 vfs: fix the stupidity with i_dentry in inode destructors
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else.  Not to mention the removal of
boilerplate code from ->destroy_inode() instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:40 -05:00
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
Miklos Szeredi
a78ef704a8 vfs: protect i_nlink
Prevent direct modification of i_nlink by making it const and adding a
non-const __i_nlink alias.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-11-02 12:53:43 +01:00
Christoph Hellwig
62a3ddef61 vfs: fix spinning prevention in prune_icache_sb
We need to move the inode to the end of the list to actually make the
spinning prevention explained in the comment above it work.  With a
plain list_move it will simply stay in place as we're always reclaiming
from the head of the list.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-10-28 14:58:55 +02:00
Josh Boyer
e096d0c7e2 lockdep: Add helper function for dir vs file i_mutex annotation
Purely in-memory filesystems do not use the inode hash as the dcache
tells us if an entry already exists.  As a result, they do not call
unlock_new_inode, and thus directory inodes do not get put into a
different lockdep class for i_sem.

We need the different lockdep classes, because the locking order for
i_mutex is different for directory inodes and regular inodes.  Directory
inodes can do "readdir()", which takes i_mutex *before* possibly taking
mm->mmap_sem (due to a page fault while copying the directory entry to
user space).

In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem
before accessing i_mutex.

The two cases can never happen for the same inode, so no real deadlock
can occur, but without the different lockdep classes, lockdep cannot
understand that.  As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this
can lead to false positives from lockdep like below:

    find/645 is trying to acquire lock:
     (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac

    but task is already holding lock:
     (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>]
    vfs_readdir+0x5b/0xb4

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}:
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361
          [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45
          [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110
          [<ffffffff81111557>] mmap_region+0x258/0x432
          [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306
          [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a
          [<ffffffff8100c858>] sys_mmap+0x22/0x24
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

    -> #0 (&mm->mmap_sem){++++++}:
          [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff81109541>] might_fault+0x89/0xac
          [<ffffffff81149cff>] filldir+0x6f/0xc7
          [<ffffffff811586ea>] dcache_readdir+0x67/0x205
          [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4
          [<ffffffff8114a073>] sys_getdents+0x7e/0xd1
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

This patch moves the directory vs file lockdep annotation into a helper
function that can be called by in-memory filesystems and has hugetlbfs
call it.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25 10:50:18 -07:00
Linus Torvalds
3ddcd0569c vfs: optimize inode cache access patterns
The inode structure layout is largely random, and some of the vfs paths
really do care.  The path lookup in particular is already quite D$
intensive, and profiles show that accessing the 'inode->i_op->xyz'
fields is quite costly.

We already optimized the dcache to not unnecessarily load the d_op
structure for members that are often NULL using the DCACHE_OP_xyz bits
in dentry->d_flags, and this does something very similar for the inode
ops that are used during pathname lookup.

It also re-orders the fields so that the fields accessed by 'stat' are
together at the beginning of the inode structure, and roughly in the
order accessed.

The effect of this seems to be in the 1-2% range for an empty kernel
"make -j" run (which is fairly kernel-intensive, mostly in filename
lookup), so it's visible.  The numbers are fairly noisy, though, and
likely depend a lot on exact microarchitecture.  So there's more tuning
to be done.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-06 22:53:23 -07:00
Eric Dumazet
c4ae0c6545 vfs: avoid call to inode_lru_list_del() if possible
inode_lru_list_del() is expensive because of per superblock lru locking,
while some inodes are not in lru list.

Adding a check in iput_final() can speedup pipe/sockets workloads on
SMP.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-08-01 01:41:17 -04:00
Eric Dumazet
f2ee7abf4c vfs: avoid taking inode_hash_lock on pipes and sockets
Some inodes (pipes, sockets, ...) are not hashed, no need to take
contended inode_hash_lock at dismantle time.

nice speedup on SMP machines on socket intensive workloads.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-08-01 01:41:17 -04:00
Eric Dumazet
b12362bdb6 vfs: conditionally call inode_wb_list_del()
Some inodes (pipes, sockets, ...) are not in bdi writeback list.

evict() can avoid calling inode_wb_list_del() and its expensive spinlock
by checking inode i_wb_list being empty or not.

At this point, no other cpu/user can concurrently manipulate this inode
i_wb_list

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-08-01 01:41:17 -04:00
Linus Torvalds
e371d46ae4 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:
  merge fchmod() and fchmodat() guts, kill ancient broken kludge
  xfs: fix misspelled S_IS...()
  xfs: get rid of open-coded S_ISREG(), etc.
  vfs: document locking requirements for d_move, __d_move and d_materialise_unique
  omfs: fix (mode & S_IFDIR) abuse
  btrfs: S_ISREG(mode) is not mode & S_IFREG...
  ima: fmode_t misspelled as mode_t...
  pci-label.c: size_t misspelled as mode_t
  jffs2: S_ISLNK(mode & S_IFMT) is pointless
  snd_msnd ->mode is fmode_t, not mode_t
  v9fs_iop_get_acl: get rid of unused variable
  vfs: dont chain pipe/anon/socket on superblock s_inodes list
  Documentation: Exporting: update description of d_splice_alias
  fs: add missing unlock in default_llseek()
2011-07-26 18:30:20 -07:00
Linus Torvalds
f01ef569cd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: (27 commits)
  mm: properly reflect task dirty limits in dirty_exceeded logic
  writeback: don't busy retry writeback on new/freeing inodes
  writeback: scale IO chunk size up to half device bandwidth
  writeback: trace global_dirty_state
  writeback: introduce max-pause and pass-good dirty limits
  writeback: introduce smoothed global dirty limit
  writeback: consolidate variable names in balance_dirty_pages()
  writeback: show bdi write bandwidth in debugfs
  writeback: bdi write bandwidth estimation
  writeback: account per-bdi accumulated written pages
  writeback: make writeback_control.nr_to_write straight
  writeback: skip tmpfs early in balance_dirty_pages_ratelimited_nr()
  writeback: trace event writeback_queue_io
  writeback: trace event writeback_single_inode
  writeback: remove .nonblocking and .encountered_congestion
  writeback: remove writeback_control.more_io
  writeback: skip balance_dirty_pages() for in-memory fs
  writeback: add bdi_dirty_limit() kernel-doc
  writeback: avoid extra sync work at enqueue time
  writeback: elevate queue_io() into wb_writeback()
  ...

Fix up trivial conflicts in fs/fs-writeback.c and mm/filemap.c
2011-07-26 10:39:54 -07:00
Eric Dumazet
a209dfc7b0 vfs: dont chain pipe/anon/socket on superblock s_inodes list
Workloads using pipes and sockets hit inode_sb_list_lock contention.

superblock s_inodes list is needed for quota, dirty, pagecache and
fsnotify management. pipe/anon/socket fs are clearly not candidates for
these.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-26 12:57:09 -04:00
Christoph Hellwig
bd5fe6c5eb fs: kill i_alloc_sem
i_alloc_sem is a rather special rw_semaphore.  It's the last one that may
be released by a non-owner, and it's write side is always mirrored by
real exclusion.  It's intended use it to wait for all pending direct I/O
requests to finish before starting a truncate.

Replace it with a hand-grown construct:

 - exclusion for truncates is already guaranteed by i_mutex, so it can
   simply fall way
 - the reader side is replaced by an i_dio_count member in struct inode
   that counts the number of pending direct I/O requests.  Truncate can't
   proceed as long as it's non-zero
 - when i_dio_count reaches non-zero we wake up a pending truncate using
   wake_up_bit on a new bit in i_flags
 - new references to i_dio_count can't appear while we are waiting for
   it to read zero because the direct I/O count always needs i_mutex
   (or an equivalent like XFS's i_iolock) for starting a new operation.

This scheme is much simpler, and saves the space of a spinlock_t and a
struct list_head in struct inode (typically 160 bits on a non-debug 64-bit
system).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:46 -04:00
Dave Chinner
4f8c19fdf3 inode: remove iprune_sem
Now that we have per-sb shrinkers with a lifecycle that is a subset
of the superblock lifecycle and can reliably detect a filesystem
being unmounted, there is not longer any race condition for the
iprune_sem to protect against. Hence we can remove it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:40 -04:00
Dave Chinner
b0d40c92ad superblock: introduce per-sb cache shrinker infrastructure
With context based shrinkers, we can implement a per-superblock
shrinker that shrinks the caches attached to the superblock. We
currently have global shrinkers for the inode and dentry caches that
split up into per-superblock operations via a coarse proportioning
method that does not batch very well.  The global shrinkers also
have a dependency - dentries pin inodes - so we have to be very
careful about how we register the global shrinkers so that the
implicit call order is always correct.

With a per-sb shrinker callout, we can encode this dependency
directly into the per-sb shrinker, hence avoiding the need for
strictly ordering shrinker registrations. We also have no need for
any proportioning code for the shrinker subsystem already provides
this functionality across all shrinkers. Allowing the shrinker to
operate on a single superblock at a time means that we do less
superblock list traversals and locking and reclaim should batch more
effectively. This should result in less CPU overhead for reclaim and
potentially faster reclaim of items from each filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:10 -04:00
Dave Chinner
09cc9fc7a7 inode: move to per-sb LRU locks
With the inode LRUs moving to per-sb structures, there is no longer
a need for a global inode_lru_lock. The locking can be made more
fine-grained by moving to a per-sb LRU lock, isolating the LRU
operations of different filesytsems completely from each other.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:36 -04:00
Dave Chinner
98b745c647 inode: Make unused inode LRU per superblock
The inode unused list is currently a global LRU. This does not match
the other global filesystem cache - the dentry cache - which uses
per-superblock LRU lists. Hence we have related filesystem object
types using different LRU reclaimation schemes.

To enable a per-superblock filesystem cache shrinker, both of these
caches need to have per-sb unused object LRU lists. Hence this patch
converts the global inode LRU to per-sb LRUs.

The patch only does rudimentary per-sb propotioning in the shrinker
infrastructure, as this gets removed when the per-sb shrinker
callouts are introduced later on.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:35 -04:00
Dave Chinner
fcb94f72d3 inode: convert inode_stat.nr_unused to per-cpu counters
Before we split up the inode_lru_lock, the unused inode counter
needs to be made independent of the global inode_lru_lock. Convert
it to per-cpu counters to do this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:34 -04:00
Al Viro
e7f5909707 kill useless checks for sb->s_op == NULL
never is...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:21 -04:00
Jan Kara
08142579b6 mm: fix assertion mapping->nrpages == 0 in end_writeback()
Under heavy memory and filesystem load, users observe the assertion
mapping->nrpages == 0 in end_writeback() trigger.  This can be caused by
page reclaim reclaiming the last page from a mapping in the following
race:

	CPU0				CPU1
  ...
  shrink_page_list()
    __remove_mapping()
      __delete_from_page_cache()
        radix_tree_delete()
					evict_inode()
					  truncate_inode_pages()
					    truncate_inode_pages_range()
					      pagevec_lookup() - finds nothing
					  end_writeback()
					    mapping->nrpages != 0 -> BUG
        page->mapping = NULL
        mapping->nrpages--

Fix the problem by doing a reliable check of mapping->nrpages under
mapping->tree_lock in end_writeback().

Analyzed by Jay <jinshan.xiong@whamcloud.com>, lost in LKML, and dug out
by Miklos Szeredi <mszeredi@suse.de>.

Cc: Jay <jinshan.xiong@whamcloud.com>
Cc: Miklos Szeredi <mszeredi@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 18:00:13 -07:00
Christoph Hellwig
f758eeabeb writeback: split inode_wb_list_lock into bdi_writeback.list_lock
Split the global inode_wb_list_lock into a per-bdi_writeback list_lock,
as it's currently the most contended lock in the system for metadata
heavy workloads.  It won't help for single-filesystem workloads for
which we'll need the I/O-less balance_dirty_pages, but at least we
can dedicate a cpu to spinning on each bdi now for larger systems.

Based on earlier patches from Nick Piggin and Dave Chinner.

It reduces lock contentions to 1/4 in this test case:
10 HDD JBOD, 100 dd on each disk, XFS, 6GB ram

lock_stat version 0.3
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                              class name    con-bounces    contentions   waittime-min   waittime-max waittime-total    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
vanilla 2.6.39-rc3:
                      inode_wb_list_lock:         42590          44433           0.12         147.74      144127.35         252274         886792           0.08         121.34      917211.23
                      ------------------
                      inode_wb_list_lock              2          [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85
                      inode_wb_list_lock             34          [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49
                      inode_wb_list_lock          12893          [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0
                      inode_wb_list_lock          10702          [<ffffffff8115afef>] writeback_single_inode+0x16d/0x20a
                      ------------------
                      inode_wb_list_lock              2          [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85
                      inode_wb_list_lock             19          [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49
                      inode_wb_list_lock           5550          [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0
                      inode_wb_list_lock           8511          [<ffffffff8115b4ad>] writeback_sb_inodes+0x10f/0x157

2.6.39-rc3 + patch:
                &(&wb->list_lock)->rlock:         11383          11657           0.14         151.69       40429.51          90825         527918           0.11         145.90      556843.37
                ------------------------
                &(&wb->list_lock)->rlock             10          [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86
                &(&wb->list_lock)->rlock           1493          [<ffffffff8115b1ed>] writeback_inodes_wb+0x3d/0x150
                &(&wb->list_lock)->rlock           3652          [<ffffffff8115a8e9>] writeback_sb_inodes+0x123/0x16f
                &(&wb->list_lock)->rlock           1412          [<ffffffff8115a38e>] writeback_single_inode+0x17f/0x223
                ------------------------
                &(&wb->list_lock)->rlock              3          [<ffffffff8110b5af>] bdi_lock_two+0x46/0x4b
                &(&wb->list_lock)->rlock              6          [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86
                &(&wb->list_lock)->rlock           2061          [<ffffffff8115af97>] __mark_inode_dirty+0x173/0x1cf
                &(&wb->list_lock)->rlock           2629          [<ffffffff8115a8e9>] writeback_sb_inodes+0x123/0x16f

hughd@google.com: fix recursive lock when bdi_lock_two() is called with new the same as old
akpm@linux-foundation.org: cleanup bdev_inode_switch_bdi() comment

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:21 +08:00