1. 15 5月, 2012 1 次提交
  2. 21 3月, 2012 1 次提交
  3. 08 7月, 2011 1 次提交
    • D
      FS-Cache: Add a helper to bulk uncache pages on an inode · c902ce1b
      David Howells 提交于
      Add an FS-Cache helper to bulk uncache pages on an inode.  This will
      only work for the circumstance where the pages in the cache correspond
      1:1 with the pages attached to an inode's page cache.
      
      This is required for CIFS and NFS: When disabling inode cookie, we were
      returning the cookie and setting cifsi->fscache to NULL but failed to
      invalidate any previously mapped pages.  This resulted in "Bad page
      state" errors and manifested in other kind of errors when running
      fsstress.  Fix it by uncaching mapped pages when we disable the inode
      cookie.
      
      This patch should fix the following oops and "Bad page state" errors
      seen during fsstress testing.
      
        ------------[ cut here ]------------
        kernel BUG at fs/cachefiles/namei.c:201!
        invalid opcode: 0000 [#1] SMP
        Pid: 5, comm: kworker/u:0 Not tainted 2.6.38.7-30.fc15.x86_64 #1 Bochs Bochs
        RIP: 0010: cachefiles_walk_to_object+0x436/0x745 [cachefiles]
        RSP: 0018:ffff88002ce6dd00  EFLAGS: 00010282
        RAX: ffff88002ef165f0 RBX: ffff88001811f500 RCX: 0000000000000000
        RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000282
        RBP: ffff88002ce6dda0 R08: 0000000000000100 R09: ffffffff81b3a300
        R10: 0000ffff00066c0a R11: 0000000000000003 R12: ffff88002ae54840
        R13: ffff88002ae54840 R14: ffff880029c29c00 R15: ffff88001811f4b0
        FS:  00007f394dd32720(0000) GS:ffff88002ef00000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
        CR2: 00007fffcb62ddf8 CR3: 000000001825f000 CR4: 00000000000006e0
        DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
        DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
        Process kworker/u:0 (pid: 5, threadinfo ffff88002ce6c000, task ffff88002ce55cc0)
        Stack:
         0000000000000246 ffff88002ce55cc0 ffff88002ce6dd58 ffff88001815dc00
         ffff8800185246c0 ffff88001811f618 ffff880029c29d18 ffff88001811f380
         ffff88002ce6dd50 ffffffff814757e4 ffff88002ce6dda0 ffffffff8106ac56
        Call Trace:
         cachefiles_lookup_object+0x78/0xd4 [cachefiles]
         fscache_lookup_object+0x131/0x16d [fscache]
         fscache_object_work_func+0x1bc/0x669 [fscache]
         process_one_work+0x186/0x298
         worker_thread+0xda/0x15d
         kthread+0x84/0x8c
         kernel_thread_helper+0x4/0x10
        RIP  cachefiles_walk_to_object+0x436/0x745 [cachefiles]
        ---[ end trace 1d481c9af1804caa ]---
      
      I tested the uncaching by the following means:
      
       (1) Create a big file on my NFS server (104857600 bytes).
      
       (2) Read the file into the cache with md5sum on the NFS client.  Look in
           /proc/fs/fscache/stats:
      
      	Pages  : mrk=25601 unc=0
      
       (3) Open the file for read/write ("bash 5<>/warthog/bigfile").  Look in proc
           again:
      
      	Pages  : mrk=25601 unc=25601
      Reported-by: NJeff Layton <jlayton@redhat.com>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Reviewed-and-Tested-by: NSuresh Jayaraman <sjayaraman@suse.de>
      cc: stable@kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c902ce1b
  4. 15 5月, 2010 1 次提交
    • C
      NFS: Squelch compiler warning · 0f15c53d
      Chuck Lever 提交于
      Seen with -Wextra:
      
      /home/cel/linux/fs/nfs/fscache.c: In function ‘__nfs_readpages_from_fscache’:
      /home/cel/linux/fs/nfs/fscache.c:479: warning: comparison between signed and unsigned integer expressions
      
      The comparison implicitly converts "int" to "unsigned", making it
      safe.  But there's no need for the implicit type conversions here, and
      the dfprintk() already uses a "%u" formatter for "npages."  Better to
      reduce confusion.
      Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
      Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
      0f15c53d
  5. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  6. 10 2月, 2010 1 次提交
  7. 20 11月, 2009 1 次提交
    • D
      FS-Cache: Handle pages pending storage that get evicted under OOM conditions · 201a1542
      David Howells 提交于
      Handle netfs pages that the vmscan algorithm wants to evict from the pagecache
      under OOM conditions, but that are waiting for write to the cache.  Under these
      conditions, vmscan calls the releasepage() function of the netfs, asking if a
      page can be discarded.
      
      The problem is typified by the following trace of a stuck process:
      
      	kslowd005     D 0000000000000000     0  4253      2 0x00000080
      	 ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007
      	 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8
      	 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8
      	Call Trace:
      	 [<ffffffffa00782d8>] __fscache_wait_on_page_write+0x8b/0xa7 [fscache]
      	 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
      	 [<ffffffffa0078240>] ? __fscache_check_page_write+0x63/0x70 [fscache]
      	 [<ffffffffa00b671d>] nfs_fscache_release_page+0x4e/0xc4 [nfs]
      	 [<ffffffffa00927f0>] nfs_release_page+0x3c/0x41 [nfs]
      	 [<ffffffff810885d3>] try_to_release_page+0x32/0x3b
      	 [<ffffffff81093203>] shrink_page_list+0x316/0x4ac
      	 [<ffffffff8109372b>] shrink_inactive_list+0x392/0x67c
      	 [<ffffffff813532fa>] ? __mutex_unlock_slowpath+0x100/0x10b
      	 [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130
      	 [<ffffffff8135330e>] ? mutex_unlock+0x9/0xb
      	 [<ffffffff81093aa2>] shrink_list+0x8d/0x8f
      	 [<ffffffff81093d1c>] shrink_zone+0x278/0x33c
      	 [<ffffffff81052d6c>] ? ktime_get_ts+0xad/0xba
      	 [<ffffffff81094b13>] try_to_free_pages+0x22e/0x392
      	 [<ffffffff81091e24>] ? isolate_pages_global+0x0/0x212
      	 [<ffffffff8108e743>] __alloc_pages_nodemask+0x3dc/0x5cf
      	 [<ffffffff81089529>] grab_cache_page_write_begin+0x65/0xaa
      	 [<ffffffff8110f8c0>] ext3_write_begin+0x78/0x1eb
      	 [<ffffffff81089ec5>] generic_file_buffered_write+0x109/0x28c
      	 [<ffffffff8103cb69>] ? current_fs_time+0x22/0x29
      	 [<ffffffff8108a509>] __generic_file_aio_write+0x350/0x385
      	 [<ffffffff8108a588>] ? generic_file_aio_write+0x4a/0xae
      	 [<ffffffff8108a59e>] generic_file_aio_write+0x60/0xae
      	 [<ffffffff810b2e82>] do_sync_write+0xe3/0x120
      	 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
      	 [<ffffffff810b18e1>] ? __dentry_open+0x1a5/0x2b8
      	 [<ffffffff810b1a76>] ? dentry_open+0x82/0x89
      	 [<ffffffffa00e693c>] cachefiles_write_page+0x298/0x335 [cachefiles]
      	 [<ffffffffa0077147>] fscache_write_op+0x178/0x2c2 [fscache]
      	 [<ffffffffa0075656>] fscache_op_execute+0x7a/0xd1 [fscache]
      	 [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1
      	 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308
      	 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
      	 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308
      	 [<ffffffff8104be91>] kthread+0x7a/0x82
      	 [<ffffffff8100beda>] child_rip+0xa/0x20
      	 [<ffffffff8100b87c>] ? restore_args+0x0/0x30
      	 [<ffffffff8102ef83>] ? tg_shares_up+0x171/0x227
      	 [<ffffffff8104be17>] ? kthread+0x0/0x82
      	 [<ffffffff8100bed0>] ? child_rip+0x0/0x20
      
      In the above backtrace, the following is happening:
      
       (1) A page storage operation is being executed by a slow-work thread
           (fscache_write_op()).
      
       (2) FS-Cache farms the operation out to the cache to perform
           (cachefiles_write_page()).
      
       (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3's
           standard write (do_sync_write()) under KERNEL_DS directly from the netfs
           page.
      
       (4) However, for Ext3 to perform the write, it must allocate some memory, in
           particular, it must allocate at least one page cache page into which it
           can copy the data from the netfs page.
      
       (5) Under OOM conditions, the memory allocator can't immediately come up with
           a page, so it uses vmscan to find something to discard
           (try_to_free_pages()).
      
       (6) vmscan finds a clean netfs page it might be able to discard (possibly the
           one it's trying to write out).
      
       (7) The netfs is called to throw the page away (nfs_release_page()) - but it's
           called with __GFP_WAIT, so the netfs decides to wait for the store to
           complete (__fscache_wait_on_page_write()).
      
       (8) This blocks a slow-work processing thread - possibly against itself.
      
      The system ends up stuck because it can't write out any netfs pages to the
      cache without allocating more memory.
      
      To avoid this, we make FS-Cache cancel some writes that aren't in the middle of
      actually being performed.  This means that some data won't make it into the
      cache this time.  To support this, a new FS-Cache function is added
      fscache_maybe_release_page() that replaces what the netfs releasepage()
      functions used to do with respect to the cache.
      
      The decisions fscache_maybe_release_page() makes are counted and displayed
      through /proc/fs/fscache/stats on a line labelled "VmScan".  There are four
      counters provided: "nos=N" - pages that weren't pending storage; "gon=N" -
      pages that were pending storage when we first looked, but weren't by the time
      we got the object lock; "bsy=N" - pages that we ignored as they were actively
      being written when we looked; and "can=N" - pages that we cancelled the storage
      of.
      
      What I'd really like to do is alter the behaviour of the cancellation
      heuristics, depending on how necessary it is to expel pages.  If there are
      plenty of other pages that aren't waiting to be written to the cache that
      could be ejected first, then it would be nice to hold up on immediate
      cancellation of cache writes - but I don't see a way of doing that.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      201a1542
  8. 24 9月, 2009 1 次提交
    • D
      NFS: Propagate 'fsc' mount option through automounts · 2df54806
      David Howells 提交于
      Propagate the NFS 'fsc' mount option through NFS automounts of various types.
      
      This is now required as commit:
      
      	commit c02d7adf
      	Author: Trond Myklebust <Trond.Myklebust@netapp.com>
      	Date:   Mon Jun 22 15:09:14 2009 -0400
      
      	NFSv4: Replace nfs4_path_walk() with VFS path lookup in a private namespace
      
      uses VFS-driven automounting to reach all submounts barring the root, thus
      preventing fscaching from being enabled on any submount other than the root.
      
      This patch gets around that by propagating the NFS_OPTION_FSCACHE flag across
      automounts.  If a uniquifier is supplied to a mount then this is propagated to
      all automounts of that mount too.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      [Trond: Fixed up the definition of nfs_fscache_get_super_cookie for the
              case of #undef CONFIG_NFS_FSCACHE]
      Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
      2df54806
  9. 03 4月, 2009 6 次提交