| Age | Commit message (Collapse) | Author |
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It is anticipated that when sb_issue_discard starts doing
real work on trim-capable devices, we may see issues. Make
this mount-time optional, and default it to off until we know
that things are working out OK.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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When an error happened in ext4_splice_branch we failed to notice that
in ext4_ind_get_blocks and mapped the buffer anyway. Fix the problem
by checking for error properly.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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We don't to issue an I/O barrier on an error or if we force commit
because we are doing data journaling.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
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Don't log the CacheFiles lookup/create object routined failing with ENOBUFS as
under high memory load or high cache load they can do this quite a lot. This
error simply means that the requested object cannot be created on disk due to
lack of space, or due to failure of the backing filesystem to find sufficient
resources.
Signed-off-by: David Howells <dhowells@redhat.com>
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Catch an overly long wait for an old, dying active object when we want to
replace it with a new one. The probability is that all the slow-work threads
are hogged, and the delete can't get a look in.
What we do instead is:
(1) if there's nothing in the slow work queue, we sleep until either the dying
object has finished dying or there is something in the slow work queue
behind which we can queue our object.
(2) if there is something in the slow work queue, we return ETIMEDOUT to
fscache_lookup_object(), which then puts us back on the slow work queue,
presumably behind the deletion that we're blocked by. We are then
deferred for a while until we work our way back through the queue -
without blocking a slow-work thread unnecessarily.
A backtrace similar to the following may appear in the log without this patch:
INFO: task kslowd004:5711 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kslowd004 D 0000000000000000 0 5711 2 0x00000080
ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000
ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8
000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8
Call Trace:
[<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf
[<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
[<ffffffffa011c4e1>] cachefiles_wait_bit+0x9/0xd [cachefiles]
[<ffffffff81353153>] __wait_on_bit+0x43/0x76
[<ffffffff8111ae39>] ? ext3_xattr_get+0x1ec/0x270
[<ffffffff813531ef>] out_of_line_wait_on_bit+0x69/0x74
[<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
[<ffffffff8104c125>] ? wake_bit_function+0x0/0x2e
[<ffffffffa011bc79>] cachefiles_mark_object_active+0x203/0x23b [cachefiles]
[<ffffffffa011c209>] cachefiles_walk_to_object+0x558/0x827 [cachefiles]
[<ffffffffa011a429>] cachefiles_lookup_object+0xac/0x12a [cachefiles]
[<ffffffffa00aa1e9>] fscache_lookup_object+0x1c7/0x214 [fscache]
[<ffffffffa00aafc5>] fscache_object_state_machine+0xa5/0x52d [fscache]
[<ffffffffa00ab4ac>] fscache_object_slow_work_execute+0x5f/0xa0 [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
[<ffffffff8104be17>] ? kthread+0x0/0x82
[<ffffffff8100bed0>] ? child_rip+0x0/0x20
1 lock held by kslowd004/5711:
#0: (&sb->s_type->i_mutex_key#7/1){+.+.+.}, at: [<ffffffffa011be64>] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles]
Signed-off-by: David Howells <dhowells@redhat.com>
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Show more debugging information if cachefiles_mark_object_active() is asked to
activate an active object.
This may happen, for instance, if the netfs tries to register an object with
the same key multiple times.
The code is changed to (a) get the appropriate object lock to protect the
cookie pointer whilst we dereference it, and (b) get and display the cookie key
if available.
Signed-off-by: David Howells <dhowells@redhat.com>
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Mark parent directory locks as I_MUTEX_PARENT in the callers of
cachefiles_bury_object() so that lockdep doesn't complain when that invokes
vfs_unlink():
=============================================
[ INFO: possible recursive locking detected ]
2.6.32-rc6-cachefs #47
---------------------------------------------
kslowd002/3089 is trying to acquire lock:
(&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff810bbf72>] vfs_unlink+0x8b/0x128
but task is already holding lock:
(&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles]
other info that might help us debug this:
1 lock held by kslowd002/3089:
#0: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles]
stack backtrace:
Pid: 3089, comm: kslowd002 Not tainted 2.6.32-rc6-cachefs #47
Call Trace:
[<ffffffff8105ad7b>] __lock_acquire+0x1649/0x16e3
[<ffffffff8118170e>] ? inode_has_perm+0x5f/0x61
[<ffffffff8105ae6c>] lock_acquire+0x57/0x6d
[<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128
[<ffffffff81353ac3>] mutex_lock_nested+0x54/0x292
[<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128
[<ffffffff8118179e>] ? selinux_inode_permission+0x8e/0x90
[<ffffffff8117e271>] ? security_inode_permission+0x1c/0x1e
[<ffffffff810bb4fb>] ? inode_permission+0x99/0xa5
[<ffffffff810bbf72>] vfs_unlink+0x8b/0x128
[<ffffffff810adb19>] ? kfree+0xed/0xf9
[<ffffffffa00e3f00>] cachefiles_bury_object+0xb6/0x420 [cachefiles]
[<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf
[<ffffffffa00e7e24>] ? cachefiles_check_object_xattr+0x233/0x293 [cachefiles]
[<ffffffffa00e51b0>] cachefiles_walk_to_object+0x4ff/0x831 [cachefiles]
[<ffffffff81032238>] ? finish_task_switch+0x0/0xb2
[<ffffffffa00e3429>] cachefiles_lookup_object+0xac/0x12a [cachefiles]
[<ffffffffa00741e9>] fscache_lookup_object+0x1c7/0x214 [fscache]
[<ffffffffa0074fc5>] fscache_object_state_machine+0xa5/0x52d [fscache]
[<ffffffffa00754ac>] fscache_object_slow_work_execute+0x5f/0xa0 [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
[<ffffffff8104be17>] ? kthread+0x0/0x82
[<ffffffff8100bed0>] ? child_rip+0x0/0x20
Signed-off-by: Daivd Howells <dhowells@redhat.com>
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Handle truncate unlocking the page we're attempting to read from the backing
device before the read has completed.
This was causing reports like the following to occur:
Pid: 4765, comm: kslowd Not tainted 2.6.30.1 #1
Call Trace:
[<ffffffffa0331d7a>] ? cachefiles_read_waiter+0xd9/0x147 [cachefiles]
[<ffffffff804b74bd>] ? __wait_on_bit+0x60/0x6f
[<ffffffff8022bbbb>] ? __wake_up_common+0x3f/0x71
[<ffffffff8022cc32>] ? __wake_up+0x30/0x44
[<ffffffff8024a41f>] ? __wake_up_bit+0x28/0x2d
[<ffffffffa003a793>] ? ext3_truncate+0x4d7/0x8ed [ext3]
[<ffffffff80281f90>] ? pagevec_lookup+0x17/0x1f
[<ffffffff8028c2ff>] ? unmap_mapping_range+0x59/0x1ff
[<ffffffff8022cc32>] ? __wake_up+0x30/0x44
[<ffffffff8028e286>] ? vmtruncate+0xc2/0xe2
[<ffffffff802b82cf>] ? inode_setattr+0x22/0x10a
[<ffffffffa003baa5>] ? ext3_setattr+0x17b/0x1e6 [ext3]
[<ffffffff802b853d>] ? notify_change+0x186/0x2c9
[<ffffffffa032d9de>] ? cachefiles_attr_changed+0x133/0x1cd [cachefiles]
[<ffffffffa032df7f>] ? cachefiles_lookup_object+0xcf/0x12a [cachefiles]
[<ffffffffa0318165>] ? fscache_lookup_object+0x110/0x122 [fscache]
[<ffffffffa03188c3>] ? fscache_object_slow_work_execute+0x590/0x6bc
[fscache]
[<ffffffff80278f82>] ? slow_work_thread+0x285/0x43a
[<ffffffff8024a446>] ? autoremove_wake_function+0x0/0x2e
[<ffffffff80278cfd>] ? slow_work_thread+0x0/0x43a
[<ffffffff8024a317>] ? kthread+0x54/0x81
[<ffffffff8020c93a>] ? child_rip+0xa/0x20
[<ffffffff8024a2c3>] ? kthread+0x0/0x81
[<ffffffff8020c930>] ? child_rip+0x0/0x20
CacheFiles: I/O Error: Readpage failed on backing file 200000000000810
FS-Cache: Cache cachefiles stopped due to I/O error
Reported-by: Christian Kujau <lists@nerdbynature.de>
Reported-by: Takashi Iwai <tiwai@suse.de>
Reported-by: Duc Le Minh <duclm.vn@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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cachefiles_write_page() writes a full page to the backing file for the last
page of the netfs file, even if the netfs file's last page is only a partial
page.
This causes the EOF on the backing file to be extended beyond the EOF of the
netfs, and thus the backing file will be truncated by cachefiles_attr_changed()
called from cachefiles_lookup_object().
So we need to limit the write we make to the backing file on that last page
such that it doesn't push the EOF too far.
Also, if a backing file that has a partial page at the end is expanded, we
discard the partial page and refetch it on the basis that we then have a hole
in the file with invalid data, and should the power go out... A better way to
deal with this could be to record a note that the partial page contains invalid
data until the correct data is written into it.
This isn't a problem for netfs's that discard the whole backing file if the
file size changes (such as NFS).
Signed-off-by: David Howells <dhowells@redhat.com>
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FS-Cache objects have an FSCACHE_OBJECT_EV_REQUEUE event that can theoretically
be raised to ask the state machine to requeue the object for further processing
before the work function returns to the slow-work facility.
However, fscache_object_work_execute() was clearing that bit before checking
the event mask to see whether the object has any pending events that require it
to be requeued immediately.
Instead, the bit should be cleared after the check and enqueue.
Signed-off-by: David Howells <dhowells@redhat.com>
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Start processing an object's operations when that object moves into the DYING
state as the object cannot be destroyed until all its outstanding operations
have completed.
Furthermore, make sure that read and allocation operations handle being woken
up on a dead object. Such events are recorded in the Allocs.abt and
Retrvls.abt statistics as viewable through /proc/fs/fscache/stats.
The code for waiting for object activation for the read and allocation
operations is also extracted into its own function as it is much the same in
all cases, differing only in the stats incremented.
Signed-off-by: David Howells <dhowells@redhat.com>
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We must make sure that FSCACHE_COOKIE_LOOKING_UP is cleared on lookup failure
(if an object reaches the LC_DYING state), and we should clear it before
clearing FSCACHE_COOKIE_CREATING.
If this doesn't happen then fscache_wait_for_deferred_lookup() may hold
allocation and retrieval operations indefinitely until they're interrupted by
signals - which in turn pins the dying object until they go away.
Signed-off-by: David Howells <dhowells@redhat.com>
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Add a stat counter to count retirement events rather than ordinary release
events (the retire argument to fscache_relinquish_cookie()).
Signed-off-by: David Howells <dhowells@redhat.com>
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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: David Howells <dhowells@redhat.com>
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FS-Cache doesn't correctly handle the netfs requesting a read from the cache
on an object that failed or was withdrawn by the cache. A trace similar to
the following might be seen:
CacheFiles: Lookup failed error -105
[exe ] unexpected submission OP165afe [OBJ6cac OBJECT_LC_DYING]
[exe ] objstate=OBJECT_LC_DYING [OBJECT_LC_DYING]
[exe ] objflags=0
[exe ] objevent=9 [fffffffffffffffb]
[exe ] ops=0 inp=0 exc=0
Pid: 6970, comm: exe Not tainted 2.6.32-rc6-cachefs #50
Call Trace:
[<ffffffffa0076477>] fscache_submit_op+0x3ff/0x45a [fscache]
[<ffffffffa0077997>] __fscache_read_or_alloc_pages+0x187/0x3c4 [fscache]
[<ffffffffa00b6480>] ? nfs_readpage_from_fscache_complete+0x0/0x66 [nfs]
[<ffffffffa00b6388>] __nfs_readpages_from_fscache+0x7e/0x176 [nfs]
[<ffffffff8108e483>] ? __alloc_pages_nodemask+0x11c/0x5cf
[<ffffffffa009d796>] nfs_readpages+0x114/0x1d7 [nfs]
[<ffffffff81090314>] __do_page_cache_readahead+0x15f/0x1ec
[<ffffffff81090228>] ? __do_page_cache_readahead+0x73/0x1ec
[<ffffffff810903bd>] ra_submit+0x1c/0x20
[<ffffffff810906bb>] ondemand_readahead+0x227/0x23a
[<ffffffff81090762>] page_cache_sync_readahead+0x17/0x19
[<ffffffff8108a99e>] generic_file_aio_read+0x236/0x5a0
[<ffffffffa00937bd>] nfs_file_read+0xe4/0xf3 [nfs]
[<ffffffff810b2fa2>] do_sync_read+0xe3/0x120
[<ffffffff81354cc3>] ? _spin_unlock_irq+0x2b/0x31
[<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
[<ffffffff811848e5>] ? selinux_file_permission+0x5d/0x10f
[<ffffffff81352bdb>] ? thread_return+0x3e/0x101
[<ffffffff8117d7b0>] ? security_file_permission+0x11/0x13
[<ffffffff810b3b06>] vfs_read+0xaa/0x16f
[<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130
[<ffffffff810b3c84>] sys_read+0x45/0x6c
[<ffffffff8100ae2b>] system_call_fastpath+0x16/0x1b
The object state might also be OBJECT_DYING or OBJECT_WITHDRAWING.
This should be handled by simply rejecting the new operation with ENOBUFS.
There's no need to log an error for it. Events of this type now appear in the
stats file under Ops:rej.
Signed-off-by: David Howells <dhowells@redhat.com>
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Don't delete pending pages from the page-store tracking tree, but rather send
them for another write as they've presumably been updated.
Signed-off-by: David Howells <dhowells@redhat.com>
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FS-Cache has two structs internally for keeping track of the internal state of
a cached file: the fscache_cookie struct, which represents the netfs's state,
and fscache_object struct, which represents the cache's state. Each has a
pointer that points to the other (when both are in existence), and each has a
spinlock for pointer maintenance.
Since netfs operations approach these structures from the cookie side, they get
the cookie lock first, then the object lock. Cache operations, on the other
hand, approach from the object side, and get the object lock first. It is not
then permitted for a cache operation to get the cookie lock whilst it is
holding the object lock lest deadlock occur; instead, it must do one of two
things:
(1) increment the cookie usage counter, drop the object lock and then get both
locks in order, or
(2) simply hold the object lock as certain parts of the cookie may not be
altered whilst the object lock is held.
It is also not permitted to follow either pointer without holding the lock at
the end you start with. To break the pointers between the cookie and the
object, both locks must be held.
fscache_write_op(), however, violates the locking rules: It attempts to get the
cookie lock without (a) checking that the cookie pointer is a valid pointer,
and (b) holding the object lock to protect the cookie pointer whilst it follows
it. This is so that it can access the pending page store tree without
interference from __fscache_write_page().
This is fixed by splitting the cookie lock, such that the page store tracking
tree is protected by its own lock, and checking that the cookie pointer is
non-NULL before we attempt to follow it whilst holding the object lock.
The new lock is subordinate to both the cookie lock and the object lock, and so
should be taken after those.
Signed-off-by: David Howells <dhowells@redhat.com>
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The object-available state in the object processing state machine (as
processed by fscache_object_available()) can't rely on the cookie to be
available because the FSCACHE_COOKIE_CREATING bit may have been cleared by
fscache_obtained_object() prior to the object being put into the
FSCACHE_OBJECT_AVAILABLE state.
Clearing the FSCACHE_COOKIE_CREATING bit on a cookie permits
__fscache_relinquish_cookie() to proceed and detach the cookie from the
object.
To deal with this, we don't dereference object->cookie in
fscache_object_available() if the object has already been detached.
In addition, a couple of assertions are added into fscache_drop_object() to
make sure the object is unbound from the cookie before it gets there.
Signed-off-by: David Howells <dhowells@redhat.com>
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Permit the operations to retrieve data from the cache or to allocate space in
the cache for future writes to be interrupted whilst they're waiting for
permission for the operation to proceed. Typically this wait occurs whilst the
cache object is being looked up on disk in the background.
If an interruption occurs, and the operation has not yet been given the
go-ahead to run, the operation is dequeued and cancelled, and control returns
to the read operation of the netfs routine with none of the requested pages
having been read or in any way marked as known by the cache.
This means that the initial wait is done interruptibly rather than
uninterruptibly.
In addition, extra stats values are made available to show the number of ops
cancelled and the number of cache space allocations interrupted.
Signed-off-by: David Howells <dhowells@redhat.com>
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__fscache_write_page() attempts to load the radix tree preallocation pool for
the CPU it is on before calling radix_tree_insert(), as the insertion must be
done inside a pair of spinlocks.
Use of the preallocation pool, however, is contingent on the radix tree being
initialised without __GFP_WAIT specified. __fscache_acquire_cookie() was
passing GFP_NOFS to INIT_RADIX_TREE() - but that includes __GFP_WAIT.
The solution is to AND out __GFP_WAIT.
Additionally, the banner comment to radix_tree_preload() is altered to make
note of this prerequisite. Possibly there should be a WARN_ON() too.
Without this fix, I have seen the following recursive deadlock caused by
radix_tree_insert() attempting to allocate memory inside the spinlocked
region, which resulted in FS-Cache being called back into to release memory -
which required the spinlock already held.
=============================================
[ INFO: possible recursive locking detected ]
2.6.32-rc6-cachefs #24
---------------------------------------------
nfsiod/7916 is trying to acquire lock:
(&cookie->lock){+.+.-.}, at: [<ffffffffa0076872>] __fscache_uncache_page+0xdb/0x160 [fscache]
but task is already holding lock:
(&cookie->lock){+.+.-.}, at: [<ffffffffa0076acc>] __fscache_write_page+0x15c/0x3f3 [fscache]
other info that might help us debug this:
5 locks held by nfsiod/7916:
#0: (nfsiod){+.+.+.}, at: [<ffffffff81048290>] worker_thread+0x19a/0x2e2
#1: (&task->u.tk_work#2){+.+.+.}, at: [<ffffffff81048290>] worker_thread+0x19a/0x2e2
#2: (&cookie->lock){+.+.-.}, at: [<ffffffffa0076acc>] __fscache_write_page+0x15c/0x3f3 [fscache]
#3: (&object->lock#2){+.+.-.}, at: [<ffffffffa0076b07>] __fscache_write_page+0x197/0x3f3 [fscache]
#4: (&cookie->stores_lock){+.+...}, at: [<ffffffffa0076b0f>] __fscache_write_page+0x19f/0x3f3 [fscache]
stack backtrace:
Pid: 7916, comm: nfsiod Not tainted 2.6.32-rc6-cachefs #24
Call Trace:
[<ffffffff8105ac7f>] __lock_acquire+0x1649/0x16e3
[<ffffffff81059ded>] ? __lock_acquire+0x7b7/0x16e3
[<ffffffff8100e27d>] ? dump_trace+0x248/0x257
[<ffffffff8105ad70>] lock_acquire+0x57/0x6d
[<ffffffffa0076872>] ? __fscache_uncache_page+0xdb/0x160 [fscache]
[<ffffffff8135467c>] _spin_lock+0x2c/0x3b
[<ffffffffa0076872>] ? __fscache_uncache_page+0xdb/0x160 [fscache]
[<ffffffffa0076872>] __fscache_uncache_page+0xdb/0x160 [fscache]
[<ffffffffa0077eb7>] ? __fscache_check_page_write+0x0/0x71 [fscache]
[<ffffffffa00b4755>] nfs_fscache_release_page+0x86/0xc4 [nfs]
[<ffffffffa00907f0>] nfs_release_page+0x3c/0x41 [nfs]
[<ffffffff81087ffb>] try_to_release_page+0x32/0x3b
[<ffffffff81092c2b>] shrink_page_list+0x316/0x4ac
[<ffffffff81058a9b>] ? mark_held_locks+0x52/0x70
[<ffffffff8135451b>] ? _spin_unlock_irq+0x2b/0x31
[<ffffffff81093153>] shrink_inactive_list+0x392/0x67c
[<ffffffff81058a9b>] ? mark_held_locks+0x52/0x70
[<ffffffff810934ca>] shrink_list+0x8d/0x8f
[<ffffffff81093744>] shrink_zone+0x278/0x33c
[<ffffffff81052c70>] ? ktime_get_ts+0xad/0xba
[<ffffffff8109453b>] try_to_free_pages+0x22e/0x392
[<ffffffff8109184c>] ? isolate_pages_global+0x0/0x212
[<ffffffff8108e16b>] __alloc_pages_nodemask+0x3dc/0x5cf
[<ffffffff810ae24a>] cache_alloc_refill+0x34d/0x6c1
[<ffffffff811bcf74>] ? radix_tree_node_alloc+0x52/0x5c
[<ffffffff810ae929>] kmem_cache_alloc+0xb2/0x118
[<ffffffff811bcf74>] radix_tree_node_alloc+0x52/0x5c
[<ffffffff811bcfd5>] radix_tree_insert+0x57/0x19c
[<ffffffffa0076b53>] __fscache_write_page+0x1e3/0x3f3 [fscache]
[<ffffffffa00b4248>] __nfs_readpage_to_fscache+0x58/0x11e [nfs]
[<ffffffffa009bb77>] nfs_readpage_release+0x34/0x9b [nfs]
[<ffffffffa009c0d9>] nfs_readpage_release_full+0x32/0x4b [nfs]
[<ffffffffa0006cff>] rpc_release_calldata+0x12/0x14 [sunrpc]
[<ffffffffa0006e2d>] rpc_free_task+0x59/0x61 [sunrpc]
[<ffffffffa0006f03>] rpc_async_release+0x10/0x12 [sunrpc]
[<ffffffff810482e5>] worker_thread+0x1ef/0x2e2
[<ffffffff81048290>] ? worker_thread+0x19a/0x2e2
[<ffffffff81352433>] ? thread_return+0x3e/0x101
[<ffffffffa0006ef3>] ? rpc_async_release+0x0/0x12 [sunrpc]
[<ffffffff8104bff5>] ? autoremove_wake_function+0x0/0x34
[<ffffffff81058d25>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff810480f6>] ? worker_thread+0x0/0x2e2
[<ffffffff8104bd21>] kthread+0x7a/0x82
[<ffffffff8100beda>] child_rip+0xa/0x20
[<ffffffff8100b87c>] ? restore_args+0x0/0x30
[<ffffffff8104c2b9>] ? add_wait_queue+0x15/0x44
[<ffffffff8104bca7>] ? kthread+0x0/0x82
[<ffffffff8100bed0>] ? child_rip+0x0/0x20
Signed-off-by: David Howells <dhowells@redhat.com>
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Clear the pointers from the fscache_cookie struct to netfs private data after
clearing the pointer to the cookie from the fscache_object struct and
releasing the object lock, rather than before.
This allows the netfs private data pointers to be relied on simply by holding
the object lock, rather than having to hold the cookie lock. This is makes
things simpler as the cookie lock has to be taken before the object lock, but
sometimes the object pointer is all that the code has.
Signed-off-by: David Howells <dhowells@redhat.com>
|
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Count entries to and exits from cache operation table functions. Maintain
these as a single counter that's added to or removed from as appropriate.
Signed-off-by: David Howells <dhowells@redhat.com>
|
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Allow the current state of all fscache objects to be dumped by doing:
cat /proc/fs/fscache/objects
By default, all objects and all fields will be shown. This can be restricted
by adding a suitable key to one of the caller's keyrings (such as the session
keyring):
keyctl add user fscache:objlist "<restrictions>" @s
The <restrictions> are:
K Show hexdump of object key (don't show if not given)
A Show hexdump of object aux data (don't show if not given)
And paired restrictions:
C Show objects that have a cookie
c Show objects that don't have a cookie
B Show objects that are busy
b Show objects that aren't busy
W Show objects that have pending writes
w Show objects that don't have pending writes
R Show objects that have outstanding reads
r Show objects that don't have outstanding reads
S Show objects that have slow work queued
s Show objects that don't have slow work queued
If neither side of a restriction pair is given, then both are implied. For
example:
keyctl add user fscache:objlist KB @s
shows objects that are busy, and lists their object keys, but does not dump
their auxiliary data. It also implies "CcWwRrSs", but as 'B' is given, 'b' is
not implied.
Signed-off-by: David Howells <dhowells@redhat.com>
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Annotate slow-work runqueue proc lines for FS-Cache work items. Objects
include the object ID and the state. Operations include the object ID, the
operation ID and the operation type and state.
Signed-off-by: David Howells <dhowells@redhat.com>
|
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Wait for outstanding slow work items belonging to a module to clear when
unregistering that module as a user of the facility. This prevents the put_ref
code of a work item from being taken away before it returns.
Signed-off-by: David Howells <dhowells@redhat.com>
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master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
drivers/net/sfc/sfe4001.c
drivers/net/wireless/libertas/cmd.c
drivers/staging/Kconfig
drivers/staging/Makefile
drivers/staging/rtl8187se/Kconfig
drivers/staging/rtl8192e/Kconfig
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For consistency drop & in front of every proc_handler. Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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This is for consistency with various ioctl() operations that include the
suffix "PGRP" in their names, and also for consistency with PRIO_PGRP,
used with setpriority() and getpriority(). Also, using PGRP instead of
GID avoids confusion with the common abbreviation of "group ID".
I'm fine with anything that makes it more consistent, and if PGRP is what
is the predominant abbreviation then I see no need to further confuse
matters by adding a third one.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix a small issue for the stack pointer in /proc/<pid>/stat. In case of a
kernel thread the value of the printed stack pointer should be 0.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: copy li_lsn before dropping AIL lock
XFS bug in log recover with quota (bugzilla id 855)
|
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* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: clear server inode number flag while autodisabling
|
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git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: deleted inconsistent comment in nilfs_load_inode_block()
nilfs2: deleted struct nilfs_dat_group_desc
nilfs2: fix lock order reversal in chcp operation
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Access to log items on the AIL is generally protected by m_ail_lock;
this is particularly needed when we're getting or setting the 64-bit
li_lsn on a 32-bit platform. This patch fixes a couple places where we
were accessing the log item after dropping the AIL lock on 32-bit
machines.
This can result in a partially-zeroed log->l_tail_lsn if
xfs_trans_ail_delete is racing with xfs_trans_ail_update, and in at
least some cases, this can leave the l_tail_lsn with a zero cycle
number, which means xlog_space_left will think the log is full (unless
CONFIG_XFS_DEBUG is set, in which case we'll trip an ASSERT), leading to
processes stuck forever in xlog_grant_log_space.
Thanks to Adrian VanderSpek for first spotting the race potential and to
Dave Chinner for debug assistance.
Signed-off-by: Nathaniel W. Turner <nate@houseofnate.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
|
|
Hi,
I was hit by a bug in linux 2.6.31 when XFS is not able to recover the
log after a crash if fs was mounted with quotas. Gory details in XFS
bugzilla: http://oss.sgi.com/bugzilla/show_bug.cgi?id=855.
It looks like wrong struct is used in buffer length check, and the following
patch should fix the problem.
xfs_dqblk_t has a size of 104+32 bytes, while xfs_disk_dquot_t is 104 bytes
long, and this is exactly what I see in system logs - "XFS: dquot too small
(104) in xlog_recover_do_dquot_trans."
Signed-off-by: Jan Rekorajski <baggins@sith.mimuw.edu.pl>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
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|
Resolve the conflict between v2.6.32-rc7 where dn_def_dev_handler
gets a small bug fix and the sysctl tree where I am removing all
sysctl strategy routines.
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Fix the commit ec06aedd44 that intended to turn off querying for server inode
numbers when server doesn't consistently support inode numbers. Presumably
the commit didn't actually clear the CIFS_MOUNT_SERVER_INUM flag, perhaps a
typo.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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The block validity checks used by ext4_data_block_valid() wasn't
correctly written to check file systems with the meta_bg feature. Fix
this.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
The number of old-style block group descriptor blocks is
s_meta_first_bg when the meta_bg feature flag is set.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
commit a71ce8c6c9bf269b192f352ea555217815cf027e updated ext4_statfs()
to update the on-disk superblock counters, but modified this buffer
directly without any journaling of the change. This is one of the
accesses that was causing the crc errors in journal replay as seen in
kernel.org bugzilla #14354.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
ext4_xattr_set_handle() was zeroing out an inode outside
of journaling constraints; this is one of the accesses that
was causing the crc errors in journal replay as seen in
kernel.org bugzilla #14354.
Reviewed-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
We need to be testing the i_flags field in the ext4 specific portion
of the inode, instead of the (confusingly aliased) i_flags field in
the generic struct inode.
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
When an inode gets unlinked, the functions ext4_clear_blocks() and
ext4_remove_blocks() call ext4_forget() for all the buffer heads
corresponding to the deleted inode's data blocks. If the inode is a
directory or a symlink, the is_metadata parameter must be non-zero so
ext4_forget() will revoke them via jbd2_journal_revoke(). Otherwise,
if these blocks are reused for a data file, and the system crashes
before a journal checkpoint, the journal replay could end up
corrupting these data blocks.
Thanks to Curt Wohlgemuth for pointing out potential problems in this
area.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Now that we are checking for failed journal checksums in the jbd2
layer, we don't need to check in the ext4 mount path --- since a
checksum fail will result in ext4_load_journal() returning an error,
causing the file system to refuse to be mounted until e2fsck can deal
with the problem.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
If there is a failed journal checksum, don't reset the journal. This
allows for userspace programs to decide how to recover from this
situation. It may be that ignoring the journal checksum failure might
be a better way of recovering the file system. Once we add per-block
checksums, we can definitely do better. Until then, a system
administrator can try backing up the file system image (or taking a
snapshot) and and trying to determine experimentally whether ignoring
the checksum failure or aborting the journal replay results in less
data loss.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
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|
The comment says, "Caller of this function MUST lock s_inode_lock",
however just above the comment, it locks s_inode_lock in the function.
Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
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|
Commit 8177e6d6dfb9cd03d9bdeb647c32161f8f58f686 ("nfsd: clean up
readdirplus encoding") introduced single character typo in nfs3 readdir+
implementation. Unfortunately that typo has quite bad side effects:
random memory corruption, followed (on my box) with immediate
spontaneous box reboot.
Using 'p1' instead of 'p' fixes my Linux box rebooting whenever VMware
ESXi box tries to list contents of my home directory.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
One of the invalid error paths in ext4_iget() forgot to brelse() the
inode buffer head. Fix it by adding a brelse() in the common error
return path, which also simplifies function.
Thanks to Andi Kleen <ak@linux.intel.com> reporting the problem.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Fix a few spelling typos in move_extent.c
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.co.jp>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
If CONFIG_PROVE_LOCKING is enabled, the double_down_write_data_sem()
will trigger a false-positive warning of a recursive lock. Since we
take i_data_sem for the two inodes ordered by their inode numbers,
this isn't a problem. Use of down_write_nested() will notify the lock
dependency checker machinery that there is no problem here.
This problem was reported by Brian Rogers:
http://marc.info/?l=linux-ext4&m=125115356928011&w=1
Reported-by: Brian Rogers <brian@xyzw.org>
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
