10 Nov, 2018
1 commit
-
commit 169b803397499be85bdd1e3d07d6f5e3d4bd669e upstream.
the victim might've been rmdir'ed just before the lock_rename();
unlike the normal callers, we do not look the source up after the
parents are locked - we know it beforehand and just recheck that it's
still the child of what used to be its parent. Unfortunately,
the check is too weak - we don't spot a dead directory since its
->d_parent is unchanged, dentry is positive, etc. So we sail all
the way to ->rename(), with hosting filesystems _not_ expecting
to be asked renaming an rmdir'ed subdirectory.The fix is easy, fortunately - the lock on parent is sufficient for
making IS_DEADDIR() on child safe.Cc: stable@vger.kernel.org
Fixes: 9ae326a69004 (CacheFiles: A cache that backs onto a mounted filesystem)
Signed-off-by: Al Viro
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman
05 Sep, 2018
1 commit
-
[ Upstream commit c2412ac45a8f8f1cd582723c1a139608694d410d ]
If we meet a conflicting object that is marked FSCACHE_OBJECT_IS_LIVE in
the active object tree, we have been emitting a BUG after logging
information about it and the new object.Instead, we should wait for the CACHEFILES_OBJECT_ACTIVE flag to be cleared
on the old object (or return an error). The ACTIVE flag should be cleared
after it has been removed from the active object tree. A timeout of 60s is
used in the wait, so we shouldn't be able to get stuck there.Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri
Signed-off-by: David Howells
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman
20 Jun, 2017
1 commit
-
Rename:
wait_queue_t => wait_queue_entry_t
'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.Start sorting this out by renaming it to 'wait_queue_entry_t'.
This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
11 Oct, 2016
2 commits
-
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning -
Pull vfs xattr updates from Al Viro:
"xattr stuff from AndreasThis completes the switch to xattr_handler ->get()/->set() from
->getxattr/->setxattr/->removexattr"* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Remove {get,set,remove}xattr inode operations
xattr: Stop calling {get,set,remove}xattr inode operations
vfs: Check for the IOP_XATTR flag in listxattr
xattr: Add __vfs_{get,set,remove}xattr helpers
libfs: Use IOP_XATTR flag for empty directory handling
vfs: Use IOP_XATTR flag for bad-inode handling
vfs: Add IOP_XATTR inode operations flag
vfs: Move xattr_resolve_name to the front of fs/xattr.c
ecryptfs: Switch to generic xattr handlers
sockfs: Get rid of getxattr iop
sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
kernfs: Switch to generic xattr handlers
hfs: Switch to generic xattr handlers
jffs2: Remove jffs2_{get,set,remove}xattr macros
xattr: Remove unnecessary NULL attribute name check
08 Oct, 2016
1 commit
-
Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations. Switch to helper functions and test for the IOP_XATTR
flag instead.Signed-off-by: Andreas Gruenbacher
Acked-by: James Morris
Signed-off-by: Al Viro
28 Sep, 2016
1 commit
-
An NULL-pointer dereference happens in cachefiles_mark_object_inactive()
when it tries to read i_blocks so that it can tell the cachefilesd daemon
how much space it's making available.The problem is that cachefiles_drop_object() calls
cachefiles_mark_object_inactive() after calling cachefiles_delete_object()
because the object being marked active staves off attempts to (re-)use the
file at that filename until after it has been deleted. This means that
d_inode is NULL by the time we come to try to access it.To fix the problem, have the caller of cachefiles_mark_object_inactive()
supply the number of blocks freed up.Without this, the following oops may occur:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
IP: [] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
...
CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1
Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011
Workqueue: fscache_object fscache_object_work_func [fscache]
task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000
RIP: 0010:[] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034
RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8
RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000
R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600
R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498
FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0
ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658
ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600
Call Trace:
[] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
[] fscache_drop_object+0xd6/0x1e0 [fscache]
[] fscache_object_work_func+0xa5/0x200 [fscache]
[] process_one_work+0x17b/0x470
[] worker_thread+0x126/0x410
[] ? rescuer_thread+0x460/0x460
[] kthread+0xcf/0xe0
[] ? kthread_create_on_node+0x140/0x140
[] ret_from_fork+0x58/0x90
[] ? kthread_create_on_node+0x140/0x140The oopsing code shows:
callq 0xffffffff810af6a0
mov 0xf8(%r12),%rax
mov 0x30(%rax),%rax
mov 0x98(%rax),%rax dentry)->i_blocksFixes: a5b3a80b899bda0f456f1246c4c5a1191ea01519 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
Reported-by: Jianhong Yin
Signed-off-by: David Howells
Reviewed-by: Jeff Layton
Reviewed-by: Steve Dickson
cc: stable@vger.kernel.org
Signed-off-by: Al Viro
27 Sep, 2016
2 commits
-
Generated patch:
sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`Signed-off-by: Miklos Szeredi
-
No in-tree uses remain.
Signed-off-by: Miklos Szeredi
04 Aug, 2016
1 commit
-
There's a race between cachefiles_mark_object_inactive() and
cachefiles_cull():(1) cachefiles_cull() can't delete a backing file until the cache object
is marked inactive, but as soon as that's the case it's fair game.(2) cachefiles_mark_object_inactive() marks the object as being inactive
and *only then* reads the i_blocks on the backing inode - but
cachefiles_cull() might've managed to delete it by this point.Fix this by making sure cachefiles_mark_object_inactive() gets any data it
needs from the backing inode before deactivating the object.Without this, the following oops may occur:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
IP: [] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
...
CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1
Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011
Workqueue: fscache_object fscache_object_work_func [fscache]
task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000
RIP: 0010:[] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034
RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8
RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000
R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600
R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498
FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0
ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658
ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600
Call Trace:
[] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
[] fscache_drop_object+0xd6/0x1e0 [fscache]
[] fscache_object_work_func+0xa5/0x200 [fscache]
[] process_one_work+0x17b/0x470
[] worker_thread+0x126/0x410
[] ? rescuer_thread+0x460/0x460
[] kthread+0xcf/0xe0
[] ? kthread_create_on_node+0x140/0x140
[] ret_from_fork+0x58/0x90
[] ? kthread_create_on_node+0x140/0x140The oopsing code shows:
callq 0xffffffff810af6a0
mov 0xf8(%r12),%rax
mov 0x30(%rax),%rax
mov 0x98(%rax),%rax dentry)->i_blocksFixes: a5b3a80b899bda0f456f1246c4c5a1191ea01519 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
Reported-by: Jianhong Yin
Signed-off-by: David Howells
Reviewed-by: Jeff Layton
Reviewed-by: Steve Dickson
cc: stable@vger.kernel.org
Signed-off-by: Al Viro
02 Feb, 2016
1 commit
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Provide read-and-reset objects- and blocks-released counters for cachefilesd
to use to work out whether there's anything new that can be culled.One of the problems cachefilesd has is that if all the objects in the cache
are pinned by inodes lying dormant in the kernel inode cache, there isn't
anything for it to cull. In such a case, it just spins around walking the
filesystem tree and scanning for something to cull. This eats up a lot of
CPU time.By telling cachefilesd if there have been any releases, the daemon can
sleep until there is the possibility of something to do.cachefilesd finds this information by the following means:
(1) When the control fd is read, the kernel presents a list of values of
interest. "freleased=N" and "breleased=N" are added to this list to
indicate the number of files released and number of blocks released
since the last read call. At this point the counters are reset.(2) POLLIN is signalled if the number of files released becomes greater
than 0.Note that by 'released' it just means that the kernel has released its
interest in those files for the moment, not necessarily that the files
should be deleted from the cache.Signed-off-by: David Howells
Reviewed-by: Steve Dickson
Signed-off-by: Al Viro
23 Jan, 2016
1 commit
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parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.Signed-off-by: Al Viro
11 Nov, 2015
1 commit
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cachefiles requires that s_blocksize in the cache is not greater than
PAGE_SIZE, and performs the check every time a block is accessed.Move the test to the place where the file is "opened", where other
file-validity tests are performed.Signed-off-by: NeilBrown
Signed-off-by: David Howells
Signed-off-by: Al Viro
24 Jun, 2015
1 commit
16 Apr, 2015
2 commits
-
Signed-off-by: David Howells
Signed-off-by: Al Viro -
Cachefiles should perform fs modifications (eg. vfs_unlink()) on the top layer
only and should not attempt to alter the lower layer.Signed-off-by: David Howells
Signed-off-by: Al Viro
24 Feb, 2015
1 commit
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Count the number of objects that get culled by the cache backend and the
number of objects that the cache backend declines to instantiate due to lack
of space in the cache.These numbers are made available through /proc/fs/fscache/stats
Signed-off-by: David Howells
Reviewed-by: Steve Dickson
Acked-by: Jeff Layton
23 Feb, 2015
2 commits
-
Fix up the following scripted S_ISDIR/S_ISREG/S_ISLNK conversions (or lack
thereof) in cachefiles:(1) Cachefiles mostly wants to use d_can_lookup() rather than d_is_dir() as
it doesn't want to deal with automounts in its cache.(2) Coccinelle didn't find S_IS* expressions in ASSERT() statements in
cachefiles.Signed-off-by: David Howells
Signed-off-by: Al Viro -
Convert the following where appropriate:
(1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).
(2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).
(3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more
complicated than it appears as some calls should be converted to
d_can_lookup() instead. The difference is whether the directory in
question is a real dir with a ->lookup op or whether it's a fake dir with
a ->d_automount op.In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer. In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was
intended for special directory entry types that don't have attached inodes.The following perl+coccinelle script was used:
use strict;
my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
die "Can't grep for S_ISDIR and co. callers";
@callers = ;
close($fd);
unless (@callers) {
print "No matches\n";
exit(0);
}my @cocci = (
'@@',
'expression E;',
'@@',
'',
'- S_ISLNK(E->d_inode->i_mode)',
'+ d_is_symlink(E)',
'',
'@@',
'expression E;',
'@@',
'',
'- S_ISDIR(E->d_inode->i_mode)',
'+ d_is_dir(E)',
'',
'@@',
'expression E;',
'@@',
'',
'- S_ISREG(E->d_inode->i_mode)',
'+ d_is_reg(E)' );my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);foreach my $file (@callers) {
chomp $file;
print "Processing ", $file, "\n";
system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
die "spatch failed";
}[AV: overlayfs parts skipped]
Signed-off-by: David Howells
Signed-off-by: Al Viro
20 Nov, 2014
1 commit
-
Signed-off-by: Al Viro
14 Oct, 2014
1 commit
-
When CacheFiles cache objects are in use, they have in-memory representations,
as defined by the cachefiles_object struct. These are kept in a tree rooted in
the cache and indexed by dentry pointer (since there's a unique mapping between
object index key and dentry).Collisions can occur between a representation already in the tree and a new
representation being set up because it takes time to dispose of an old
representation - particularly if it must be unlinked or renamed.When such a collision occurs, cachefiles_mark_object_active() is meant to check
to see if the old, already-present representation is in the process of being
discarded (ie. FSCACHE_OBJECT_IS_LIVE is not set on it) - and, if so, wait for
the representation to be removed (ie. CACHEFILES_OBJECT_ACTIVE is then
cleared).However, the test for whether the old representation is still live is checking
the new object - which always will be live at this point. This leads to an
oops looking like:CacheFiles: Error: Unexpected object collision
object: OBJ1b354
objstate=LOOK_UP_OBJECT fl=8 wbusy=2 ev=0[0]
ops=0 inp=0 exc=0
parent=ffff88053f5417c0
cookie=ffff880538f202a0 [pr=ffff8805381b7160 nd=ffff880509c6eb78 fl=27]
key=[8] '2490000000000000'
xobject: OBJ1a600
xobjstate=DROP_OBJECT fl=70 wbusy=2 ev=0[0]
xops=0 inp=0 exc=0
xparent=ffff88053f5417c0
xcookie=ffff88050f4cbf70 [pr=ffff8805381b7160 nd= (null) fl=12]
------------[ cut here ]------------
kernel BUG at fs/cachefiles/namei.c:200!
...
Workqueue: fscache_object fscache_object_work_func [fscache]
...
RIP: ... cachefiles_walk_to_object+0x7ea/0x860 [cachefiles]
...
Call Trace:
[] ? cachefiles_lookup_object+0x58/0x100 [cachefiles]
[] ? fscache_look_up_object+0xb9/0x1d0 [fscache]
[] ? fscache_parent_ready+0x2d/0x80 [fscache]
[] ? fscache_object_work_func+0x92/0x1f0 [fscache]
[] ? process_one_work+0x16b/0x400
[] ? worker_thread+0x116/0x380
[] ? manage_workers.isra.21+0x290/0x290
[] ? kthread+0xbc/0xe0
[] ? flush_kthread_worker+0x80/0x80
[] ? ret_from_fork+0x7c/0xb0
[] ? flush_kthread_worker+0x80/0x80Reported-by: Manuel Schölling
Signed-off-by: David Howells
Acked-by: Steve Dickson
26 Sep, 2014
1 commit
-
Commit 0227d6abb378 ("fs/cachefiles: replace kerror by pr_err") didn't
include newline featuring in original kerror definitionSigned-off-by: Fabian Frederick
Reported-by: David Howells
Acked-by: David Howells
Cc: [3.16.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Sep, 2014
1 commit
-
Not all filesystems now provide the rename i_op - ext4 for one - but rather
provide the rename2 i_op. CacheFiles checks that the filesystem has rename
and so will reject ext4 now with EPERM:CacheFiles: Failed to register: -1
Fix this by checking for rename2 as an alternative. The call to vfs_rename()
actually handles selection of the appropriate function, so we needn't worry
about that.Turning on debugging shows:
[cachef] ==> cachefiles_get_directory(,,cache)
[cachef] subdir -> ffff88000b22b778 positive
[cachef]
07 Jun, 2014
2 commits
-
Also add pr_fmt in internal.h
Signed-off-by: Fabian Frederick
Cc: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Fabian Frederick
Cc: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Apr, 2014
1 commit
-
Pull vfs updates from Al Viro:
"The first vfs pile, with deep apologies for being very late in this
window.Assorted cleanups and fixes, plus a large preparatory part of iov_iter
work. There's a lot more of that, but it'll probably go into the next
merge window - it *does* shape up nicely, removes a lot of
boilerplate, gets rid of locking inconsistencie between aio_write and
splice_write and I hope to get Kent's direct-io rewrite merged into
the same queue, but some of the stuff after this point is having
(mostly trivial) conflicts with the things already merged into
mainline and with some I want more testing.This one passes LTP and xfstests without regressions, in addition to
usual beating. BTW, readahead02 in ltp syscalls testsuite has started
giving failures since "mm/readahead.c: fix readahead failure for
memoryless NUMA nodes and limit readahead pages" - might be a false
positive, might be a real regression..."* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
missing bits of "splice: fix racy pipe->buffers uses"
cifs: fix the race in cifs_writev()
ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
kill generic_file_buffered_write()
ocfs2_file_aio_write(): switch to generic_perform_write()
ceph_aio_write(): switch to generic_perform_write()
xfs_file_buffered_aio_write(): switch to generic_perform_write()
export generic_perform_write(), start getting rid of generic_file_buffer_write()
generic_file_direct_write(): get rid of ppos argument
btrfs_file_aio_write(): get rid of ppos
kill the 5th argument of generic_file_buffered_write()
kill the 4th argument of __generic_file_aio_write()
lustre: don't open-code kernel_recvmsg()
ocfs2: don't open-code kernel_recvmsg()
drbd: don't open-code kernel_recvmsg()
constify blk_rq_map_user_iov() and friends
lustre: switch to kernel_sendmsg()
ocfs2: don't open-code kernel_sendmsg()
take iov_iter stuff to mm/iov_iter.c
process_vm_access: tidy up a bit
...
02 Apr, 2014
1 commit
-
Signed-off-by: Al Viro
01 Apr, 2014
2 commits
-
Add flags to security_path_rename() and security_inode_rename() hooks.
Signed-off-by: Miklos Szeredi
Reviewed-by: J. Bruce Fields -
Add new renameat2 syscall, which is the same as renameat with an added
flags argument.Pass flags to vfs_rename() and to i_op->rename() as well.
Signed-off-by: Miklos Szeredi
Reviewed-by: J. Bruce Fields
09 Nov, 2013
2 commits
-
Cc: David Howells
Acked-by: Jeff Layton
Signed-off-by: J. Bruce Fields
Signed-off-by: Al Viro -
We need to break delegations on any operation that changes the set of
links pointing to an inode. Start with unlink.Such operations also hold the i_mutex on a parent directory. Breaking a
delegation may require waiting for a timeout (by default 90 seconds) in
the case of a unresponsive NFS client. To avoid blocking all directory
operations, we therefore drop locks before waiting for the delegation.
The logic then looks like:acquire locks
...
test for delegation; if found:
take reference on inode
release locks
wait for delegation break
drop reference on inode
retryIt is possible this could never terminate. (Even if we take precautions
to prevent another delegation being acquired on the same inode, we could
get a different inode on each retry.) But this seems very unlikely.The initial test for a delegation happens after the lock on the target
inode is acquired, but the directory inode may have been acquired
further up the call stack. We therefore add a "struct inode **"
argument to any intervening functions, which we use to pass the inode
back up to the caller in the case it needs a delegation synchronously
broken.Cc: David Howells
Cc: Tyler Hicks
Cc: Dustin Kirkland
Acked-by: Jeff Layton
Signed-off-by: J. Bruce Fields
Signed-off-by: Al Viro
21 Sep, 2013
1 commit
-
Don't try to dump the index key that distinguishes an object if netfs
data in the cookie the object refers to has been cleared (ie. the
cookie has passed most of the way through
__fscache_relinquish_cookie()).Since the netfs holds the index key, we can't get at it once the ->def
and ->netfs_data pointers have been cleared - and a NULL pointer
exception will ensue, usually just after a:CacheFiles: Error: Unexpected object collision
error is reported.
Signed-off-by: David Howells
Signed-off-by: Linus Torvalds
19 Jun, 2013
3 commits
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Fix object state machine to have separate work and wait states as that makes
it easier to envision.There are now three kinds of state:
(1) Work state. This is an execution state. No event processing is performed
by a work state. The function attached to a work state returns a pointer
indicating the next state to which the OSM should transition. Returning
NO_TRANSIT repeats the current state, but goes back to the scheduler
first.(2) Wait state. This is an event processing state. No execution is
performed by a wait state. Wait states are just tables of "if event X
occurs, clear it and transition to state Y". The dispatcher returns to
the scheduler if none of the events in which the wait state has an
interest are currently pending.(3) Out-of-band state. This is a special work state. Transitions to normal
states can be overridden when an unexpected event occurs (eg. I/O error).
Instead the dispatcher disables and clears the OOB event and transits to
the specified work state. This then acts as an ordinary work state,
though object->state points to the overridden destination. Returning
NO_TRANSIT resumes the overridden transition.In addition, the states have names in their definitions, so there's no need for
tables of state names. Further, the EV_REQUEUE event is no longer necessary as
that is automatic for work states.Since the states are now separate structs rather than values in an enum, it's
not possible to use comparisons other than (non-)equality between them, so use
some object->flags to indicate what phase an object is in.The EV_RELEASE, EV_RETIRE and EV_WITHDRAW events have been squished into one
(EV_KILL). An object flag now carries the information about retirement.Similarly, the RELEASING, RECYCLING and WITHDRAWING states have been merged
into an KILL_OBJECT state and additional states have been added for handling
waiting dependent objects (JUMPSTART_DEPS and KILL_DEPENDENTS).A state has also been added for synchronising with parent object initialisation
(WAIT_FOR_PARENT) and another for initiating look up (PARENT_READY).Signed-off-by: David Howells
Tested-By: Milosz Tanski
Acked-by: Jeff Layton -
Wrap checks on object state (mostly outside of fs/fscache/object.c) with
inline functions so that the mechanism can be replaced.Some of the state checks within object.c are left as-is as they will be
replaced.Signed-off-by: David Howells
Tested-By: Milosz Tanski
Acked-by: Jeff Layton -
Just some cleanup.
(And note the caller of this function may, for example, call vfs_unlink
on a child, so the "1" (I_MUTEX_PARENT) really was what was intended
here.)Signed-off-by: J. Bruce Fields
Signed-off-by: David Howells
Tested-By: Milosz Tanski
Acked-by: Jeff Layton
21 Dec, 2012
1 commit
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Don't mask off the object event mask when printing it. That way it can be seen
if threre are bits set that shouldn't be.Signed-off-by: David Howells
14 Jul, 2012
1 commit
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all we want is a boolean flag, same as the method gets now
Signed-off-by: Al Viro
21 Mar, 2012
1 commit
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Signed-off-by: Al Viro
24 Jan, 2011
1 commit
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Add calls to path-based security hooks into CacheFiles as, unlike inode-based
security, these aren't implicit in the vfs_mkdir() and similar calls.Reported-by: Tetsuo Handa
Signed-off-by: David Howells
Signed-off-by: James Morris
23 Jul, 2010
1 commit
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Make fscache object state transition callbacks use workqueue instead
of slow-work. New dedicated unbound CPU workqueue fscache_object_wq
is created. get/put callbacks are renamed and modified to take
@object and called directly from the enqueue wrapper and the work
function. While at it, make all open coded instances of get/put to
use fscache_get/put_object().* Unbound workqueue is used.
* work_busy() output is printed instead of slow-work flags in object
debugging outputs. They mean basically the same thing bit-for-bit.* sysctl fscache.object_max_active added to control concurrency. The
default value is nr_cpus clamped between 4 and
WQ_UNBOUND_MAX_ACTIVE.* slow_work_sleep_till_thread_needed() is replaced with fscache
private implementation fscache_object_sleep_till_congested() which
waits on fscache_object_wq congestion.* debugfs support is dropped for now. Tracing API based debug
facility is planned to be added.Signed-off-by: Tejun Heo
Acked-by: David Howells
