__kernel_write doesn't take a sb_writers references, which we need here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
set from Mauro toward the completion of the RST conversion. I *really*
hope we are getting close to the end of this. Meanwhile, those patches
reach pretty far afield to update document references around the tree;
there should be no actual code changes there. There will be, alas, more of
the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots of
fixes.
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Merge tag 'docs-5.8' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fair amount of stuff this time around, dominated by yet another
massive set from Mauro toward the completion of the RST conversion. I
*really* hope we are getting close to the end of this. Meanwhile,
those patches reach pretty far afield to update document references
around the tree; there should be no actual code changes there. There
will be, alas, more of the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots
of fixes"
* tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits)
Documentation: fixes to the maintainer-entry-profile template
zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst
tracing: Fix events.rst section numbering
docs: acpi: fix old http link and improve document format
docs: filesystems: add info about efivars content
Documentation: LSM: Correct the basic LSM description
mailmap: change email for Ricardo Ribalda
docs: sysctl/kernel: document unaligned controls
Documentation: admin-guide: update bug-hunting.rst
docs: sysctl/kernel: document ngroups_max
nvdimm: fixes to maintainter-entry-profile
Documentation/features: Correct RISC-V kprobes support entry
Documentation/features: Refresh the arch support status files
Revert "docs: sysctl/kernel: document ngroups_max"
docs: move locking-specific documents to locking/
docs: move digsig docs to the security book
docs: move the kref doc into the core-api book
docs: add IRQ documentation at the core-api book
docs: debugging-via-ohci1394.txt: add it to the core-api book
docs: fix references for ipmi.rst file
...
The patch which changed cachefiles from calling ->bmap() to using the
bmap() wrapper overwrote the running return value with the result of
calling bmap(). This causes an assertion failure elsewhere in the code.
Fix this by using ret2 rather than ret to hold the return value.
The oops looks like:
kernel BUG at fs/nfs/fscache.c:468!
...
RIP: 0010:__nfs_readpages_from_fscache+0x18b/0x190 [nfs]
...
Call Trace:
nfs_readpages+0xbf/0x1c0 [nfs]
? __alloc_pages_nodemask+0x16c/0x320
read_pages+0x67/0x1a0
__do_page_cache_readahead+0x1cf/0x1f0
ondemand_readahead+0x172/0x2b0
page_cache_async_readahead+0xaa/0xe0
generic_file_buffered_read+0x852/0xd50
? mem_cgroup_commit_charge+0x6e/0x140
? nfs4_have_delegation+0x19/0x30 [nfsv4]
generic_file_read_iter+0x100/0x140
? nfs_revalidate_mapping+0x176/0x2b0 [nfs]
nfs_file_read+0x6d/0xc0 [nfs]
new_sync_read+0x11a/0x1c0
__vfs_read+0x29/0x40
vfs_read+0x8e/0x140
ksys_read+0x61/0xd0
__x64_sys_read+0x1a/0x20
do_syscall_64+0x60/0x1e0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f5d148267e0
Fixes: 10d83e11a5 ("cachefiles: drop direct usage of ->bmap method.")
Reported-by: David Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: David Wysochanski <dwysocha@redhat.com>
cc: Carlos Maiolino <cmaiolino@redhat.com>
Replace the direct usage of ->bmap method by a bmap() call.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public licence as published by
the free software foundation either version 2 of the licence or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 114 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
linux/xattr.h is included more than once.
Link: http://lkml.kernel.org/r/5c86803d.1c69fb81.1a7c6.2b78@mx.google.com
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variable 'cache' is being assigned but is never used hence it is
redundant and can be removed.
Cleans up clang warning:
warning: variable 'cache' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
get_seconds() returns an unsigned long can overflow on some architectures
and is deprecated because of that. In cachefs, we cast that number to
a a 32-bit integer, which will overflow in year 2106 on all architectures.
As confirmed by David Howells, the overflow probably isn't harmful
in the end, since the timestamps are only used to make the file names
unique, but they don't strictly have to be in monotonically increasing
order since the files only exist in order to be deleted as quickly
as possible.
Moving to ktime_get_real_seconds() avoids the deprecated interface.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Clang warns when one enumerated type is implicitly converted to another.
fs/cachefiles/namei.c:247:50: warning: implicit conversion from
enumeration type 'enum cachefiles_obj_ref_trace' to different
enumeration type 'enum fscache_obj_ref_trace' [-Wenum-conversion]
cache->cache.ops->put_object(&xobject->fscache,
cachefiles_obj_put_wait_retry);
Silence this warning by explicitly casting to fscache_obj_ref_trace,
which is also done in put_object.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
[Description]
In a heavily loaded system where the system pagecache is nearing memory
limits and fscache is enabled, pages can be leaked by fscache while trying
read pages from cachefiles backend. This can happen because two
applications can be reading same page from a single mount, two threads can
be trying to read the backing page at same time. This results in one of
the threads finding that a page for the backing file or netfs file is
already in the radix tree. During the error handling cachefiles does not
clean up the reference on backing page, leading to page leak.
[Fix]
The fix is straightforward, to decrement the reference when error is
encountered.
[dhowells: Note that I've removed the clearance and put of newpage as
they aren't attested in the commit message and don't appear to actually
achieve anything since a new page is only allocated is newpage!=NULL and
any residual new page is cleared before returning.]
[Testing]
I have tested the fix using following method for 12+ hrs.
1) mkdir -p /mnt/nfs ; mount -o vers=3,fsc <server_ip>:/export /mnt/nfs
2) create 10000 files of 2.8MB in a NFS mount.
3) start a thread to simulate heavy VM presssure
(while true ; do echo 3 > /proc/sys/vm/drop_caches ; sleep 1 ; done)&
4) start multiple parallel reader for data set at same time
find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
..
..
find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
find /mnt/nfs -type f | xargs -P 80 cat > /dev/null &
5) finally check using cat /proc/fs/fscache/stats | grep -i pages ;
free -h , cat /proc/meminfo and page-types -r -b lru
to ensure all pages are freed.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Shantanu Goel <sgoel01@yahoo.com>
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
[dja: forward ported to current upstream]
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: David Howells <dhowells@redhat.com>
If cachefiles gets an error other then ENOENT when trying to look up an
object in the cache (in this case, EACCES), the object state machine will
eventually transition to the DROP_OBJECT state.
This state invokes fscache_drop_object() which tries to sync the auxiliary
data with the cache (this is done lazily since commit 402cb8dda9) on an
incomplete cache object struct.
The problem comes when cachefiles_update_object_xattr() is called to
rewrite the xattr holding the data. There's an assertion there that the
cache object points to a dentry as we're going to update its xattr. The
assertion trips, however, as dentry didn't get set.
Fix the problem by skipping the update in cachefiles if the object doesn't
refer to a dentry. A better way to do it could be to skip the update from
the DROP_OBJECT state handler in fscache, but that might deny the cache the
opportunity to update intermediate state.
If this error occurs, the kernel log includes lines that look like the
following:
CacheFiles: Lookup failed error -13
CacheFiles:
CacheFiles: Assertion failed
------------[ cut here ]------------
kernel BUG at fs/cachefiles/xattr.c:138!
...
Workqueue: fscache_object fscache_object_work_func [fscache]
RIP: 0010:cachefiles_update_object_xattr.cold.4+0x18/0x1a [cachefiles]
...
Call Trace:
cachefiles_update_object+0xdd/0x1c0 [cachefiles]
fscache_update_aux_data+0x23/0x30 [fscache]
fscache_drop_object+0x18e/0x1c0 [fscache]
fscache_object_work_func+0x74/0x2b0 [fscache]
process_one_work+0x18d/0x340
worker_thread+0x2e/0x390
? pwq_unbound_release_workfn+0xd0/0xd0
kthread+0x112/0x130
? kthread_bind+0x30/0x30
ret_from_fork+0x35/0x40
Note that there are actually two issues here: (1) EACCES happened on a
cache object and (2) an oops occurred. I think that the second is a
consequence of the first (it certainly looks like it ought to be). This
patch only deals with the second.
Fixes: 402cb8dda9 ("fscache: Attach the index key and aux data to the cookie")
Reported-by: Zhibin Li <zhibli@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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: 9ae326a690 (CacheFiles: A cache that backs onto a mounted filesystem)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In cachefiles_mark_object_active(), the new object is marked active and
then we try to add it to the active object tree. If a conflicting object
is already present, we want to wait for that to go away. After the wait,
we go round again and try to re-mark the object as being active - but it's
already marked active from the first time we went through and a BUG is
issued.
Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again.
Analysis from Kiran Kumar Modukuri:
[Impact]
Oops during heavy NFS + FSCache + Cachefiles
CacheFiles: Error: Overlong wait for old active object to go away.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000002
CacheFiles: Error: Object already active kernel BUG at
fs/cachefiles/namei.c:163!
[Cause]
In a heavily loaded system with big files being read and truncated, an
fscache object for a cookie is being dropped and a new object being
looked. The new object being looked for has to wait for the old object
to go away before the new object is moved to active state.
[Fix]
Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when
retrying the object lookup.
[Testcase]
Have run ~100 hours of NFS stress tests and have not seen this bug recur.
[Regression Potential]
- Limited to fscache/cachefiles.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
When a cookie is allocated that causes fscache_object structs to be
allocated, those objects are initialised with the cookie pointer, but
aren't blessed with a ref on that cookie unless the attachment is
successfully completed in fscache_attach_object().
If attachment fails because the parent object was dying or there was a
collision, fscache_attach_object() returns without incrementing the cookie
counter - but upon failure of this function, the object is released which
then puts the cookie, whether or not a ref was taken on the cookie.
Fix this by taking a ref on the cookie when it is assigned in
fscache_object_init(), even when we're creating a root object.
Analysis from Kiran Kumar:
This bug has been seen in 4.4.0-124-generic #148-Ubuntu kernel
BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776277
fscache cookie ref count updated incorrectly during fscache object
allocation resulting in following Oops.
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/internal.h:321!
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
[Cause]
Two threads are trying to do operate on a cookie and two objects.
(1) One thread tries to unmount the filesystem and in process goes over a
huge list of objects marking them dead and deleting the objects.
cookie->usage is also decremented in following path:
nfs_fscache_release_super_cookie
-> __fscache_relinquish_cookie
->__fscache_cookie_put
->BUG_ON(atomic_read(&cookie->usage) <= 0);
(2) A second thread tries to lookup an object for reading data in following
path:
fscache_alloc_object
1) cachefiles_alloc_object
-> fscache_object_init
-> assign cookie, but usage not bumped.
2) fscache_attach_object -> fails in cant_attach_object because the
cookie's backing object or cookie's->parent object are going away
3) fscache_put_object
-> cachefiles_put_object
->fscache_object_destroy
->fscache_cookie_put
->BUG_ON(atomic_read(&cookie->usage) <= 0);
[NOTE from dhowells] It's unclear as to the circumstances in which (2) can
take place, given that thread (1) is in nfs_kill_super(), however a
conflicting NFS mount with slightly different parameters that creates a
different superblock would do it. A backtrace from Kiran seems to show
that this is a possibility:
kernel BUG at/build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
...
RIP: __fscache_cookie_put+0x3a/0x40 [fscache]
Call Trace:
__fscache_relinquish_cookie+0x87/0x120 [fscache]
nfs_fscache_release_super_cookie+0x2d/0xb0 [nfs]
nfs_kill_super+0x29/0x40 [nfs]
deactivate_locked_super+0x48/0x80
deactivate_super+0x5c/0x60
cleanup_mnt+0x3f/0x90
__cleanup_mnt+0x12/0x20
task_work_run+0x86/0xb0
exit_to_usermode_loop+0xc2/0xd0
syscall_return_slowpath+0x4e/0x60
int_ret_from_sys_call+0x25/0x9f
[Fix] Bump up the cookie usage in fscache_object_init, when it is first
being assigned a cookie atomically such that the cookie is added and bumped
up if its refcount is not zero. Remove the assignment in
fscache_attach_object().
[Testcase]
I have run ~100 hours of NFS stress tests and not seen this bug recur.
[Regression Potential]
- Limited to fscache/cachefiles.
Fixes: ccc4fc3d11 ("FS-Cache: Implement the cookie management part of the netfs API")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview. However, it has no ref on that monitor object or on the
associated operation.
What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object. However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.
If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.
Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock. The op can then be enqueued after the lock is
dropped.
The bug can manifest in one of a couple of ways. The first manifestation
looks like:
FS-Cache:
FS-Cache: Assertion failed
FS-Cache: 6 == 5 is false
------------[ cut here ]------------
kernel BUG at fs/fscache/operation.c:494!
RIP: 0010:fscache_put_operation+0x1e3/0x1f0
...
fscache_op_work_func+0x26/0x50
process_one_work+0x131/0x290
worker_thread+0x45/0x360
kthread+0xf8/0x130
? create_worker+0x190/0x190
? kthread_cancel_work_sync+0x10/0x10
ret_from_fork+0x1f/0x30
This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().
The bug can also manifest like the following:
kernel BUG at fs/fscache/operation.c:69!
...
[exception RIP: fscache_enqueue_operation+246]
...
#7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
#8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
#9 [ffff883fff083c48] __wake_up_common at ffffffff810af028
I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <carmark.dlut@gmail.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Reported-by: Anthony DeRobertis <aderobertis@metrics.net>
Reported-by: NeilBrown <neilb@suse.com>
Reported-by: Daniel Axtens <dja@axtens.net>
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
That can (and does, on some filesystems) happen - ->mkdir() (and thus
vfs_mkdir()) can legitimately leave its argument negative and just
unhash it, counting upon the lookup to pick the object we'd created
next time we try to look at that name.
Some vfs_mkdir() callers forget about that possibility...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Variants of proc_create{,_data} that directly take a struct seq_operations
argument and drastically reduces the boilerplate code in the callers.
All trivial callers converted over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pass the object size in to fscache_acquire_cookie() and
fscache_write_page() rather than the netfs providing a callback by which it
can be received. This makes it easier to update the size of the object
when a new page is written that extends the object.
The current object size is also passed by fscache to the check_aux
function, obviating the need to store it in the aux data.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
Attach copies of the index key and auxiliary data to the fscache cookie so
that:
(1) The callbacks to the netfs for this stuff can be eliminated. This
can simplify things in the cache as the information is still
available, even after the cache has relinquished the cookie.
(2) Simplifies the locking requirements of accessing the information as we
don't have to worry about the netfs object going away on us.
(3) The cache can do lazy updating of the coherency information on disk.
As long as the cache is flushed before reboot/poweroff, there's no
need to update the coherency info on disk every time it changes.
(4) Cookies can be hashed or put in a tree as the index key is easily
available. This allows:
(a) Checks for duplicate cookies can be made at the top fscache layer
rather than down in the bowels of the cache backend.
(b) Caching can be added to a netfs object that has a cookie if the
cache is brought online after the netfs object is allocated.
A certain amount of space is made in the cookie for inline copies of the
data, but if it won't fit there, extra memory will be allocated for it.
The downside of this is that live cache operation requires more memory.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
Add some tracepoints to fscache:
(*) fscache_cookie - Tracks a cookie's usage count.
(*) fscache_netfs - Logs registration of a network filesystem, including
the pointer to the cookie allocated.
(*) fscache_acquire - Logs cookie acquisition.
(*) fscache_relinquish - Logs cookie relinquishment.
(*) fscache_enable - Logs enablement of a cookie.
(*) fscache_disable - Logs disablement of a cookie.
(*) fscache_osm - Tracks execution of states in the object state machine.
and cachefiles:
(*) cachefiles_ref - Tracks a cachefiles object's usage count.
(*) cachefiles_lookup - Logs result of lookup_one_len().
(*) cachefiles_mkdir - Logs result of vfs_mkdir().
(*) cachefiles_create - Logs result of vfs_create().
(*) cachefiles_unlink - Logs calls to vfs_unlink().
(*) cachefiles_rename - Logs calls to vfs_rename().
(*) cachefiles_mark_active - Logs an object becoming active.
(*) cachefiles_wait_active - Logs a wait for an old object to be
destroyed.
(*) cachefiles_mark_inactive - Logs an object becoming inactive.
(*) cachefiles_mark_buried - Logs the burial of an object.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix a couple of checker warnings in fscache and cachefiles:
(1) fscache_n_op_requeue is never used, so get rid of it.
(2) cachefiles_uncache_page() is passed in a lock that it releases, so
this needs annotating.
Signed-off-by: David Howells <dhowells@redhat.com>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As the page free path makes no distinction between cache hot and cold
pages, there is no real useful ordering of pages in the free list that
allocation requests can take advantage of. Juding from the users of
__GFP_COLD, it is likely that a number of them are the result of copying
other sites instead of actually measuring the impact. Remove the
__GFP_COLD parameter which simplifies a number of paths in the page
allocator.
This is potentially controversial but bear in mind that the size of the
per-cpu pagelists versus modern cache sizes means that the whole per-cpu
list can often fit in the L3 cache. Hence, there is only a potential
benefit for microbenchmarks that alloc/free pages in a tight loop. It's
even worse when THP is taken into account which has little or no chance
of getting a cache-hot page as the per-cpu list is bypassed and the
zeroing of multiple pages will thrash the cache anyway.
The truncate microbenchmarks are not shown as this patch affects the
allocation path and not the free path. A page fault microbenchmark was
tested but it showed no sigificant difference which is not surprising
given that the __GFP_COLD branches are a miniscule percentage of the
fault path.
Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Every pagevec_init user claims the pages being released are hot even in
cases where it is unlikely the pages are hot. As no one cares about the
hotness of pages being released to the allocator, just ditch the
parameter.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Firstly by applying the following with coccinelle's spatch:
@@ expression SB; @@
-SB->s_flags & MS_RDONLY
+sb_rdonly(SB)
to effect the conversion to sb_rdonly(sb), then by applying:
@@ expression A, SB; @@
(
-(!sb_rdonly(SB)) && A
+!sb_rdonly(SB) && A
|
-A != (sb_rdonly(SB))
+A != sb_rdonly(SB)
|
-A == (sb_rdonly(SB))
+A == sb_rdonly(SB)
|
-!(sb_rdonly(SB))
+!sb_rdonly(SB)
|
-A && (sb_rdonly(SB))
+A && sb_rdonly(SB)
|
-A || (sb_rdonly(SB))
+A || sb_rdonly(SB)
|
-(sb_rdonly(SB)) != A
+sb_rdonly(SB) != A
|
-(sb_rdonly(SB)) == A
+sb_rdonly(SB) == A
|
-(sb_rdonly(SB)) && A
+sb_rdonly(SB) && A
|
-(sb_rdonly(SB)) || A
+sb_rdonly(SB) || A
)
@@ expression A, B, SB; @@
(
-(sb_rdonly(SB)) ? 1 : 0
+sb_rdonly(SB)
|
-(sb_rdonly(SB)) ? A : B
+sb_rdonly(SB) ? A : B
)
to remove left over excess bracketage and finally by applying:
@@ expression A, SB; @@
(
-(A & MS_RDONLY) != sb_rdonly(SB)
+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
|
-(A & MS_RDONLY) == sb_rdonly(SB)
+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
)
to make comparisons against the result of sb_rdonly() (which is a bool)
work correctly.
Signed-off-by: David Howells <dhowells@redhat.com>
So I've noticed a number of instances where it was not obvious from the
code whether ->task_list was for a wait-queue head or a wait-queue entry.
Furthermore, there's a number of wait-queue users where the lists are
not for 'tasks' but other entities (poll tables, etc.), in which case
the 'task_list' name is actively confusing.
To clear this all up, name the wait-queue head and entry list structure
fields unambiguously:
struct wait_queue_head::task_list => ::head
struct wait_queue_entry::task_list => ::entry
For example, this code:
rqw->wait.task_list.next != &wait->task_list
... is was pretty unclear (to me) what it's doing, while now it's written this way:
rqw->wait.head.next != &wait->entry
... which makes it pretty clear that we are iterating a list until we see the head.
Other examples are:
list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
list_for_each_entry(wq, &fence->wait.task_list, task_list) {
... where it's unclear (to me) what we are iterating, and during review it's
hard to tell whether it's trying to walk a wait-queue entry (which would be
a bug), while now it's written as:
list_for_each_entry_safe(pos, next, &x->head, entry) {
list_for_each_entry(wq, &fence->wait.head, entry) {
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The wait_bit*() types and APIs are mixed into wait.h, but they
are a pretty orthogonal extension of wait-queues.
Furthermore, only about 50 kernel files use these APIs, while
over 1000 use the regular wait-queue functionality.
So clean up the main wait.h by moving the wait-bit functionality
out of it, into a separate .h and .c file:
include/linux/wait_bit.h for types and APIs
kernel/sched/wait_bit.c for the implementation
Update all header dependencies.
This reduces the size of wait.h rather significantly, by about 30%.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h
doing that for them.
Note that even if the count where we need to add extra headers seems high,
it's still a net win, because <linux/sched.h> is included in over
2,200 files ...
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 Andreas
This 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
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 <agruenba@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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: [<ffffffffa06c5cc1>] 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:[<ffffffffa06c5cc1>] 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:
[<ffffffffa06c48cb>] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
[<ffffffffa085d846>] fscache_drop_object+0xd6/0x1e0 [fscache]
[<ffffffffa085d615>] fscache_object_work_func+0xa5/0x200 [fscache]
[<ffffffff810a605b>] process_one_work+0x17b/0x470
[<ffffffff810a6e96>] worker_thread+0x126/0x410
[<ffffffff810a6d70>] ? rescuer_thread+0x460/0x460
[<ffffffff810ae64f>] kthread+0xcf/0xe0
[<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140
[<ffffffff81695418>] ret_from_fork+0x58/0x90
[<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140
The oopsing code shows:
callq 0xffffffff810af6a0 <wake_up_bit>
mov 0xf8(%r12),%rax
mov 0x30(%rax),%rax
mov 0x98(%rax),%rax <---- oops here
lock add %rax,0x130(%rbx)
where this is:
d_backing_inode(object->dentry)->i_blocks
Fixes: a5b3a80b89 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
Reported-by: Jianhong Yin <jiyin@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
__fscache_check_consistency() calls check_consistency() callback
and return the callback's return value. But the return type of
check_consistency() is bool. So __fscache_check_consistency()
return 1 if the cache is inconsistent. This is inconsistent with
the document.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
it's not needed for file_operations of inodes located on fs defined
in the hosting module and for file_operations that go into procfs.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <dhowells@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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 <viro@zeniv.linux.org.uk>
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Christoph Hellwig