Current handling of Partition Descriptors in Volume Descriptor Sequence
is buggy in several ways. Firstly, it does not take descriptor sequence
numbers into account at all, thus any volume making serious use of them
would be unmountable. Secondly, it does not handle Volume Descriptor
Pointers or Volume Descriptor Sequence without Terminating Descriptor.
Fix these problems by properly remembering all Partition Descriptors in
the Volume Descriptor Sequence and their sequence numbers. This is made
more complicated by the fact that we don't know number of partitions in
advance and sequence numbers have to be tracked on per-partition basis.
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
When scanning Volume Descriptor Sequence, several descriptors have
exactly the same handling. Unify it.
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
When specifying string type mount option (e.g., logdev)
several times in a mount, current option parsing may
cause memory leak. Hence, call kfree for previous one
in this case.
Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
When blkdev_open() races with device removal and creation it can happen
that unhashed bdev inode gets associated with newly created gendisk
like:
CPU0 CPU1
blkdev_open()
bdev = bd_acquire()
del_gendisk()
bdev_unhash_inode(bdev);
remove device
create new device with the same number
__blkdev_get()
disk = get_gendisk()
- gets reference to gendisk of the new device
Now another blkdev_open() will not find original 'bdev' as it got
unhashed, create a new one and associate it with the same 'disk' at
which point problems start as we have two independent page caches for
one device.
Fix the problem by verifying that the bdev inode didn't get unhashed
before we acquired gendisk reference. That way we make sure gendisk can
get associated only with visible bdev inodes.
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When two blkdev_open() calls race with device removal and recreation,
__blkdev_get() can use looked up gendisk after it is freed:
CPU0 CPU1 CPU2
del_gendisk(disk);
bdev_unhash_inode(inode);
blkdev_open() blkdev_open()
bdev = bd_acquire(inode);
- creates and returns new inode
bdev = bd_acquire(inode);
- returns the same inode
__blkdev_get(devt) __blkdev_get(devt)
disk = get_gendisk(devt);
- got structure of device going away
<finish device removal>
<new device gets
created under the same
device number>
disk = get_gendisk(devt);
- got new device structure
if (!bdev->bd_openers) {
does the first open
}
if (!bdev->bd_openers)
- false
} else {
put_disk_and_module(disk)
- remember this was old device - this was last ref and disk is
now freed
}
disk_unblock_events(disk); -> oops
Fix the problem by making sure we drop reference to disk in
__blkdev_get() only after we are really done with it.
Reported-by: Hou Tao <houtao1@huawei.com>
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a proper counterpart to get_disk_and_module() -
put_disk_and_module(). Currently it is opencoded in several places.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit e864f39569 "fs: add RWF_DSYNC aand RWF_SYNC" added additional
way for direct IO to become synchronous and thus trigger fsync from the
IO completion handler. Then commit 9830f4be15 "fs: Use RWF_* flags for
AIO operations" allowed these flags to be set for AIO as well. However
that commit forgot to update the condition checking whether the IO
completion handling should be defered to a workqueue and thus AIO DIO
with RWF_[D]SYNC set will call fsync() from IRQ context resulting in
sleep in atomic.
Fix the problem by checking directly iocb flags (the same way as it is
done in dio_complete()) instead of checking all conditions that could
lead to IO being synchronous.
CC: Christoph Hellwig <hch@lst.de>
CC: Goldwyn Rodrigues <rgoldwyn@suse.com>
CC: stable@vger.kernel.org
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9830f4be15
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
redirect_dir=nofollow should not follow a redirect. But in a specific
configuration it can still follow it. For example try this.
$ mkdir -p lower0 lower1/foo upper work merged
$ touch lower1/foo/lower-file.txt
$ setfattr -n "trusted.overlay.opaque" -v "y" lower1/foo
$ mount -t overlay -o lowerdir=lower1:lower0,workdir=work,upperdir=upper,redirect_dir=on none merged
$ cd merged
$ mv foo foo-renamed
$ umount merged
# mount again. This time with redirect_dir=nofollow
$ mount -t overlay -o lowerdir=lower1:lower0,workdir=work,upperdir=upper,redirect_dir=nofollow none merged
$ ls merged/foo-renamed/
# This lists lower-file.txt, while it should not have.
Basically, we are doing redirect check after we check for d.stop. And
if this is not last lower, and we find an opaque lower, d.stop will be
set.
ovl_lookup_single()
if (!d->last && ovl_is_opaquedir(this)) {
d->stop = d->opaque = true;
goto out;
}
To fix this, first check redirect is allowed. And after that check if
d.stop has been set or not.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Fixes: 438c84c2f0 ("ovl: don't follow redirects if redirect_dir=off")
Cc: <stable@vger.kernel.org> #v4.15
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When failing from ceph_fs_debugfs_init() in ceph_real_mount(),
there is lack of dput of root_dentry and it causes slab errors,
so change the calling order of ceph_fs_debugfs_init() and
open_root_dentry() and do some cleanups to avoid this issue.
Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
When parsing string option, in order to avoid memory leak we need to
carefully free it first in case of specifying same option several times.
Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
fs/overlayfs/export.c:459:10-16: WARNING: PTR_ERR_OR_ZERO can be used
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Generated by: scripts/coccinelle/api/ptr_ret.cocci
Fixes: 4b91c30a5a ("ovl: lookup connected ancestor of dir in inode cache")
CC: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Pull NFS client bugfixes from Trond Myklebust:
- fix a broken cast in nfs4_callback_recallany()
- fix an Oops during NFSv4 migration events
- make struct nlmclnt_fl_close_lock_ops static
* tag 'nfs-for-4.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: make struct nlmclnt_fl_close_lock_ops static
nfs: system crashes after NFS4ERR_MOVED recovery
NFSv4: Fix broken cast in nfs4_callback_recallany()
i_dir_seq is subject to concurrent modification by a cmpxchg or
store-release operation, so ensure that the relaxed access in
d_alloc_parallel uses READ_ONCE.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If d_alloc_parallel runs concurrently with __d_add, it is possible for
d_alloc_parallel to continuously retry whilst i_dir_seq has been
incremented to an odd value by __d_add:
CPU0:
__d_add
n = start_dir_add(dir);
cmpxchg(&dir->i_dir_seq, n, n + 1) == n
CPU1:
d_alloc_parallel
retry:
seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
hlist_bl_lock(b);
bit_spin_lock(0, (unsigned long *)b); // Always succeeds
CPU0:
__d_lookup_done(dentry)
hlist_bl_lock
bit_spin_lock(0, (unsigned long *)b); // Never succeeds
CPU1:
if (unlikely(parent->d_inode->i_dir_seq != seq)) {
hlist_bl_unlock(b);
goto retry;
}
Since the simple bit_spin_lock used to implement hlist_bl_lock does not
provide any fairness guarantees, then CPU1 can starve CPU0 of the lock
and prevent it from reaching end_dir_add(dir), therefore CPU1 cannot
exit its retry loop because the sequence number always has the bottom
bit set.
This patch resolves the livelock by not taking hlist_bl_lock in
d_alloc_parallel if the sequence counter is odd, since any subsequent
masked comparison with i_dir_seq will fail anyway.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Naresh Madhusudana <naresh.madhusudana@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In case when dentry passed to lock_parent() is protected from freeing only
by the fact that it's on a shrink list and trylock of parent fails, we
could get hit by __dentry_kill() (and subsequent dentry_kill(parent))
between unlocking dentry and locking presumed parent. We need to recheck
that dentry is alive once we lock both it and parent *and* postpone
rcu_read_unlock() until after that point. Otherwise we could return
a pointer to struct dentry that already is rcu-scheduled for freeing, with
->d_lock held on it; caller's subsequent attempt to unlock it can end
up with memory corruption.
Cc: stable@vger.kernel.org # 3.12+, counting backports
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull siginfo fix from Eric Biederman:
"This fixes a build error that only shows up on blackfin"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
fs/signalfd: fix build error for BUS_MCEERR_AR
During log recovery, the per-AG reservations aren't yet set up, so log
recovery has to reserve enough blocks to handle all possible btree
splits.
Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Apparently different gcc versions have competing and
incompatible notions of how to initialize at declaration,
so just give up and fall back to the time-tested memset().
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Fix build error in fs/signalfd.c by using same method that is used in
kernel/signal.c: separate blocks for different signal si_code values.
./fs/signalfd.c: error: 'BUS_MCEERR_AR' undeclared (first use in this function)
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Each read from a file in efivarfs results in two calls to EFI
(one to get the file size, another to get the actual data).
On X86 these EFI calls result in broadcast system management
interrupts (SMI) which affect performance of the whole system.
A malicious user can loop performing reads from efivarfs bringing
the system to its knees.
Linus suggested per-user rate limit to solve this.
So we add a ratelimit structure to "user_struct" and initialize
it for the root user for no limit. When allocating user_struct for
other users we set the limit to 100 per second. This could be used
for other places that want to limit the rate of some detrimental
user action.
In efivarfs if the limit is exceeded when reading, we take an
interruptible nap for 50ms and check the rate limit again.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The structure nlmclnt_fl_close_lock_ops s local to the source and does
not need to be in global scope, so make it static.
Cleans up sparse warning:
fs/nfs/nfs3proc.c:876:33: warning: symbol 'nlmclnt_fl_close_lock_ops' was not
declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs4_update_server unconditionally releases the nfs_client for the
source server. If migration fails, this can cause the source server's
nfs_client struct to be left with a low reference count, resulting in
use-after-free. Also, adjust reference count handling for ELOOP.
NFS: state manager: migration failed on NFSv4 server nfsvmu10 with error 6
WARNING: CPU: 16 PID: 17960 at fs/nfs/client.c:281 nfs_put_client+0xfa/0x110 [nfs]()
nfs_put_client+0xfa/0x110 [nfs]
nfs4_run_state_manager+0x30/0x40 [nfsv4]
kthread+0xd8/0xf0
BUG: unable to handle kernel NULL pointer dereference at 00000000000002a8
nfs4_xdr_enc_write+0x6b/0x160 [nfsv4]
rpcauth_wrap_req+0xac/0xf0 [sunrpc]
call_transmit+0x18c/0x2c0 [sunrpc]
__rpc_execute+0xa6/0x490 [sunrpc]
rpc_async_schedule+0x15/0x20 [sunrpc]
process_one_work+0x160/0x470
worker_thread+0x112/0x540
? rescuer_thread+0x3f0/0x3f0
kthread+0xd8/0xf0
This bug was introduced by 32e62b7c ("NFS: Add nfs4_update_server"),
but the fix applies cleanly to 52442f9b ("NFS4: Avoid migration loops")
Reported-by: Helen Chao <helen.chao@oracle.com>
Fixes: 52442f9b11 ("NFS4: Avoid migration loops")
Signed-off-by: Bill Baker <bill.baker@oracle.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
When reading the inode or block allocation bitmap, if the bitmap needs
to be initialized, do not update the checksum in the block group
descriptor. That's because we're not set up to journal those changes.
Instead, just set the verified bit on the bitmap block, so that it's
not necessary to validate the checksum.
When a block or inode allocation actually happens, at that point the
checksum will be calculated, and update of the bg descriptor block
will be properly journalled.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
This updates the jbd2 superblock unnecessarily, and on an abort we
shouldn't truncate the log.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Previously the jbd2 layer assumed that a file system check would be
required after a journal abort. In the case of the deliberate file
system shutdown, this should not be necessary. Allow the jbd2 layer
to distinguish between these two cases by using the ESHUTDOWN errno.
Also add proper locking to __journal_abort_soft().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The msleep() when processing EXT4_GOING_FLAGS_NOLOGFLUSH was a hack to
avoid some races (that are now fixed), but in fact it introduced its
own race.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The ext4 forced shutdown flag needs to prevent new handles from being
started, but it needs to allow existing handles to complete. So the
forced shutdown flag should not force ext4_journal_get_write_access to
fail.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
There were two error messages emitted by jbd2, one for a bad checksum
for a jbd2 descriptor block, and one for a bad checksum for a jbd2
data block. Change the data block checksum error so that the two can
be disambiguated.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Pull btrfs fixes from David Sterba:
"We have a few assorted fixes, some of them show up during fstests so I
gave them more testing"
* tag 'for-4.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
Btrfs: fix null pointer dereference when replacing missing device
btrfs: remove spurious WARN_ON(ref->count < 0) in find_parent_nodes
btrfs: Ignore errors from btrfs_qgroup_trace_extent_post
Btrfs: fix unexpected -EEXIST when creating new inode
Btrfs: fix use-after-free on root->orphan_block_rsv
Btrfs: fix btrfs_evict_inode to handle abnormal inodes correctly
Btrfs: fix extent state leak from tree log
Btrfs: fix crash due to not cleaning up tree log block's dirty bits
Btrfs: fix deadlock in run_delalloc_nocow
This change relaxes copy up on encode of merge dir with lower layer > 1
and handles the case of encoding a merge dir with lower layer 1, where an
ancestor is a non-indexed merge dir. In that case, decode of the lower
file handle will not have been possible if the non-indexed ancestor is
redirected before or after encode.
Before encoding a non-upper directory file handle from real layer N, we
need to check if it will be possible to reconnect an overlay dentry from
the real lower decoded dentry. This is done by following the overlay
ancestry up to a "layer N connected" ancestor and verifying that all
parents along the way are "layer N connectable". If an ancestor that is
NOT "layer N connectable" is found, we need to copy up an ancestor, which
is "layer N connectable", thus making that ancestor "layer N connected".
For example:
layer 1: /a
layer 2: /a/b/c
The overlay dentry /a is NOT "layer 2 connectable", because if dir /a is
copied up and renamed, upper dir /a will be indexed by lower dir /a from
layer 1. The dir /a from layer 2 will never be indexed, so the algorithm
in ovl_lookup_real_ancestor() (*) will not be able to lookup a connected
overlay dentry from the connected lower dentry /a/b/c.
To avoid this problem on decode time, we need to copy up an ancestor of
/a/b/c, which is "layer 2 connectable", on encode time. That ancestor is
/a/b. After copy up (and index) of /a/b, it will become "layer 2 connected"
and when the time comes to decode the file handle from lower dentry /a/b/c,
ovl_lookup_real_ancestor() will find the indexed ancestor /a/b and decoding
a connected overlay dentry will be accomplished.
(*) the algorithm in ovl_lookup_real_ancestor() can be improved to lookup
an entry /a in the lower layers above layer N and find the indexed dir /a
from layer 1. If that improvement is made, then the check for "layer N
connected" will need to verify there are no redirects in lower layers above
layer N. In the example above, /a will be "layer 2 connectable". However,
if layer 2 dir /a is a target of a layer 1 redirect, then /a will NOT be
"layer 2 connectable":
layer 1: /A (redirect = /a)
layer 2: /a/b/c
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Commit 31747eda41 ("ovl: hash directory inodes for fsnotify")
fixed an issue of inotify watch on directory that stops getting
events after dropping dentry caches.
A similar issue exists for non-dir non-upper files, for example:
$ mkdir -p lower upper work merged
$ touch lower/foo
$ mount -t overlay -o
lowerdir=lower,workdir=work,upperdir=upper none merged
$ inotifywait merged/foo &
$ echo 2 > /proc/sys/vm/drop_caches
$ cat merged/foo
inotifywait doesn't get the OPEN event, because ovl_lookup() called
from 'cat' allocates a new overlay inode and does not reuse the
watched inode.
Fix this by hashing non-dir overlay inodes by lower real inode in
the following cases that were not hashed before this change:
- A non-upper overlay mount
- A lower non-hardlink when index=off
A helper ovl_hash_bylower() was added to put all the logic and
documentation about which real inode an overlay inode is hashed by
into one place.
The issue dates back to initial version of overlayfs, but this
patch depends on ovl_inode code that was introduced in kernel v4.13.
Cc: <stable@vger.kernel.org> #v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Convert index definitions from defines to enum. It is a shorter
description and easier to modify. Also remove VDS_POS_VOL_DESC_PTR since
it is unused.
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
According to ECMA-167 3/8.4.2 a volume descriptor sequence can be
terminated also by an unrecorded block within the extent of volume
descriptor sequence. Currently we errored out in such case making such
volumes unmountable. Handle that case by treating any invalid block as a
block terminating the sequence.
Reported-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
According to ECMA-167 3/8.4.2 Volume Descriptor Pointer is terminating
current extent of Volume Descriptor Sequence. Also according to ECMA-167
3/8.4.3 Volume Descriptor Sequence Number is not significant for Volume
Descriptor Pointers. Simplify the handling of Volume Descriptor Pointers
to take this into account.
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
We pass one block beyond end of volume descriptor sequence into
process_sequence() as 'lastblock' instead of the last block of the
sequence. When the sequence is not terminated with TD descriptor, this
could lead to false errors due to invalid blocks in volume descriptor
sequence and thus unmountable volumes.
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This function will be used to obtain net of tun device.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86 fixes from Ingo Molnar:
"Misc fixes all across the map:
- /proc/kcore vsyscall related fixes
- LTO fix
- build warning fix
- CPU hotplug fix
- Kconfig NR_CPUS cleanups
- cpu_has() cleanups/robustification
- .gitignore fix
- memory-failure unmapping fix
- UV platform fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
x86/error_inject: Make just_return_func() globally visible
x86/platform/UV: Fix GAM Range Table entries less than 1GB
x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore
x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU
x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally
vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
x86/Kconfig: Further simplify the NR_CPUS config
x86/Kconfig: Simplify NR_CPUS config
x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"
x86/cpufeature: Update _static_cpu_has() to use all named variables
x86/cpufeature: Reindent _static_cpu_has()
Pull gfs2 fix from Bob Peterson:
"Fix regressions in the gfs2 iomap for block_map implementation we
recently discovered in commit 3974320ca6"
* tag 'gfs2-4.16.rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fixes to "Implement iomap for block_map"
Watch descriptor is id of the watch created by inotify_add_watch().
It is allocated in inotify_add_to_idr(), and takes the numbers
starting from 1. Every new inotify watch obtains next available
number (usually, old + 1), as served by idr_alloc_cyclic().
CRIU (Checkpoint/Restore In Userspace) project supports inotify
files, and restores watched descriptors with the same numbers,
they had before dump. Since there was no kernel support, we
had to use cycle to add a watch with specific descriptor id:
while (1) {
int wd;
wd = inotify_add_watch(inotify_fd, path, mask);
if (wd < 0) {
break;
} else if (wd == desired_wd_id) {
ret = 0;
break;
}
inotify_rm_watch(inotify_fd, wd);
}
(You may find the actual code at the below link:
https://github.com/checkpoint-restore/criu/blob/v3.7/criu/fsnotify.c#L577)
The cycle is suboptiomal and very expensive, but since there is no better
kernel support, it was the only way to restore that. Happily, we had met
mostly descriptors with small id, and this approach had worked somehow.
But recent time containers with inotify with big watch descriptors
begun to come, and this way stopped to work at all. When descriptor id
is something about 0x34d71d6, the restoring process spins in busy loop
for a long time, and the restore hungs and delay of migration from node
to node could easily be watched.
This patch aims to solve this problem. It introduces new ioctl
INOTIFY_IOC_SETNEXTWD, which allows to request the number of next created
watch descriptor from userspace. It simply calls idr_set_cursor() primitive
to populate idr::idr_next, so that next idr_alloc_cyclic() allocation
will return this id, if it is not occupied. This is the way which is
used to restore some other resources from userspace. For example,
/proc/sys/kernel/ns_last_pid works the same for task pids.
The new code is under CONFIG_CHECKPOINT_RESTORE #define, so small system
may exclude it.
v2: Use INT_MAX instead of custom definition of max id,
as IDR subsystem guarantees id is between 0 and INT_MAX.
CC: Jan Kara <jack@suse.cz>
CC: Matthew Wilcox <willy@infradead.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
It turns out that commit 3974320ca6 "Implement iomap for block_map"
introduced a few bugs that trigger occasional failures with xfstest
generic/476:
In gfs2_iomap_begin, we jump to do_alloc when we determine that we are
beyond the end of the allocated metadata (height > ip->i_height).
There, we can end up calling hole_size with a metapath that doesn't
match the current metadata tree, which doesn't make sense. After
untangling the code at do_alloc, fix this by checking if the block we
are looking for is within the range of allocated metadata.
In addition, add a BUG() in case gfs2_iomap_begin is accidentally called
for reading stuffed files: this is handled separately. Make sure we
don't truncate iomap->length for reads beyond the end of the file; in
that case, the entire range counts as a hole.
Finally, revert to taking a bitmap write lock when doing allocations.
It's unclear why that change didn't lead to any failures during testing.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch starts to convert pernet_subsys, registered
before initcalls.
proc_net_ns_ops::proc_net_ns_init()/proc_net_ns_exit()
{un,}register pernet net->proc_net and ->proc_net_stat.
Constructors and destructors of another pernet_operations
are not interested in foreign net's proc_net and proc_net_stat.
Proc filesystem privitives are synchronized on proc_subdir_lock.
So, proc_net_ns_ops methods are able to be executed
in parallel with methods of any other pernet operations.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changes since v1:
Added changes in these files:
drivers/infiniband/hw/usnic/usnic_transport.c
drivers/staging/lustre/lnet/lnet/lib-socket.c
drivers/target/iscsi/iscsi_target_login.c
drivers/vhost/net.c
fs/dlm/lowcomms.c
fs/ocfs2/cluster/tcp.c
security/tomoyo/network.c
Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.
"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.
None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.
This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.
Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.
rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.
Userspace API is not changed.
text data bss dec hex filename
30108430 2633624 873672 33615726 200ef6e vmlinux.before.o
30108109 2633612 873672 33615393 200ee21 vmlinux.o
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
