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allocate_segment_by_default is the only caller of change_curseg passing
@reuse with 'false', but commit 763bfe1bc575 ("f2fs: remove reusing any
prefree segments") removes the calling, after that, @reuse in
change_curseg always be true, so, let's clean up the unneeded parameter.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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f2fs enables hash-indexed directory by default, so we need to tag
FS_INDEX_FL in inode::i_flags during directory creataion, in order
to show correct status of inode in lsattr:
Before:
------------------- /mnt/f2fs/dir/
After:
-----------I------- /mnt/f2fs/dir/
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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If another thread already made the page dirtied or writebacked, we must avoid
to verify checksum. If we got an error, we need to remove its uptodate as well.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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This patch fixes "f2fs: support inode checksum".
The recovered inode page will be rewritten with valid checksum.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here is the "big" driver core update for 4.14-rc1.
It's really not all that big, the largest thing here being some
firmware tests to help ensure that that crazy api is working properly.
There's also a new uevent for when a driver is bound or unbound from a
device, fixing a hole in the driver model that's been there since the
very beginning. Many thanks to Dmitry for being persistent and
pointing out how wrong I was about this all along :)
Patches for the new uevents are already in the systemd tree, if people
want to play around with them.
Otherwise just a number of other small api changes and updates here,
nothing major. All of these patches have been in linux-next for a
while with no reported issues"
* tag 'driver-core-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (28 commits)
driver core: bus: Fix a potential double free
Do not disable driver and bus shutdown hook when class shutdown hook is set.
base: topology: constify attribute_group structures.
base: Convert to using %pOF instead of full_name
kernfs: Clarify lockdep name for kn->count
fbdev: uvesafb: remove DRIVER_ATTR() usage
xen: xen-pciback: remove DRIVER_ATTR() usage
driver core: Document struct device:dma_ops
mod_devicetable: Remove excess description from structured comment
test_firmware: add batched firmware tests
firmware: enable a debug print for batched requests
firmware: define pr_fmt
firmware: send -EINTR on signal abort on fallback mechanism
test_firmware: add test case for SIGCHLD on sync fallback
initcall_debug: add deferred probe times
Input: axp20x-pek - switch to using devm_device_add_group()
Input: synaptics_rmi4 - use devm_device_add_group() for attributes in F01
Input: gpio_keys - use devm_device_add_group() for attributes
driver core: add devm_device_add_group() and friends
driver core: add device_{add|remove}_group() helpers
...
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In the case of a kzalloc failure when allocating sbi we end up
with a null pointer dereference on sbi when assigning sbi->s_daxdev.
Fix this by moving the assignment of sbi->s_daxdev to after the
null pointer check of sbi.
Detected by CoverityScan CID#1455379 ("Dereference before null check")
Fixes: 5e405595e5bf ("ext4: perform dax_device lookup at mount")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Those two ioctls were never used within the Kernel. Still, there
used to have compat32 code there (and an if #0 block at the core).
Get rid of them.
Fixes: 286fe1ca3fa1 ("media: dmx.h: get rid of DMX_GET_CAPS")
Fixes: 13adefbe9e56 ("media: dmx.h: get rid of DMX_SET_SOURCE")
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Problem with ioctl() is that it's a file operation, yet often used as an
inode operation (i.e. modify the inode despite the file being opened for
read-only).
mnt_want_write_file() is used by filesystems in such cases to get write
access on an arbitrary open file.
Since overlayfs lets filesystems do all file operations, including ioctl,
this can lead to mnt_want_write_file() returning OK for a lower file and
modification of that lower file.
This patch prevents modification by checking if the file is from an
overlayfs lower layer and returning EPERM in that case.
Need to introduce a mnt_want_write_file_path() variant that still does the
old thing for inode operations that can do the copy up + modification
correctly in such cases (fchown, fsetxattr, fremovexattr).
This does not address the correctness of such ioctls on overlayfs (the
correct way would be to copy up and attempt to perform ioctl on upper
file).
In theory this could be a regression. We very much hope that nobody is
relying on such a hack in any sane setup.
While this patch meddles in VFS code, it has no effect on non-overlayfs
filesystems.
Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Need to treat non-regular overlayfs files the same as regular files when
checking for an atime update.
Add a d_real() flag to make it return the upper dentry for all file types.
Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Some servers seem to accept connections while booting but never send
the SMBNegotiate response neither close the connection, causing all
processes accessing the share hang on uninterruptible sleep state.
This happens when the cifs_demultiplex_thread detects the server is
unresponsive so releases the socket and start trying to reconnect.
At some point, the faulty server will accept the socket and the TCP
status will be set to NeedNegotiate. The first issued command accessing
the share will start the negotiation (pid 5828 below), but the response
will never arrive so other commands will be blocked waiting on the mutex
(pid 55352).
This patch checks for unresponsive servers also on the negotiate stage
releasing the socket and reconnecting if the response is not received
and checking again the tcp state when the mutex is acquired.
PID: 55352 TASK: ffff880fd6cc02c0 CPU: 0 COMMAND: "ls"
#0 [ffff880fd9add9f0] schedule at ffffffff81467eb9
#1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0
#2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a
#3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs]
#4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs]
#5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs]
....
Which is waiting a mutex owned by:
PID: 5828 TASK: ffff880fcc55e400 CPU: 0 COMMAND: "xxxx"
#0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9
#1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs]
#2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs]
#3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs]
#4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs]
#5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs]
#6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs]
#7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs]
....
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurélien Aptel <aaptel@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
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We've got no modular users left, and any potential modular user is better
of with iov_iter based variants.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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No modular users left. Given that they take user pointers there is no
good reason to export it to drivers to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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No modular users left, and any new ones should use kernel_read/write
or iov_iter variants instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Instead of playing with the addressing limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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This matches kernel_read and kernel_write and avoids any need for casts in
the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Make the position an in/out argument like all the other read/write
helpers and and make the buf argument a void pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Use proper ssize_t and size_t types for the return value and count
argument, move the offset last and make it an in/out argument like
all other read/write helpers, and make the buf argument a void pointer
to get rid of lots of casts in the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Instead of playing games with the address limit..
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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All support is already there in the generic code, we just need to wire
it up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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This is based on the old idea and code from Milosz Tanski. With the aio
nowait code it becomes mostly trivial now. Buffered writes continue to
return -EOPNOTSUPP if RWF_NOWAIT is passed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Add a separate flags argument (in addition to the open flags) to control
the behavior of d_real().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This adds support for writing extended attributes on SMB2+ shares.
Attributes can be written using the setfattr command.
RH-bz: 1110709
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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SMB1 already has support to read attributes. This adds similar support
to SMB2+.
With this patch, tools such as 'getfattr' will now work with SMB2+ shares.
RH-bz: 1110709
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Add 'cross-release' support to lockdep, which allows APIs like
completions, where it's not the 'owner' who releases the lock, to be
tracked. It's all activated automatically under
CONFIG_PROVE_LOCKING=y.
- Clean up (restructure) the x86 atomics op implementation to be more
readable, in preparation of KASAN annotations. (Dmitry Vyukov)
- Fix static keys (Paolo Bonzini)
- Add killable versions of down_read() et al (Kirill Tkhai)
- Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini)
- Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra)
- Remove smp_mb__before_spinlock() and convert its usages, introduce
smp_mb__after_spinlock() (Peter Zijlstra)
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
locking/lockdep/selftests: Fix mixed read-write ABBA tests
sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK()
acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse
locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures
smp: Avoid using two cache lines for struct call_single_data
locking/lockdep: Untangle xhlock history save/restore from task independence
locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
futex: Remove duplicated code and fix undefined behaviour
Documentation/locking/atomic: Finish the document...
locking/lockdep: Fix workqueue crossrelease annotation
workqueue/lockdep: 'Fix' flush_work() annotation
locking/lockdep/selftests: Add mixed read-write ABBA tests
mm, locking/barriers: Clarify tlb_flush_pending() barriers
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive
locking/lockdep: Explicitly initialize wq_barrier::done::map
locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS
locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING
locking/refcounts, x86/asm: Implement fast refcount overflow protection
locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- fix affine wakeups (Peter Zijlstra)
- improve CPU onlining (and general bootup) scalability on systems
with ridiculous number (thousands) of CPUs (Peter Zijlstra)
- sched/numa updates (Rik van Riel)
- sched/deadline updates (Byungchul Park)
- sched/cpufreq enhancements and related cleanups (Viresh Kumar)
- sched/debug enhancements (Xie XiuQi)
- various fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
sched/debug: Optimize sched_domain sysctl generation
sched/topology: Avoid pointless rebuild
sched/topology, cpuset: Avoid spurious/wrong domain rebuilds
sched/topology: Improve comments
sched/topology: Fix memory leak in __sdt_alloc()
sched/completion: Document that reinit_completion() must be called after complete_all()
sched/autogroup: Fix error reporting printk text in autogroup_create()
sched/fair: Fix wake_affine() for !NUMA_BALANCING
sched/debug: Intruduce task_state_to_char() helper function
sched/debug: Show task state in /proc/sched_debug
sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
sched/core: Remove unnecessary initialization init_idle_bootup_task()
sched/deadline: Change return value of cpudl_find()
sched/deadline: Make find_later_rq() choose a closer CPU in topology
sched/numa: Scale scan period with tasks in group and shared/private
sched/numa: Slow down scan rate if shared faults dominate
sched/pelt: Fix false running accounting
sched: Mark pick_next_task_dl() and build_sched_domain() as static
sched/cpupri: Don't re-initialize 'struct cpupri'
sched/deadline: Don't re-initialize 'struct cpudl'
...
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d_real() is never called with a negative dentry. So remove the
d_is_negative() check (which would never trigger anyway, since d_is_reg()
returns false for a negative dentry).
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Conflicts:
mm/page_alloc.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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struct timespec is not y2038 safe on 32 bit machines.
Replace timespec with y2038 safe struct timespec64.
Note that the patch only changes the internals without
modifying the syscall interfaces. This will be part
of a separate series.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc fixes from Al Viro:
"Loose ends and regressions from the last merge window.
Strictly speaking, only binfmt_flat thing is a build regression per
se - the rest is 'only sparse cares about that' stuff"
[ This came in before the 4.13 release and could have gone there, but it
was late in the release and nothing seemed critical enough to care, so
I'm pulling it in the 4.14 merge window instead - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
binfmt_flat: fix arch/m32r and arch/microblaze flat_put_addr_at_rp()
compat_hdio_ioctl: Fix a declaration
<linux/uaccess.h>: Fix copy_in_user() declaration
annotate RWF_... flags
teach SYSCALL_DEFINE/COMPAT_SYSCALL_DEFINE to handle __bitwise arguments
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In function xfs_test_remount_options(), kfree() is used to free memory
allocated by kmem_zalloc(). But it is better to use kmem_free().
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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Our loop in xfs_finish_page_writeback, which iterates over all buffer
heads in a page and then calls end_buffer_async_write, which also
iterates over all buffers in the page to check if any I/O is in flight
is not only inefficient, but also potentially dangerous as
end_buffer_async_write can cause the page and all buffers to be freed.
Replace it with a single loop that does the work of end_buffer_async_write
on a per-page basis.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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Reject attempts to set XFLAGS that correspond to di_flags2 inode flags
if the inode isn't a v3 inode, because di_flags2 only exists on v3.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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Fix up all the compiler warnings that have crept in.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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Pull cifs version warning fix from Steve French:
"As requested, additional kernel warning messages to clarify the
default dialect changes"
[ There is still some discussion about exactly which version should be
the new default. Longer-term we have auto-negotiation coming, but
that's not there yet.. - Linus ]
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
Fix warning messages when mounting to older servers
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Three cases of simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
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In Christoph's patch to refactor xfs_bmse_merge, the updated rmap code
does more work than it needs to (because map-extent auto-merges
records). Remove the unnecessary unmap and save ourselves a deferred
op.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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When calling into _xfs_log_force{,_lsn}() with a pointer
to log_flushed variable, log_flushed will be set to 1 if:
1. xlog_sync() is called to flush the active log buffer
AND/OR
2. xlog_wait() is called to wait on a syncing log buffers
xfs_file_fsync() checks the value of log_flushed after
_xfs_log_force_lsn() call to optimize away an explicit
PREFLUSH request to the data block device after writing
out all the file's pages to disk.
This optimization is incorrect in the following sequence of events:
Task A Task B
-------------------------------------------------------
xfs_file_fsync()
_xfs_log_force_lsn()
xlog_sync()
[submit PREFLUSH]
xfs_file_fsync()
file_write_and_wait_range()
[submit WRITE X]
[endio WRITE X]
_xfs_log_force_lsn()
xlog_wait()
[endio PREFLUSH]
The write X is not guarantied to be on persistent storage
when PREFLUSH request in completed, because write A was submitted
after the PREFLUSH request, but xfs_file_fsync() of task A will
be notified of log_flushed=1 and will skip explicit flush.
If the system crashes after fsync of task A, write X may not be
present on disk after reboot.
This bug was discovered and demonstrated using Josef Bacik's
dm-log-writes target, which can be used to record block io operations
and then replay a subset of these operations onto the target device.
The test goes something like this:
- Use fsx to execute ops of a file and record ops on log device
- Every now and then fsync the file, store md5 of file and mark
the location in the log
- Then replay log onto device for each mark, mount fs and compare
md5 of file to stored value
Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <jbacik@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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Currently flag switching can be used to easily crash the kernel. Disable
the per-inode DAX flag until that is sorted out.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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Use the existing functionality instead of directly poking into the extent
list.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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This avoids poking into the internals of the extent list. Also return
the number of extents as the return value instead of an additional
by reference argument, and make it available to callers outside of
xfs_bmap_util.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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This abstracts the function away from details of the low-level extent
list implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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This abstracts the function away from details of the low-level extent
list implementation.
Note that it seems like the previous implementation of rmap for
the merge case was completely broken, but it no seems appear to
trigger that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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For the first right move we need to look up next_fsb. That means
our last fsb that contains next_fsb must also be the current extent,
so take advantage of that by moving the code around a bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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The race was introduced by me in commit 971316f0503a ("epoll:
ep_unregister_pollwait() can use the freed pwq->whead"). I did not
realize that nothing can protect eventpoll after ep_poll_callback() sets
->whead = NULL, only whead->lock can save us from the race with
ep_free() or ep_remove().
Move ->whead = NULL to the end of ep_poll_callback() and add the
necessary barriers.
TODO: cleanup the ewake/EPOLLEXCLUSIVE logic, it was confusing even
before this patch.
Hopefully this explains use-after-free reported by syzcaller:
BUG: KASAN: use-after-free in debug_spin_lock_before
...
_raw_spin_lock_irqsave+0x4a/0x60 kernel/locking/spinlock.c:159
ep_poll_callback+0x29f/0xff0 fs/eventpoll.c:1148
this is spin_lock(eventpoll->lock),
...
Freed by task 17774:
...
kfree+0xe8/0x2c0 mm/slub.c:3883
ep_free+0x22c/0x2a0 fs/eventpoll.c:865
Fixes: 971316f0503a ("epoll: ep_unregister_pollwait() can use the freed pwq->whead")
Reported-by: 范龙飞 <long7573@126.com>
Cc: stable@vger.kernel.org
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Root in a non-initial user ns cannot be trusted to write a traditional
security.capability xattr. If it were allowed to do so, then any
unprivileged user on the host could map his own uid to root in a private
namespace, write the xattr, and execute the file with privilege on the
host.
However supporting file capabilities in a user namespace is very
desirable. Not doing so means that any programs designed to run with
limited privilege must continue to support other methods of gaining and
dropping privilege. For instance a program installer must detect
whether file capabilities can be assigned, and assign them if so but set
setuid-root otherwise. The program in turn must know how to drop
partial capabilities, and do so only if setuid-root.
This patch introduces v3 of the security.capability xattr. It builds a
vfs_ns_cap_data struct by appending a uid_t rootid to struct
vfs_cap_data. This is the absolute uid_t (that is, the uid_t in user
namespace which mounted the filesystem, usually init_user_ns) of the
root id in whose namespaces the file capabilities may take effect.
When a task asks to write a v2 security.capability xattr, if it is
privileged with respect to the userns which mounted the filesystem, then
nothing should change. Otherwise, the kernel will transparently rewrite
the xattr as a v3 with the appropriate rootid. This is done during the
execution of setxattr() to catch user-space-initiated capability writes.
Subsequently, any task executing the file which has the noted kuid as
its root uid, or which is in a descendent user_ns of such a user_ns,
will run the file with capabilities.
Similarly when asking to read file capabilities, a v3 capability will
be presented as v2 if it applies to the caller's namespace.
If a task writes a v3 security.capability, then it can provide a uid for
the xattr so long as the uid is valid in its own user namespace, and it
is privileged with CAP_SETFCAP over its namespace. The kernel will
translate that rootid to an absolute uid, and write that to disk. After
this, a task in the writer's namespace will not be able to use those
capabilities (unless rootid was 0), but a task in a namespace where the
given uid is root will.
Only a single security.capability xattr may exist at a time for a given
file. A task may overwrite an existing xattr so long as it is
privileged over the inode. Note this is a departure from previous
semantics, which required privilege to remove a security.capability
xattr. This check can be re-added if deemed useful.
This allows a simple setxattr to work, allows tar/untar to work, and
allows us to tar in one namespace and untar in another while preserving
the capability, without risking leaking privilege into a parent
namespace.
Example using tar:
$ cp /bin/sleep sleepx
$ mkdir b1 b2
$ lxc-usernsexec -m b:0:100000:1 -m b:1:$(id -u):1 -- chown 0:0 b1
$ lxc-usernsexec -m b:0:100001:1 -m b:1:$(id -u):1 -- chown 0:0 b2
$ lxc-usernsexec -m b:0:100000:1000 -- tar --xattrs-include=security.capability --xattrs -cf b1/sleepx.tar sleepx
$ lxc-usernsexec -m b:0:100001:1000 -- tar --xattrs-include=security.capability --xattrs -C b2 -xf b1/sleepx.tar
$ lxc-usernsexec -m b:0:100001:1000 -- getcap b2/sleepx
b2/sleepx = cap_sys_admin+ep
# /opt/ltp/testcases/bin/getv3xattr b2/sleepx
v3 xattr, rootid is 100001
A patch to linux-test-project adding a new set of tests for this
functionality is in the nsfscaps branch at github.com/hallyn/ltp
Changelog:
Nov 02 2016: fix invalid check at refuse_fcap_overwrite()
Nov 07 2016: convert rootid from and to fs user_ns
(From ebiederm: mar 28 2017)
commoncap.c: fix typos - s/v4/v3
get_vfs_caps_from_disk: clarify the fs_ns root access check
nsfscaps: change the code split for cap_inode_setxattr()
Apr 09 2017:
don't return v3 cap for caps owned by current root.
return a v2 cap for a true v2 cap in non-init ns
Apr 18 2017:
. Change the flow of fscap writing to support s_user_ns writing.
. Remove refuse_fcap_overwrite(). The value of the previous
xattr doesn't matter.
Apr 24 2017:
. incorporate Eric's incremental diff
. move cap_convert_nscap to setxattr and simplify its usage
May 8, 2017:
. fix leaking dentry refcount in cap_inode_getsecurity
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Pull ceph fix from Ilya Dryomov:
"ceph fscache page locking fix from Zheng, marked for stable"
* tag 'ceph-for-4.13-rc8' of git://github.com/ceph/ceph-client:
ceph: fix readpage from fscache
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Use the bmap abstraction instead of open-coding bmbt details here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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