This patch relaxes async discard commands to avoid waiting its end_io during
checkpoint.
Instead of waiting them during checkpoint, it will be done when actually reusing
them.
Test on initial partition of nvme drive.
# time fstrim /mnt/test
Before : 6.158s
After : 4.822s
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
A test program gets the SEEK_DATA with two values between
a new created file and the exist file on f2fs filesystem.
F2FS filesystem, (the first "test1" is a new file)
SEEK_DATA size != 0 (offset = 8192)
SEEK_DATA size != 0 (offset = 4096)
PNFS filesystem, (the first "test1" is a new file)
SEEK_DATA size != 0 (offset = 4096)
SEEK_DATA size != 0 (offset = 4096)
int main(int argc, char **argv)
{
char *filename = argv[1];
int offset = 1, i = 0, fd = -1;
if (argc < 2) {
printf("Usage: %s f2fsfilename\n", argv[0]);
return -1;
}
/*
if (!access(filename, F_OK) || errno != ENOENT) {
printf("Needs a new file for test, %m\n");
return -1;
}*/
fd = open(filename, O_RDWR | O_CREAT, 0777);
if (fd < 0) {
printf("Create test file %s failed, %m\n", filename);
return -1;
}
for (i = 0; i < 20; i++) {
offset = 1 << i;
ftruncate(fd, 0);
lseek(fd, offset, SEEK_SET);
write(fd, "test", 5);
/* Get the alloc size by seek data equal zero*/
if (lseek(fd, 0, SEEK_DATA)) {
printf("SEEK_DATA size != 0 (offset = %d)\n", offset);
break;
}
}
close(fd);
return 0;
}
Reported-and-Tested-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes the renaming bug on encrypted filenames, which was pointed by
(ext4: don't allow encrypted operations without keys)
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to show the max number of atomic operations which are
conducting concurrently.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch implements IO alignment by filling dummy blocks in DATA and NODE
write bios. If we can guarantee, for example, 32KB or 64KB for such the IOs,
we can eliminate underlying dummy page problem which FTL conducts in order to
close MLC or TLC partial written pages.
Note that,
- it requires "-o mode=lfs".
- IO size should be power of 2, not exceed BIO_MAX_PAGES, 256.
- read IO is still 4KB.
- do checkpoint at fsync, if dummy NODE page was written.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If userspace issue a fstrim with a range not involve prefree segments,
it will reuse these segments without discard. This patch fix it.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If the range we write cover the whole valid data in the last page,
we do not need to read it.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
[Jaegeuk Kim: nullify the remaining area (fix: xfstests/f2fs/001)]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We checked that "inode" is not an error pointer earlier so there is
no need to check again here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we run out of memory, in cache_nat_entry, it's better to avoid loop
for allocating memory to cache nat entry, so in low memory scenario, for
read path of node block, I expect this can avoid unneeded latency.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch remove unused values in function recover_fsync_data
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull NFS client bugfixes from Trond Myklebust:
"Stable patches:
- NFSv4.1: Fix a deadlock in layoutget
- NFSv4 must not bump sequence ids on NFS4ERR_MOVED errors
- NFSv4 Fix a regression with OPEN EXCLUSIVE4 mode
- Fix a memory leak when removing the SUNRPC module
Bugfixes:
- Fix a reference leak in _pnfs_return_layout"
* tag 'nfs-for-4.10-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
pNFS: Fix a reference leak in _pnfs_return_layout
nfs: Fix "Don't increment lock sequence ID after NFS4ERR_MOVED"
SUNRPC: cleanup ida information when removing sunrpc module
NFSv4.0: always send mode in SETATTR after EXCLUSIVE4
nfs: Don't increment lock sequence ID after NFS4ERR_MOVED
NFSv4.1: Fix a deadlock in layoutget
And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data. To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related
structures from struct task_struct and struct signal_struct as they
won't contain anything useful and shouldn't be relied upon by mistake.
Code still referencing those structures is also disabled here.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Pull xfs uodates from Darrick Wong:
"I have some more fixes this week: better input validation, corruption
avoidance, build fixes, memory leak fixes, and a couple from Christoph
to avoid an ENOSPC failure.
Summary:
- Fix race conditions in the CoW code
- Fix some incorrect input validation checks
- Avoid crashing fs by running out of space when freeing inodes
- Fix toctou race wrt whether or not an inode has an attr
- Fix build error on arm
- Fix page refcount corruption when readahead fails
- Don't corrupt userspace in the bmap ioctl"
* tag 'xfs-for-linus-4.10-rc6-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: prevent quotacheck from overloading inode lru
xfs: fix bmv_count confusion w/ shared extents
xfs: clear _XBF_PAGES from buffers when readahead page
xfs: extsize hints are not unlikely in xfs_bmap_btalloc
xfs: remove racy hasattr check from attr ops
xfs: use per-AG reservations for the finobt
xfs: only update mount/resv fields on success in __xfs_ag_resv_init
xfs: verify dirblocklog correctly
xfs: fix COW writeback race
Pull btrfs updates from Chris Mason:
"Some fixes that we've collected from the list.
We still have one more pending to nail down a regression in lzo
compression, but I wanted to get this batch out the door"
* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: remove ->{get, set}_acl() from btrfs_dir_ro_inode_operations
Btrfs: disable xattr operations on subvolume directories
Btrfs: remove old tree_root case in btrfs_read_locked_inode()
Btrfs: fix truncate down when no_holes feature is enabled
Btrfs: Fix deadlock between direct IO and fast fsync
btrfs: fix false enospc error when truncating heavily reflinked file
Pull block fixes from Jens Axboe:
"A set of fixes for this series. This contains:
- Set of fixes for the nvme target code
- A revert of patch from this merge window, causing a regression with
WRITE_SAME on iSCSI targets at least.
- A fix for a use-after-free in the new O_DIRECT bdev code.
- Two fixes for the xen-blkfront driver"
* 'for-linus' of git://git.kernel.dk/linux-block:
Revert "sd: remove __data_len hack for WRITE SAME"
nvme-fc: use blk_rq_nr_phys_segments
nvmet-rdma: Fix missing dma sync to nvme data structures
nvmet: Call fatal_error from keep-alive timout expiration
nvmet: cancel fatal error and flush async work before free controller
nvmet: delete controllers deletion upon subsystem release
nvmet_fc: correct logic in disconnect queue LS handling
block: fix use after free in __blkdev_direct_IO
xen-blkfront: correct maximum segment accounting
xen-blkfront: feature flags handling adjustments
ext4_journalled_write_end() did not propely handle all the cases when
generic_perform_write() did not copy all the data into the target page
and could mark buffers with uninitialized contents as uptodate and dirty
leading to possible data corruption (which would be quickly fixed by
generic_perform_write() retrying the write but still). Fix the problem
by carefully handling the case when the page that is written to is not
uptodate.
CC: stable@vger.kernel.org
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If filesystem groups are artifically small (using parameter -g to
mkfs.ext4), ext4_mb_normalize_request() can result in a request that is
larger than a block group. Trim the request size to not confuse
allocation code.
Reported-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Quotacheck runs at mount time in situations where quota accounting must
be recalculated. In doing so, it uses bulkstat to visit every inode in
the filesystem. Historically, every inode processed during quotacheck
was released and immediately tagged for reclaim because quotacheck runs
before the superblock is marked active by the VFS. In other words,
the final iput() lead to an immediate ->destroy_inode() call, which
allowed the XFS background reclaim worker to start reclaiming inodes.
Commit 17c12bcd3 ("xfs: when replaying bmap operations, don't let
unlinked inodes get reaped") marks the XFS superblock active sooner as
part of the mount process to support caching inodes processed during log
recovery. This occurs before quotacheck and thus means all inodes
processed by quotacheck are inserted to the LRU on release. The
s_umount lock is held until the mount has completed and thus prevents
the shrinkers from operating on the sb. This means that quotacheck can
excessively populate the inode LRU and lead to OOM conditions on systems
without sufficient RAM.
Update the quotacheck bulkstat handler to set XFS_IGET_DONTCACHE on
inodes processed by quotacheck. This causes ->drop_inode() to return 1
and in turn causes iput_final() to evict the inode. This preserves the
original quotacheck behavior and prevents it from overloading the LRU
and running out of memory.
CC: stable@vger.kernel.org # v4.9
Reported-by: Martin Svec <martin.svec@zoner.cz>
Signed-off-by: Brian Foster <bfoster@redhat.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>
This patch simply combines function meta_lo_add with its only
caller, trans_add_meta. This makes the code easier to read and
will make it easier to reduce contention on gfs2_log_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch eliminates the int variable tr_touched in favor of a
new flag in the transaction. This is a step toward reducing contention
on the gfs2_log_lock spin_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
When you snapshot a subvolume containing a subvolume, you get a
placeholder directory where the subvolume would be. These directory
inodes have ->i_ops set to btrfs_dir_ro_inode_operations. Previously,
these i_ops didn't include the xattr operation callbacks. The conversion
to xattr_handlers missed this case, leading to bogus attempts to set
xattrs on these inodes. This manifested itself as failures when running
delayed inodes.
To fix this, clear IOP_XATTR in ->i_opflags on these inodes.
Fixes: 6c6ef9f26e ("xattr: Stop calling {get,set,remove}xattr inode operations")
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Reported-by: Chris Murphy <lists@colorremedies.com>
Tested-by: Chris Murphy <lists@colorremedies.com>
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
As Jeff explained in c2951f32d3 ("btrfs: remove old tree_root dirent
processing in btrfs_real_readdir()"), supporting this old format is no
longer necessary since the Btrfs magic number has been updated since we
changed to the current format. There are other places where we still
handle this old format, but since this is part of a fix that is going to
stable, I'm only removing this one for now.
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
IF NFS_LAYOUT_RETURN_REQUESTED is not set, then we currently exit
without freeing the list of invalidated layout segments, leading
to a reference leak.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 24408f5282 ("pNFS: Fix bugs in _pnfs_return_layout")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Lock sequence IDs are bumped in decode_lock by calling
nfs_increment_seqid(). nfs_increment_sequid() does not use the
seqid_mutating_err() function fixed in commit 059aa73482 ("Don't
increment lock sequence ID after NFS4ERR_MOVED").
Fixes: 059aa73482 ("Don't increment lock sequence ID after ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Xuan Qi <xuan.qi@oracle.com>
Cc: stable@vger.kernel.org # v3.7+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
In a bmapx call, bmv_count is the total size of the array, including the
zeroth element that userspace uses to supply the search key. The output
array starts at offset 1 so that we can set up the user for the next
invocation. Since we now can split an extent into multiple bmap records
due to shared/unshared status, we have to be careful that we don't
overflow the output array.
In the original patch f86f403794 ("xfs: teach get_bmapx about shared
extents and the CoW fork") I used cur_ext (the output index) to check
for overflows, albeit with an off-by-one error. Since nexleft no longer
describes the number of unfilled slots in the output, we can rip all
that out and use cur_ext for the overflow check directly.
Failure to do this causes heap corruption in bmapx callers such as
xfs_io and xfs_scrub. xfs/328 can reproduce this problem.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
If we try to allocate memory pages to back an xfs_buf that we're trying
to read, it's possible that we'll be so short on memory that the page
allocation fails. For a blocking read we'll just wait, but for
readahead we simply dump all the pages we've collected so far.
Unfortunately, after dumping the pages we neglect to clear the
_XBF_PAGES state, which means that the subsequent call to xfs_buf_free
thinks that b_pages still points to pages we own. It then double-frees
the b_pages pages.
This results in screaming about negative page refcounts from the memory
manager, which xfs oughtn't be triggering. To reproduce this case,
mount a filesystem where the size of the inodes far outweighs the
availalble memory (a ~500M inode filesystem on a VM with 300MB memory
did the trick here) and run bulkstat in parallel with other memory
eating processes to put a huge load on the system. The "check summary"
phase of xfs_scrub also works for this purpose.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
With COW files they are the hotpath, just like for files with the
extent size hint attribute. We really shouldn't micro-manage anything
but failure cases with unlikely.
Additionally Arnd Bergmann recently reported that one of these two
unlikely annotations causes link failures together with an upcoming
kernel instrumentation patch, so let's get rid of it ASAP.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
xfs_attr_[get|remove]() have unlocked attribute fork checks to optimize
away a lock cycle in cases where the fork does not exist or is otherwise
empty. This check is not safe, however, because an attribute fork short
form to extent format conversion includes a transient state that causes
the xfs_inode_hasattr() check to fail. Specifically,
xfs_attr_shortform_to_leaf() creates an empty extent format attribute
fork and then adds the existing shortform attributes to it.
This means that lookup of an existing xattr can spuriously return
-ENOATTR when racing against a setxattr that causes the associated
format conversion. This was originally reproduced by an untar on a
particularly configured glusterfs volume, but can also be reproduced on
demand with properly crafted xattr requests.
The format conversion occurs under the exclusive ilock. xfs_attr_get()
and xfs_attr_remove() already have the proper locking and checks further
down in the functions to handle this situation correctly. Drop the
unlocked checks to avoid the spurious failure and rely on the existing
logic.
Signed-off-by: Brian Foster <bfoster@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>
Currently we try to rely on the global reserved block pool for block
allocations for the free inode btree, but I have customer reports
(fairly complex workload, need to find an easier reproducer) where that
is not enough as the AG where we free an inode that requires a new
finobt block is entirely full. This causes us to cancel a dirty
transaction and thus a file system shutdown.
I think the right way to guard against this is to treat the finot the same
way as the refcount btree and have a per-AG reservations for the possible
worst case size of it, and the patch below implements that.
Note that this could increase mount times with large finobt trees. In
an ideal world we would have added a field for the number of finobt
fields to the AGI, similar to what we did for the refcount blocks.
We should do add it next time we rev the AGI or AGF format by adding
new fields.
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>
Try to reserve the blocks first and only then update the fields in
or hanging off the mount structure. This way we can call __xfs_ag_resv_init
again after a previous failure.
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>
Linux 4.9 added two ioctl() operations that can be used to discover:
* the parental relationships for hierarchical namespaces (user and PID)
[NS_GET_PARENT]
* the user namespaces that owns a specified non-user-namespace
[NS_GET_USERNS]
For no good reason that I can glean, NS_GET_USERNS was made synonymous
with NS_GET_PARENT for user namespaces. It might have been better if
NS_GET_USERNS had returned an error if the supplied file descriptor
referred to a user namespace, since it suggests that the caller may be
confused. More particularly, if it had generated an error, then I wouldn't
need the new ioctl() operation proposed here. (On the other hand, what
I propose here may be more generally useful.)
I would like to write code that discovers namespace relationships for
the purpose of understanding the namespace setup on a running system.
In particular, given a file descriptor (or pathname) for a namespace,
N, I'd like to obtain the corresponding user namespace. Namespace N
might be a user namespace (in which case my code would just use N) or
a non-user namespace (in which case my code will use NS_GET_USERNS to
get the user namespace associated with N). The problem is that there
is no way to tell the difference by looking at the file descriptor
(and if I try to use NS_GET_USERNS on an N that is a user namespace, I
get the parent user namespace of N, which is not what I want).
This patch therefore adds a new ioctl(), NS_GET_NSTYPE, which, given
a file descriptor that refers to a user namespace, returns the
namespace type (one of the CLONE_NEW* constants).
Signed-off-by: Michael Kerrisk <mtk-manpages@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Commit 8a59f5d252 ("fs/romfs: return f_fsid for statfs(2)") generates
a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is
defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with
CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev
will triger an oops.
Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y,
both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined.
Therefore when calling huge_encode_dev() to generate a 64bit id, I use
the follow order to choose parameter,
- CONFIG_ROMFS_ON_BLOCK defined
use sb->s_bdev->bd_dev
- CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined
use sb->s_dev when,
- both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined
leave id as 0
When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev
is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index,
otherwise sb->s_dev is 0.
This is a try-best effort to generate a uniq file system ID, if all the
above conditions are not meet, f_fsid of this romfs instance will be 0.
Generally only one romfs can be built on single MTD block device, this
method is enough to identify multiple romfs instances in a computer.
Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de
Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Nong Li <nongli1031@gmail.com>
Tested-by: Nong Li <nongli1031@gmail.com>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With >=32 CPUs the userfaultfd selftest triggered a graceful but
unexpected SIGBUS because VM_FAULT_RETRY was returned by
handle_userfault() despite the UFFDIO_COPY wasn't completed.
This seems caused by rwsem waking the thread blocked in
handle_userfault() and we can't run up_read() before the wait_event
sequence is complete.
Keeping the wait_even sequence identical to the first one, would require
running userfaultfd_must_wait() again to know if the loop should be
repeated, and it would also require retaking the rwsem and revalidating
the whole vma status.
It seems simpler to wait the targeted wakeup so that if false wakeups
materialize we still wait for our specific wakeup event, unless of
course there are signals or the uffd was released.
Debug code collecting the stack trace of the wakeup showed this:
$ ./userfaultfd 100 99999
nr_pages: 25600, nr_pages_per_cpu: 800
bounces: 99998, mode: racing ver poll, userfaults: 32 35 90 232 30 138 69 82 34 30 139 40 40 31 20 19 43 13 15 28 27 38 21 43 56 22 1 17 31 8 4 2
bounces: 99997, mode: rnd ver poll, Bus error (core dumped)
save_stack_trace+0x2b/0x50
try_to_wake_up+0x2a6/0x580
wake_up_q+0x32/0x70
rwsem_wake+0xe0/0x120
call_rwsem_wake+0x1b/0x30
up_write+0x3b/0x40
vm_mmap_pgoff+0x9c/0xc0
SyS_mmap_pgoff+0x1a9/0x240
SyS_mmap+0x22/0x30
entry_SYSCALL_64_fastpath+0x1f/0xbd
0xffffffffffffffff
FAULT_FLAG_ALLOW_RETRY missing 70
CPU: 24 PID: 1054 Comm: userfaultfd Tainted: G W 4.8.0+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
Call Trace:
dump_stack+0xb8/0x112
handle_userfault+0x572/0x650
handle_mm_fault+0x12cb/0x1520
__do_page_fault+0x175/0x500
trace_do_page_fault+0x61/0x270
do_async_page_fault+0x19/0x90
async_page_fault+0x25/0x30
This always happens when the main userfault selftest thread is running
clone() while glibc runs either mprotect or mmap (both taking mmap_sem
down_write()) to allocate the thread stack of the background threads,
while locking/userfault threads already run at full throttle and are
susceptible to false wakeups that may cause handle_userfault() to return
before than expected (which results in graceful SIGBUS at the next
attempt).
This was reproduced only with >=32 CPUs because the loop to start the
thread where clone() is too quick with fewer CPUs, while with 32 CPUs
there's already significant activity on ~32 locking and userfault
threads when the last background threads are started with clone().
This >=32 CPUs SMP race condition is likely reproducible only with the
selftest because of the much heavier userfault load it generates if
compared to real apps.
We'll have to allow "one more" VM_FAULT_RETRY for the WP support and a
patch floating around that provides it also hidden this problem but in
reality only is successfully at hiding the problem.
False wakeups could still happen again the second time
handle_userfault() is invoked, even if it's a so rare race condition
that getting false wakeups twice in a row is impossible to reproduce.
This full fix is needed for correctness, the only alternative would be
to allow VM_FAULT_RETRY to be returned infinitely. With this fix the WP
support can stick to a strict "one more" VM_FAULT_RETRY logic (no need
of returning it infinite times to avoid the SIGBUS).
Link: http://lkml.kernel.org/r/20170111005535.13832-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Shubham Kumar Sharma <shubham.kumar.sharma@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Arnd:
https://lkml.org/lkml/2017/1/10/756
Compiling with the following configuration:
# CONFIG_EXT2_FS is not set
# CONFIG_EXT4_FS is not set
# CONFIG_XFS_FS is not set
# CONFIG_FS_IOMAP depends on the above filesystems, as is not set
CONFIG_FS_DAX=y
generates build warnings about unused functions in fs/dax.c:
fs/dax.c:878:12: warning: `dax_insert_mapping' defined but not used [-Wunused-function]
static int dax_insert_mapping(struct address_space *mapping,
^~~~~~~~~~~~~~~~~~
fs/dax.c:572:12: warning: `copy_user_dax' defined but not used [-Wunused-function]
static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size,
^~~~~~~~~~~~~
fs/dax.c:542:12: warning: `dax_load_hole' defined but not used [-Wunused-function]
static int dax_load_hole(struct address_space *mapping, void **entry,
^~~~~~~~~~~~~
fs/dax.c:312:14: warning: `grab_mapping_entry' defined but not used [-Wunused-function]
static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
^~~~~~~~~~~~~~~~~~
Now that the struct buffer_head based DAX fault paths and I/O path have
been removed we really depend on iomap support being present for DAX.
Make this explicit by selecting FS_IOMAP if we compile in DAX support.
This allows us to remove conditional selections of FS_IOMAP when FS_DAX
was present for ext2 and ext4, and to remove an #ifdef in fs/dax.c.
Link: http://lkml.kernel.org/r/1484087383-29478-1-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sb_dirblklog is added to sb_blocklog to compute the directory block size
in bytes. Therefore, we must compare the sum of both those values
against XFS_MAX_BLOCKSIZE_LOG, not just dirblklog.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Some nfsv4.0 servers may return a mode for the verifier following an open
with EXCLUSIVE4 createmode, but this does not mean the client should skip
setting the mode in the following SETATTR. It should only do that for
EXCLUSIVE4_1 or UNGAURDED createmode.
Fixes: 5334c5bdac ("NFS: Send attributes in OPEN request for NFS4_CREATE_EXCLUSIVE4_1")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We can't dereference the dio structure after submitting the last bio for
this request, as I/O completion might have happened before the code is
run. Introduce a local is_sync variable instead.
Fixes: 542ff7bf ("block: new direct I/O implementation")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Matias Bjørling <m@bjorling.me>
Tested-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
We cannot call nfs4_handle_exception() without first ensuring that the
slot has been freed. If not, we end up deadlocking with the process
waiting for recovery to complete, and recovery waiting for the slot
table to drain.
Fixes: 2e80dbe7ac ("NFSv4.1: Close callback races for OPEN, LAYOUTGET...")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Instead of making the files owned by the GLOBAL_ROOT_USER. Make
non-dumpable files whose mm has always lived in a user namespace owned
by the user namespace root. This allows the container root to have
things work as expected in a container.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
