Commit Graph

87 Commits

Author SHA1 Message Date
Xu Yu
9295566a13 mm/swap: consider max pages in iomap_swapfile_add_extent
[ Upstream commit 36ca7943ac18aebf8aad4c50829eb2ea5ec847df ]

When the max pages (last_page in the swap header + 1) is smaller than
the total pages (inode size) of the swapfile, iomap_swapfile_activate
overwrites sis->max with total pages.

However, frontswap_map is a swap page state bitmap allocated using the
initial sis->max page count read from the swap header.  If swapfile
activation increases sis->max, it's possible for the frontswap code to
walk off the end of the bitmap, thereby corrupting kernel memory.

[djwong: modify the description a bit; the original paragraph reads:

"However, frontswap_map is allocated using max pages. When test and clear
the sis offset, which is larger than max pages, of frontswap_map in
__frontswap_invalidate_page(), neighbors of frontswap_map may be
overwritten, i.e., slab is polluted."

Note also that this bug resulted in a behavioral change: activating a
swap file that was formatted and later extended results in all pages
being activated, not the number of pages recorded in the swap header.]

This fixes the issue by considering the limitation of max pages of swap
info in iomap_swapfile_add_extent().

To reproduce the case, compile kernel with slub RED ZONE, then run test:
$ sudo stress-ng -a 1 -x softlockup,resources -t 72h --metrics --times \
 --verify -v -Y /root/tmpdir/stress-ng/stress-statistic-12.yaml \
 --log-file /root/tmpdir/stress-ng/stress-logfile-12.txt \
 --temp-path /root/tmpdir/stress-ng/

We'll get the error log as below:

[ 1151.015141] =============================================================================
[ 1151.016489] BUG kmalloc-16 (Not tainted): Right Redzone overwritten
[ 1151.017486] -----------------------------------------------------------------------------
[ 1151.017486]
[ 1151.018997] Disabling lock debugging due to kernel taint
[ 1151.019873] INFO: 0x0000000084e43932-0x0000000098d17cae @offset=7392. First byte 0x0 instead of 0xcc
[ 1151.021303] INFO: Allocated in __do_sys_swapon+0xcf6/0x1170 age=43417 cpu=9 pid=3816
[ 1151.022538]  __slab_alloc+0xe/0x20
[ 1151.023069]  __kmalloc_node+0xfd/0x4b0
[ 1151.023704]  __do_sys_swapon+0xcf6/0x1170
[ 1151.024346]  do_syscall_64+0x33/0x40
[ 1151.024925]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.025749] INFO: Freed in put_cred_rcu+0xa1/0xc0 age=43424 cpu=3 pid=2041
[ 1151.026889]  kfree+0x276/0x2b0
[ 1151.027405]  put_cred_rcu+0xa1/0xc0
[ 1151.027949]  rcu_do_batch+0x17d/0x410
[ 1151.028566]  rcu_core+0x14e/0x2b0
[ 1151.029084]  __do_softirq+0x101/0x29e
[ 1151.029645]  asm_call_irq_on_stack+0x12/0x20
[ 1151.030381]  do_softirq_own_stack+0x37/0x40
[ 1151.031037]  do_softirq.part.15+0x2b/0x30
[ 1151.031710]  __local_bh_enable_ip+0x4b/0x50
[ 1151.032412]  copy_fpstate_to_sigframe+0x111/0x360
[ 1151.033197]  __setup_rt_frame+0xce/0x480
[ 1151.033809]  arch_do_signal+0x1a3/0x250
[ 1151.034463]  exit_to_user_mode_prepare+0xcf/0x110
[ 1151.035242]  syscall_exit_to_user_mode+0x27/0x190
[ 1151.035970]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.036795] INFO: Slab 0x000000003b9de4dc objects=44 used=9 fp=0x00000000539e349e flags=0xfffffc0010201
[ 1151.038323] INFO: Object 0x000000004855ba01 @offset=7376 fp=0x0000000000000000
[ 1151.038323]
[ 1151.039683] Redzone  000000008d0afd3d: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
[ 1151.041180] Object   000000004855ba01: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[ 1151.042714] Redzone  0000000084e43932: 00 00 00 c0 cc cc cc cc                          ........
[ 1151.044120] Padding  000000000864c042: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[ 1151.045615] CPU: 5 PID: 3816 Comm: stress-ng Tainted: G    B             5.10.50+ #7
[ 1151.046846] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 1151.048633] Call Trace:
[ 1151.049072]  dump_stack+0x57/0x6a
[ 1151.049585]  check_bytes_and_report+0xed/0x110
[ 1151.050320]  check_object+0x1eb/0x290
[ 1151.050924]  ? __x64_sys_swapoff+0x39a/0x540
[ 1151.051646]  free_debug_processing+0x151/0x350
[ 1151.052333]  __slab_free+0x21a/0x3a0
[ 1151.052938]  ? _cond_resched+0x2d/0x40
[ 1151.053529]  ? __vunmap+0x1de/0x220
[ 1151.054139]  ? __x64_sys_swapoff+0x39a/0x540
[ 1151.054796]  ? kfree+0x276/0x2b0
[ 1151.055307]  kfree+0x276/0x2b0
[ 1151.055832]  __x64_sys_swapoff+0x39a/0x540
[ 1151.056466]  do_syscall_64+0x33/0x40
[ 1151.057084]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.057866] RIP: 0033:0x150340b0ffb7
[ 1151.058481] Code: Unable to access opcode bytes at RIP 0x150340b0ff8d.
[ 1151.059537] RSP: 002b:00007fff7f4ee238 EFLAGS: 00000246 ORIG_RAX: 00000000000000a8
[ 1151.060768] RAX: ffffffffffffffda RBX: 00007fff7f4ee66c RCX: 0000150340b0ffb7
[ 1151.061904] RDX: 000000000000000a RSI: 0000000000018094 RDI: 00007fff7f4ee860
[ 1151.063033] RBP: 00007fff7f4ef980 R08: 0000000000000000 R09: 0000150340a672bd
[ 1151.064135] R10: 00007fff7f4edca0 R11: 0000000000000246 R12: 0000000000018094
[ 1151.065253] R13: 0000000000000005 R14: 000000000160d930 R15: 00007fff7f4ee66c
[ 1151.066413] FIX kmalloc-16: Restoring 0x0000000084e43932-0x0000000098d17cae=0xcc
[ 1151.066413]
[ 1151.067890] FIX kmalloc-16: Object at 0x000000004855ba01 not freed

Fixes: 67482129cd ("iomap: add a swapfile activation function")
Fixes: a45c0eccc5 ("iomap: move the swapfile code into a separate file")
Signed-off-by: Gang Deng <gavin.dg@linux.alibaba.com>
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:50:42 +02:00
Christoph Hellwig
3510b9b41c iomap: remove the length variable in iomap_seek_hole
[ Upstream commit 49694d14ff68fa4b5f86019dbcfb44a8bd213e58 ]

The length variable is rather pointless given that it can be trivially
deduced from offset and size.  Also the initial calculation can lead
to KASAN warnings.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Leizhen (ThunderTown) <thunder.leizhen@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:16:12 +02:00
Christoph Hellwig
8659186e72 iomap: remove the length variable in iomap_seek_data
[ Upstream commit 3ac1d426510f97ace05093ae9f2f710d9cbe6215 ]

The length variable is rather pointless given that it can be trivially
deduced from offset and size.  Also the initial calculation can lead
to KASAN warnings.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Leizhen (ThunderTown) <thunder.leizhen@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-31 08:16:12 +02:00
Ritesh Harjani
4eff80b140 iomap: Fix negative assignment to unsigned sis->pages in iomap_swapfile_activate
[ Upstream commit 5808fecc572391867fcd929662b29c12e6d08d81 ]

In case if isi.nr_pages is 0, we are making sis->pages (which is
unsigned int) a huge value in iomap_swapfile_activate() by assigning -1.
This could cause a kernel crash in kernel v4.18 (with below signature).
Or could lead to unknown issues on latest kernel if the fake big swap gets
used.

Fix this issue by returning -EINVAL in case of nr_pages is 0, since it
is anyway a invalid swapfile. Looks like this issue will be hit when
we have pagesize < blocksize type of configuration.

I was able to hit the issue in case of a tiny swap file with below
test script.
https://raw.githubusercontent.com/riteshharjani/LinuxStudy/master/scripts/swap-issue.sh

kernel crash analysis on v4.18
==============================
On v4.18 kernel, it causes a kernel panic, since sis->pages becomes
a huge value and isi.nr_extents is 0. When 0 is returned it is
considered as a swapfile over NFS and SWP_FILE is set (sis->flags |= SWP_FILE).
Then when swapoff was getting called it was calling a_ops->swap_deactivate()
if (sis->flags & SWP_FILE) is true. Since a_ops->swap_deactivate() is
NULL in case of XFS, it causes below panic.

Panic signature on v4.18 kernel:
=======================================
root@qemu:/home/qemu# [ 8291.723351] XFS (loop2): Unmounting Filesystem
[ 8292.123104] XFS (loop2): Mounting V5 Filesystem
[ 8292.132451] XFS (loop2): Ending clean mount
[ 8292.263362] Adding 4294967232k swap on /mnt1/test/swapfile.  Priority:-2 extents:1 across:274877906880k
[ 8292.277834] Unable to handle kernel paging request for instruction fetch
[ 8292.278677] Faulting instruction address: 0x00000000
cpu 0x19: Vector: 400 (Instruction Access) at [c0000009dd5b7ad0]
    pc: 0000000000000000
    lr: c0000000003eb9dc: destroy_swap_extents+0xfc/0x120
    sp: c0000009dd5b7d50
   msr: 8000000040009033
  current = 0xc0000009b6710080
  paca    = 0xc00000003ffcb280   irqmask: 0x03   irq_happened: 0x01
    pid   = 5604, comm = swapoff
Linux version 4.18.0 (riteshh@xxxxxxx) (gcc version 8.4.0 (Ubuntu 8.4.0-1ubuntu1~18.04)) #57 SMP Wed Mar 3 01:33:04 CST 2021
enter ? for help
[link register   ] c0000000003eb9dc destroy_swap_extents+0xfc/0x120
[c0000009dd5b7d50] c0000000025a7058 proc_poll_event+0x0/0x4 (unreliable)
[c0000009dd5b7da0] c0000000003f0498 sys_swapoff+0x3f8/0x910
[c0000009dd5b7e30] c00000000000bbe4 system_call+0x5c/0x70
Exception: c01 (System Call) at 00007ffff7d208d8

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
[djwong: rework the comment to provide more details]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 15:00:04 +02:00
Brian Foster
50e7d6c7a5 iomap: clean up writeback state logic on writepage error
The iomap writepage error handling logic is a mash of old and
slightly broken XFS writepage logic. When keepwrite writeback state
tracking was introduced in XFS in commit 0d085a529b ("xfs: ensure
WB_SYNC_ALL writeback handles partial pages correctly"), XFS had an
additional cluster writeback context that scanned ahead of
->writepage() to process dirty pages over the current ->writepage()
extent mapping. This context expected a dirty page and required
retention of the TOWRITE tag on partial page processing so the
higher level writeback context would revisit the page (in contrast
to ->writepage(), which passes a page with the dirty bit already
cleared).

The cluster writeback mechanism was eventually removed and some of
the error handling logic folded into the primary writeback path in
commit 150d5be09c ("xfs: remove xfs_cancel_ioend"). This patch
accidentally conflated the two contexts by using the keepwrite logic
in ->writepage() without accounting for the fact that the page is
not dirty. Further, the keepwrite logic has no practical effect on
the core ->writepage() caller (write_cache_pages()) because it never
revisits a page in the current function invocation.

Technically, the page should be redirtied for the keepwrite logic to
have any effect. Otherwise, write_cache_pages() may find the tagged
page but will skip it since it is clean. Even if the page was
redirtied, however, there is still no practical effect to keepwrite
since write_cache_pages() does not wrap around within a single
invocation of the function. Therefore, the dirty page would simply
end up retagged on the next writeback sequence over the associated
range.

All that being said, none of this really matters because redirtying
a partially processed page introduces a potential infinite redirty
-> writeback failure loop that deviates from the current design
principle of clearing the dirty state on writepage failure to avoid
building up too much dirty, unreclaimable memory on the system.
Therefore, drop the spurious keepwrite usage and dirty state
clearing logic from iomap_writepage_map(), treat the partially
processed page the same as a fully processed page, and let the
imminent ioend failure clean up the writeback state.

Signed-off-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>
2020-11-04 08:52:46 -08:00
Brian Foster
763e4cdc0f iomap: support partial page discard on writeback block mapping failure
iomap writeback mapping failure only calls into ->discard_page() if
the current page has not been added to the ioend. Accordingly, the
XFS callback assumes a full page discard and invalidation. This is
problematic for sub-page block size filesystems where some portion
of a page might have been mapped successfully before a failure to
map a delalloc block occurs. ->discard_page() is not called in that
error scenario and the bio is explicitly failed by iomap via the
error return from ->prepare_ioend(). As a result, the filesystem
leaks delalloc blocks and corrupts the filesystem block counters.

Since XFS is the only user of ->discard_page(), tweak the semantics
to invoke the callback unconditionally on mapping errors and provide
the file offset that failed to map. Update xfs_discard_page() to
discard the corresponding portion of the file and pass the range
along to iomap_invalidatepage(). The latter already properly handles
both full and sub-page scenarios by not changing any iomap or page
state on sub-page invalidations.

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>
2020-11-04 08:52:46 -08:00
Goldwyn Rodrigues
1a31182edd iomap: Call inode_dio_end() before generic_write_sync()
iomap complete routine can deadlock with btrfs_fallocate because of the
call to generic_write_sync().

P0                      P1
inode_lock()            fallocate(FALLOC_FL_ZERO_RANGE)
__iomap_dio_rw()        inode_lock()
                        <block>
<submits IO>
<completes IO>
inode_unlock()
                        <gets inode_lock()>
                        inode_dio_wait()
iomap_dio_complete()
  generic_write_sync()
    btrfs_file_fsync()
      inode_lock()
      <deadlock>

inode_dio_end() is used to notify the end of DIO data in order
to synchronize with truncate. Call inode_dio_end() before calling
generic_write_sync(), so filesystems can lock i_rwsem during a sync.

This matches the way it is done in fs/direct-io.c:dio_complete().

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-28 08:51:08 -07:00
Christoph Hellwig
c3d4ed1abe iomap: Allow filesystem to call iomap_dio_complete without i_rwsem
This is to avoid the deadlock caused in btrfs because of O_DIRECT |
O_DSYNC.

Filesystems such as btrfs require i_rwsem while performing sync on a
file. iomap_dio_rw() is called under i_rw_sem. This leads to a
deadlock because of:

iomap_dio_complete()
  generic_write_sync()
    btrfs_sync_file()

Separate out iomap_dio_complete() from iomap_dio_rw(), so filesystems
can call iomap_dio_complete() after unlocking i_rwsem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-28 08:51:08 -07:00
Matthew Wilcox (Oracle)
4595a298d5 iomap: Set all uptodate bits for an Uptodate page
For filesystems with block size < page size, we need to set all the
per-block uptodate bits if the page was already uptodate at the time
we create the per-block metadata.  This can happen if the page is
invalidated (eg by a write to drop_caches) but ultimately not removed
from the page cache.

This is a data corruption issue as page writeback skips blocks which
are marked !uptodate.

Fixes: 9dc55f1389 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Qian Cai <cai@redhat.com>
Cc: Brian Foster <bfoster@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-28 08:47:01 -07:00
Matthew Wilcox (Oracle)
81ee8e52a7 iomap: Change calling convention for zeroing
Pass the full length to iomap_zero() and dax_iomap_zero(), and have
them return how many bytes they actually handled.  This is preparatory
work for handling THP, although it looks like DAX could actually take
advantage of it if there's a larger contiguous area.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-21 08:59:27 -07:00
Matthew Wilcox (Oracle)
e25ba8cbfd iomap: Convert iomap_write_end types
iomap_write_end cannot return an error, so switch it to return
size_t instead of int and remove the error checking from the callers.
Also convert the arguments to size_t from unsigned int, in case anyone
ever wants to support a page size larger than 2GB.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
0fb2d7209d iomap: Convert write_count to write_bytes_pending
Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
7d636676d2 iomap: Convert read_count to read_bytes_pending
Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
0a195b91e8 iomap: Support arbitrarily many blocks per page
Size the uptodate array dynamically to support larger pages in the
page cache.  With a 64kB page, we're only saving 8 bytes per page today,
but with a 2MB maximum page size, we'd have to allocate more than 4kB
per page.  Add a few debugging assertions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
b21866f514 iomap: Use bitmap ops to set uptodate bits
Now that the bitmap is protected by a spinlock, we can use the
more efficient bitmap ops instead of individual test/set bit ops.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
a6901d4d14 iomap: Use kzalloc to allocate iomap_page
We can skip most of the initialisation, although spinlocks still
need explicit initialisation as architectures may use a non-zero
value to indicate unlocked.  The comment is no longer useful as
attach_page_private() handles the refcount now.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
24addd848a fs: Introduce i_blocks_per_page
This helper is useful for both THPs and for supporting block size larger
than page size.  Convert all users that I could find (we have a few
different ways of writing this idiom, and I may have missed some).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2020-09-21 08:59:26 -07:00
Matthew Wilcox (Oracle)
7ed3cd1a69 iomap: Fix misplaced page flushing
If iomap_unshare_actor() unshares to an inline iomap, the page was
not being flushed.  block_write_end() and __iomap_write_end() already
contain flushes, so adding it to iomap_write_end_inline() seems like
the best place.  That means we can remove it from iomap_write_actor().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-21 08:59:26 -07:00
Nikolay Borisov
6cc19c5fad iomap: Use round_down/round_up macros in __iomap_write_begin
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-09-21 08:59:25 -07:00
Matthew Wilcox (Oracle)
14284fedf5 iomap: Mark read blocks uptodate in write_begin
When bringing (portions of) a page uptodate, we were marking blocks that
were zeroed as being uptodate, but not blocks that were read from storage.

Like the previous commit, this problem was found with generic/127 and
a kernel which failed readahead I/Os.  This bug causes writes to be
silently lost when working with flaky storage.

Fixes: 9dc55f1389 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-10 08:26:18 -07:00
Matthew Wilcox (Oracle)
e6e7ca9262 iomap: Clear page error before beginning a write
If we find a page in write_begin which is !Uptodate, we need
to clear any error on the page before starting to read data
into it.  This matches how filemap_fault(), do_read_cache_page()
and generic_file_buffered_read() handle PageError on !Uptodate pages.
When calling iomap_set_range_uptodate() in __iomap_write_begin(), blocks
were not being marked as uptodate.

This was found with generic/127 and a specially modified kernel which
would fail (some) readahead I/Os.  The test read some bytes in a prior
page which caused readahead to extend into page 0x34.  There was
a subsequent write to page 0x34, followed by a read to page 0x34.
Because the blocks were still marked as !Uptodate, the read caused all
blocks to be re-read, overwriting the write.  With this change, and the
next one, the bytes which were written are marked as being Uptodate, so
even though the page is still marked as !Uptodate, the blocks containing
the written data are not re-read from storage.

Fixes: 9dc55f1389 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-10 08:26:17 -07:00
Andreas Gruenbacher
c114bbc6c4 iomap: Fix direct I/O write consistency check
When a direct I/O write falls back to buffered I/O entirely, dio->size
will be 0 in iomap_dio_complete.  Function invalidate_inode_pages2_range
will try to invalidate the rest of the address space.  If there are any
dirty pages in that range, the write will fail and a "Page cache
invalidation failure on direct I/O" error will be logged.

On gfs2, this can be reproduced as follows:

  xfs_io \
    -c "open -ft foo" -c "pwrite 4k 4k" -c "close" \
    -c "open -d foo" -c "pwrite 0 4k"

Fix this by recognizing 0-length writes.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-10 08:26:16 -07:00
Qian Cai
a805c11165 iomap: fix WARN_ON_ONCE() from unprivileged users
It is trivial to trigger a WARN_ON_ONCE(1) in iomap_dio_actor() by
unprivileged users which would taint the kernel, or worse - panic if
panic_on_warn or panic_on_taint is set. Hence, just convert it to
pr_warn_ratelimited() to let users know their workloads are racing.
Thank Dave Chinner for the initial analysis of the racing reproducers.

Signed-off-by: Qian Cai <cai@lca.pw>
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>
2020-09-10 08:26:15 -07:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Christoph Hellwig
60263d5889 iomap: fall back to buffered writes for invalidation failures
Failing to invalid the page cache means data in incoherent, which is
a very bad state for the system.  Always fall back to buffered I/O
through the page cache if we can't invalidate mappings.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu> # for ext4
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> # for gfs2
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
2020-08-05 09:24:16 -07:00
Dave Chinner
54752de928 iomap: Only invalidate page cache pages on direct IO writes
The historic requirement for XFS to invalidate cached pages on
direct IO reads has been lost in the twisty pages of history - it was
inherited from Irix, which implemented page cache invalidation on
read as a method of working around problems synchronising page
cache state with uncached IO.

XFS has carried this ever since. In the initial linux ports it was
necessary to get mmap and DIO to play "ok" together and not
immediately corrupt data. This was the state of play until the linux
kernel had infrastructure to track unwritten extents and synchronise
page faults with allocations and unwritten extent conversions
(->page_mkwrite infrastructure). IOws, the page cache invalidation
on DIO read was necessary to prevent trivial data corruptions. This
didn't solve all the problems, though.

There were peformance problems if we didn't invalidate the entire
page cache over the file on read - we couldn't easily determine if
the cached pages were over the range of the IO, and invalidation
required taking a serialising lock (i_mutex) on the inode. This
serialising lock was an issue for XFS, as it was the only exclusive
lock in the direct Io read path.

Hence if there were any cached pages, we'd just invalidate the
entire file in one go so that subsequent IOs didn't need to take the
serialising lock. This was a problem that prevented ranged
invalidation from being particularly useful for avoiding the
remaining coherency issues. This was solved with the conversion of
i_mutex to i_rwsem and the conversion of the XFS inode IO lock to
use i_rwsem. Hence we could now just do ranged invalidation and the
performance problem went away.

However, page cache invalidation was still needed to serialise
sub-page/sub-block zeroing via direct IO against buffered IO because
bufferhead state attached to the cached page could get out of whack
when direct IOs were issued.  We've removed bufferheads from the
XFS code, and we don't carry any extent state on the cached pages
anymore, and so this problem has gone away, too.

IOWs, it would appear that we don't have any good reason to be
invalidating the page cache on DIO reads anymore. Hence remove the
invalidation on read because it is unnecessary overhead,
not needed to maintain coherency between mmap/buffered access and
direct IO anymore, and prevents anyone from using direct IO reads
from intentionally invalidating the page cache of a file.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-08-05 09:24:16 -07:00
Andreas Gruenbacher
856473cd5d iomap: Make sure iomap_end is called after iomap_begin
Make sure iomap_end is always called when iomap_begin succeeds.

Without this fix, iomap_end won't be called when a filesystem's
iomap_begin operation returns an invalid mapping, bypassing any
unlocking done in iomap_end.  With this fix, the unlocking will still
happen.

This bug was found by Bob Peterson during code review.  It's unlikely
that such iomap_begin bugs will survive to affect users, so backporting
this fix seems unnecessary.

Fixes: ae259a9c85 ("fs: introduce iomap infrastructure")
Signed-off-by: Andreas Gruenbacher <agruenba@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>
2020-07-06 10:49:27 -07:00
Linus Torvalds
593bd5e5d3 New code for 5.8:
- Fix an integer overflow problem in the unshare actor.
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Merge tag 'iomap-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap fix from Darrick Wong:
 "A single iomap bug fix for a variable type mistake on 32-bit
  architectures, fixing an integer overflow problem in the unshare
  actor"

* tag 'iomap-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Fix unsharing of an extent >2GB on a 32-bit machine
2020-06-13 12:44:30 -07:00
Matthew Wilcox (Oracle)
d4ff3b2ef9 iomap: Fix unsharing of an extent >2GB on a 32-bit machine
Widen the type used for counting the number of bytes unshared.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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>
2020-06-08 20:58:29 -07:00
Linus Torvalds
0b166a57e6 A lot of bug fixes and cleanups for ext4, including:
* Fix performance problems found in dioread_nolock now that it is the
   default, caused by transaction leaks.
 * Clean up fiemap handling in ext4
 * Clean up and refactor multiple block allocator (mballoc) code
 * Fix a problem with mballoc with a smaller file systems running out
   of blocks because they couldn't properly use blocks that had been
   reserved by inode preallocation.
 * Fixed a race in ext4_sync_parent() versus rename()
 * Simplify the error handling in the extent manipulation code
 * Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and
   ext4_make_inode_dirty()'s callers.
 * Avoid passing an error pointer to brelse in ext4_xattr_set()
 * Fix race which could result to freeing an inode on the dirty last
   in data=journal mode.
 * Fix refcount handling if ext4_iget() fails
 * Fix a crash in generic/019 caused by a corrupted extent node
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "A lot of bug fixes and cleanups for ext4, including:

   - Fix performance problems found in dioread_nolock now that it is the
     default, caused by transaction leaks.

   - Clean up fiemap handling in ext4

   - Clean up and refactor multiple block allocator (mballoc) code

   - Fix a problem with mballoc with a smaller file systems running out
     of blocks because they couldn't properly use blocks that had been
     reserved by inode preallocation.

   - Fixed a race in ext4_sync_parent() versus rename()

   - Simplify the error handling in the extent manipulation code

   - Make sure all metadata I/O errors are felected to
     ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.

   - Avoid passing an error pointer to brelse in ext4_xattr_set()

   - Fix race which could result to freeing an inode on the dirty last
     in data=journal mode.

   - Fix refcount handling if ext4_iget() fails

   - Fix a crash in generic/019 caused by a corrupted extent node"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
  ext4: avoid unnecessary transaction starts during writeback
  ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
  ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
  fs: remove the access_ok() check in ioctl_fiemap
  fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
  fs: move fiemap range validation into the file systems instances
  iomap: fix the iomap_fiemap prototype
  fs: move the fiemap definitions out of fs.h
  fs: mark __generic_block_fiemap static
  ext4: remove the call to fiemap_check_flags in ext4_fiemap
  ext4: split _ext4_fiemap
  ext4: fix fiemap size checks for bitmap files
  ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
  add comment for ext4_dir_entry_2 file_type member
  jbd2: avoid leaking transaction credits when unreserving handle
  ext4: drop ext4_journal_free_reserved()
  ext4: mballoc: use lock for checking free blocks while retrying
  ext4: mballoc: refactor ext4_mb_good_group()
  ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
  ext4: mballoc: refactor ext4_mb_discard_preallocations()
  ...
2020-06-05 16:19:28 -07:00
Christoph Hellwig
45dd052e67 fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
By moving FIEMAP_FLAG_SYNC handling to fiemap_prep we ensure it is
handled once instead of duplicated, but can still be done under fs locks,
like xfs/iomap intended with its duplicate handling.  Also make sure the
error value of filemap_write_and_wait is propagated to user space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-8-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03 23:16:55 -04:00
Christoph Hellwig
cddf8a2c4a fs: move fiemap range validation into the file systems instances
Replace fiemap_check_flags with a fiemap_prep helper that also takes the
inode and mapped range, and performs the sanity check and truncation
previously done in fiemap_check_range.  This way the validation is inside
the file system itself and thus properly works for the stacked overlayfs
case as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-7-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03 23:16:55 -04:00
Christoph Hellwig
2732881894 iomap: fix the iomap_fiemap prototype
iomap_fiemap should take u64 start and len arguments, just like the
->fiemap prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-6-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03 23:16:55 -04:00
Christoph Hellwig
10c5db2864 fs: move the fiemap definitions out of fs.h
No need to pull the fiemap definitions into almost every file in the
kernel build.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-5-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03 23:16:55 -04:00
Linus Torvalds
f3cdc8ae11 for-5.8-tag
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Merge tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Highlights:

   - speedup dead root detection during orphan cleanup, eg. when there
     are many deleted subvolumes waiting to be cleaned, the trees are
     now looked up in radix tree instead of a O(N^2) search

   - snapshot creation with inherited qgroup will mark the qgroup
     inconsistent, requires a rescan

   - send will emit file capabilities after chown, this produces a
     stream that does not need postprocessing to set the capabilities
     again

   - direct io ported to iomap infrastructure, cleaned up and simplified
     code, notably removing last use of struct buffer_head in btrfs code

  Core changes:

   - factor out backreference iteration, to be used by ordinary
     backreferences and relocation code

   - improved global block reserve utilization
      * better logic to serialize requests
      * increased maximum available for unlink
      * improved handling on large pages (64K)

   - direct io cleanups and fixes
      * simplify layering, where cloned bios were unnecessarily created
        for some cases
      * error handling fixes (submit, endio)
      * remove repair worker thread, used to avoid deadlocks during
        repair

   - refactored block group reading code, preparatory work for new type
     of block group storage that should improve mount time on large
     filesystems

  Cleanups:

   - cleaned up (and slightly sped up) set/get helpers for metadata data
     structure members

   - root bit REF_COWS got renamed to SHAREABLE to reflect the that the
     blocks of the tree get shared either among subvolumes or with the
     relocation trees

  Fixes:

   - when subvolume deletion fails due to ENOSPC, the filesystem is not
     turned read-only

   - device scan deals with devices from other filesystems that changed
     ownership due to overwrite (mkfs)

   - fix a race between scrub and block group removal/allocation

   - fix long standing bug of a runaway balance operation, printing the
     same line to the syslog, caused by a stale status bit on a reloc
     tree that prevented progress

   - fix corrupt log due to concurrent fsync of inodes with shared
     extents

   - fix space underflow for NODATACOW and buffered writes when it for
     some reason needs to fallback to COW mode"

* tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (133 commits)
  btrfs: fix space_info bytes_may_use underflow during space cache writeout
  btrfs: fix space_info bytes_may_use underflow after nocow buffered write
  btrfs: fix wrong file range cleanup after an error filling dealloc range
  btrfs: remove redundant local variable in read_block_for_search
  btrfs: open code key_search
  btrfs: split btrfs_direct_IO to read and write part
  btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK
  fs: remove dio_end_io()
  btrfs: switch to iomap_dio_rw() for dio
  iomap: remove lockdep_assert_held()
  iomap: add a filesystem hook for direct I/O bio submission
  fs: export generic_file_buffered_read()
  btrfs: turn space cache writeout failure messages into debug messages
  btrfs: include error on messages about failure to write space/inode caches
  btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks()
  btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums
  btrfs: make checksum item extension more efficient
  btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents
  btrfs: unexport btrfs_compress_set_level()
  btrfs: simplify iget helpers
  ...
2020-06-02 19:59:25 -07:00
Linus Torvalds
750a02ab8d for-5.8/block-2020-06-01
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Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Core block changes that have been queued up for this release:

   - Remove dead blk-throttle and blk-wbt code (Guoqing)

   - Include pid in blktrace note traces (Jan)

   - Don't spew I/O errors on wouldblock termination (me)

   - Zone append addition (Johannes, Keith, Damien)

   - IO accounting improvements (Konstantin, Christoph)

   - blk-mq hardware map update improvements (Ming)

   - Scheduler dispatch improvement (Salman)

   - Inline block encryption support (Satya)

   - Request map fixes and improvements (Weiping)

   - blk-iocost tweaks (Tejun)

   - Fix for timeout failing with error injection (Keith)

   - Queue re-run fixes (Douglas)

   - CPU hotplug improvements (Christoph)

   - Queue entry/exit improvements (Christoph)

   - Move DMA drain handling to the few drivers that use it (Christoph)

   - Partition handling cleanups (Christoph)"

* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
  block: mark bio_wouldblock_error() bio with BIO_QUIET
  blk-wbt: rename __wbt_update_limits to wbt_update_limits
  blk-wbt: remove wbt_update_limits
  blk-throttle: remove tg_drain_bios
  blk-throttle: remove blk_throtl_drain
  null_blk: force complete for timeout request
  blk-mq: drain I/O when all CPUs in a hctx are offline
  blk-mq: add blk_mq_all_tag_iter
  blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
  blk-mq: use BLK_MQ_NO_TAG in more places
  blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
  blk-mq: move more request initialization to blk_mq_rq_ctx_init
  blk-mq: simplify the blk_mq_get_request calling convention
  blk-mq: remove the bio argument to ->prepare_request
  nvme: force complete cancelled requests
  blk-mq: blk-mq: provide forced completion method
  block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
  block: blk-crypto-fallback: remove redundant initialization of variable err
  block: reduce part_stat_lock() scope
  block: use __this_cpu_add() instead of access by smp_processor_id()
  ...
2020-06-02 15:29:19 -07:00
Guoqing Jiang
58aeb73196 iomap: use attach/detach_page_private
Since the new pair function is introduced, we can call them to clean the
code in iomap.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Link: http://lkml.kernel.org/r/20200517214718.468-7-guoqing.jiang@cloud.ionos.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:07 -07:00
Matthew Wilcox (Oracle)
9d24a13a93 iomap: convert from readpages to readahead
Use the new readahead operation in iomap.  Convert XFS and ZoneFS to use
it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-26-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:07 -07:00
Matthew Wilcox (Oracle)
d4388340ae fs: convert mpage_readpages to mpage_readahead
Implement the new readahead aop and convert all callers (block_dev,
exfat, ext2, fat, gfs2, hpfs, isofs, jfs, nilfs2, ocfs2, omfs, qnx6,
reiserfs & udf).

The callers are all trivial except for GFS2 & OCFS2.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> # ocfs2
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> # ocfs2
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-17-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:07 -07:00
Goldwyn Rodrigues
3ad99bec6e iomap: remove lockdep_assert_held()
Filesystems such as btrfs can perform direct I/O without holding the
inode->i_rwsem in some of the cases like writing within i_size.  So,
remove the check for lockdep_assert_held() in iomap_dio_rw().

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 13:12:53 +02:00
Goldwyn Rodrigues
8cecd0ba85 iomap: add a filesystem hook for direct I/O bio submission
This helps filesystems to perform tasks on the bio while submitting for
I/O. This could be post-write operations such as data CRC or data
replication for fs-handled RAID.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 13:12:53 +02:00
Ming Lei
e6249cdd46 block: add blk_io_schedule() for avoiding task hung in sync dio
Sync dio could be big, or may take long time in discard or in case of
IO failure.

We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
so apply the same trick for prevent task hung from happening in sync dio.

Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
task hung warning.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Salman Qazi <sqazi@google.com>
Cc: Jesse Barnes <jsbarnes@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:32:42 -06:00
Ritesh Harjani
b75dfde121 fibmap: Warn and return an error in case of block > INT_MAX
We better warn the fibmap user and not return a truncated and therefore
an incorrect block map address if the bmap() returned block address
is greater than INT_MAX (since user supplied integer pointer).

It's better to pr_warn() all user of ioctl_fibmap() and return a proper
error code rather than silently letting a FS corruption happen if the
user tries to fiddle around with the returned block map address.

We fix this by returning an error code of -ERANGE and returning 0 as the
block mapping address in case if it is > INT_MAX.

Now iomap_bmap() could be called from either of these two paths.
Either when a user is calling an ioctl_fibmap() interface to get
the block mapping address or by some filesystem via use of bmap()
internal kernel API.
bmap() kernel API is well equipped with handling of u64 addresses.

WARN condition in iomap_bmap_actor() was mainly added to warn all
the fibmap users. But now that we have directly added this warning
for all fibmap users and also made sure to return 0 as block map address
in case if addr > INT_MAX.
So we can now remove this logic from iomap_bmap_actor().

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-04-30 07:57:46 -07:00
Linus Torvalds
9744b923d5 Bug fixes for 5.7:
- Fix a problem in readahead where we can crash if we can't allocate a
 full bio due to GFP_NORETRY.
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Merge tag 'iomap-5.7-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap fix from Darrick Wong:
 "Fix a problem in readahead where we can crash if we can't allocate a
  full bio due to GFP_NORETRY"

* tag 'iomap-5.7-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Handle memory allocation failure in readahead
2020-04-08 21:37:18 -07:00
Linus Torvalds
9b06860d7c libnvdimm for 5.7
- Add support for region alignment configuration and enforcement to
   fix compatibility across architectures and PowerPC page size
   configurations.
 
 - Introduce 'zero_page_range' as a dax operation. This facilitates
   filesystem-dax operation without a block-device.
 
 - Introduce phys_to_target_node() to facilitate drivers that want to
   know resulting numa node if a given reserved address range was
   onlined.
 
 - Advertise a persistence-domain for of_pmem and papr_scm. The
   persistence domain indicates where cpu-store cycles need to reach in
   the platform-memory subsystem before the platform will consider them
   power-fail protected.
 
 - Promote numa_map_to_online_node() to a cross-kernel generic facility.
 
 - Save x86 numa information to allow for node-id lookups for reserved
   memory ranges, deploy that capability for the e820-pmem driver.
 
 - Pick up some miscellaneous minor fixes, that missed v5.6-final,
   including a some smatch reports in the ioctl path and some unit test
   compilation fixups.
 
 - Fixup some flexible-array declarations.
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Merge tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm and dax updates from Dan Williams:
 "There were multiple touches outside of drivers/nvdimm/ this round to
  add cross arch compatibility to the devm_memremap_pages() interface,
  enhance numa information for persistent memory ranges, and add a
  zero_page_range() dax operation.

  This cycle I switched from the patchwork api to Konstantin's b4 script
  for collecting tags (from x86, PowerPC, filesystem, and device-mapper
  folks), and everything looks to have gone ok there. This has all
  appeared in -next with no reported issues.

  Summary:

   - Add support for region alignment configuration and enforcement to
     fix compatibility across architectures and PowerPC page size
     configurations.

   - Introduce 'zero_page_range' as a dax operation. This facilitates
     filesystem-dax operation without a block-device.

   - Introduce phys_to_target_node() to facilitate drivers that want to
     know resulting numa node if a given reserved address range was
     onlined.

   - Advertise a persistence-domain for of_pmem and papr_scm. The
     persistence domain indicates where cpu-store cycles need to reach
     in the platform-memory subsystem before the platform will consider
     them power-fail protected.

   - Promote numa_map_to_online_node() to a cross-kernel generic
     facility.

   - Save x86 numa information to allow for node-id lookups for reserved
     memory ranges, deploy that capability for the e820-pmem driver.

   - Pick up some miscellaneous minor fixes, that missed v5.6-final,
     including a some smatch reports in the ioctl path and some unit
     test compilation fixups.

   - Fixup some flexible-array declarations"

* tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (29 commits)
  dax: Move mandatory ->zero_page_range() check in alloc_dax()
  dax,iomap: Add helper dax_iomap_zero() to zero a range
  dax: Use new dax zero page method for zeroing a page
  dm,dax: Add dax zero_page_range operation
  s390,dcssblk,dax: Add dax zero_page_range operation to dcssblk driver
  dax, pmem: Add a dax operation zero_page_range
  pmem: Add functions for reading/writing page to/from pmem
  libnvdimm: Update persistence domain value for of_pmem and papr_scm device
  tools/test/nvdimm: Fix out of tree build
  libnvdimm/region: Fix build error
  libnvdimm/region: Replace zero-length array with flexible-array member
  libnvdimm/label: Replace zero-length array with flexible-array member
  ACPI: NFIT: Replace zero-length array with flexible-array member
  libnvdimm/region: Introduce an 'align' attribute
  libnvdimm/region: Introduce NDD_LABELING
  libnvdimm/namespace: Enforce memremap_compat_align()
  libnvdimm/pfn: Prevent raw mode fallback if pfn-infoblock valid
  libnvdimm: Out of bounds read in __nd_ioctl()
  acpi/nfit: improve bounds checking for 'func'
  mm/memremap_pages: Introduce memremap_compat_align()
  ...
2020-04-08 21:03:40 -07:00
Vivek Goyal
4f3b4f161d dax,iomap: Add helper dax_iomap_zero() to zero a range
Add a helper dax_ioamp_zero() to zero a range. This patch basically
merges __dax_zero_page_range() and iomap_dax_zero().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200228163456.1587-7-vgoyal@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-04-02 19:15:03 -07:00
Matthew Wilcox (Oracle)
457df33e03 iomap: Handle memory allocation failure in readahead
bio_alloc() can fail when we use GFP_NORETRY.  If it does, allocate
a bio large enough for a single page like mpage_readpages() does.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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>
2020-04-02 09:08:53 -07:00
yangerkun
d9973ce2fe iomap: fix comments in iomap_dio_rw
Double 'three' exists in the comments of iomap_dio_rw.

Signed-off-by: yangerkun <yangerkun@huawei.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>
2020-03-18 08:04:36 -07:00
Matthew Wilcox (Oracle)
1ac994525b iomap: Remove pgoff from tracepoints
The 'pgoff' displayed by the tracepoints wasn't a pgoff at all; it
was a byte offset from the start of the file.  We already emit that in
the form of the 'offset', so we can just remove pgoff.  That means we
can remove 'page' as an argument to the tracepoint, and rename this
type of tracepoint from being a page class to being a range class.

Fixes: 0b1b213fcf ("xfs: event tracing support")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-03-05 07:30:54 -08:00
Andreas Gruenbacher
243145bc43 fs: Fix page_mkwrite off-by-one errors
The check in block_page_mkwrite that is meant to determine whether an
offset is within the inode size is off by one.  This bug has been copied
into iomap_page_mkwrite and several filesystems (ubifs, ext4, f2fs,
ceph).

Fix that by introducing a new page_mkwrite_check_truncate helper that
checks for truncate and computes the bytes in the page up to EOF.  Use
the helper in iomap.

NOTE from Darrick: The original patch fixed a number of filesystems, but
then there were merge conflicts with the f2fs for-next tree; a
subsequent re-submission of the patch had different btrfs changes with
no explanation; and Christoph complained that each per-fs fix should be
a separate patch.  In my view that's too much risk to take on, so I
decided to drop all the hunks except for iomap, since I've actually QA'd
XFS.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: drop everything but the iomap parts]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-06 08:58:23 -08:00