Commit Graph

145 Commits

Author SHA1 Message Date
Xu Yu
36ca7943ac mm/swap: consider max pages in iomap_swapfile_add_extent
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>
2021-08-18 12:47:52 -07:00
Darrick J. Wong
8d04fbe71f iomap: move loop control code to iter.c
Now that we've moved iomap to the iterator model, rename this file to be
in sync with the functions contained inside of it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
fad0a1ab34 iomap: constify iomap_iter_srcmap
The srcmap returned from iomap_iter_srcmap is never modified, so mark
the iomap returned from it const and constify a lot of code that never
modifies the iomap.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
b74b1293e6 iomap: rework unshare flag
Instead of another internal flags namespace inside of buffered-io.c,
just pass a UNSHARE hint in the main iomap flags field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
1b5c1e36dc iomap: pass an iomap_iter to various buffered I/O helpers
Pass the iomap_iter structure instead of individual parameters to
various internal helpers for buffered I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
57320a01fe iomap: remove iomap_apply
iomap_apply is unused now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: rebase this patch to preserve git history of iomap loop control]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
3d99a1ce38 iomap: switch iomap_swapfile_activate to use iomap_iter
Switch iomap_swapfile_activate to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
c4740bf1ed iomap: switch iomap_seek_data to use iomap_iter
Rewrite iomap_seek_data to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
40670d18e8 iomap: switch iomap_seek_hole to use iomap_iter
Rewrite iomap_seek_hole to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
6d8a1287a4 iomap: switch iomap_bmap to use iomap_iter
Rewrite the ->bmap implementation based on iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: restructure the loop to make its behavior a little clearer]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
7892386d35 iomap: switch iomap_fiemap to use iomap_iter
Rewrite the ->fiemap implementation based on iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
a6d3d49587 iomap: switch __iomap_dio_rw to use iomap_iter
Switch __iomap_dio_rw to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
253564baff iomap: switch iomap_page_mkwrite to use iomap_iter
Switch iomap_page_mkwrite to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
2aa3048e03 iomap: switch iomap_zero_range to use iomap_iter
Switch iomap_zero_range to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
8fc274d1f4 iomap: switch iomap_file_unshare to use iomap_iter
Switch iomap_file_unshare to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
ce83a0251c iomap: switch iomap_file_buffered_write to use iomap_iter
Switch iomap_file_buffered_write to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
f6d480006c iomap: switch readahead and readpage to use iomap_iter
Switch the page cache read functions to use iomap_iter instead of
iomap_apply.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
f4b896c213 iomap: add the new iomap_iter model
The iomap_iter struct provides a convenient way to package up and
maintain all the arguments to the various mapping and operation
functions.  It is operated on using the iomap_iter() function that
is called in loop until the whole range has been processed.  Compared
to the existing iomap_apply() function this avoid an indirect call
for each iteration.

For now iomap_iter() calls back into the existing ->iomap_begin and
->iomap_end methods, but in the future this could be further optimized
to avoid indirect calls entirely.

Based on an earlier patch from Matthew Wilcox <willy@infradead.org>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: add to apply.c to preserve git history of iomap loop control]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
740499c784 iomap: fix the iomap_readpage_actor return value for inline data
The actor should never return a larger value than the length that was
passed in.  The current code handles this gracefully, but the opcoming
iter model will be more picky.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
1acd9e9c01 iomap: mark the iomap argument to iomap_read_page_sync const
iomap_read_page_sync never modifies the passed in iomap, so mark
it const.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
78c64b00f8 iomap: mark the iomap argument to iomap_read_inline_data const
iomap_read_inline_data never modifies the passed in iomap, so mark
it const.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
1d25d0aecf iomap: remove the iomap arguments to ->page_{prepare,done}
These aren't actually used by the only instance implementing the methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Christoph Hellwig
d9d381f3ef iomap: fix a trivial comment typo in trace.h
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16 21:26:33 -07:00
Darrick J. Wong
b69eea82d3 iomap: pass writeback errors to the mapping
Modern-day mapping_set_error has the ability to squash the usual
negative error code into something appropriate for long-term storage in
a struct address_space -- ENOSPC becomes AS_ENOSPC, and everything else
becomes EIO.  iomap squashes /everything/ to EIO, just as XFS did before
that, but this doesn't make sense.

Fix this by making it so that we can pass ENOSPC to userspace when
writeback fails due to space problems.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-08-16 12:12:52 -07:00
Matthew Wilcox (Oracle)
ae44f9c286 iomap: Add another assertion to inline data handling
Check that the file tail does not cross a page boundary.  Requested by
Andreas.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-05 10:30:33 -07:00
Matthew Wilcox (Oracle)
ab069d5fdc iomap: Use kmap_local_page instead of kmap_atomic
kmap_atomic() has the side-effect of disabling pagefaults and
preemption.  kmap_local_page() does not do this and is preferred.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-05 10:30:33 -07:00
Andreas Gruenbacher
f1f264b4c1 iomap: Fix some typos and bad grammar
Fix some typos and bad grammar in buffered-io.c to make the comments
easier to read.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-03 09:43:14 -07:00
Matthew Wilcox (Oracle)
b405435b41 iomap: Support inline data with block size < page size
Remove the restriction that inline data must start on a page boundary
in a file.  This allows, for example, the first 2KiB to be stored out
of line and the trailing 30 bytes to be stored inline.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-03 09:43:13 -07:00
Gao Xiang
69f4a26c1e iomap: support reading inline data from non-zero pos
The existing inline data support only works for cases where the entire
file is stored as inline data.  For larger files, EROFS stores the
initial blocks separately and the remainder of the file ("file tail")
adjacent to the inode.  Generalise inline data to allow reading the
inline file tail.  Tails may not cross a page boundary in memory.

We currently have no filesystems that support tails and writing,
so that case is currently disabled (see iomap_write_begin_inline).

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-03 09:43:13 -07:00
Christoph Hellwig
c1b79f11f4 iomap: simplify iomap_add_to_ioend
Now that the outstanding writes are counted in bytes, there is no need
to use the low-level __bio_try_merge_page API, we can switch back to
always using bio_add_page and simply iomap_add_to_ioend again.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-03 09:43:13 -07:00
Christoph Hellwig
d0364f9490 iomap: simplify iomap_readpage_actor
Now that the outstanding reads are counted in bytes, there is no need
to use the low-level __bio_try_merge_page API, we can switch back to
always using bio_add_page and simplify iomap_readpage_actor again.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-03 09:43:13 -07:00
Andreas Gruenbacher
229adf3c64 iomap: Don't create iomap_page objects in iomap_page_mkwrite_actor
Now that we create those objects in iomap_writepage_map when needed,
there's no need to pre-create them in iomap_page_mkwrite_actor anymore.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-07-15 09:58:06 -07:00
Andreas Gruenbacher
637d337595 iomap: Don't create iomap_page objects for inline files
In iomap_readpage_actor, don't create iop objects for inline inodes.
Otherwise, iomap_read_inline_data will set PageUptodate without setting
iop->uptodate, and iomap_page_release will eventually complain.

To prevent this kind of bug from occurring in the future, make sure the
page doesn't have private data attached in iomap_read_inline_data.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-07-15 09:58:05 -07:00
Andreas Gruenbacher
8e1bcef8e1 iomap: Permit pages without an iop to enter writeback
Create an iop in the writeback path if one doesn't exist.  This allows us
to avoid creating the iop in some cases.  We'll initially do that for pages
with inline data, but it can be extended to pages which are entirely within
an extent.  It also allows for an iop to be removed from pages in the
future (eg page split).

Co-developed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-07-15 09:58:05 -07:00
Christoph Hellwig
49694d14ff iomap: remove the length variable in iomap_seek_hole
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>
2021-07-15 09:58:04 -07:00
Christoph Hellwig
3ac1d42651 iomap: remove the length variable in iomap_seek_data
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>
2021-07-15 09:58:04 -07:00
Linus Torvalds
d3acb15a3a Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
 "iov_iter cleanups and fixes.

  There are followups, but this is what had sat in -next this cycle. IMO
  the macro forest in there became much thinner and easier to follow..."

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  csum_and_copy_to_pipe_iter(): leave handling of csum_state to caller
  clean up copy_mc_pipe_to_iter()
  pipe_zero(): we don't need no stinkin' kmap_atomic()...
  iov_iter: clean csum_and_copy_...() primitives up a bit
  copy_page_from_iter(): don't need kmap_atomic() for kvec/bvec cases
  copy_page_to_iter(): don't bother with kmap_atomic() for bvec/kvec cases
  iterate_xarray(): only of the first iteration we might get offset != 0
  pull handling of ->iov_offset into iterate_{iovec,bvec,xarray}
  iov_iter: make iterator callbacks use base and len instead of iovec
  iov_iter: make the amount already copied available to iterator callbacks
  iov_iter: get rid of separate bvec and xarray callbacks
  iov_iter: teach iterate_{bvec,xarray}() about possible short copies
  iterate_bvec(): expand bvec.h macro forest, massage a bit
  iov_iter: unify iterate_iovec and iterate_kvec
  iov_iter: massage iterate_iovec and iterate_kvec to logics similar to iterate_bvec
  iterate_and_advance(): get rid of magic in case when n is 0
  csum_and_copy_to_iter(): massage into form closer to csum_and_copy_from_iter()
  iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
  [xarray] iov_iter_npages(): just use DIV_ROUND_UP()
  iov_iter_npages(): don't bother with iterate_all_kinds()
  ...
2021-07-03 11:30:04 -07:00
Matthew Wilcox (Oracle)
fd7353f88b iomap: use __set_page_dirty_nobuffers
The only difference between iomap_set_page_dirty() and
__set_page_dirty_nobuffers() is that the latter includes a debugging check
that a !Uptodate page has private data.

Link: https://lkml.kernel.org/r/20210615162342.1669332-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:48 -07:00
Al Viro
f0b65f39ac iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the
callers do *not* need to do iov_iter_advance() after it.  In case when they end
up consuming less than they'd been given they need to do iov_iter_revert() on
everything they had not consumed.  That, however, needs to be done only on slow
paths.

All in-tree callers converted.  And that kills the last user of iterate_all_kinds()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10 11:45:14 -04:00
Al Viro
bc1bb416bb generic_perform_write()/iomap_write_actor(): saner logics for short copy
if we run into a short copy and ->write_end() refuses to advance at all,
use the amount we'd managed to copy for the next iteration to handle.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-02 17:50:44 -04:00
Matthew Wilcox (Oracle)
076171a677 mm/filemap: fix readahead return types
A readahead request will not allocate more memory than can be represented
by a size_t, even on systems that have HIGHMEM available.  Change the
length functions from returning an loff_t to a size_t.

Link: https://lkml.kernel.org/r/20210510201201.1558972-1-willy@infradead.org
Fixes: 32c0a6bcaa ("btrfs: add and use readahead_batch_length")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-14 19:41:32 -07:00
Brian Foster
6e552494fb iomap: remove unused private field from ioend
The only remaining user of ->io_private is the generic ioend merging
infrastructure. The only user of that is XFS, which no longer sets
->io_private or passes an associated merge callback. Remove the
unused parameter and the ->io_private field.

CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-05-04 08:54:29 -07:00
Jens Axboe
985b71db17 iomap: use filemap_range_needs_writeback() for O_DIRECT reads
For reads, use the better variant of checking for the need to call
filemap_write_and_wait_range() when doing O_DIRECT.  This avoids falling
back to the slow path for IOCB_NOWAIT, if there are no pages to wait for
(or write out).

Link: https://lkml.kernel.org/r/20210224164455.1096727-4-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:36 -07:00
Linus Torvalds
b34b95ebbb New code for 5.13:
- When a swap file is rejected, actually log the /name/ of the swapfile.
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Merge tag 'iomap-5.13-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap update from Darrick Wong:
 "A single patch to the iomap code, which augments what gets logged when
  someone tries to swapon an unacceptable swap file. (Yes, this is a
  continuation of the swapfile drama from last season...)"

* tag 'iomap-5.13-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: improve the warnings from iomap_swapfile_activate
2021-04-27 12:27:23 -07:00
Sami Tolvanen
4f0f586bf0 treewide: Change list_sort to use const pointers
list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.

Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
2021-04-08 16:04:22 -07:00
Christoph Hellwig
ad89b66cba iomap: improve the warnings from iomap_swapfile_activate
Print the path name of the swapfile that failed to active to ease
debugging the problem and to avoid a scare if xfstests hits these
cases.  Also reword one warning a bit, as the error is not about
a file being on multiple devices, but one that has at least an
extent outside the main device known to the VFS and swap code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-03-26 10:55:40 -07:00
Linus Torvalds
8ff0f3bf5d Merge branch 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap fix from Darrick Wong:
 "A single fix to the iomap code which fixes some drama when someone
  gives us a {de,ma}liciously fragmented swap file"

* 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Fix negative assignment to unsigned sis->pages in iomap_swapfile_activate
2021-03-18 10:37:30 -07:00
Christoph Hellwig
a8affc03a9 block: rename BIO_MAX_PAGES to BIO_MAX_VECS
Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed.  Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-11 07:47:48 -07:00
Ritesh Harjani
5808fecc57 iomap: Fix negative assignment to unsigned sis->pages in iomap_swapfile_activate
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>
2021-03-09 09:29:11 -08:00
Linus Torvalds
03dc748bf1 More new code for 5.12:
- Restore a disused sysctl control knob that was inadvertently dropped
   during the merge window to avoid fstests regressions.
 - Don't speculatively release freed blocks from the busy list until
   we're actually allocating them, which fixes a rare log recovery
   regression.
 - Don't nest transactions when scanning for free space.
 - Add an idiot^Wmaintainer light to detect nested transactions. ;)
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Merge tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
 "The most notable fix here prevents premature reuse of freed metadata
  blocks, and adding the ability to detect accidental nested
  transactions, which are not allowed here.

   - Restore a disused sysctl control knob that was inadvertently
     dropped during the merge window to avoid fstests regressions.

   - Don't speculatively release freed blocks from the busy list until
     we're actually allocating them, which fixes a rare log recovery
     regression.

   - Don't nest transactions when scanning for free space.

   - Add an idiot^Wmaintainer light to detect nested transactions. ;)"

* tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: use current->journal_info for detecting transaction recursion
  xfs: don't nest transactions when scanning for eofblocks
  xfs: don't reuse busy extents on extent trim
  xfs: restore speculative_cow_prealloc_lifetime sysctl
2021-02-28 11:45:25 -08:00