This patch fixes the following KASAN report. The @ioend has been
freed by dio_put(), but the iomap_finish_ioend() still trys to access
its data.
[20563.631624] BUG: KASAN: use-after-free in iomap_finish_ioend+0x58c/0x5c0
[20563.638319] Read of size 8 at addr fffffc0c54a36928 by task kworker/123:2/22184
[20563.647107] CPU: 123 PID: 22184 Comm: kworker/123:2 Not tainted 5.4.0+ #1
[20563.653887] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019
[20563.664499] Workqueue: xfs-conv/sda5 xfs_end_io [xfs]
[20563.669547] Call trace:
[20563.671993] dump_backtrace+0x0/0x370
[20563.675648] show_stack+0x1c/0x28
[20563.678958] dump_stack+0x138/0x1b0
[20563.682455] print_address_description.isra.9+0x60/0x378
[20563.687759] __kasan_report+0x1a4/0x2a8
[20563.691587] kasan_report+0xc/0x18
[20563.694985] __asan_report_load8_noabort+0x18/0x20
[20563.699769] iomap_finish_ioend+0x58c/0x5c0
[20563.703944] iomap_finish_ioends+0x110/0x270
[20563.708396] xfs_end_ioend+0x168/0x598 [xfs]
[20563.712823] xfs_end_io+0x1e0/0x2d0 [xfs]
[20563.716834] process_one_work+0x7f0/0x1ac8
[20563.720922] worker_thread+0x334/0xae0
[20563.724664] kthread+0x2c4/0x348
[20563.727889] ret_from_fork+0x10/0x18
[20563.732941] Allocated by task 83403:
[20563.736512] save_stack+0x24/0xb0
[20563.739820] __kasan_kmalloc.isra.9+0xc4/0xe0
[20563.744169] kasan_slab_alloc+0x14/0x20
[20563.747998] slab_post_alloc_hook+0x50/0xa8
[20563.752173] kmem_cache_alloc+0x154/0x330
[20563.756185] mempool_alloc_slab+0x20/0x28
[20563.760186] mempool_alloc+0xf4/0x2a8
[20563.763845] bio_alloc_bioset+0x2d0/0x448
[20563.767849] iomap_writepage_map+0x4b8/0x1740
[20563.772198] iomap_do_writepage+0x200/0x8d0
[20563.776380] write_cache_pages+0x8a4/0xed8
[20563.780469] iomap_writepages+0x4c/0xb0
[20563.784463] xfs_vm_writepages+0xf8/0x148 [xfs]
[20563.788989] do_writepages+0xc8/0x218
[20563.792658] __writeback_single_inode+0x168/0x18f8
[20563.797441] writeback_sb_inodes+0x370/0xd30
[20563.801703] wb_writeback+0x2d4/0x1270
[20563.805446] wb_workfn+0x344/0x1178
[20563.808928] process_one_work+0x7f0/0x1ac8
[20563.813016] worker_thread+0x334/0xae0
[20563.816757] kthread+0x2c4/0x348
[20563.819979] ret_from_fork+0x10/0x18
[20563.825028] Freed by task 22184:
[20563.828251] save_stack+0x24/0xb0
[20563.831559] __kasan_slab_free+0x10c/0x180
[20563.835648] kasan_slab_free+0x10/0x18
[20563.839389] slab_free_freelist_hook+0xb4/0x1c0
[20563.843912] kmem_cache_free+0x8c/0x3e8
[20563.847745] mempool_free_slab+0x20/0x28
[20563.851660] mempool_free+0xd4/0x2f8
[20563.855231] bio_free+0x33c/0x518
[20563.858537] bio_put+0xb8/0x100
[20563.861672] iomap_finish_ioend+0x168/0x5c0
[20563.865847] iomap_finish_ioends+0x110/0x270
[20563.870328] xfs_end_ioend+0x168/0x598 [xfs]
[20563.874751] xfs_end_io+0x1e0/0x2d0 [xfs]
[20563.878755] process_one_work+0x7f0/0x1ac8
[20563.882844] worker_thread+0x334/0xae0
[20563.886584] kthread+0x2c4/0x348
[20563.889804] ret_from_fork+0x10/0x18
[20563.894855] The buggy address belongs to the object at fffffc0c54a36900
which belongs to the cache bio-1 of size 248
[20563.906844] The buggy address is located 40 bytes inside of
248-byte region [fffffc0c54a36900, fffffc0c54a369f8)
[20563.918485] The buggy address belongs to the page:
[20563.923269] page:ffffffff82f528c0 refcount:1 mapcount:0 mapping:fffffc8e4ba31900 index:0xfffffc0c54a33300
[20563.932832] raw: 17ffff8000000200 ffffffffa3060100 0000000700000007 fffffc8e4ba31900
[20563.940567] raw: fffffc0c54a33300 0000000080aa0042 00000001ffffffff 0000000000000000
[20563.948300] page dumped because: kasan: bad access detected
[20563.955345] Memory state around the buggy address:
[20563.960129] fffffc0c54a36800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
[20563.967342] fffffc0c54a36880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[20563.974554] >fffffc0c54a36900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[20563.981766] ^
[20563.986288] fffffc0c54a36980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
[20563.993501] fffffc0c54a36a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[20564.000713] ==================================================================
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205703
Signed-off-by: Zorro Lang <zlang@redhat.com>
Fixes: 9cd0ed63ca ("iomap: enhance writeback error message")
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>
bio completions can race when a page spans more than one file system
block. Add a spinlock to synchronize marking the page uptodate.
Fixes: 9dc55f1389 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-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>
The 'start' variable indicates the start of a filemap and is set to the
iocb's position, which we have already cached as 'pos', upon function
entry.
'pos' is used as a cursor indicating the current position and updated
later in iomap_dio_rw(), but not before the last use of 'start'.
Remove 'start' as it's synonym for 'pos' before we're entering the loop
calling iomapp_apply().
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
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>
iomap_dio_bio_actor() copies iter to a local variable and then limits it
to a file extent we have mapped. When IO is submitted,
iomap_dio_bio_actor() advances the original iter while the copied iter
is advanced inside bio_iov_iter_get_pages(). This logic is non-obvious
especially because both iters still point to same shared structures
(such as pipe info) so if iov_iter_advance() changes anything in the
shared structure, this scheme breaks. Let's just truncate and reexpand
the original iter as needed instead of playing games with copying iters
and keeping them in sync.
Signed-off-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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When splicing using iomap_dio_rw() to a pipe, we may leak pipe pages
because bio_iov_iter_get_pages() records that the pipe will have full
extent worth of data however if file size is not block size aligned
iomap_dio_rw() returns less than what bio_iov_iter_get_pages() set up
and splice code gets confused leaking a pipe page with the file tail.
Handle the situation similarly to the old direct IO implementation and
revert iter to actually returned read amount which makes iter consistent
with value returned from iomap_dio_rw() and thus the splice code is
happy.
Fixes: ff6a9292e6 ("iomap: implement direct I/O")
CC: stable@vger.kernel.org
Reported-by: syzbot+991400e8eba7e00a26e1@syzkaller.appspotmail.com
Signed-off-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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add some tracepoints so that we can more easily debug what the
filesystem is returning from ->iomap_begin.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Naresh reported LTP diotest4 failing for 32bit x86 and arm -next
kernels on ext4. Same problem exists in 5.4-rc7 on xfs.
The failure comes down to:
openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4
mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000
read(4, 0xb7f7b000, 4096) = 0 // expects -EFAULT
Problem is conversion at iomap_dio_bio_actor() return. Ternary
operator has a return type and an attempt is made to convert each
of operands to the type of the other. In this case "ret" (int)
is converted to type of "copied" (unsigned long). Both have size
of 4 bytes:
size_t copied = 0;
int ret = -14;
long long actor_ret = copied ? copied : ret;
On x86_64: actor_ret == -14;
On x86 : actor_ret == 4294967282
Replace ternary operator with 2 return statements to avoid this
unwanted conversion.
Fixes: 4721a60109 ("iomap: dio data corruption and spurious errors when pipes fill")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jan Stancek <jstancek@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>
Coverity caught this fairly minor bug, but we should check the return
value of iomap_apply regardless.
Coverity-id: 1437065
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
On architectures where loff_t is wider than pgoff_t, the expression
((page->index + 1) << PAGE_SHIFT) can overflow. Rewrite to use the page
offset, which we already compute here anyway.
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>
We've already check if it is READ iov_iter, no need check again.
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The srcmap is used to identify where the read is to be performed from.
It is passed to ->iomap_begin, which can fill it in if we need to read
data for partially written blocks from a different location than the
write target. The srcmap is only supported for buffered writes so far.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
[hch: merged two patches, removed the IOMAP_F_COW flag, use iomap as
srcmap if not set, adjust length down to srcmap end as well]
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>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Use the existing iomap write_begin code to read the pages unshared
by iomap_file_unshare. That avoids the extra ->readpage call and
extent tree lookup currently done by read_mapping_page.
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>
That keeps the function a little easier to understand, and easier to
modify for pending enhancements.
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>
xfs_file_dirty is used to unshare reflink blocks. Rename the function
to xfs_file_unshare to better document that purpose, and skip iomaps
that are not shared and don't need zeroing. This will allow to simplify
the caller.
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>
All callers pass AOP_FLAG_NOFS, so lift that flag to iomap_write_begin
to allow reusing the flags arguments for an internal flags namespace
soon. Also remove the local index variable that is only used once.
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>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
If we encounter an IO error during writeback, log the inode, offset, and
sector number of the failure, instead of forcing the user to do some
sort of reverse mapping to figure out which file is affected.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
No need to pass the full bio_vec.
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>
Move the initialization of ia and ib to the declaration line and remove
a superflous else.
Signed-off-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>
Now that all the writepage code is in the iomap code there is no
need to keep this structure public.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
And inline mapping should never mark the page dirty and thus never end up
in writepages. Add a check for that condition and warn if it happens.
Signed-off-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>
Take the xfs writeback code and move it to fs/iomap. A new structure
with three methods is added as the abstraction from the generic writeback
code to the file system. These methods are used to map blocks, submit an
ioend, and cancel a page that encountered an error before it was added to
an ioend.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[darrick: rename ->submit_ioend to ->prepare_ioend to clarify what it
does]
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>
Lift the xfs code for tracing address space operations to the iomap
layer.
Signed-off-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>
File systems like gfs2 don't support delayed allocations or unwritten
extents and thus allocate normal mapped blocks to fill holes. To
cover the case of such file systems allocating new blocks to fill holes
also zero out mapped blocks with the new flag.
Signed-off-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>
Filesystems do not support doing IO as asynchronous in some cases. For
example in case of unaligned writes or in case file size needs to be
extended (e.g. for ext4). Instead of forcing filesystem to wait for AIO
in such cases, add argument to iomap_dio_rw() which makes the function
wait for IO completion. This also results in executing
iomap_dio_complete() inline in iomap_dio_rw() providing its return value
to the caller as for ordinary sync IO.
Signed-off-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>
Add a new iomap_dio_ops structure that for now just contains the end_io
handler. This avoid storing the function pointer in a mutable structure,
which is a possible exploit vector for kernel code execution, and prepares
for adding a submit_io handler that btrfs needs.
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>
Modify the calling convention for the iomap_dio_rw ->end_io() callback.
Rather than passing either dio->error or dio->size as the 'size' argument,
instead pass both the dio->error and the dio->size value separately.
In the instance that an error occurred during a write, we currently cannot
determine whether any blocks have been allocated beyond the current EOF and
data has subsequently been written to these blocks within the ->end_io()
callback. As a result, we cannot judge whether we should take the truncate
failed write path. Having both dio->error and dio->size will allow us to
perform such checks within this callback.
Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org>
[hch: minor cleanups]
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>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
- Regroup the fs/iomap.c code by major functional area so that we can
start development for 5.4 from a more stable base.
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Merge tag 'iomap-5.3-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap split/cleanup from Darrick Wong:
"As promised, here's the second part of the iomap merge for 5.3, in
which we break up iomap.c into smaller files grouped by functional
area so that it'll be easier in the long run to maintain cohesiveness
of code units and to review incoming patches. There are no functional
changes and fs/iomap.c split cleanly.
Summary:
- Regroup the fs/iomap.c code by major functional area so that we can
start development for 5.4 from a more stable base"
* tag 'iomap-5.3-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
iomap: move internal declarations into fs/iomap/
iomap: move the main iteration code into a separate file
iomap: move the buffered IO code into a separate file
iomap: move the direct IO code into a separate file
iomap: move the SEEK_HOLE code into a separate file
iomap: move the file mapping reporting code into a separate file
iomap: move the swapfile code into a separate file
iomap: start moving code to fs/iomap/
Move internal function declarations out of fs/internal.h into
include/linux/iomap.h so that our transition is complete.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the main iteration code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the buffered IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the direct IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the SEEK_HOLE/SEEK_DATA code into a separate file so that we can
group related functions in a single file instead of having a single
enormous source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the file mapping reporting code (FIEMAP/FIBMAP) into a separate
file so that we can group related functions in a single file instead of
having a single enormous source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the swapfile activation code into a separate file so that we can
group related functions in a single file instead of having a single
enormous source file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create the build infrastructure we need to start migrating iomap code to
fs/iomap/ from fs/iomap.c.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
