[ Upstream commit a805c11165 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e6e7ca9262 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit add66fcbd3 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e9f930ac88 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 419e9c38aa upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Qian Cai