Resolves a conflict in gfs2_inode_lookup() between the following commits:
gfs2: Use TRY lock in gfs2_inode_lookup for UNLINKED inodes
gfs2: Mark the remaining process-independent glock holders as GL_NOPID
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
* more new_sync_{read,write}() speedups - ITER_UBUF introduction
* ITER_PIPE cleanups
* unification of iov_iter_get_pages/iov_iter_get_pages_alloc and
switching them to advancing semantics
* making ITER_PIPE take high-order pages without splitting them
* handling copy_page_from_iter() for high-order pages properly
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more iov_iter updates from Al Viro:
- more new_sync_{read,write}() speedups - ITER_UBUF introduction
- ITER_PIPE cleanups
- unification of iov_iter_get_pages/iov_iter_get_pages_alloc and
switching them to advancing semantics
- making ITER_PIPE take high-order pages without splitting them
- handling copy_page_from_iter() for high-order pages properly
* tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
fix copy_page_from_iter() for compound destinations
hugetlbfs: copy_page_to_iter() can deal with compound pages
copy_page_to_iter(): don't split high-order page in case of ITER_PIPE
expand those iov_iter_advance()...
pipe_get_pages(): switch to append_pipe()
get rid of non-advancing variants
ceph: switch the last caller of iov_iter_get_pages_alloc()
9p: convert to advancing variant of iov_iter_get_pages_alloc()
af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages()
iter_to_pipe(): switch to advancing variant of iov_iter_get_pages()
block: convert to advancing variants of iov_iter_get_pages{,_alloc}()
iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()
iov_iter: saner helper for page array allocation
fold __pipe_get_pages() into pipe_get_pages()
ITER_XARRAY: don't open-code DIV_ROUND_UP()
unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts
unify xarray_get_pages() and xarray_get_pages_alloc()
unify pipe_get_pages() and pipe_get_pages_alloc()
iov_iter_get_pages(): sanity-check arguments
iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper
...
Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(),
checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC
ones.
We are going to expose the things like ->write_iter() et.al. to those
in subsequent commits.
New predicate (user_backed_iter()) that is true for ITER_IOVEC and
ITER_UBUF; places like direct-IO handling should use that for
checking that pages we modify after getting them from iov_iter_get_pages()
would need to be dirtied.
DO NOT assume that replacing iter_is_iovec() with user_backed_iter()
will solve all problems - there's code that uses iter_is_iovec() to
decide how to poke around in iov_iter guts and for that the predicate
replacement obviously won't suffice.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Include flock glocks in the "glockfd" debugfs file. Those are similar to the
iopen glocks; while an open file is holding an flock, it is holding the file's
flock glock.
We cannot take f_fl_mutex in gfs2_glockfd_seq_show_flock() or else dumping the
"glockfd" file would block on flock operations. Instead, use the file->f_lock
spin lock to protect the f_fl_gh.gh_gl glock pointer.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
kfree on NULL pointer is a no-op.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
- Clean up the allocation of glocks that have an address space attached.
- Quota locking fix and quota iomap conversion.
- Fix the FITRIM error reporting.
- Some list iterator cleanups.
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Merge tag 'gfs2-v5.18-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 updates from Andreas Gruenbacher:
- Clean up the allocation of glocks that have an address space attached
- Quota locking fix and quota iomap conversion
- Fix the FITRIM error reporting
- Some list iterator cleanups
* tag 'gfs2-v5.18-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Convert function bh_get to use iomap
gfs2: use i_lock spin_lock for inode qadata
gfs2: Return more useful errors from gfs2_rgrp_send_discards()
gfs2: Use container_of() for gfs2_glock(aspace)
gfs2: Explain some direct I/O oddities
gfs2: replace 'found' with dedicated list iterator variable
Allow the file system to keep state for all iterations. For now only
wire it up for direct I/O as there is an immediate need for it there.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're having unresolved issues with the glock holder auto-demotion mechanism
introduced in commit dc732906c2. This mechanism was assumed to be essential
for avoiding frequent short reads and writes until commit 296abc0d91
("gfs2: No short reads or writes upon glock contention"). Since then,
when the inode glock is lost, it is simply re-acquired and the operation
is resumed. This means that apart from the performance penalty, we
might as well drop the inode glock before faulting in pages, and
re-acquire it afterwards.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_file_buffered_write, to increase the likelihood that all the
user memory we're trying to write will be resident in memory, carry out
the write in chunks and fault in each chunk of user memory before trying
to write it. Otherwise, some workloads will trigger frequent short
"internal" writes, causing filesystem blocks to be allocated and then
partially deallocated again when writing into holes, which is wasteful
and breaks reservations.
Neither the chunked writes nor any of the short "internal" writes are
user visible.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Align the chunks that reads and writes are carried out in to the page
cache rather than the user buffers. This will be more efficient in
general, especially for allocating writes. Optimizing the case that the
user buffer is gfs2 backed isn't very useful; we only need to make sure
we won't deadlock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Pull the return value test of the previous read or write operation out
of should_fault_in_pages(). In a following patch, we'll fault in pages
before the I/O and there will be no return value to check.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Instead of counting the number of bytes read from the filesystem,
functions gfs2_file_direct_read and gfs2_file_read_iter count the number
of bytes written into the user buffer. Conversely, functions
gfs2_file_direct_write and gfs2_file_buffered_write count the number of
bytes read from the user buffer. This is nothing but confusing, so
change the read functions to count how many bytes they have read, and
the write functions to count how many bytes they have written.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Commit 00bfe02f47 ("gfs2: Fix mmap + page fault deadlocks for buffered
I/O") changed gfs2_file_read_iter() and gfs2_file_buffered_write() to
allow dropping the inode glock while faulting in user buffers. When the
lock was dropped, a short result was returned to indicate that the
operation was interrupted.
As pointed out by Linus (see the link below), this behavior is broken
and the operations should always re-acquire the inode glock and resume
the operation instead.
Link: https://lore.kernel.org/lkml/CAHk-=whaz-g_nOOoo8RRiWNjnv2R+h6_xk2F1J4TuSRxk1MtLw@mail.gmail.com/
Fixes: 00bfe02f47 ("gfs2: Fix mmap + page fault deadlocks for buffered I/O")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Only re-check for direct I/O writes past the end of the file after
re-acquiring the inode glock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When direct writes fail with -ENOTBLK because we're writing into a
hole (gfs2_iomap_begin()) or because of a page invalidation failure
(iomap_dio_rw()), we're falling back to buffered writes. In that case,
when we lose the inode glock in gfs2_file_buffered_write(), we want to
re-acquire it instead of returning a short write.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Function iomap_dio_rw() only returns -ENOTBLK for write requests and
gfs2_file_direct_read() no longer returns -ENOTBLK since commit
1d45bb7f9d ("gfs2: Use iomap for stuffed direct I/O reads"), so there
is no need to check for -ENOTBLK in gfs2_file_read_iter() anymore.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Since commit 554c577cee, gfs2_file_buffered_write() can accidentally
return a truncated iov_iter, which might confuse callers. Fix that.
Fixes: 554c577cee ("gfs2: Prevent endless loops in gfs2_file_buffered_write")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
During lockless buffered reads, filemap_read() holds page cache page
references while trying to copy data to the user-space buffer. The
calling process isn't holding the inode glock, but the page references
it holds prevent those pages from being removed from the page cache, and
that prevents the underlying inode glock from being moved to another
node. Thus, we can end up in the same kinds of distributed deadlock
situations as with normal (non-lockless) buffered reads.
Fix that by disabling page faults during lockless reads as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Fix the fault-in window size logic:
* Use a maximum window size of 1 MiB instead of BIO_MAX_VECS * PAGE_SIZE.
The previous window size was always one page because the pages variable
was accidentally being defined and then redefined in
should_fault_in_pages().
* The nr_dirtied heuristic for guessing when there might be memory
pressure often results in very small window sizes. Don't let
nr_dirtied drop below 8 pages (as btrfs does).
* Compute the window size in units of bytes, not pages.
* Account for page overlap (unaligned iterators).
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The gh_error field if a glock holder is initialized to zero in
gfs2_holder_init(). When a locking operation fails, gh_error is set to
an error code; when it succeeds, the gh_error value is left unchanged.
The field isn't initialized in gfs2_holder_reinit(), which is a problem.
Instead of fixing that directly, initialize gh_error in gfs2_glock_nq().
That also obsoletes the assignment in do_flock().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When gfs2_setattr_size() fails, it calls gfs2_rs_delete(ip, NULL) to get
rid of any reservations the inode may have. Instead, it should pass in
the inode's write count as the second parameter to allow
gfs2_rs_delete() to figure out if the inode has any writers left.
In a next step, there are two instances of gfs2_rs_delete(ip, NULL) left
where we know that there can be no other users of the inode. Replace
those with gfs2_rs_deltree(&ip->i_res) to avoid the unnecessary write
count check.
With that, gfs2_rs_delete() is only called with the inode's actual write
count, so get rid of the second parameter.
Fixes: a097dc7e24 ("GFS2: Make rgrp reservations part of the gfs2_inode structure")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When a file is opened for writing, the vfs code (do_dentry_open)
calls get_write_access for the inode, thus incrementing the inode's write
count. That writer normally then creates a multi-block reservation for
the inode (i_res) that can be re-used by other writers, which speeds up
writes for applications that stupidly loop on open/write/close.
When the writes are all done, the multi-block reservation should be
deleted when the file is closed by the last "writer."
Commit 0ec9b9ea4f broke that concept when it moved the call to
gfs2_rs_delete before the check for FMODE_WRITE. Non-writers have no
business removing the multi-block reservations of writers. In fact, if
someone opens and closes the file for RO while a writer has a
multi-block reservation, the RO closer will delete the reservation
midway through the write, and this results in:
kernel BUG at fs/gfs2/rgrp.c:677! (or thereabouts) which is:
BUG_ON(rs->rs_requested); from function gfs2_rs_deltree.
This patch moves the check back inside the check for FMODE_WRITE.
Fixes: 0ec9b9ea4f ("gfs2: Check for active reservation in gfs2_release")
Cc: stable@vger.kernel.org # v5.12+
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Currently, instead of performing a short write,
iomap_file_buffered_write will fail when part of its iov iterator cannot
be read. In contrast, gfs2_file_buffered_write will loop around if it
can read part of the iov iterator, so we can end up in an endless loop.
This should be fixed in iomap_file_buffered_write (and also
generic_perform_write), but this comes a bit late in the 5.16
development cycle, so work around it in the filesystem by
trimming the iov iterator to the known-good size for now.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
* Fix a locking order inversion between the inode and iopen glocks in
gfs2_inode_lookup.
* Implement proper queuing of glock holders for glocks that require
instantiation (like reading an inode or bitmap blocks from disk).
Before, multiple glock holders could race with each other and
half-initialized objects could be exposed; the GL_SKIP flag further
exacerbated this problem.
* Fix a rare deadlock between inode lookup / creation and remote delete
work.
* Fix a rare scheduling-while-atomic bug in dlm during glock hash table
walks.
* Various other minor fixes and cleanups.
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Merge tag 'gfs2-v5.15-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 updates from Andreas Gruenbacher:
- Fix a locking order inversion between the inode and iopen glocks in
gfs2_inode_lookup.
- Implement proper queuing of glock holders for glocks that require
instantiation (like reading an inode or bitmap blocks from disk).
Before, multiple glock holders could race with each other and
half-initialized objects could be exposed; the GL_SKIP flag further
exacerbated this problem.
- Fix a rare deadlock between inode lookup / creation and remote delete
work.
- Fix a rare scheduling-while-atomic bug in dlm during glock hash table
walks.
- Various other minor fixes and cleanups.
* tag 'gfs2-v5.15-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: (21 commits)
gfs2: Fix unused value warning in do_gfs2_set_flags()
gfs2: check context in gfs2_glock_put
gfs2: Fix glock_hash_walk bugs
gfs2: Cancel remote delete work asynchronously
gfs2: set glock object after nq
gfs2: remove RDF_UPTODATE flag
gfs2: Eliminate GIF_INVALID flag
gfs2: fix GL_SKIP node_scope problems
gfs2: split glock instantiation off from do_promote
gfs2: further simplify do_promote
gfs2: re-factor function do_promote
gfs2: Remove 'first' trace_gfs2_promote argument
gfs2: change go_lock to go_instantiate
gfs2: dump glocks from gfs2_consist_OBJ_i
gfs2: dequeue iopen holder in gfs2_inode_lookup error
gfs2: Save ip from gfs2_glock_nq_init
gfs2: Allow append and immutable bits to coexist
gfs2: Switch some BUG_ON to GLOCK_BUG_ON for debug
gfs2: move GL_SKIP check from glops to do_promote
gfs2: Add GL_SKIP holder flag to dump_holder
...
Functions gfs2_file_read_iter and gfs2_file_write_iter are both
accessing the user buffer to write to or read from while holding the
inode glock. In the most basic scenario, that buffer will not be
resident and it will be mapped to the same file. Accessing the buffer
will trigger a page fault, and gfs2 will deadlock trying to take the
same inode glock again while trying to handle that fault.
Fix that and similar, more complex scenarios by disabling page faults
while accessing user buffers. To make this work, introduce a small
amount of new infrastructure and fix some bugs that didn't trigger so
far, with page faults enabled.
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Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher:
"Functions gfs2_file_read_iter and gfs2_file_write_iter are both
accessing the user buffer to write to or read from while holding the
inode glock.
In the most basic deadlock scenario, that buffer will not be resident
and it will be mapped to the same file. Accessing the buffer will
trigger a page fault, and gfs2 will deadlock trying to take the same
inode glock again while trying to handle that fault.
Fix that and similar, more complex scenarios by disabling page faults
while accessing user buffers. To make this work, introduce a small
amount of new infrastructure and fix some bugs that didn't trigger so
far, with page faults enabled"
* tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fix mmap + page fault deadlocks for direct I/O
iov_iter: Introduce nofault flag to disable page faults
gup: Introduce FOLL_NOFAULT flag to disable page faults
iomap: Add done_before argument to iomap_dio_rw
iomap: Support partial direct I/O on user copy failures
iomap: Fix iomap_dio_rw return value for user copies
gfs2: Fix mmap + page fault deadlocks for buffered I/O
gfs2: Eliminate ip->i_gh
gfs2: Move the inode glock locking to gfs2_file_buffered_write
gfs2: Introduce flag for glock holder auto-demotion
gfs2: Clean up function may_grant
gfs2: Add wrapper for iomap_file_buffered_write
iov_iter: Introduce fault_in_iov_iter_writeable
iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
powerpc/kvm: Fix kvm_use_magic_page
iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value
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Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- mq-deadline accounting improvements (Bart)
- blk-wbt timer fix (Andrea)
- Untangle the block layer includes (Christoph)
- Rework the poll support to be bio based, which will enable adding
support for polling for bio based drivers (Christoph)
- Block layer core support for multi-actuator drives (Damien)
- blk-crypto improvements (Eric)
- Batched tag allocation support (me)
- Request completion batching support (me)
- Plugging improvements (me)
- Shared tag set improvements (John)
- Concurrent queue quiesce support (Ming)
- Cache bdev in ->private_data for block devices (Pavel)
- bdev dio improvements (Pavel)
- Block device invalidation and block size improvements (Xie)
- Various cleanups, fixes, and improvements (Christoph, Jackie,
Masahira, Tejun, Yu, Pavel, Zheng, me)
* tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits)
blk-mq-debugfs: Show active requests per queue for shared tags
block: improve readability of blk_mq_end_request_batch()
virtio-blk: Use blk_validate_block_size() to validate block size
loop: Use blk_validate_block_size() to validate block size
nbd: Use blk_validate_block_size() to validate block size
block: Add a helper to validate the block size
block: re-flow blk_mq_rq_ctx_init()
block: prefetch request to be initialized
block: pass in blk_mq_tags to blk_mq_rq_ctx_init()
block: add rq_flags to struct blk_mq_alloc_data
block: add async version of bio_set_polled
block: kill DIO_MULTI_BIO
block: kill unused polling bits in __blkdev_direct_IO()
block: avoid extra iter advance with async iocb
block: Add independent access ranges support
blk-mq: don't issue request directly in case that current is to be blocked
sbitmap: silence data race warning
blk-cgroup: synchronize blkg creation against policy deactivation
block: refactor bio_iov_bvec_set()
block: add single bio async direct IO helper
...
Coverity complains of an unused value:
CID 119623 (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value -1 to error here, but that stored value is
overwritten before it can be used.
237 error = -EPERM;
Fix it by removing the assignment.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, function do_gfs2_set_flags checked if the append
and immutable flags were being set while already set. If so, error -EPERM
was given. There's no reason why these two flags should be mutually
exclusive, and if you set them separately, you will, in essence, set
one while it is already set. For example:
chattr +a /mnt/gfs2/file1
chattr +i /mnt/gfs2/file1
The first command sets the append-only flag. Since they are additive,
the second command sets the immutable flag AND append-only flag,
since they both coexist in i_diskflags. So the second command should
not return an error. This bug caused xfstests generic/545 to fail.
This patch simply removes the invalid checks.
I also eliminated an unused parm from do_gfs2_set_flags.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Also disable page faults during direct I/O requests and implement a
similar kind of retry logic as in the buffered I/O case.
The retry logic in the direct I/O case differs from the buffered I/O
case in the following way: direct I/O doesn't provide the kinds of
consistency guarantees between concurrent reads and writes that buffered
I/O provides, so once we lose the inode glock while faulting in user
pages, we always resume the operation. We never need to return a
partial read or write.
This locking problem was originally reported by Jan Kara. Linus came up
with the idea of disabling page faults. Many thanks to Al Viro and
Matthew Wilcox for their feedback.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Add a done_before argument to iomap_dio_rw that indicates how much of
the request has already been transferred. When the request succeeds, we
report that done_before additional bytes were tranferred. This is
useful for finishing a request asynchronously when part of the request
has already been completed synchronously.
We'll use that to allow iomap_dio_rw to be used with page faults
disabled: when a page fault occurs while submitting a request, we
synchronously complete the part of the request that has already been
submitted. The caller can then take care of the page fault and call
iomap_dio_rw again for the rest of the request, passing in the number of
bytes already tranferred.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
In the .read_iter and .write_iter file operations, we're accessing
user-space memory while holding the inode glock. There is a possibility
that the memory is mapped to the same file, in which case we'd recurse
on the same glock.
We could detect and work around this simple case of recursive locking,
but more complex scenarios exist that involve multiple glocks,
processes, and cluster nodes, and working around all of those cases
isn't practical or even possible.
Avoid these kinds of problems by disabling page faults while holding the
inode glock. If a page fault would occur, we either end up with a
partial read or write or with -EFAULT if nothing could be read or
written. In either case, we know that we're not done with the
operation, so we indicate that we're willing to give up the inode glock
and then we fault in the missing pages. If that made us lose the inode
glock, we return a partial read or write. Otherwise, we resume the
operation.
This locking problem was originally reported by Jan Kara. Linus came up
with the idea of disabling page faults. Many thanks to Al Viro and
Matthew Wilcox for their feedback.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Now that gfs2_file_buffered_write is the only remaining user of
ip->i_gh, we can move the glock holder to the stack (or rather, use the
one we already have on the stack); there is no need for keeping the
holder in the inode anymore.
This is slightly complicated by the fact that we're using ip->i_gh for
the statfs inode in gfs2_file_buffered_write as well. Writing to the
statfs inode isn't very common, so allocate the statfs holder
dynamically when needed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
So far, for buffered writes, we were taking the inode glock in
gfs2_iomap_begin and dropping it in gfs2_iomap_end with the intention of
not holding the inode glock while iomap_write_actor faults in user
pages. It turns out that iomap_write_actor is called inside iomap_begin
... iomap_end, so the user pages were still faulted in while holding the
inode glock and the locking code in iomap_begin / iomap_end was
completely pointless.
Move the locking into gfs2_file_buffered_write instead. We'll take care
of the potential deadlocks due to faulting in user pages while holding a
glock in a subsequent patch.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Add a wrapper around iomap_file_buffered_write. We'll add code for when
the operation needs to be retried here later.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.
Polling for the bio itself leads to a few advantages:
- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As best I can tell, the logic for these has been broken for a long time
(at least before the move to git), such that they never conflict with
anything. Also, nothing checks for these flags and prevented opens or
read/write behavior on the files. They don't seem to do anything.
Given that, we can rip these symbols out of the kernel, and just make
flock(2) return 0 when LOCK_MAND is set in order to preserve existing
behavior.
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.
I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.
This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Split __gfs2_unstuff_inode off from gfs2_unstuff_dinode and clean up the
code a little. All remaining callers now pass NULL as the page argument
of gfs2_unstuff_dinode, so remove that argument.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_page_mkwrite, unstuff inodes before locking the page. That
way, we won't have to pass in the locked page to gfs2_unstuff_inode,
and gfs2_unstuff_inode can look up and lock the page itself.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
We're setting an error number so that block_page_mkwrite_return
translates it into the corresponding VM_FAULT_* code in several places,
but this is getting confusing, so set the VM_FAULT_* codes directly
instead. (No change in functionality.)
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
On filesystems with a block size smaller than PAGE_SIZE and non-empty
files smaller then PAGE_SIZE, gfs2_page_mkwrite could end up allocating
excess blocks beyond the end of the file, similar to fallocate. This
doesn't make sense; fix it.
Reported-by: Bob Peterson <rpeterso@redhat.com>
Fixes: 184b4e6085 ("gfs2: Fix end-of-file handling in gfs2_page_mkwrite")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Commit 88b631cbfb ("gfs2: convert to fileattr") changed the argument list
without updating the description.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This reverts commit b7f55d928e.
As explained by Linus in [*], write faults on a mmap region are reads
from a filesysten point of view, so taking the inode glock exclusively
on write faults is incorrect.
Instead, when a page is marked writable, the .page_mkwrite vm operation
will be called, which is where the exclusive lock taking needs to
happen. I got this wrong because of a broken test case that made me
believe .page_mkwrite isn't getting called when it actually is.
[*] https://lore.kernel.org/lkml/CAHk-=wj8EWr_D65i4oRSj2FTbrc6RdNydNNCGxeabRnwtoU=3Q@mail.gmail.com/
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When a write fault occurs, we need to take the inode glock of the underlying
inode in exclusive mode. Otherwise, there's no guarantee that the dirty page
will be written back to disk.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Andreas Gruenbacher