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With the NVMe support for this gone, there are no consumers of these hints
left, so remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220304175556.407719-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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* for-5.18/block: (96 commits)
block: remove bio_devname
ext4: stop using bio_devname
raid5-ppl: stop using bio_devname
raid1: stop using bio_devname
md-multipath: stop using bio_devname
dm-integrity: stop using bio_devname
dm-crypt: stop using bio_devname
pktcdvd: remove a pointless debug check in pkt_submit_bio
block: remove handle_bad_sector
block: fix and cleanup bio_check_ro
bfq: fix use-after-free in bfq_dispatch_request
blk-crypto: show crypto capabilities in sysfs
block: don't delete queue kobject before its children
block: simplify calling convention of elv_unregister_queue()
block: remove redundant semicolon
block: default BLOCK_LEGACY_AUTOLOAD to y
block: update io_ticks when io hang
block, bfq: don't move oom_bfqq
block, bfq: avoid moving bfqq to it's parent bfqg
block, bfq: cleanup bfq_bfqq_to_bfqg()
...
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The return value from function gfs2_indirect_init is never used, so
remove it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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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>
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Use list_is_first() instead of open-coding it.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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This patch tries to fix the continual ABBA deadlocks we keep having
between the iopen and inode glocks. This switches the lock order in
gfs2_inode_lookup and gfs2_create_inode so the iopen glock is always
locked first.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
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The gfs2 evict code tries to upgrade the iopen glock from SH to EX. If
the attempt to upgrade times out, gfs2 needs to tell dlm to cancel the
lock request or it can deadlock. We also need to wake up the process
waiting for the lock when dlm sends its AST back to gfs2.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
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Due to the asynchronous nature of the dlm api, when we request a pending
locking request to be canceled with dlm_unlock(DLM_LKF_CANCEL), the
locking request will either complete before it could be canceled, or the
cancellation will succeed. In either case, gdlm_ast will be called once
and the status will indicate the outcome of the locking request, with
-DLM_ECANCEL indicating a canceled request.
Inside dlm, when a locking request completes before its cancel request
could be processed, gdlm_ast will be called, but the lock will still be
considered busy until a DLM_MSG_CANCEL_REPLY message completes the
cancel request. During that time, successive dlm_lock() or dlm_unlock()
requests for that lock will return -EBUSY. In other words, waiting for
the gdlm_ast call before issuing the next locking request is not enough.
There is no way of waiting for a cancel request to actually complete,
either.
We rarely cancel locking requests, but when we do, we don't know when
the next locking request for that lock will occur. This means that any
dlm_lock() or dlm_unlock() call can potentially return -EBUSY. When
that happens, this patch simply repeats the request after a short pause.
This workaround could be improved upon by tracking for which dlm locks
cancel requests have been issued, but that isn't strictly necessary and
it would complicate the code. We haven't seen -EBUSY errors from dlm
without cancel requests.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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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: a097dc7e24cb ("GFS2: Make rgrp reservations part of the gfs2_inode structure")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, function read_rindex_entry called compute_bitstructs
before it allocated a glock for the rgrp. But if compute_bitstructs found
a problem with the rgrp, it called gfs2_consist_rgrpd, and that called
gfs2_dump_glock for rgd->rd_gl which had not yet been assigned.
read_rindex_entry
compute_bitstructs
gfs2_consist_rgrpd
gfs2_dump_glock <---------rgd->rd_gl was not set.
This patch changes read_rindex_entry so it assigns an rgrp glock before
calling compute_bitstructs so gfs2_dump_glock does not reference an
unassigned pointer. If an error is discovered, the glock must also be
put, so a new goto and label were added.
Reported-by: syzbot+c6fd14145e2f62ca0784@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fixes from Andreas Gruenbacher:
- Revert debug commit that causes unexpected data corruption
- Fix muti-block reservation regression
* tag 'gfs2-v5.16-rc3-fixes2' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fix gfs2_release for non-writers regression
Revert "gfs2: check context in gfs2_glock_put"
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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 0ec9b9ea4f83 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: 0ec9b9ea4f83 ("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>
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It turns out that the might_sleep() call that commit 660a6126f8c3 adds
is triggering occasional data corruption in testing. We're not sure
about the root cause yet, but since this commit was added as a debugging
aid only, revert it for now.
This reverts commit 660a6126f8c3208f6df8d552039cda078a8426d1.
Fixes: 660a6126f8c3 ("gfs2: check context in gfs2_glock_put")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment. NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.
Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it. So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of changes for the driver core for 5.17-rc1.
Lots of little things here, including:
- kobj_type cleanups
- auxiliary_bus documentation updates
- auxiliary_device conversions for some drivers (relevant subsystems
all have provided acks for these)
- kernfs lock contention reduction for some workloads
- other tiny cleanups and changes.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits)
kobject documentation: remove default_attrs information
drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb
debugfs: lockdown: Allow reading debugfs files that are not world readable
driver core: Make bus notifiers in right order in really_probe()
driver core: Move driver_sysfs_remove() after driver_sysfs_add()
firmware: edd: remove empty default_attrs array
firmware: dmi-sysfs: use default_groups in kobj_type
qemu_fw_cfg: use default_groups in kobj_type
firmware: memmap: use default_groups in kobj_type
sh: sq: use default_groups in kobj_type
headers/uninline: Uninline single-use function: kobject_has_children()
devtmpfs: mount with noexec and nosuid
driver core: Simplify async probe test code by using ktime_ms_delta()
nilfs2: use default_groups in kobj_type
kobject: remove kset from struct kset_uevent_ops callbacks
driver core: make kobj_type constant.
driver core: platform: document registration-failure requirement
vdpa/mlx5: Use auxiliary_device driver data helpers
net/mlx5e: Use auxiliary_device driver data helpers
soundwire: intel: Use auxiliary_device driver data helpers
...
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Before this patch, glock dumps would not dump the gl_object for iopen
glocks. This information can help us debug problems related to eviction:
when AN iopen glock is blocked we can see the status of its underlying
inode and its flags, etc.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
entirely.
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com>
Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The description of gfs2_instantiate accidentally lists a glock argument,
but the function takes a glock holder.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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If the GLF_INSTANTIATE_NEEDED flag isn't set, gfs2_instantiate() is a
no-op.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Function rgrp_go_inval calls gfs2_rgrp_brelse to invalidate the
in-core rgrp structures. After the call it set GLF_INSTANTIATE_NEEDED,
which is redundant, since gfs2_rgrp_brelse also sets it.
This patch simply removes the redundant set_bit.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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The function name in the kernel-doc comment wasn't updated when the
function was renamed.
Fixes: b016d9a84abd ("gfs2: Save ip from gfs2_glock_nq_init")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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When gfs2_lookup_by_inum() calls gfs2_inode_lookup() for an uncached
inode, gfs2_inode_lookup() will place a new tentative inode into the
inode cache before verifying that there is a valid inode at the given
address. This can race with gfs2_create_inode() which doesn't check for
duplicates inodes. gfs2_create_inode() will try to assign the new inode
to the corresponding inode glock, and glock_set_object() will complain
that the glock is still in use by gfs2_inode_lookup's tentative inode.
We noticed this bug after adding commit 486408d690e1 ("gfs2: Cancel
remote delete work asynchronously") which allowed delete_work_func() to
race with gfs2_create_inode(), but the same race exists for
open-by-handle.
Fix that by switching from insert_inode_hash() to
insert_inode_locked4(), which does check for duplicate inodes. We know
we've just managed to to allocate the new inode, so an inode tentatively
created by gfs2_inode_lookup() will eventually go away and
insert_inode_locked4() will always succeed.
In addition, don't flush the inode glock work anymore (this can now only
make things worse) and clean up glock_{set,clear}_object for the inode
glock somewhat.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Rework gfs2_inode_lookup() to only set up the new inode's glocks after
verifying that the new inode is valid.
There is no need for flushing the inode glock work queue anymore now,
so remove that as well.
While at it, get rid of the useless wrapper around iget5_locked() and
its unnecessary is_bad_inode() check.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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In gfs2_inode_lookup, once the inode has been looked up, we check if the
inode generation (no_formal_ino) is the one we're looking for. If it
isn't and the inode wasn't in the inode cache, we discard the newly
looked up inode. This is unnecessary, complicates the code, and makes
future changes to gfs2_inode_lookup harder, so change the code to retain
newly looked up inodes instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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When we mock up a temporary holder in gfs2_glock_cb to demote weak holders in
response to a remote locking conflict, we don't set the HIF_HOLDER flag. This
causes function may_grant to BUG. Fix by setting the missing HIF_HOLDER flag
in the mock glock holder.
In addition, define the mock glock holder where it is used.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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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>
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Function demote_incompat_holders iterates over the list of glock holders
with list_for_each_entry, and it then sometimes removes the current
holder from the list. This will get the loop stuck; we must use
list_for_each_entry_safe instead.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Fix the length of holes reported at the end of a file: the length is
relative to the beginning of the extent, not the seek position which is
rounded down to the filesystem block size.
This bug went unnoticed for some time, but is now caught by the
following assertion in iomap_iter_done():
WARN_ON_ONCE(iter->iomap.offset + iter->iomap.length <= iter->pos)
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, evict would clear the iopen glock's gl_object after
releasing the inode glock. In the meantime, another process could reuse
the same block and thus glocks for a new inode. It would lock the inode
glock (exclusively), and then the iopen glock (shared). The shared
locking mode doesn't provide any ordering against the evict, so by the
time the iopen glock is reused, evict may not have gotten to setting
gl_object to NULL.
Fix that by releasing the iopen glock before the inode glock in
gfs2_evict_inode.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>gl_object
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Replace test_bit() + set_bit() with test_and_set_bit() where we need an atomic
operation. Use clear_and_wake_up_bit() instead of open coding it.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Only dereference i->iov after establishing that i is of type ITER_IOVEC.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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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
...
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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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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
...
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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>
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Add a might_sleep call into gfs2_glock_put which can sleep in DLM when
the last reference is released. This will show problems earlier, and
not only when the last reference is put.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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So far, glock_hash_walk took a reference on each glock it iterated over, and it
was the examiner's responsibility to drop those references. Dropping the final
reference to a glock can sleep and the examiners are called in a RCU critical
section with spin locks held, so examiners that didn't need the extra reference
had to drop it asynchronously via gfs2_glock_queue_put or similar. This wasn't
done correctly in thaw_glock which did call gfs2_glock_put, and not at all in
dump_glock_func.
Change glock_hash_walk to not take glock references at all. That way, the
examiners that don't need them won't have to bother with slow asynchronous
puts, and the examiners that do need references can take them themselves.
Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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In gfs2_inode_lookup and gfs2_create_inode, we're calling
gfs2_cancel_delete_work which currently cancels any remote delete work
(delete_work_func) synchronously. This means that if the work is
currently running, it will wait for it to finish. We're doing this to
pevent a previous instance of an inode from having any influence on the
next instance.
However, delete_work_func uses gfs2_inode_lookup internally, and we can
end up in a deadlock when delete_work_func gets interrupted at the wrong
time. For example,
(1) An inode's iopen glock has delete work queued, but the inode
itself has been evicted from the inode cache.
(2) The delete work is preempted before reaching gfs2_inode_lookup.
(3) Another process recreates the inode (gfs2_create_inode). It tries
to cancel any outstanding delete work, which blocks waiting for
the ongoing delete work to finish.
(4) The delete work calls gfs2_inode_lookup, which blocks waiting for
gfs2_create_inode to instantiate and unlock the new inode =>
deadlock.
It turns out that when the delete work notices that its inode has been
re-instantiated, it will do nothing. This means that it's safe to
cancel the delete work asynchronously. This prevents the kind of
deadlock described above.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
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Before this patch, function gfs2_create_inode called glock_set_object to
set the gl_object for inode and iopen glocks before the glock was locked.
That's wrong because other competing processes like evict may be
blocked waiting for the glock and still have gl_object set before the
actual eviction can take place.
This patch moves the call to glock_set_object until after the glock is
acquire in function gfs2_create_inode, so it waits for possibly
competing evicts to finish their processing first.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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The new GLF_INSTANTIATE_NEEDED flag obsoletes the old rgrp flag
GFS2_RDF_UPTODATE, so this patch replaces it like we did with inodes.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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With the addition of the new GLF_INSTANTIATE_NEEDED flag, the
GIF_INVALID flag is now redundant. This patch removes it.
Since inode_instantiate is only called when instantiation is needed,
the check in inode_instantiate is removed too.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, when a glock was locked, the very first holder on the
queue would unlock the lockref and call the go_instantiate glops function
(if one existed), unless GL_SKIP was specified. When we introduced the new
node-scope concept, we allowed multiple holders to lock glocks in EX mode
and share the lock.
But node-scope introduced a new problem: if the first holder has GL_SKIP
and the next one does NOT, since it is not the first holder on the queue,
the go_instantiate op was not called. Eventually the GL_SKIP holder may
call the instantiate sub-function (e.g. gfs2_rgrp_bh_get) but there was
still a window of time in which another non-GL_SKIP holder assumes the
instantiate function had been called by the first holder. In the case of
rgrp glocks, this led to a NULL pointer dereference on the buffer_heads.
This patch tries to fix the problem by introducing two new glock flags:
GLF_INSTANTIATE_NEEDED, which keeps track of when the instantiate function
needs to be called to "fill in" or "read in" the object before it is
referenced.
GLF_INSTANTIATE_IN_PROG which is used to determine when a process is
in the process of reading in the object. Whenever a function needs to
reference the object, it checks the GLF_INSTANTIATE_NEEDED flag, and if
set, it sets GLF_INSTANTIATE_IN_PROG and calls the glops "go_instantiate"
function.
As before, the gl_lockref spin_lock is unlocked during the IO operation,
which may take a relatively long amount of time to complete. While
unlocked, if another process determines go_instantiate is still needed,
it sees GLF_INSTANTIATE_IN_PROG is set, and waits for the go_instantiate
glop operation to be completed. Once GLF_INSTANTIATE_IN_PROG is cleared,
it needs to check GLF_INSTANTIATE_NEEDED again because the other process's
go_instantiate operation may not have been successful.
Functions that previously called the instantiate sub-functions now call
directly into gfs2_instantiate so the new bits are managed properly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, function do_promote had a section of code that did
the actual instantiation. This patch splits that off into its own
function, gfs2_instantiate, which prepares us for the next patch that
will use that function.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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This patch further simplifies function do_promote by eliminating some
redundant code in favor of using a lock_released flag. This is just
prep work for a future patch.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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This patch simply re-factors function do_promote to reduce the indents.
The logic should be unchanged. This makes future patches more readable.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Remove the 'first' argument of trace_gfs2_promote: with GL_SKIP, the
'first' holder isn't the one that instantiates the glock
(gl_instantiate), which is what the 'first' flag was apparently supposed
to indicate.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, the go_lock glock operations (glops) did not do
any actual locking. They were used to instantiate objects, like reading
in dinodes and rgrps from the media.
This patch renames the functions to go_instantiate for clarity.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, failed consistency checks printed out the object
that failed, but not the object's glock. This patch makes it also
print out the object glock so we can see the glock's holders and flags
to aid with debugging.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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Before this patch, if function gfs2_inode_lookup encountered an error
after it had locked the iopen glock, it never unlocked it, relying on
the evict code to do the cleanup. The evict code then took the
inode glock while holding the iopen glock, which violates the locking
order. For example,
(1) node A does a gfs2_inode_lookup that fails, leaving the iopen glock
locked.
(2) node B calls delete_work_func -> gfs2_lookup_by_inum ->
gfs2_inode_lookup. It locks the inode glock and blocks trying to
lock the iopen glock, which is held by node A.
(3) node A eventually calls gfs2_evict_inode -> evict_should_delete.
It blocks trying to lock the inode glock, which is now held by
node B.
This patch introduces error handling to function gfs2_inode_lookup
so it properly dequeues held iopen glocks on errors.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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