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409 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
8834147f95 |
fscache rewrite
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Merge tag 'fscache-rewrite-20220111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull fscache rewrite from David Howells:
"This is a set of patches that rewrites the fscache driver and the
cachefiles driver, significantly simplifying the code compared to
what's upstream, removing the complex operation scheduling and object
state machine in favour of something much smaller and simpler.
The series is structured such that the first few patches disable
fscache use by the network filesystems using it, remove the cachefiles
driver entirely and as much of the fscache driver as can be got away
with without causing build failures in the network filesystems.
The patches after that recreate fscache and then cachefiles,
attempting to add the pieces in a logical order. Finally, the
filesystems are reenabled and then the very last patch changes the
documentation.
[!] Note: I have dropped the cifs patch for the moment, leaving local
caching in cifs disabled. I've been having trouble getting that
working. I think I have it done, but it needs more testing (there
seem to be some test failures occurring with v5.16 also from
xfstests), so I propose deferring that patch to the end of the
merge window.
WHY REWRITE?
============
Fscache's operation scheduling API was intended to handle sequencing
of cache operations, which were all required (where possible) to run
asynchronously in parallel with the operations being done by the
network filesystem, whilst allowing the cache to be brought online and
offline and to interrupt service for invalidation.
With the advent of the tmpfile capacity in the VFS, however, an
opportunity arises to do invalidation much more simply, without having
to wait for I/O that's actually in progress: Cachefiles can simply
create a tmpfile, cut over the file pointer for the backing object
attached to a cookie and abandon the in-progress I/O, dismissing it
upon completion.
Future work here would involve using Omar Sandoval's vfs_link() with
AT_LINK_REPLACE[1] to allow an extant file to be displaced by a new
hard link from a tmpfile as currently I have to unlink the old file
first.
These patches can also simplify the object state handling as I/O
operations to the cache don't all have to be brought to a stop in
order to invalidate a file. To that end, and with an eye on to writing
a new backing cache model in the future, I've taken the opportunity to
simplify the indexing structure.
I've separated the index cookie concept from the file cookie concept
by C type now. The former is now called a "volume cookie" (struct
fscache_volume) and there is a container of file cookies. There are
then just the two levels. All the index cookie levels are collapsed
into a single volume cookie, and this has a single printable string as
a key. For instance, an AFS volume would have a key of something like
"afs,example.com,1000555", combining the filesystem name, cell name
and volume ID. This is freeform, but must not have '/' chars in it.
I've also eliminated all pointers back from fscache into the network
filesystem. This required the duplication of a little bit of data in
the cookie (cookie key, coherency data and file size), but it's not
actually that much. This gets rid of problems with making sure we keep
netfs data structures around so that the cache can access them.
These patches mean that most of the code that was in the drivers
before is simply gone and those drivers are now almost entirely new
code. That being the case, there doesn't seem any particular reason to
try and maintain bisectability across it. Further, there has to be a
point in the middle where things are cut over as there's a single
point everything has to go through (ie. /dev/cachefiles) and it can't
be in use by two drivers at once.
ISSUES YET OUTSTANDING
======================
There are some issues still outstanding, unaddressed by this patchset,
that will need fixing in future patchsets, but that don't stop this
series from being usable:
(1) The cachefiles driver needs to stop using the backing filesystem's
metadata to store information about what parts of the cache are
populated. This is not reliable with modern extent-based
filesystems.
Fixing this is deferred to a separate patchset as it involves
negotiation with the network filesystem and the VM as to how much
data to download to fulfil a read - which brings me on to (2)...
(2) NFS (and CIFS with the dropped patch) do not take account of how
the cache would like I/O to be structured to meet its granularity
requirements. Previously, the cache used page granularity, which
was fine as the network filesystems also dealt in page
granularity, and the backing filesystem (ext4, xfs or whatever)
did whatever it did out of sight. However, we now have folios to
deal with and the cache will now have to store its own metadata to
track its contents.
The change I'm looking at making for cachefiles is to store
content bitmaps in one or more xattrs and making a bit in the map
correspond to something like a 256KiB block. However, the size of
an xattr and the fact that they have to be read/updated in one go
means that I'm looking at covering 1GiB of data per 512-byte map
and storing each map in an xattr. Cachefiles has the potential to
grow into a fully fledged filesystem of its very own if I'm not
careful.
However, I'm also looking at changing things even more radically
and going to a different model of how the cache is arranged and
managed - one that's more akin to the way, say, openafs does
things - which brings me on to (3)...
(3) The way cachefilesd does culling is very inefficient for large
caches and it would be better to move it into the kernel if I can
as cachefilesd has to keep asking the kernel if it can cull a
file. Changing the way the backend works would allow this to be
addressed.
BITS THAT MAY BE CONTROVERSIAL
==============================
There are some bits I've added that may be controversial:
(1) I've provided a flag, S_KERNEL_FILE, that cachefiles uses to check
if a files is already being used by some other kernel service
(e.g. a duplicate cachefiles cache in the same directory) and
reject it if it is. This isn't entirely necessary, but it helps
prevent accidental data corruption.
I don't want to use S_SWAPFILE as that has other effects, but
quite possibly swapon() should set S_KERNEL_FILE too.
Note that it doesn't prevent userspace from interfering, though
perhaps it should. (I have made it prevent a marked directory from
being rmdir-able).
(2) Cachefiles wants to keep the backing file for a cookie open whilst
we might need to write to it from network filesystem writeback.
The problem is that the network filesystem unuses its cookie when
its file is closed, and so we have nothing pinning the cachefiles
file open and it will get closed automatically after a short time
to avoid EMFILE/ENFILE problems.
Reopening the cache file, however, is a problem if this is being
done due to writeback triggered by exit(). Some filesystems will
oops if we try to open a file in that context because they want to
access current->fs or suchlike.
To get around this, I added the following:
(A) An inode flag, I_PINNING_FSCACHE_WB, to be set on a network
filesystem inode to indicate that we have a usage count on the
cookie caching that inode.
(B) A flag in struct writeback_control, unpinned_fscache_wb, that
is set when __writeback_single_inode() clears the last dirty
page from i_pages - at which point it clears
I_PINNING_FSCACHE_WB and sets this flag.
This has to be done here so that clearing I_PINNING_FSCACHE_WB
can be done atomically with the check of PAGECACHE_TAG_DIRTY
that clears I_DIRTY_PAGES.
(C) A function, fscache_set_page_dirty(), which if it is not set,
sets I_PINNING_FSCACHE_WB and calls fscache_use_cookie() to
pin the cache resources.
(D) A function, fscache_unpin_writeback(), to be called by
->write_inode() to unuse the cookie.
(E) A function, fscache_clear_inode_writeback(), to be called when
the inode is evicted, before clear_inode() is called. This
cleans up any lingering I_PINNING_FSCACHE_WB.
The network filesystem can then use these tools to make sure that
fscache_write_to_cache() can write locally modified data to the
cache as well as to the server.
For the future, I'm working on write helpers for netfs lib that
should allow this facility to be removed by keeping track of the
dirty regions separately - but that's incomplete at the moment and
is also going to be affected by folios, one way or another, since
it deals with pages"
Link: https://lore.kernel.org/all/510611.1641942444@warthog.procyon.org.uk/
Tested-by: Dominique Martinet <asmadeus@codewreck.org> # 9p
Tested-by: kafs-testing@auristor.com # afs
Tested-by: Jeff Layton <jlayton@kernel.org> # ceph
Tested-by: Dave Wysochanski <dwysocha@redhat.com> # nfs
Tested-by: Daire Byrne <daire@dneg.com> # nfs
* tag 'fscache-rewrite-20220111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (67 commits)
9p, afs, ceph, nfs: Use current_is_kswapd() rather than gfpflags_allow_blocking()
fscache: Add a tracepoint for cookie use/unuse
fscache: Rewrite documentation
ceph: add fscache writeback support
ceph: conversion to new fscache API
nfs: Implement cache I/O by accessing the cache directly
nfs: Convert to new fscache volume/cookie API
9p: Copy local writes to the cache when writing to the server
9p: Use fscache indexing rewrite and reenable caching
afs: Skip truncation on the server of data we haven't written yet
afs: Copy local writes to the cache when writing to the server
afs: Convert afs to use the new fscache API
fscache, cachefiles: Display stat of culling events
fscache, cachefiles: Display stats of no-space events
cachefiles: Allow cachefiles to actually function
fscache, cachefiles: Store the volume coherency data
cachefiles: Implement the I/O routines
cachefiles: Implement cookie resize for truncate
cachefiles: Implement begin and end I/O operation
cachefiles: Implement backing file wrangling
...
|
||
David Howells
|
08276bdae6 |
vfs, fscache: Implement pinning of cache usage for writeback
Cachefiles has a problem in that it needs to keep the backing file for a
cookie open whilst there are local modifications pending that need to be
written to it. However, we don't want to keep the file open indefinitely,
as that causes EMFILE/ENFILE/ENOMEM problems.
Reopening the cache file, however, is a problem if this is being done due
to writeback triggered by exit(). Some filesystems will oops if we try to
open a file in that context because they want to access current->fs or
other resources that have already been dismantled.
To get around this, I added the following:
(1) An inode flag, I_PINNING_FSCACHE_WB, to be set on a network filesystem
inode to indicate that we have a usage count on the cookie caching
that inode.
(2) A flag in struct writeback_control, unpinned_fscache_wb, that is set
when __writeback_single_inode() clears the last dirty page from
i_pages - at which point it clears I_PINNING_FSCACHE_WB and sets this
flag.
This has to be done here so that clearing I_PINNING_FSCACHE_WB can be
done atomically with the check of PAGECACHE_TAG_DIRTY that clears
I_DIRTY_PAGES.
(3) A function, fscache_set_page_dirty(), which if it is not set, sets
I_PINNING_FSCACHE_WB and calls fscache_use_cookie() to pin the cache
resources.
(4) A function, fscache_unpin_writeback(), to be called by ->write_inode()
to unuse the cookie.
(5) A function, fscache_clear_inode_writeback(), to be called when the
inode is evicted, before clear_inode() is called. This cleans up any
lingering I_PINNING_FSCACHE_WB.
The network filesystem can then use these tools to make sure that
fscache_write_to_cache() can write locally modified data to the cache as
well as to the server.
For the future, I'm working on write helpers for netfs lib that should
allow this facility to be removed by keeping track of the dirty regions
separately - but that's incomplete at the moment and is also going to be
affected by folios, one way or another, since it deals with pages
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819615157.215744.17623791756928043114.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906917856.143852.8224898306177154573.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967124567.1823006.14188359004568060298.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021524705.640689.17824932021727663017.stgit@warthog.procyon.org.uk/ # v4
|
||
Matthew Wilcox (Oracle)
|
22b3c8d661 |
fs/writeback: Convert inode_switch_wbs_work_fn to folios
This gets the statistics correct for large folios by modifying the counters by the number of pages in the folio instead of by 1. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Linus Torvalds
|
bf953917be |
Various hardening fixes and cleanups for 5.16-rc1
Hi Linus,
Please, pull the following hardening fixes and cleanups that I've
been collecting during the last development cycle. All of them have
been baking in linux-next.
Fix -Wcast-function-type error:
- firewire: Remove function callback casts (Oscar Carter)
Fix application of sizeof operator:
- firmware/psci: fix application of sizeof to pointer (jing yangyang)
Replace open coded instances with size_t saturating arithmetic helpers:
- assoc_array: Avoid open coded arithmetic in allocator arguments (Len Baker)
- writeback: prefer struct_size over open coded arithmetic (Len Baker)
- aio: Prefer struct_size over open coded arithmetic (Len Baker)
- dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic (Len Baker)
Flexible array transformation:
- KVM: PPC: Replace zero-length array with flexible array member (Len Baker)
Use 2-factor argument multiplication form:
- nouveau/svm: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)
- xfs: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)
Thanks
--
Gustavo
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Merge tag 'kspp-misc-fixes-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull hardening fixes and cleanups from Gustavo A. R. Silva:
"Various hardening fixes and cleanups that I've been collecting during
the last development cycle:
Fix -Wcast-function-type error:
- firewire: Remove function callback casts (Oscar Carter)
Fix application of sizeof operator:
- firmware/psci: fix application of sizeof to pointer (jing yangyang)
Replace open coded instances with size_t saturating arithmetic
helpers:
- assoc_array: Avoid open coded arithmetic in allocator arguments
(Len Baker)
- writeback: prefer struct_size over open coded arithmetic (Len
Baker)
- aio: Prefer struct_size over open coded arithmetic (Len Baker)
- dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
(Len Baker)
Flexible array transformation:
- KVM: PPC: Replace zero-length array with flexible array member (Len
Baker)
Use 2-factor argument multiplication form:
- nouveau/svm: Use kvcalloc() instead of kvzalloc() (Gustavo A. R.
Silva)
- xfs: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)"
* tag 'kspp-misc-fixes-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
firewire: Remove function callback casts
nouveau/svm: Use kvcalloc() instead of kvzalloc()
firmware/psci: fix application of sizeof to pointer
dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
KVM: PPC: Replace zero-length array with flexible array member
aio: Prefer struct_size over open coded arithmetic
writeback: prefer struct_size over open coded arithmetic
xfs: Use kvcalloc() instead of kvzalloc()
assoc_array: Avoid open coded arithmetic in allocator arguments
|
||
Len Baker
|
98b160c828 |
writeback: prefer struct_size over open coded arithmetic
As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. In this case these are not actually dynamic sizes: all the operands involved in the calculation are constant values. However it is better to refactor them anyway, just to keep the open-coded math idiom out of code. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() functions. This code was detected with the help of Coccinelle and audited and fixed manually. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker <len.baker@gmx.com> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> |
||
Christoph Hellwig
|
008f75a20e |
block: cleanup the flush plug helpers
Consolidate the various helpers into a single blk_flush_plug helper that takes a plk_plug and the from_scheduler bool and switch all callsites to call it directly. Checks that the plug is non-NULL must be performed by the caller, something that most already do anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211020144119.142582-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
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Linus Torvalds
|
14726903c8 |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ... |
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Shakeel Butt
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7490a2d248 |
writeback: memcg: simplify cgroup_writeback_by_id
Currently cgroup_writeback_by_id calls mem_cgroup_wb_stats() to get dirty pages for a memcg. However mem_cgroup_wb_stats() does a lot more than just get the number of dirty pages. Just directly get the number of dirty pages instead of calling mem_cgroup_wb_stats(). Also cgroup_writeback_by_id() is only called for best-effort dirty flushing, so remove the unused 'nr' parameter and no need to explicitly flush memcg stats. Link: https://lkml.kernel.org/r/20210722182627.2267368-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jan Kara
|
fee468fdf4 |
writeback: reliably update bandwidth estimation
Currently we trigger writeback bandwidth estimation from balance_dirty_pages() and from wb_writeback(). However neither of these need to trigger when the system is relatively idle and writeback is triggered e.g. from fsync(2). Make sure writeback estimates happen reliably by triggering them from do_writepages(). Link: https://lkml.kernel.org/r/20210713104716.22868-2-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Michael Stapelberg <stapelberg+linux@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jan Kara
|
633a2abb9e |
writeback: track number of inodes under writeback
Patch series "writeback: Fix bandwidth estimates", v4. Fix estimate of writeback throughput when device is not fully busy doing writeback. Michael Stapelberg has reported that such workload (e.g. generated by linking) tends to push estimated throughput down to 0 and as a result writeback on the device is practically stalled. The first three patches fix the reported issue, the remaining two patches are unrelated cleanups of problems I've noticed when reading the code. This patch (of 4): Track number of inodes under writeback for each bdi_writeback structure. We will use this to decide whether wb does any IO and so we can estimate its writeback throughput. In principle we could use number of pages under writeback (WB_WRITEBACK counter) for this however normal percpu counter reads are too inaccurate for our purposes and summing the counter is too expensive. Link: https://lkml.kernel.org/r/20210713104519.16394-1-jack@suse.cz Link: https://lkml.kernel.org/r/20210713104716.22868-1-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Michael Stapelberg <stapelberg+linux@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Josef Bacik
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5662c967c6 |
fs: kill sync_inode
Now that all users of sync_inode() have been deleted, remove sync_inode(). Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
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Roman Gushchin
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593311e85b |
writeback, cgroup: do not reparent dax inodes
The inode switching code is not suited for dax inodes. An attempt to
switch a dax inode to a parent writeback structure (as a part of a
writeback cleanup procedure) results in a panic like this:
run fstests generic/270 at 2021-07-15 05:54:02
XFS (pmem0p2): EXPERIMENTAL big timestamp feature in use. Use at your own risk!
XFS (pmem0p2): DAX enabled. Warning: EXPERIMENTAL, use at your own risk
XFS (pmem0p2): EXPERIMENTAL inode btree counters feature in use. Use at your own risk!
XFS (pmem0p2): Mounting V5 Filesystem
XFS (pmem0p2): Ending clean mount
XFS (pmem0p2): Quotacheck needed: Please wait.
XFS (pmem0p2): Quotacheck: Done.
XFS (pmem0p2): xlog_verify_grant_tail: space > BBTOB(tail_blocks)
XFS (pmem0p2): xlog_verify_grant_tail: space > BBTOB(tail_blocks)
XFS (pmem0p2): xlog_verify_grant_tail: space > BBTOB(tail_blocks)
BUG: unable to handle page fault for address: 0000000005b0f669
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 13 PID: 10479 Comm: kworker/13:16 Not tainted 5.14.0-rc1-master-8096acd7442e+ #8
Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 09/13/2016
Workqueue: inode_switch_wbs inode_switch_wbs_work_fn
RIP: 0010:inode_do_switch_wbs+0xaf/0x470
Code: 00 30 0f 85 c1 03 00 00 0f 1f 44 00 00 31 d2 48 c7 c6 ff ff ff ff 48 8d 7c 24 08 e8 eb 49 1a 00 48 85 c0 74 4a bb ff ff ff ff <48> 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 48 8b 00 a8 08 0f 85
RSP: 0018:ffff9c66691abdc8 EFLAGS: 00010002
RAX: 0000000005b0f661 RBX: 00000000ffffffff RCX: ffff89e6a21382b0
RDX: 0000000000000001 RSI: ffff89e350230248 RDI: ffffffffffffffff
RBP: ffff89e681d19400 R08: 0000000000000000 R09: 0000000000000228
R10: ffffffffffffffff R11: ffffffffffffffc0 R12: ffff89e6a2138130
R13: ffff89e316af7400 R14: ffff89e316af6e78 R15: ffff89e6a21382b0
FS: 0000000000000000(0000) GS:ffff89ee5fb40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000005b0f669 CR3: 0000000cb2410004 CR4: 00000000001706e0
Call Trace:
inode_switch_wbs_work_fn+0xb6/0x2a0
process_one_work+0x1e6/0x380
worker_thread+0x53/0x3d0
kthread+0x10f/0x130
ret_from_fork+0x22/0x30
Modules linked in: xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_counter nf_tables nfnetlink bridge stp llc rfkill sunrpc intel_rapl_msr intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ipmi_ssif kvm mgag200 i2c_algo_bit iTCO_wdt irqbypass drm_kms_helper iTCO_vendor_support acpi_ipmi rapl syscopyarea sysfillrect intel_cstate ipmi_si sysimgblt ioatdma dax_pmem_compat fb_sys_fops ipmi_devintf device_dax i2c_i801 pcspkr intel_uncore hpilo nd_pmem cec dax_pmem_core dca i2c_smbus acpi_tad lpc_ich ipmi_msghandler acpi_power_meter drm fuse xfs libcrc32c sd_mod t10_pi crct10dif_pclmul crc32_pclmul crc32c_intel tg3 ghash_clmulni_intel serio_raw hpsa hpwdt scsi_transport_sas wmi dm_mirror dm_region_hash dm_log dm_mod
CR2: 0000000005b0f669
---[ end trace ed2105faff8384f3 ]---
RIP: 0010:inode_do_switch_wbs+0xaf/0x470
Code: 00 30 0f 85 c1 03 00 00 0f 1f 44 00 00 31 d2 48 c7 c6 ff ff ff ff 48 8d 7c 24 08 e8 eb 49 1a 00 48 85 c0 74 4a bb ff ff ff ff <48> 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 48 8b 00 a8 08 0f 85
RSP: 0018:ffff9c66691abdc8 EFLAGS: 00010002
RAX: 0000000005b0f661 RBX: 00000000ffffffff RCX: ffff89e6a21382b0
RDX: 0000000000000001 RSI: ffff89e350230248 RDI: ffffffffffffffff
RBP: ffff89e681d19400 R08: 0000000000000000 R09: 0000000000000228
R10: ffffffffffffffff R11: ffffffffffffffc0 R12: ffff89e6a2138130
R13: ffff89e316af7400 R14: ffff89e316af6e78 R15: ffff89e6a21382b0
FS: 0000000000000000(0000) GS:ffff89ee5fb40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000005b0f669 CR3: 0000000cb2410004 CR4: 00000000001706e0
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x15200000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception ]---
The crash happens on an attempt to iterate over attached pagecache pages
and check the dirty flag: a dax inode's xarray contains pfn's instead of
generic struct page pointers.
This happens for DAX and not for other kinds of non-page entries in the
inodes because it's a tagged iteration, and shadow/swap entries are
never tagged; only DAX entries get tagged.
Fix the problem by bailing out (with the false return value) of
inode_prepare_sbs_switch() if a dax inode is passed.
[willy@infradead.org: changelog addition]
Link: https://lkml.kernel.org/r/20210719171350.3876830-1-guro@fb.com
Fixes:
|
||
|
Linus Torvalds
|
911a2997a5 |
\n
-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmDcl7AACgkQnJ2qBz9k QNnsBQf+LBAPsfykQ/f8EdHErO1lfbVTmwf2g/JzTkjrIVZTZ6Ic47aCIiFxgHU2 Js9ufaPxpsbbopzpn2PAoCUzxNsZDqgXtnC03MOUAqoSFbAvgLHz2sQwjqeYJUGQ P6n7VipEA/qBVpQI5zeCUhHYcahoNrRjSLzaFnE2Z8CrQYQ6Ry9gVEhduvu2OTru 62cWlAWlTJfx/FcR1Y0F/ZznnNSKMiAHcEe3F6Beztplg2ooq+z6FclJYrkmnxMq SXSOsqTCdi1/oFx36NpvLkykrIS9I7N/iqCnKwbm6X+nyZZKyAwYZhWVqkbozPPu +u1Ppq8o0IuWwEA6/UAmxgAO3m/Gkw== =tn0h -----END PGP SIGNATURE----- Merge tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull misc fs updates from Jan Kara: "The new quotactl_fd() syscall (remake of quotactl_path() syscall that got introduced & disabled in 5.13 cycle), and couple of udf, reiserfs, isofs, and writeback fixes and cleanups" * tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: writeback: fix obtain a reference to a freeing memcg css quota: remove unnecessary oom message isofs: remove redundant continue statement quota: Wire up quotactl_fd syscall quota: Change quotactl_path() systcall to an fd-based one reiserfs: Remove unneed check in reiserfs_write_full_page() udf: Fix NULL pointer dereference in udf_symlink function reiserfs: add check for invalid 1st journal block |
||
|
Linus Torvalds
|
df668a5fe4 |
for-5.14/block-2021-06-29
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmDbXAwQHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpr0HEADDJaSgjpnWQwH1RVLNagJa9KnktxZYsEs+ as3QmDdpKRG3rEC9bdE7FLe/xq3WBaO5j1hTQ9P6IguqLyS1Df72DtTlKyaCrZoe zv9eIlY4lZUfksE2nzWmlN9uG0FBVXeEQpHCLSNbUZeK1zvV6+NNhQqw2kc0sEqu hReUFeMUbsMcu/w5T3XMVJNsTMCql9wta2H0q5hONQyJQSrIwa1D+sUdE5I8fO4j bnoYX9yxHX26EztX1UJiGRgoq5Trz7LY7hAfljKSkewpFwiHE2vBdq2L0C2RKsIV tTs2DjMCMQyPNeA7WAG8HlR4aPG+7+/fuBP1KJHkykjWXglWN7OqISuBv6rrBgQs gNRnZ4qmb1CzD6aLEBk59nHt6po6eMxXIW856YktKy8rKcrgK29qP44Z+oomkPKo ZjQ0wqN5CvpObM/dIKxl9bAJ4zQDHBt49d5nTTQLfWl/mgevu6ZNWD/hONyCQmFy zKKqQ/wkxWHutOsjC5/MKNb3ZRNH9tt9X+HfULO2DU6IqqifYw/ex4z4MVsBopJC 7pPfd81kgC73TgXe1AaCwHqNWsrqYCuTK0ew1CtGudlS3lucMwtap4GBiCgg5gbu M8pEgwO4OcCLHyRUc8zdfqI7HumbprbFmojPkwGSEe0ofVD74lMhzbUj5jvTYY2B t8D2XcgyOA== =lhon -----END PGP SIGNATURE----- Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block Pull core block updates from Jens Axboe: - disk events cleanup (Christoph) - gendisk and request queue allocation simplifications (Christoph) - bdev_disk_changed cleanups (Christoph) - IO priority improvements (Bart) - Chained bio completion trace fix (Edward) - blk-wbt fixes (Jan) - blk-wbt enable/disable fix (Zhang) - Scheduler dispatch improvements (Jan, Ming) - Shared tagset scheduler improvements (John) - BFQ updates (Paolo, Luca, Pietro) - BFQ lock inversion fix (Jan) - Documentation improvements (Kir) - CLONE_IO block cgroup fix (Tejun) - Remove of ancient and deprecated block dump feature (zhangyi) - Discard merge fix (Ming) - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas, Yang) * tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits) block: fix discard request merge block/mq-deadline: Remove a WARN_ON_ONCE() call blk-mq: update hctx->dispatch_busy in case of real scheduler blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block: pass a gendisk to bdev_disk_changed block: move bdev_disk_changed block: add the events* attributes to disk_attrs block: move the disk events code to a separate file block: fix trace completion for chained bio block/partitions/msdos: Fix typo inidicator -> indicator block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising blk-wbt: make sure throttle is enabled properly blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() ... |
||
|
Roman Gushchin
|
c22d70a162 |
writeback, cgroup: release dying cgwbs by switching attached inodes
Asynchronously try to release dying cgwbs by switching attached inodes to the nearest living ancestor wb. It helps to get rid of per-cgroup writeback structures themselves and of pinned memory and block cgroups, which are significantly larger structures (mostly due to large per-cpu statistics data). This prevents memory waste and helps to avoid different scalability problems caused by large piles of dying cgroups. Reuse the existing mechanism of inode switching used for foreign inode detection. To speed things up batch up to 115 inode switching in a single operation (the maximum number is selected so that the resulting struct inode_switch_wbs_context can fit into 1024 bytes). Because every switching consists of two steps divided by an RCU grace period, it would be too slow without batching. Please note that the whole batch counts as a single operation (when increasing/decreasing isw_nr_in_flight). This allows to keep umounting working (flush the switching queue), however prevents cleanups from consuming the whole switching quota and effectively blocking the frn switching. A cgwb cleanup operation can fail due to different reasons (e.g. not enough memory, the cgwb has an in-flight/pending io, an attached inode in a wrong state, etc). In this case the next scheduled cleanup will make a new attempt. An attempt is made each time a new cgwb is offlined (in other words a memcg and/or a blkcg is deleted by a user). In the future an additional attempt scheduled by a timer can be implemented. [guro@fb.com: replace open-coded "115" with arithmetic] Link: https://lkml.kernel.org/r/YMEcSBcq/VXMiPPO@carbon.dhcp.thefacebook.com [guro@fb.com: add smp_mb() to inode_prepare_wbs_switch()] Link: https://lkml.kernel.org/r/YMFa+guFw7OFjf3X@carbon.dhcp.thefacebook.com [willy@infradead.org: fix documentation] Link: https://lkml.kernel.org/r/20210615200242.1716568-2-willy@infradead.org Link: https://lkml.kernel.org/r/20210608230225.2078447-9-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
f5fbe6b7ad |
writeback, cgroup: support switching multiple inodes at once
Currently only a single inode can be switched to another writeback structure at once. That means to switch an inode a separate inode_switch_wbs_context structure must be allocated, and a separate rcu callback and work must be scheduled. It's fine for the existing ad-hoc switching, which is not happening that often, but sub-optimal for massive switching required in order to release a writeback structure. To prepare for it, let's add a support for switching multiple inodes at once. Instead of containing a single inode pointer, inode_switch_wbs_context will contain a NULL-terminated array of inode pointers. inode_do_switch_wbs() will be called for each inode. To optimize the locking bdi->wb_switch_rwsem, old_wb's and new_wb's list_locks will be acquired and released only once altogether for all inodes. wb_wakeup() will be also be called only once. Instead of calling wb_put(old_wb) after each successful switch, wb_put_many() is introduced and used. Link: https://lkml.kernel.org/r/20210608230225.2078447-8-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dennis Zhou <dennis@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
72d4512e9c |
writeback, cgroup: split out the functional part of inode_switch_wbs_work_fn()
Split out the functional part of the inode_switch_wbs_work_fn() function as inode_do switch_wbs() to reuse it later for switching inodes attached to dying cgwbs. This commit doesn't bring any functional changes. Link: https://lkml.kernel.org/r/20210608230225.2078447-7-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Dennis Zhou <dennis@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
f3b6a6df38 |
writeback, cgroup: keep list of inodes attached to bdi_writeback
Currently there is no way to iterate over inodes attached to a specific cgwb structure. It limits the ability to efficiently reclaim the writeback structure itself and associated memory and block cgroup structures without scanning all inodes belonging to a sb, which can be prohibitively expensive. While dirty/in-active-writeback an inode belongs to one of the bdi_writeback's io lists: b_dirty, b_io, b_more_io and b_dirty_time. Once cleaned up, it's removed from all io lists. So the inode->i_io_list can be reused to maintain the list of inodes, attached to a bdi_writeback structure. This patch introduces a new wb->b_attached list, which contains all inodes which were dirty at least once and are attached to the given cgwb. Inodes attached to the root bdi_writeback structures are never placed on such list. The following patch will use this list to try to release cgwbs structures more efficiently. Link: https://lkml.kernel.org/r/20210608230225.2078447-6-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Dennis Zhou <dennis@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
29264d92a0 |
writeback, cgroup: switch to rcu_work API in inode_switch_wbs()
Inode's wb switching requires two steps divided by an RCU grace period. It's currently implemented as an RCU callback inode_switch_wbs_rcu_fn(), which schedules inode_switch_wbs_work_fn() as a work. Switching to the rcu_work API allows to do the same in a cleaner and slightly shorter form. Link: https://lkml.kernel.org/r/20210608230225.2078447-5-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Dennis Zhou <dennis@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
8826ee4fe7 |
writeback, cgroup: increment isw_nr_in_flight before grabbing an inode
isw_nr_in_flight is used to determine whether the inode switch queue should be flushed from the umount path. Currently it's increased after grabbing an inode and even scheduling the switch work. It means the umount path can walk past cleanup_offline_cgwb() with active inode references, which can result in a "Busy inodes after unmount." message and use-after-free issues (with inode->i_sb which gets freed). Fix it by incrementing isw_nr_in_flight before doing anything with the inode and decrementing in the case when switching wasn't scheduled. The problem hasn't yet been seen in the real life and was discovered by Jan Kara by looking into the code. Link: https://lkml.kernel.org/r/20210608230225.2078447-4-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Jan Kara <jack@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
592fa00218 |
writeback, cgroup: add smp_mb() to cgroup_writeback_umount()
A full memory barrier is required between clearing SB_ACTIVE flag in generic_shutdown_super() and checking isw_nr_in_flight in cgroup_writeback_umount(), otherwise a new switch operation might be scheduled after atomic_read(&isw_nr_in_flight) returned 0. This would result in a non-flushed isw_wq, and a potential crash. The problem hasn't yet been seen in the real life and was discovered by Jan Kara by looking into the code. Link: https://lkml.kernel.org/r/20210608230225.2078447-3-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Jan Kara <jack@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
4ade5867b4 |
writeback, cgroup: do not switch inodes with I_WILL_FREE flag
Patch series "cgroup, blkcg: prevent dirty inodes to pin dying memory cgroups", v9. When an inode is getting dirty for the first time it's associated with a wb structure (see __inode_attach_wb()). It can later be switched to another wb (if e.g. some other cgroup is writing a lot of data to the same inode), but otherwise stays attached to the original wb until being reclaimed. The problem is that the wb structure holds a reference to the original memory and blkcg cgroups. So if an inode has been dirty once and later is actively used in read-only mode, it has a good chance to pin down the original memory and blkcg cgroups forever. This is often the case with services bringing data for other services, e.g. updating some rpm packages. In the real life it becomes a problem due to a large size of the memcg structure, which can easily be 1000x larger than an inode. Also a really large number of dying cgroups can raise different scalability issues, e.g. making the memory reclaim costly and less effective. To solve the problem inodes should be eventually detached from the corresponding writeback structure. It's inefficient to do it after every writeback completion. Instead it can be done whenever the original memory cgroup is offlined and writeback structure is getting killed. Scanning over a (potentially long) list of inodes and detach them from the writeback structure can take quite some time. To avoid scanning all inodes, attached inodes are kept on a new list (b_attached). To make it less noticeable to a user, the scanning and switching is performed from a work context. Big thanks to Jan Kara, Dennis Zhou, Hillf Danton and Tejun Heo for their ideas and contribution to this patchset. This patch (of 8): If an inode's state has I_WILL_FREE flag set, the inode will be freed soon, so there is no point in trying to switch the inode to a different cgwb. I_WILL_FREE was ignored since the introduction of the inode switching, so it looks like it doesn't lead to any noticeable issues for a user. This is why the patch is not intended for a stable backport. Link: https://lkml.kernel.org/r/20210608230225.2078447-1-guro@fb.com Link: https://lkml.kernel.org/r/20210608230225.2078447-2-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dennis Zhou <dennis@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Muchun Song
|
8b0ed8443a |
writeback: fix obtain a reference to a freeing memcg css
The caller of wb_get_create() should pin the memcg, because
wb_get_create() relies on this guarantee. The rcu read lock
only can guarantee that the memcg css returned by css_from_id()
cannot be released, but the reference of the memcg can be zero.
rcu_read_lock()
memcg_css = css_from_id()
wb_get_create(memcg_css)
cgwb_create(memcg_css)
// css_get can change the ref counter from 0 back to 1
css_get(memcg_css)
rcu_read_unlock()
Fix it by holding a reference to the css before calling
wb_get_create(). This is not a problem I encountered in the
real world. Just the result of a code review.
Fixes:
|
||
zhangyi (F)
|
12e0613715 |
block_dump: remove block_dump feature in mark_inode_dirty()
block_dump is an old debugging interface, one of it's functions is used to print the information about who write which file on disk. If we enable block_dump through /proc/sys/vm/block_dump and turn on debug log level, we can gather information about write process name, target file name and disk from kernel message. This feature is realized in block_dump___mark_inode_dirty(), it print above information into kernel message directly when marking inode dirty, so it is noisy and can easily trigger log storm. At the same time, get the dentry refcount is also not safe, we found it will lead to deadlock on ext4 file system with data=journal mode. After tracepoints has been introduced into the kernel, we got a tracepoint in __mark_inode_dirty(), which is a better replacement of block_dump___mark_inode_dirty(). The only downside is that it only trace the inode number and not a file name, but it probably doesn't matter because the original printed file name in block_dump is not accurate in some cases, and we can still find it through the inode number and device id. So this patch delete the dirting inode part of block_dump feature. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210313030146.2882027-2-yi.zhang@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
Eric Biggers
|
da0c4c60d8 |
fs: improve comments for writeback_single_inode()
Some comments for writeback_single_inode() and __writeback_single_inode() are outdated or not very helpful, especially with regards to writeback list handling. Update them. Link: https://lore.kernel.org/r/20210112190253.64307-10-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Eric Biggers
|
83dc881d67 |
fs: drop redundant check from __writeback_single_inode()
wbc->for_sync implies wbc->sync_mode == WB_SYNC_ALL, so there's no need to check for both. Just check for WB_SYNC_ALL. Link: https://lore.kernel.org/r/20210112190253.64307-9-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Eric Biggers
|
35d14f278e |
fs: clean up __mark_inode_dirty() a bit
Improve some comments, and don't bother checking for the I_DIRTY_TIME flag in the case where we just cleared it. Also, warn if I_DIRTY_TIME and I_DIRTY_PAGES are passed to __mark_inode_dirty() at the same time, as this case isn't handled. Link: https://lore.kernel.org/r/20210112190253.64307-8-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Eric Biggers
|
a38ed483a7 |
fs: pass only I_DIRTY_INODE flags to ->dirty_inode
->dirty_inode is now only called when I_DIRTY_INODE (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) is set. However it may still be passed other dirty flags at the same time, provided that these other flags happened to be passed to __mark_inode_dirty() at the same time as I_DIRTY_INODE. This doesn't make sense because there is no reason for filesystems to care about these extra flags. Nor are filesystems notified about all updates to these other flags. Therefore, mask the flags before passing them to ->dirty_inode. Also properly document ->dirty_inode in vfs.rst. Link: https://lore.kernel.org/r/20210112190253.64307-7-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Eric Biggers
|
e2728c5621 |
fs: don't call ->dirty_inode for lazytime timestamp updates
There is no need to call ->dirty_inode for lazytime timestamp updates (i.e. for __mark_inode_dirty(I_DIRTY_TIME)), since by the definition of lazytime, filesystems must ignore these updates. Filesystems only need to care about the updated timestamps when they expire. Therefore, only call ->dirty_inode when I_DIRTY_INODE is set. Based on a patch from Christoph Hellwig: https://lore.kernel.org/r/20200325122825.1086872-4-hch@lst.de Link: https://lore.kernel.org/r/20210112190253.64307-6-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Eric Biggers
|
1e249cb5b7 |
fs: fix lazytime expiration handling in __writeback_single_inode()
When lazytime is enabled and an inode is being written due to its in-memory updated timestamps having expired, either due to a sync() or syncfs() system call or due to dirtytime_expire_interval having elapsed, the VFS needs to inform the filesystem so that the filesystem can copy the inode's timestamps out to the on-disk data structures. This is done by __writeback_single_inode() calling mark_inode_dirty_sync(), which then calls ->dirty_inode(I_DIRTY_SYNC). However, this occurs after __writeback_single_inode() has already cleared the dirty flags from ->i_state. This causes two bugs: - mark_inode_dirty_sync() redirties the inode, causing it to remain dirty. This wastefully causes the inode to be written twice. But more importantly, it breaks cases where sync_filesystem() is expected to clean dirty inodes. This includes the FS_IOC_REMOVE_ENCRYPTION_KEY ioctl (as reported at https://lore.kernel.org/r/20200306004555.GB225345@gmail.com), as well as possibly filesystem freezing (freeze_super()). - Since ->i_state doesn't contain I_DIRTY_TIME when ->dirty_inode() is called from __writeback_single_inode() for lazytime expiration, xfs_fs_dirty_inode() ignores the notification. (XFS only cares about lazytime expirations, and it assumes that i_state will contain I_DIRTY_TIME during those.) Therefore, lazy timestamps aren't persisted by sync(), syncfs(), or dirtytime_expire_interval on XFS. Fix this by moving the call to mark_inode_dirty_sync() to earlier in __writeback_single_inode(), before the dirty flags are cleared from i_state. This makes filesystems be properly notified of the timestamp expiration, and it avoids incorrectly redirtying the inode. This fixes xfstest generic/580 (which tests FS_IOC_REMOVE_ENCRYPTION_KEY) when run on ext4 or f2fs with lazytime enabled. It also fixes the new lazytime xfstest I've proposed, which reproduces the above-mentioned XFS bug (https://lore.kernel.org/r/20210105005818.92978-1-ebiggers@kernel.org). Alternatively, we could call ->dirty_inode(I_DIRTY_SYNC) directly. But due to the introduction of I_SYNC_QUEUED, mark_inode_dirty_sync() is the right thing to do because mark_inode_dirty_sync() now knows not to move the inode to a writeback list if it is currently queued for sync. Fixes: |
||
|
Christoph Hellwig
|
f738717033 |
writeback: don't warn on an unregistered BDI in __mark_inode_dirty
BDIs get unregistered during device removal, and this WARN can be trivially triggered by hot-removing a NVMe device while running fsx It is otherwise harmless as we still hold a BDI reference, and the writeback has been shut down already. Link: https://lore.kernel.org/r/20200928122613.434820-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Linus Torvalds
|
3ad11d7ac8 |
block-5.10-2020-10-12
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl+EWUgQHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpnoxEADCVSNBRkpV0OVkOEC3wf8EGhXhk01Jnjtl u5Mg2V55hcgJ0thQxBV/V28XyqmsEBrmAVi0Yf8Vr9Qbq4Ze08Wae4ChS4rEOyh1 jTcGYWx5aJB3ChLvV/HI0nWQ3bkj03mMrL3SW8rhhf5DTyKHsVeTenpx42Qu/FKf fRzi09FSr3Pjd0B+EX6gunwJnlyXQC5Fa4AA0GhnXJzAznANXxHkkcXu8a6Yw75x e28CfhIBliORsK8sRHLoUnPpeTe1vtxCBhBMsE+gJAj9ZUOWMzvNFIPP4FvfawDy 6cCQo2m1azJ/IdZZCDjFUWyjh+wxdKMp+NNryEcoV+VlqIoc3n98rFwrSL+GIq5Z WVwEwq+AcwoMCsD29Lu1ytL2PQ/RVqcJP5UheMrbL4vzefNfJFumQVZLIcX0k943 8dFL2QHL+H/hM9Dx5y5rjeiWkAlq75v4xPKVjh/DHb4nehddCqn/+DD5HDhNANHf c1kmmEuYhvLpIaC4DHjE6DwLh8TPKahJjwsGuBOTr7D93NUQD+OOWsIhX6mNISIl FFhP8cd0/ZZVV//9j+q+5B4BaJsT+ZtwmrelKFnPdwPSnh+3iu8zPRRWO+8P8fRC YvddxuJAmE6BLmsAYrdz6Xb/wqfyV44cEiyivF0oBQfnhbtnXwDnkDWSfJD1bvCm ZwfpDh2+Tg== =LzyE -----END PGP SIGNATURE----- Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block Pull block updates from Jens Axboe: - Series of merge handling cleanups (Baolin, Christoph) - Series of blk-throttle fixes and cleanups (Baolin) - Series cleaning up BDI, seperating the block device from the backing_dev_info (Christoph) - Removal of bdget() as a generic API (Christoph) - Removal of blkdev_get() as a generic API (Christoph) - Cleanup of is-partition checks (Christoph) - Series reworking disk revalidation (Christoph) - Series cleaning up bio flags (Christoph) - bio crypt fixes (Eric) - IO stats inflight tweak (Gabriel) - blk-mq tags fixes (Hannes) - Buffer invalidation fixes (Jan) - Allow soft limits for zone append (Johannes) - Shared tag set improvements (John, Kashyap) - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel) - DM no-wait support (Mike, Konstantin) - Request allocation improvements (Ming) - Allow md/dm/bcache to use IO stat helpers (Song) - Series improving blk-iocost (Tejun) - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang, Xianting, Yang, Yufen, yangerkun) * tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits) block: fix uapi blkzoned.h comments blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue blk-mq: get rid of the dead flush handle code path block: get rid of unnecessary local variable block: fix comment and add lockdep assert blk-mq: use helper function to test hw stopped block: use helper function to test queue register block: remove redundant mq check block: invoke blk_mq_exit_sched no matter whether have .exit_sched percpu_ref: don't refer to ref->data if it isn't allocated block: ratelimit handle_bad_sector() message blk-throttle: Re-use the throtl_set_slice_end() blk-throttle: Open code __throtl_de/enqueue_tg() blk-throttle: Move service tree validation out of the throtl_rb_first() blk-throttle: Move the list operation after list validation blk-throttle: Fix IO hang for a corner case blk-throttle: Avoid tracking latency if low limit is invalid blk-throttle: Avoid getting the current time if tg->last_finish_time is 0 blk-throttle: Remove a meaningless parameter for throtl_downgrade_state() block: Remove redundant 'return' statement ... |
||
|
Christoph Hellwig
|
f56753ac2a |
bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag
Replace the two negative flags that are always used together with a single positive flag that indicates the writeback capability instead of two related non-capabilities. Also remove the pointless wrappers to just check the flag. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
Tobias Klauser
|
9ca48e20ec |
fs/fs-writeback.c: adjust dirtytime_interval_handler definition to match prototype
Commit |
||
|
Jan Kara
|
5fcd57505c |
writeback: Drop I_DIRTY_TIME_EXPIRE
The only use of I_DIRTY_TIME_EXPIRE is to detect in __writeback_single_inode() that inode got there because flush worker decided it's time to writeback the dirty inode time stamps (either because we are syncing or because of age). However we can detect this directly in __writeback_single_inode() and there's no need for the strange propagation with I_DIRTY_TIME_EXPIRE flag. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Jan Kara
|
f9cae926f3 |
writeback: Fix sync livelock due to b_dirty_time processing
When we are processing writeback for sync(2), move_expired_inodes()
didn't set any inode expiry value (older_than_this). This can result in
writeback never completing if there's steady stream of inodes added to
b_dirty_time list as writeback rechecks dirty lists after each writeback
round whether there's more work to be done. Fix the problem by using
sync(2) start time is inode expiry value when processing b_dirty_time
list similarly as for ordinarily dirtied inodes. This requires some
refactoring of older_than_this handling which simplifies the code
noticeably as a bonus.
Fixes:
|
||
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Jan Kara
|
5afced3bf2 |
writeback: Avoid skipping inode writeback
Inode's i_io_list list head is used to attach inode to several different
lists - wb->{b_dirty, b_dirty_time, b_io, b_more_io}. When flush worker
prepares a list of inodes to writeback e.g. for sync(2), it moves inodes
to b_io list. Thus it is critical for sync(2) data integrity guarantees
that inode is not requeued to any other writeback list when inode is
queued for processing by flush worker. That's the reason why
writeback_single_inode() does not touch i_io_list (unless the inode is
completely clean) and why __mark_inode_dirty() does not touch i_io_list
if I_SYNC flag is set.
However there are two flaws in the current logic:
1) When inode has only I_DIRTY_TIME set but it is already queued in b_io
list due to sync(2), concurrent __mark_inode_dirty(inode, I_DIRTY_SYNC)
can still move inode back to b_dirty list resulting in skipping
writeback of inode time stamps during sync(2).
2) When inode is on b_dirty_time list and writeback_single_inode() races
with __mark_inode_dirty() like:
writeback_single_inode() __mark_inode_dirty(inode, I_DIRTY_PAGES)
inode->i_state |= I_SYNC
__writeback_single_inode()
inode->i_state |= I_DIRTY_PAGES;
if (inode->i_state & I_SYNC)
bail
if (!(inode->i_state & I_DIRTY_ALL))
- not true so nothing done
We end up with I_DIRTY_PAGES inode on b_dirty_time list and thus
standard background writeback will not writeback this inode leading to
possible dirty throttling stalls etc. (thanks to Martijn Coenen for this
analysis).
Fix these problems by tracking whether inode is queued in b_io or
b_more_io lists in a new I_SYNC_QUEUED flag. When this flag is set, we
know flush worker has queued inode and we should not touch i_io_list.
On the other hand we also know that once flush worker is done with the
inode it will requeue the inode to appropriate dirty list. When
I_SYNC_QUEUED is not set, __mark_inode_dirty() can (and must) move inode
to appropriate dirty list.
Reported-by: Martijn Coenen <maco@android.com>
Reviewed-by: Martijn Coenen <maco@android.com>
Tested-by: Martijn Coenen <maco@android.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes:
|
||
|
Jan Kara
|
b35250c081 |
writeback: Protect inode->i_io_list with inode->i_lock
Currently, operations on inode->i_io_list are protected by wb->list_lock. In the following patches we'll need to maintain consistency between inode->i_state and inode->i_io_list so change the code so that inode->i_lock protects also all inode's i_io_list handling. Reviewed-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> CC: stable@vger.kernel.org # Prerequisite for "writeback: Avoid skipping inode writeback" Signed-off-by: Jan Kara <jack@suse.cz> |
||
|
Linus Torvalds
|
0b166a57e6 |
A lot of bug fixes and cleanups for ext4, including:
* Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
* Clean up fiemap handling in ext4
* Clean up and refactor multiple block allocator (mballoc) code
* Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
* Fixed a race in ext4_sync_parent() versus rename()
* Simplify the error handling in the extent manipulation code
* Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and
ext4_make_inode_dirty()'s callers.
* Avoid passing an error pointer to brelse in ext4_xattr_set()
* Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
* Fix refcount handling if ext4_iget() fails
* Fix a crash in generic/019 caused by a corrupted extent node
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"A lot of bug fixes and cleanups for ext4, including:
- Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
- Clean up fiemap handling in ext4
- Clean up and refactor multiple block allocator (mballoc) code
- Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
- Fixed a race in ext4_sync_parent() versus rename()
- Simplify the error handling in the extent manipulation code
- Make sure all metadata I/O errors are felected to
ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.
- Avoid passing an error pointer to brelse in ext4_xattr_set()
- Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
- Fix refcount handling if ext4_iget() fails
- Fix a crash in generic/019 caused by a corrupted extent node"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
ext4: avoid unnecessary transaction starts during writeback
ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
fs: remove the access_ok() check in ioctl_fiemap
fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
fs: move fiemap range validation into the file systems instances
iomap: fix the iomap_fiemap prototype
fs: move the fiemap definitions out of fs.h
fs: mark __generic_block_fiemap static
ext4: remove the call to fiemap_check_flags in ext4_fiemap
ext4: split _ext4_fiemap
ext4: fix fiemap size checks for bitmap files
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
add comment for ext4_dir_entry_2 file_type member
jbd2: avoid leaking transaction credits when unreserving handle
ext4: drop ext4_journal_free_reserved()
ext4: mballoc: use lock for checking free blocks while retrying
ext4: mballoc: refactor ext4_mb_good_group()
ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
ext4: mballoc: refactor ext4_mb_discard_preallocations()
...
|
||
|
Jan Kara
|
4301efa4c7 |
writeback: Export inode_io_list_del()
Ext4 needs to remove inode from writeback lists after it is out of visibility of its journalling machinery (which can still dirty the inode). Export inode_io_list_del() for it. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200421085445.5731-3-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> |
||
|
Linus Torvalds
|
750a02ab8d |
for-5.8/block-2020-06-01
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||
NeilBrown
|
8d92890bd6 |
mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead
After an NFS page has been written it is considered "unstable" until a
COMMIT request succeeds. If the COMMIT fails, the page will be
re-written.
These "unstable" pages are currently accounted as "reclaimable", either
in WB_RECLAIMABLE, or in NR_UNSTABLE_NFS which is included in a
'reclaimable' count. This might have made sense when sending the COMMIT
required a separate action by the VFS/MM (e.g. releasepage() used to
send a COMMIT). However now that all writes generated by ->writepages()
will automatically be followed by a COMMIT (since commit
|
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|
Christoph Hellwig
|
1cd925d583 |
bdi: remove the name field in struct backing_dev_info
The name is only printed for a not registered bdi in writeback. Use the device name there as is more useful anyway for the unlike case that the warning triggers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Theodore Ts'o
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68f23b8906 |
memcg: fix a crash in wb_workfn when a device disappears
Without memcg, there is a one-to-one mapping between the bdi and bdi_writeback structures. In this world, things are fairly straightforward; the first thing bdi_unregister() does is to shutdown the bdi_writeback structure (or wb), and part of that writeback ensures that no other work queued against the wb, and that the wb is fully drained. With memcg, however, there is a one-to-many relationship between the bdi and bdi_writeback structures; that is, there are multiple wb objects which can all point to a single bdi. There is a refcount which prevents the bdi object from being released (and hence, unregistered). So in theory, the bdi_unregister() *should* only get called once its refcount goes to zero (bdi_put will drop the refcount, and when it is zero, release_bdi gets called, which calls bdi_unregister). Unfortunately, del_gendisk() in block/gen_hd.c never got the memo about the Brave New memcg World, and calls bdi_unregister directly. It does this without informing the file system, or the memcg code, or anything else. This causes the root wb associated with the bdi to be unregistered, but none of the memcg-specific wb's are shutdown. So when one of these wb's are woken up to do delayed work, they try to dereference their wb->bdi->dev to fetch the device name, but unfortunately bdi->dev is now NULL, thanks to the bdi_unregister() called by del_gendisk(). As a result, *boom*. Fortunately, it looks like the rest of the writeback path is perfectly happy with bdi->dev and bdi->owner being NULL, so the simplest fix is to create a bdi_dev_name() function which can handle bdi->dev being NULL. This also allows us to bulletproof the writeback tracepoints to prevent them from dereferencing a NULL pointer and crashing the kernel if one is tracing with memcg's enabled, and an iSCSI device dies or a USB storage stick is pulled. The most common way of triggering this will be hotremoval of a device while writeback with memcg enabled is going on. It was triggering several times a day in a heavily loaded production environment. Google Bug Id: 145475544 Link: https://lore.kernel.org/r/20191227194829.150110-1-tytso@mit.edu Link: http://lkml.kernel.org/r/20191228005211.163952-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Tejun Heo
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65de03e251 |
cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead
cgroup writeback tries to refresh the associated wb immediately if the current wb is dead. This is to avoid keeping issuing IOs on the stale wb after memcg - blkcg association has changed (ie. when blkcg got disabled / enabled higher up in the hierarchy). Unfortunately, the logic gets triggered spuriously on inodes which are associated with dead cgroups. When the logic is triggered on dead cgroups, the attempt fails only after doing quite a bit of work allocating and initializing a new wb. While |
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Randy Dunlap
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b46ec1da5e |
fs/fs-writeback.c: fix kernel-doc warning
Fix kernel-doc warning in fs/fs-writeback.c:
fs/fs-writeback.c:913: warning: Excess function parameter 'nr_pages' description in 'cgroup_writeback_by_id'
Link: http://lkml.kernel.org/r/756645ac-0ce8-d47e-d30a-04d9e4923a4f@infradead.org
Fixes:
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Tejun Heo
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8e00c4e9dd |
writeback: fix use-after-free in finish_writeback_work()
finish_writeback_work() reads @done->waitq after decrementing
@done->cnt. However, once @done->cnt reaches zero, @done may be freed
(from stack) at any moment and @done->waitq can contain something
unrelated by the time finish_writeback_work() tries to read it. This
led to the following crash.
"BUG: kernel NULL pointer dereference, address: 0000000000000002"
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
CPU: 40 PID: 555153 Comm: kworker/u98:50 Kdump: loaded Not tainted
...
Workqueue: writeback wb_workfn (flush-btrfs-1)
RIP: 0010:_raw_spin_lock_irqsave+0x10/0x30
Code: 48 89 d8 5b c3 e8 50 db 6b ff eb f4 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 53 9c 5b fa 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 05 48 89 d8 5b c3 89 c6 e8 fe ca 6b ff eb f2 66 90
RSP: 0018:ffffc90049b27d98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffff889fff407600 R11: ffff88ba9395d740 R12: 000000000000e300
R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88bfdfa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 0000000002409005 CR4: 00000000001606e0
Call Trace:
__wake_up_common_lock+0x63/0xc0
wb_workfn+0xd2/0x3e0
process_one_work+0x1f5/0x3f0
worker_thread+0x2d/0x3d0
kthread+0x111/0x130
ret_from_fork+0x1f/0x30
Fix it by reading and caching @done->waitq before decrementing
@done->cnt.
Link: http://lkml.kernel.org/r/20190924010631.GH2233839@devbig004.ftw2.facebook.com
Fixes:
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Tejun Heo
|
3a8e9ac89e |
writeback: add tracepoints for cgroup foreign writebacks
cgroup foreign inode handling has quite a bit of heuristics and internal states which sometimes makes it difficult to understand what's going on. Add tracepoints to improve visibility. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Tejun Heo
|
d62241c7a4 |
writeback, memcg: Implement cgroup_writeback_by_id()
Implement cgroup_writeback_by_id() which initiates cgroup writeback
from bdi and memcg IDs. This will be used by memcg foreign inode
flushing.
v2: Use wb_get_lookup() instead of wb_get_create() to avoid creating
spurious wbs.
v3: Interpret 0 @nr as 1.25 * nr_dirty to implement best-effort
flushing while avoding possible livelocks.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Tejun Heo
|
5b9cce4c7e |
writeback: Generalize and expose wb_completion
wb_completion is used to track writeback completions. We want to use it from memcg side for foreign inode flushes. This patch updates it to remember the target waitq instead of assuming bdi->wb_waitq and expose it outside of fs-writeback.c. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |