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517 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Li Zhijian
|
7f7b850689 |
fs/inode: Prevent dump_mapping() accessing invalid dentry.d_name.name
It's observed that a crash occurs during hot-remove a memory device, in which user is accessing the hugetlb. See calltrace as following: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 14045 at arch/x86/mm/fault.c:1278 do_user_addr_fault+0x2a0/0x790 Modules linked in: kmem device_dax cxl_mem cxl_pmem cxl_port cxl_pci dax_hmem dax_pmem nd_pmem cxl_acpi nd_btt cxl_core crc32c_intel nvme virtiofs fuse nvme_core nfit libnvdimm dm_multipath scsi_dh_rdac scsi_dh_emc s mirror dm_region_hash dm_log dm_mod CPU: 1 PID: 14045 Comm: daxctl Not tainted 6.10.0-rc2-lizhijian+ #492 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:do_user_addr_fault+0x2a0/0x790 Code: 48 8b 00 a8 04 0f 84 b5 fe ff ff e9 1c ff ff ff 4c 89 e9 4c 89 e2 be 01 00 00 00 bf 02 00 00 00 e8 b5 ef 24 00 e9 42 fe ff ff <0f> 0b 48 83 c4 08 4c 89 ea 48 89 ee 4c 89 e7 5b 5d 41 5c 41 5d 41 RSP: 0000:ffffc90000a575f0 EFLAGS: 00010046 RAX: ffff88800c303600 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffffffff82504162 RDI: ffffffff824b2c36 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90000a57658 R13: 0000000000001000 R14: ffff88800bc2e040 R15: 0000000000000000 FS: 00007f51cb57d880(0000) GS:ffff88807fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000001000 CR3: 00000000072e2004 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __warn+0x8d/0x190 ? do_user_addr_fault+0x2a0/0x790 ? report_bug+0x1c3/0x1d0 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 ? do_user_addr_fault+0x2a0/0x790 ? exc_page_fault+0x31/0x200 exc_page_fault+0x68/0x200 <...snip...> BUG: unable to handle page fault for address: 0000000000001000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000000ad92067 P4D 800000000ad92067 PUD 7677067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI ---[ end trace 0000000000000000 ]--- BUG: unable to handle page fault for address: 0000000000001000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000000ad92067 P4D 800000000ad92067 PUD 7677067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 14045 Comm: daxctl Kdump: loaded Tainted: G W 6.10.0-rc2-lizhijian+ #492 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:dentry_name+0x1f4/0x440 <...snip...> ? dentry_name+0x2fa/0x440 vsnprintf+0x1f3/0x4f0 vprintk_store+0x23a/0x540 vprintk_emit+0x6d/0x330 _printk+0x58/0x80 dump_mapping+0x10b/0x1a0 ? __pfx_free_object_rcu+0x10/0x10 __dump_page+0x26b/0x3e0 ? vprintk_emit+0xe0/0x330 ? _printk+0x58/0x80 ? dump_page+0x17/0x50 dump_page+0x17/0x50 do_migrate_range+0x2f7/0x7f0 ? do_migrate_range+0x42/0x7f0 ? offline_pages+0x2f4/0x8c0 offline_pages+0x60a/0x8c0 memory_subsys_offline+0x9f/0x1c0 ? lockdep_hardirqs_on+0x77/0x100 ? _raw_spin_unlock_irqrestore+0x38/0x60 device_offline+0xe3/0x110 state_store+0x6e/0xc0 kernfs_fop_write_iter+0x143/0x200 vfs_write+0x39f/0x560 ksys_write+0x65/0xf0 do_syscall_64+0x62/0x130 Previously, some sanity check have been done in dump_mapping() before the print facility parsing '%pd' though, it's still possible to run into an invalid dentry.d_name.name. Since dump_mapping() only needs to dump the filename only, retrieve it by itself in a safer way to prevent an unnecessary crash. Note that either retrieving the filename with '%pd' or strncpy_from_kernel_nofault(), the filename could be unreliable. Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Link: https://lore.kernel.org/r/20240826055503.1522320-1-lizhijian@fujitsu.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Christian Brauner
|
f469e6e6f5 |
inode: port __I_LRU_ISOLATING to var event
Port the __I_LRU_ISOLATING mechanism to use the new var event mechanism. Link: https://lore.kernel.org/r/20240823-work-i_state-v3-5-5cd5fd207a57@kernel.org Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christian Brauner
|
0fe340a98b |
inode: port __I_NEW to var event
Port the __I_NEW mechanism to use the new var event mechanism. Link: https://lore.kernel.org/r/20240823-work-i_state-v3-4-5cd5fd207a57@kernel.org Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christian Brauner
|
da18ecbf0f |
fs: add i_state helpers
The i_state member is an unsigned long so that it can be used with the wait bit infrastructure which expects unsigned long. This wastes 4 bytes which we're unlikely to ever use. Switch to using the var event wait mechanism using the address of the bit. Thanks to Linus for the address idea. Link: https://lore.kernel.org/r/20240823-work-i_state-v3-1-5cd5fd207a57@kernel.org Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Julian Sun
|
88b1afbf0f |
vfs: fix race between evice_inodes() and find_inode()&iput()
Hi, all
Recently I noticed a bug[1] in btrfs, after digged it into
and I believe it'a race in vfs.
Let's assume there's a inode (ie ino 261) with i_count 1 is
called by iput(), and there's a concurrent thread calling
generic_shutdown_super().
cpu0: cpu1:
iput() // i_count is 1
->spin_lock(inode)
->dec i_count to 0
->iput_final() generic_shutdown_super()
->__inode_add_lru() ->evict_inodes()
// cause some reason[2] ->if (atomic_read(inode->i_count)) continue;
// return before // inode 261 passed the above check
// list_lru_add_obj() // and then schedule out
->spin_unlock()
// note here: the inode 261
// was still at sb list and hash list,
// and I_FREEING|I_WILL_FREE was not been set
btrfs_iget()
// after some function calls
->find_inode()
// found the above inode 261
->spin_lock(inode)
// check I_FREEING|I_WILL_FREE
// and passed
->__iget()
->spin_unlock(inode) // schedule back
->spin_lock(inode)
// check (I_NEW|I_FREEING|I_WILL_FREE) flags,
// passed and set I_FREEING
iput() ->spin_unlock(inode)
->spin_lock(inode) ->evict()
// dec i_count to 0
->iput_final()
->spin_unlock()
->evict()
Now, we have two threads simultaneously evicting
the same inode, which may trigger the BUG(inode->i_state & I_CLEAR)
statement both within clear_inode() and iput().
To fix the bug, recheck the inode->i_count after holding i_lock.
Because in the most scenarios, the first check is valid, and
the overhead of spin_lock() can be reduced.
If there is any misunderstanding, please let me know, thanks.
[1]: https://lore.kernel.org/linux-btrfs/000000000000eabe1d0619c48986@google.com/
[2]: The reason might be 1. SB_ACTIVE was removed or 2. mapping_shrinkable()
return false when I reproduced the bug.
Reported-by: syzbot+67ba3c42bcbb4665d3ad@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=67ba3c42bcbb4665d3ad
CC: stable@vger.kernel.org
Fixes:
|
||
Mateusz Guzik
|
57510c58b5 |
vfs: drop one lock trip in evict()
Most commonly neither I_LRU_ISOLATING nor I_SYNC are set, but the stock kernel takes a back-to-back relock trip to check for them. It probably can be avoided altogether, but for now massage things back to just one lock acquire. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240813143626.1573445-1-mjguzik@gmail.com Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christian Brauner
|
1c48d44146 |
inode: remove __I_DIO_WAKEUP
Afaict, we can just rely on inode->i_dio_count for waiting instead of this awkward indirection through __I_DIO_WAKEUP. This survives LTP dio and xfstests dio tests. Link: https://lore.kernel.org/r/20240816-vfs-misc-dio-v1-1-80fe21a2c710@kernel.org Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
122381a469 |
vfs: use RCU in ilookup
A soft lockup in ilookup was reported when stress-testing a 512-way system [1] (see [2] for full context) and it was verified that not taking the lock shifts issues back to mm. [1] https://lore.kernel.org/linux-mm/56865e57-c250-44da-9713-cf1404595bcc@amd.com/ [2] https://lore.kernel.org/linux-mm/d2841226-e27b-4d3d-a578-63587a3aa4f3@amd.com/ Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240715071324.265879-1-mjguzik@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Zhihao Cheng
|
2a0629834c
|
vfs: Don't evict inode under the inode lru traversing context
The inode reclaiming process(See function prune_icache_sb) collects all
reclaimable inodes and mark them with I_FREEING flag at first, at that
time, other processes will be stuck if they try getting these inodes
(See function find_inode_fast), then the reclaiming process destroy the
inodes by function dispose_list(). Some filesystems(eg. ext4 with
ea_inode feature, ubifs with xattr) may do inode lookup in the inode
evicting callback function, if the inode lookup is operated under the
inode lru traversing context, deadlock problems may happen.
Case 1: In function ext4_evict_inode(), the ea inode lookup could happen
if ea_inode feature is enabled, the lookup process will be stuck
under the evicting context like this:
1. File A has inode i_reg and an ea inode i_ea
2. getfattr(A, xattr_buf) // i_ea is added into lru // lru->i_ea
3. Then, following three processes running like this:
PA PB
echo 2 > /proc/sys/vm/drop_caches
shrink_slab
prune_dcache_sb
// i_reg is added into lru, lru->i_ea->i_reg
prune_icache_sb
list_lru_walk_one
inode_lru_isolate
i_ea->i_state |= I_FREEING // set inode state
inode_lru_isolate
__iget(i_reg)
spin_unlock(&i_reg->i_lock)
spin_unlock(lru_lock)
rm file A
i_reg->nlink = 0
iput(i_reg) // i_reg->nlink is 0, do evict
ext4_evict_inode
ext4_xattr_delete_inode
ext4_xattr_inode_dec_ref_all
ext4_xattr_inode_iget
ext4_iget(i_ea->i_ino)
iget_locked
find_inode_fast
__wait_on_freeing_inode(i_ea) ----→ AA deadlock
dispose_list // cannot be executed by prune_icache_sb
wake_up_bit(&i_ea->i_state)
Case 2: In deleted inode writing function ubifs_jnl_write_inode(), file
deleting process holds BASEHD's wbuf->io_mutex while getting the
xattr inode, which could race with inode reclaiming process(The
reclaiming process could try locking BASEHD's wbuf->io_mutex in
inode evicting function), then an ABBA deadlock problem would
happen as following:
1. File A has inode ia and a xattr(with inode ixa), regular file B has
inode ib and a xattr.
2. getfattr(A, xattr_buf) // ixa is added into lru // lru->ixa
3. Then, following three processes running like this:
PA PB PC
echo 2 > /proc/sys/vm/drop_caches
shrink_slab
prune_dcache_sb
// ib and ia are added into lru, lru->ixa->ib->ia
prune_icache_sb
list_lru_walk_one
inode_lru_isolate
ixa->i_state |= I_FREEING // set inode state
inode_lru_isolate
__iget(ib)
spin_unlock(&ib->i_lock)
spin_unlock(lru_lock)
rm file B
ib->nlink = 0
rm file A
iput(ia)
ubifs_evict_inode(ia)
ubifs_jnl_delete_inode(ia)
ubifs_jnl_write_inode(ia)
make_reservation(BASEHD) // Lock wbuf->io_mutex
ubifs_iget(ixa->i_ino)
iget_locked
find_inode_fast
__wait_on_freeing_inode(ixa)
| iput(ib) // ib->nlink is 0, do evict
| ubifs_evict_inode
| ubifs_jnl_delete_inode(ib)
↓ ubifs_jnl_write_inode
ABBA deadlock ←-----make_reservation(BASEHD)
dispose_list // cannot be executed by prune_icache_sb
wake_up_bit(&ixa->i_state)
Fix the possible deadlock by using new inode state flag I_LRU_ISOLATING
to pin the inode in memory while inode_lru_isolate() reclaims its pages
instead of using ordinary inode reference. This way inode deletion
cannot be triggered from inode_lru_isolate() thus avoiding the deadlock.
evict() is made to wait for I_LRU_ISOLATING to be cleared before
proceeding with inode cleanup.
Link: https://lore.kernel.org/all/37c29c42-7685-d1f0-067d-63582ffac405@huaweicloud.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219022
Fixes:
|
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Joel Granados
|
78eb4ea25c |
sysctl: treewide: constify the ctl_table argument of proc_handlers
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.
This patch has been generated by the following coccinelle script:
```
virtual patch
@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);
@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }
@r3@
identifier func;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);
@r4@
identifier func, ctl;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);
@r5@
identifier func, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);
```
* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.
* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.
Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
|
||
|
Christian Brauner
|
f5e5e97c71
|
inode: clarify what's locked
In __wait_on_freeing_inode() we warn in case the inode_hash_lock is held but the inode is unhashed. We then release the inode_lock. So using "locked" as parameter name is confusing. Use is_inode_hash_locked as parameter name instead. Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
5bc9ad78c2
|
vfs: handle __wait_on_freeing_inode() and evict() race
Lockless hash lookup can find and lock the inode after it gets the
I_FREEING flag set, at which point it blocks waiting for teardown in
evict() to finish.
However, the flag is still set even after evict() wakes up all waiters.
This results in a race where if the inode lock is taken late enough, it
can happen after both hash removal and wakeups, meaning there is nobody
to wake the racing thread up.
This worked prior to RCU-based lookup because the entire ordeal was
synchronized with the inode hash lock.
Since unhashing requires the inode lock, we can safely check whether it
happened after acquiring it.
Link: https://lore.kernel.org/v9fs/20240717102458.649b60be@kernel.org/
Reported-by: Dominique Martinet <asmadeus@codewreck.org>
Fixes:
|
||
Linus Torvalds
|
2aae1d67fd |
vfs-6.11.inode
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Merge tag 'vfs-6.11.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode / dentry updates from Christian Brauner:
"This contains smaller performance improvements to inodes and dentries:
inode:
- Add rcu based inode lookup variants.
They avoid one inode hash lock acquire in the common case thereby
significantly reducing contention. We already support RCU-based
operations but didn't take advantage of them during inode
insertion.
Callers of iget_locked() get the improvement without any code
changes. Callers that need a custom callback can switch to
iget5_locked_rcu() as e.g., did btrfs.
With 20 threads each walking a dedicated 1000 dirs * 1000 files
directory tree to stat(2) on a 32 core + 24GB ram vm:
before: 3.54s user 892.30s system 1966% cpu 45.549 total
after: 3.28s user 738.66s system 1955% cpu 37.932 total (-16.7%)
Long-term we should pick up the effort to introduce more
fine-grained locking and possibly improve on the currently used
hash implementation.
- Start zeroing i_state in inode_init_always() instead of doing it in
individual filesystems.
This allows us to remove an unneeded lock acquire in new_inode()
and not burden individual filesystems with this.
dcache:
- Move d_lockref out of the area used by RCU lookup to avoid
cacheline ping poing because the embedded name is sharing a
cacheline with d_lockref.
- Fix dentry size on 32bit with CONFIG_SMP=y so it does actually end
up with 128 bytes in total"
* tag 'vfs-6.11.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: fix dentry size
vfs: move d_lockref out of the area used by RCU lookup
bcachefs: remove now spurious i_state initialization
xfs: remove now spurious i_state initialization in xfs_inode_alloc
vfs: partially sanitize i_state zeroing on inode creation
xfs: preserve i_state around inode_init_always in xfs_reinit_inode
btrfs: use iget5_locked_rcu
vfs: add rcu-based find_inode variants for iget ops
|
||
Youling Tang
|
9b6a14f08b
|
fs: Export in_group_or_capable()
Export in_group_or_capable() as a VFS helper function. Signed-off-by: Youling Tang <tangyouling@kylinos.cn> Link: https://lore.kernel.org/r/20240620032335.147136-1-youling.tang@linux.dev Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
5a9b911b8a |
vfs: partially sanitize i_state zeroing on inode creation
new_inode used to have the following: spin_lock(&inode_lock); inodes_stat.nr_inodes++; list_add(&inode->i_list, &inode_in_use); list_add(&inode->i_sb_list, &sb->s_inodes); inode->i_ino = ++last_ino; inode->i_state = 0; spin_unlock(&inode_lock); over time things disappeared, got moved around or got replaced (global inode lock with a per-inode lock), eventually this got reduced to: spin_lock(&inode->i_lock); inode->i_state = 0; spin_unlock(&inode->i_lock); But the lock acquire here does not synchronize against anyone. Additionally iget5_locked performs i_state = 0 assignment without any locks to begin with, the two combined look confusing at best. It looks like the current state is a leftover which was not cleaned up. Ideally it would be an invariant that i_state == 0 to begin with, but achieving that would require dealing with all filesystem alloc handlers one by one. In the meantime drop the misleading locking and move i_state zeroing to inode_init_always so that others don't need to deal with it by hand. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240611120626.513952-3-mjguzik@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
7180f8d91f |
vfs: add rcu-based find_inode variants for iget ops
This avoids one inode hash lock acquire in the common case on inode
creation, in effect significantly reducing contention.
On the stock kernel said lock is typically taken twice:
1. once to check if the inode happens to already be present
2. once to add it to the hash
The back-to-back lock/unlock pattern is known to degrade performance
significantly, which is further exacerbated if the hash is heavily
populated (long chains to walk, extending hold time). Arguably hash
sizing and hashing algo need to be revisited, but that's beyond the
scope of this patch.
With the acquire from step 1 eliminated with RCU lookup throughput
increases significantly at the scale of 20 cores (benchmark results at
the bottom).
So happens the hash already supports RCU-based operation, but lookups on
inode insertions didn't take advantage of it.
This of course has its limits as the global lock is still a bottleneck.
There was a patchset posted which introduced fine-grained locking[1] but
it appears staled. Apart from that doubt was expressed whether a
handrolled hash implementation is appropriate to begin with, suggesting
replacement with rhashtables. Nobody committed to carrying [1] across
the finish line or implementing anything better, thus the bandaid below.
iget_locked consumers (notably ext4) get away without any changes
because inode comparison method is built-in.
iget5_locked consumers pass a custom callback. Since removal of locking
adds more problems (inode can be changing) it's not safe to assume all
filesystems happen to cope. Thus iget5_locked_rcu gets added, requiring
manual conversion of interested filesystems.
In order to reduce code duplication find_inode and find_inode_fast grow
an argument indicating whether inode hash lock is held, which is passed
down in case sleeping is necessary. They always rcu_read_lock, which is
redundant but harmless. Doing it conditionally reduces readability for
no real gain that I can see. RCU-alike restrictions were already put on
callbacks due to the hash spinlock being held.
Benchmarking:
There is a real cache-busting workload scanning millions of files in
parallel (it's a backup appliance), where the initial lookup is
guaranteed to fail resulting in the two lock acquires on stock kernel
(and one with the patch at hand).
Implemented below is a synthetic benchmark providing the same behavior.
[I shall note the workload is not running on Linux, instead it was
causing trouble elsewhere. Benchmark below was used while addressing
said problems and was found to adequately represent the real workload.]
Total real time fluctuates by 1-2s.
With 20 threads each walking a dedicated 1000 dirs * 1000 files
directory tree to stat(2) on a 32 core + 24GB RAM vm:
ext4 (needed mkfs.ext4 -N 24000000):
before: 3.77s user 890.90s system 1939% cpu 46.118 total
after: 3.24s user 397.73s system 1858% cpu 21.581 total (-53%)
That's 20 million files to visit, while the machine can only cache about
15 million at a time (obtained from ext4_inode_cache object count in
/proc/slabinfo). Since each terminal inode is only visited once per run
this amounts to 0% hit ratio for the dentry cache and the hash table
(there are however hits for the intermediate directories).
On repeated runs the kernel caches the last ~15 mln, meaning there is ~5
mln of uncached inodes which are going to be visited first, evicting the
previously cached state as it happens.
Lack of hits can be trivially verified with bpftrace, like so:
bpftrace -e 'kretprobe:find_inode_fast { @[kstack(), retval != 0] = count(); }'\
-c "/bin/sh walktrees /testfs 20"
Best ran more than once.
Expected results after "warmup":
[snip]
@[
__ext4_iget+275
ext4_lookup+224
__lookup_slow+130
walk_component+219
link_path_walk.part.0.constprop.0+614
path_lookupat+62
filename_lookup+204
vfs_statx+128
vfs_fstatat+131
__do_sys_newfstatat+38
do_syscall_64+87
entry_SYSCALL_64_after_hwframe+118
, 1]: 20000
@[
__ext4_iget+275
ext4_lookup+224
__lookup_slow+130
walk_component+219
path_lookupat+106
filename_lookup+204
vfs_statx+128
vfs_fstatat+131
__do_sys_newfstatat+38
do_syscall_64+87
entry_SYSCALL_64_after_hwframe+118
, 1]: 20000000
That is 20 million calls for the initial lookup and 20 million after
allocating a new inode, all of them failing to return a value != 0
(i.e., they are returning NULL -- no match found).
Of course aborting the benchmark in the middle and starting it again (or
messing with the state in other ways) is going to alter these results.
Benchmark can be found here: https://people.freebsd.org/~mjg/fstree.tgz
[1] https://lore.kernel.org/all/20231206060629.2827226-1-david@fromorbit.com/
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20240611173824.535995-2-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
||
|
Linus Torvalds
|
32a50540c3 |
bcachefs updates for 6.9
- Subvolume children btree; this is needed for providing a userspace
interface for walking subvolumes, which will come later
- Lots of improvements to directory structure checking
- Improved journal pipelining, significantly improving performance on
high iodepth write workloads
- Discard path improvements: the discard path is more efficient, and no
longer flushes the journal unnecessarily
- Buffered write path can now avoid taking the inode lock
- new mm helper: memalloc_flags_{save|restore}
- mempool now does kvmalloc mempools
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Merge tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefs
Pull bcachefs updates from Kent Overstreet:
- Subvolume children btree; this is needed for providing a userspace
interface for walking subvolumes, which will come later
- Lots of improvements to directory structure checking
- Improved journal pipelining, significantly improving performance on
high iodepth write workloads
- Discard path improvements: the discard path is more efficient, and no
longer flushes the journal unnecessarily
- Buffered write path can now avoid taking the inode lock
- new mm helper: memalloc_flags_{save|restore}
- mempool now does kvmalloc mempools
* tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefs: (128 commits)
bcachefs: time_stats: shrink time_stat_buffer for better alignment
bcachefs: time_stats: split stats-with-quantiles into a separate structure
bcachefs: mean_and_variance: put struct mean_and_variance_weighted on a diet
bcachefs: time_stats: add larger units
bcachefs: pull out time_stats.[ch]
bcachefs: reconstruct_alloc cleanup
bcachefs: fix bch_folio_sector padding
bcachefs: Fix btree key cache coherency during replay
bcachefs: Always flush write buffer in delete_dead_inodes()
bcachefs: Fix order of gc_done passes
bcachefs: fix deletion of indirect extents in btree_gc
bcachefs: Prefer struct_size over open coded arithmetic
bcachefs: Kill unused flags argument to btree_split()
bcachefs: Check for writing superblocks with nonsense member seq fields
bcachefs: fix bch2_journal_buf_to_text()
lib/generic-radix-tree.c: Make nodes more reasonably sized
bcachefs: copy_(to|from)_user_errcode()
bcachefs: Split out bkey_types.h
bcachefs: fix lost journal buf wakeup due to improved pipelining
bcachefs: intercept mountoption value for bool type
...
|
||
Kent Overstreet
|
66a67c860c |
fs: file_remove_privs_flags()
Rename and export __file_remove_privs(); for a buffered write path that doesn't take the inode lock we need to be able to check if the operation needs to do work first. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> |
||
|
Linus Torvalds
|
54126fafea |
vfs-6.9.iomap
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZem4UQAKCRCRxhvAZXjc ouERAQDg63R9s3bKmUgGqngf9cfr//VCTE+WVARwOUTdn2iDbwEA1IME7X1kL/Vz EdhEjyqO6xom+ao/Vqxe0XIDNz70vgs= =8RdE -----END PGP SIGNATURE----- Merge tag 'vfs-6.9.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull iomap updates from Christian Brauner: - Restore read-write hints in struct bio through the bi_write_hint member for the sake of UFS devices in mobile applications. This can result in up to 40% lower write amplification in UFS devices. The patch series that builds on this will be coming in via the SCSI maintainers (Bart) - Overhaul the iomap writeback code. Afterwards ->map_blocks() is able to map multiple blocks at once as long as they're in the same folio. This reduces CPU usage for buffered write workloads on e.g., xfs on systems with lots of cores (Christoph) - Record processed bytes in iomap_iter() trace event (Kassey) - Extend iomap_writepage_map() trace event after Christoph's ->map_block() changes to map mutliple blocks at once (Zhang) * tag 'vfs-6.9.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits) iomap: Add processed for iomap_iter iomap: add pos and dirty_len into trace_iomap_writepage_map block, fs: Restore the per-bio/request data lifetime fields fs: Propagate write hints to the struct block_device inode fs: Move enum rw_hint into a new header file fs: Split fcntl_rw_hint() fs: Verify write lifetime constants at compile time fs: Fix rw_hint validation iomap: pass the length of the dirty region to ->map_blocks iomap: map multiple blocks at a time iomap: submit ioends immediately iomap: factor out a iomap_writepage_map_block helper iomap: only call mapping_set_error once for each failed bio iomap: don't chain bios iomap: move the iomap_sector sector calculation out of iomap_add_to_ioend iomap: clean up the iomap_alloc_ioend calling convention iomap: move all remaining per-folio logic into iomap_writepage_map iomap: factor out a iomap_writepage_handle_eof helper iomap: move the PF_MEMALLOC check to iomap_writepages iomap: move the io_folios field out of struct iomap_ioend ... |
||
Nguyen Dinh Phi
|
24a8b7bfb9
|
fs: use inode_set_ctime_to_ts to set inode ctime to current time
The function inode_set_ctime_current simply retrieves the current time and assigns it to the field __i_ctime without any alterations. Therefore, it is possible to set ctime to now directly using inode_set_ctime_to_ts Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com> Link: https://lore.kernel.org/r/20240228173031.3208743-1-phind.uet@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Chengming Zhou
|
c997d683d9 |
vfs: remove SLAB_MEM_SPREAD flag usage
The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
removed as of v6.8-rc1 (see [1]), so it became a dead flag since the
commit
|
||
Bart Van Assche
|
fe3944fb24
|
fs: Move enum rw_hint into a new header file
Move enum rw_hint into a new header file to prepare for using this data type in the block layer. Add the attribute __packed to reduce the space occupied by instances of this data type from four bytes to one byte. Change the data type of i_write_hint from u8 into enum rw_hint. Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Chao Yu <chao@kernel.org> # for the F2FS part Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20240202203926.2478590-5-bvanassche@acm.org Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Baolin Wang
|
8b3d838139 |
fs: improve dump_mapping() robustness
We met a kernel crash issue when running stress-ng testing, and the
system crashes when printing the dentry name in dump_mapping().
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
pc : dentry_name+0xd8/0x224
lr : pointer+0x22c/0x370
sp : ffff800025f134c0
......
Call trace:
dentry_name+0xd8/0x224
pointer+0x22c/0x370
vsnprintf+0x1ec/0x730
vscnprintf+0x2c/0x60
vprintk_store+0x70/0x234
vprintk_emit+0xe0/0x24c
vprintk_default+0x3c/0x44
vprintk_func+0x84/0x2d0
printk+0x64/0x88
__dump_page+0x52c/0x530
dump_page+0x14/0x20
set_migratetype_isolate+0x110/0x224
start_isolate_page_range+0xc4/0x20c
offline_pages+0x124/0x474
memory_block_offline+0x44/0xf4
memory_subsys_offline+0x3c/0x70
device_offline+0xf0/0x120
......
The root cause is that, one thread is doing page migration, and we will
use the target page's ->mapping field to save 'anon_vma' pointer between
page unmap and page move, and now the target page is locked and refcount
is 1.
Currently, there is another stress-ng thread performing memory hotplug,
attempting to offline the target page that is being migrated. It discovers
that the refcount of this target page is 1, preventing the offline operation,
thus proceeding to dump the page. However, page_mapping() of the target
page may return an incorrect file mapping to crash the system in dump_mapping(),
since the target page->mapping only saves 'anon_vma' pointer without setting
PAGE_MAPPING_ANON flag.
The page migration issue has been fixed by commit
|
||
|
Linus Torvalds
|
bf4e7080ae |
fix directory locking scheme on rename
broken in 6.5; we really can't lock two unrelated directories without holding ->s_vfs_rename_mutex first and in case of same-parent rename of a subdirectory 6.5 ends up doing just that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZZ+lyQAKCRBZ7Krx/gZQ 60MWAP94hTqeMIpjhsUIkrTnylrIFaiw4UCWFJzIRG1QQYKqCgD/XUaWI9np7dL6 0wR/j4CQSdJjiEFKUFE2pD3QoSuJYAQ= =+x0+ -----END PGP SIGNATURE----- Merge tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull rename updates from Al Viro: "Fix directory locking scheme on rename This was broken in 6.5; we really can't lock two unrelated directories without holding ->s_vfs_rename_mutex first and in case of same-parent rename of a subdirectory 6.5 ends up doing just that" * tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: rename(): avoid a deadlock in the case of parents having no common ancestor kill lock_two_inodes() rename(): fix the locking of subdirectories f2fs: Avoid reading renamed directory if parent does not change ext4: don't access the source subdirectory content on same-directory rename ext2: Avoid reading renamed directory if parent does not change udf_rename(): only access the child content on cross-directory rename ocfs2: Avoid touching renamed directory if parent does not change reiserfs: Avoid touching renamed directory if parent does not change |
||
|
Linus Torvalds
|
a05aea98d4 |
sysctl-6.8-rc1
To help make the move of sysctls out of kernel/sysctl.c not incur a size
penalty sysctl has been changed to allow us to not require the sentinel, the
final empty element on the sysctl array. Joel Granados has been doing all this
work. On the v6.6 kernel we got the major infrastructure changes required to
support this. For v6.7 we had all arch/ and drivers/ modified to remove
the sentinel. For v6.8-rc1 we get a few more updates for fs/ directory only.
The kernel/ directory is left but we'll save that for v6.9-rc1 as those patches
are still being reviewed. After that we then can expect also the removal of the
no longer needed check for procname == NULL.
Let us recap the purpose of this work:
- this helps reduce the overall build time size of the kernel and run time
memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move sysctls
out from kernel/sysctl.c to their own files
Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to see further
work by Thomas Weißschuh with the constificatin of the struct ctl_table.
Due to Joel Granados's work, and to help bring in new blood, I have suggested
for him to become a maintainer and he's accepted. So for v6.9-rc1 I look forward
to seeing him sent you a pull request for further sysctl changes. This also
removes Iurii Zaikin as a maintainer as he has moved on to other projects and
has had no time to help at all.
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Merge tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"To help make the move of sysctls out of kernel/sysctl.c not incur a
size penalty sysctl has been changed to allow us to not require the
sentinel, the final empty element on the sysctl array. Joel Granados
has been doing all this work.
In the v6.6 kernel we got the major infrastructure changes required to
support this. For v6.7 we had all arch/ and drivers/ modified to
remove the sentinel. For v6.8-rc1 we get a few more updates for fs/
directory only.
The kernel/ directory is left but we'll save that for v6.9-rc1 as
those patches are still being reviewed. After that we then can expect
also the removal of the no longer needed check for procname == NULL.
Let us recap the purpose of this work:
- this helps reduce the overall build time size of the kernel and run
time memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move
sysctls out from kernel/sysctl.c to their own files
Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to
see further work by Thomas Weißschuh with the constificatin of the
struct ctl_table.
Due to Joel Granados's work, and to help bring in new blood, I have
suggested for him to become a maintainer and he's accepted. So for
v6.9-rc1 I look forward to seeing him sent you a pull request for
further sysctl changes. This also removes Iurii Zaikin as a maintainer
as he has moved on to other projects and has had no time to help at
all"
* tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
sysctl: remove struct ctl_path
sysctl: delete unused define SYSCTL_PERM_EMPTY_DIR
coda: Remove the now superfluous sentinel elements from ctl_table array
sysctl: Remove the now superfluous sentinel elements from ctl_table array
fs: Remove the now superfluous sentinel elements from ctl_table array
cachefiles: Remove the now superfluous sentinel element from ctl_table array
sysclt: Clarify the results of selftest run
sysctl: Add a selftest for handling empty dirs
sysctl: Fix out of bounds access for empty sysctl registers
MAINTAINERS: Add Joel Granados as co-maintainer for proc sysctl
MAINTAINERS: remove Iurii Zaikin from proc sysctl
|
||
|
Linus Torvalds
|
fb46e22a9e |
Many singleton patches against the MM code. The patch series which
are included in this merge do the following:
- Peng Zhang has done some mapletree maintainance work in the
series
"maple_tree: add mt_free_one() and mt_attr() helpers"
"Some cleanups of maple tree"
- In the series "mm: use memmap_on_memory semantics for dax/kmem"
Vishal Verma has altered the interworking between memory-hotplug
and dax/kmem so that newly added 'device memory' can more easily
have its memmap placed within that newly added memory.
- Matthew Wilcox continues folio-related work (including a few
fixes) in the patch series
"Add folio_zero_tail() and folio_fill_tail()"
"Make folio_start_writeback return void"
"Fix fault handler's handling of poisoned tail pages"
"Convert aops->error_remove_page to ->error_remove_folio"
"Finish two folio conversions"
"More swap folio conversions"
- Kefeng Wang has also contributed folio-related work in the series
"mm: cleanup and use more folio in page fault"
- Jim Cromie has improved the kmemleak reporting output in the
series "tweak kmemleak report format".
- In the series "stackdepot: allow evicting stack traces" Andrey
Konovalov to permits clients (in this case KASAN) to cause
eviction of no longer needed stack traces.
- Charan Teja Kalla has fixed some accounting issues in the page
allocator's atomic reserve calculations in the series "mm:
page_alloc: fixes for high atomic reserve caluculations".
- Dmitry Rokosov has added to the samples/ dorectory some sample
code for a userspace memcg event listener application. See the
series "samples: introduce cgroup events listeners".
- Some mapletree maintanance work from Liam Howlett in the series
"maple_tree: iterator state changes".
- Nhat Pham has improved zswap's approach to writeback in the
series "workload-specific and memory pressure-driven zswap
writeback".
- DAMON/DAMOS feature and maintenance work from SeongJae Park in
the series
"mm/damon: let users feed and tame/auto-tune DAMOS"
"selftests/damon: add Python-written DAMON functionality tests"
"mm/damon: misc updates for 6.8"
- Yosry Ahmed has improved memcg's stats flushing in the series
"mm: memcg: subtree stats flushing and thresholds".
- In the series "Multi-size THP for anonymous memory" Ryan Roberts
has added a runtime opt-in feature to transparent hugepages which
improves performance by allocating larger chunks of memory during
anonymous page faults.
- Matthew Wilcox has also contributed some cleanup and maintenance
work against eh buffer_head code int he series "More buffer_head
cleanups".
- Suren Baghdasaryan has done work on Andrea Arcangeli's series
"userfaultfd move option". UFFDIO_MOVE permits userspace heap
compaction algorithms to move userspace's pages around rather than
UFFDIO_COPY'a alloc/copy/free.
- Stefan Roesch has developed a "KSM Advisor", in the series
"mm/ksm: Add ksm advisor". This is a governor which tunes KSM's
scanning aggressiveness in response to userspace's current needs.
- Chengming Zhou has optimized zswap's temporary working memory
use in the series "mm/zswap: dstmem reuse optimizations and
cleanups".
- Matthew Wilcox has performed some maintenance work on the
writeback code, both code and within filesystems. The series is
"Clean up the writeback paths".
- Andrey Konovalov has optimized KASAN's handling of alloc and
free stack traces for secondary-level allocators, in the series
"kasan: save mempool stack traces".
- Andrey also performed some KASAN maintenance work in the series
"kasan: assorted clean-ups".
- David Hildenbrand has gone to town on the rmap code. Cleanups,
more pte batching, folio conversions and more. See the series
"mm/rmap: interface overhaul".
- Kinsey Ho has contributed some maintenance work on the MGLRU
code in the series "mm/mglru: Kconfig cleanup".
- Matthew Wilcox has contributed lruvec page accounting code
cleanups in the series "Remove some lruvec page accounting
functions".
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Merge tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
- Peng Zhang has done some mapletree maintainance work in the series
'maple_tree: add mt_free_one() and mt_attr() helpers'
'Some cleanups of maple tree'
- In the series 'mm: use memmap_on_memory semantics for dax/kmem'
Vishal Verma has altered the interworking between memory-hotplug
and dax/kmem so that newly added 'device memory' can more easily
have its memmap placed within that newly added memory.
- Matthew Wilcox continues folio-related work (including a few fixes)
in the patch series
'Add folio_zero_tail() and folio_fill_tail()'
'Make folio_start_writeback return void'
'Fix fault handler's handling of poisoned tail pages'
'Convert aops->error_remove_page to ->error_remove_folio'
'Finish two folio conversions'
'More swap folio conversions'
- Kefeng Wang has also contributed folio-related work in the series
'mm: cleanup and use more folio in page fault'
- Jim Cromie has improved the kmemleak reporting output in the series
'tweak kmemleak report format'.
- In the series 'stackdepot: allow evicting stack traces' Andrey
Konovalov to permits clients (in this case KASAN) to cause eviction
of no longer needed stack traces.
- Charan Teja Kalla has fixed some accounting issues in the page
allocator's atomic reserve calculations in the series 'mm:
page_alloc: fixes for high atomic reserve caluculations'.
- Dmitry Rokosov has added to the samples/ dorectory some sample code
for a userspace memcg event listener application. See the series
'samples: introduce cgroup events listeners'.
- Some mapletree maintanance work from Liam Howlett in the series
'maple_tree: iterator state changes'.
- Nhat Pham has improved zswap's approach to writeback in the series
'workload-specific and memory pressure-driven zswap writeback'.
- DAMON/DAMOS feature and maintenance work from SeongJae Park in the
series
'mm/damon: let users feed and tame/auto-tune DAMOS'
'selftests/damon: add Python-written DAMON functionality tests'
'mm/damon: misc updates for 6.8'
- Yosry Ahmed has improved memcg's stats flushing in the series 'mm:
memcg: subtree stats flushing and thresholds'.
- In the series 'Multi-size THP for anonymous memory' Ryan Roberts
has added a runtime opt-in feature to transparent hugepages which
improves performance by allocating larger chunks of memory during
anonymous page faults.
- Matthew Wilcox has also contributed some cleanup and maintenance
work against eh buffer_head code int he series 'More buffer_head
cleanups'.
- Suren Baghdasaryan has done work on Andrea Arcangeli's series
'userfaultfd move option'. UFFDIO_MOVE permits userspace heap
compaction algorithms to move userspace's pages around rather than
UFFDIO_COPY'a alloc/copy/free.
- Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm:
Add ksm advisor'. This is a governor which tunes KSM's scanning
aggressiveness in response to userspace's current needs.
- Chengming Zhou has optimized zswap's temporary working memory use
in the series 'mm/zswap: dstmem reuse optimizations and cleanups'.
- Matthew Wilcox has performed some maintenance work on the writeback
code, both code and within filesystems. The series is 'Clean up the
writeback paths'.
- Andrey Konovalov has optimized KASAN's handling of alloc and free
stack traces for secondary-level allocators, in the series 'kasan:
save mempool stack traces'.
- Andrey also performed some KASAN maintenance work in the series
'kasan: assorted clean-ups'.
- David Hildenbrand has gone to town on the rmap code. Cleanups, more
pte batching, folio conversions and more. See the series 'mm/rmap:
interface overhaul'.
- Kinsey Ho has contributed some maintenance work on the MGLRU code
in the series 'mm/mglru: Kconfig cleanup'.
- Matthew Wilcox has contributed lruvec page accounting code cleanups
in the series 'Remove some lruvec page accounting functions'"
* tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits)
mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER
mm, treewide: introduce NR_PAGE_ORDERS
selftests/mm: add separate UFFDIO_MOVE test for PMD splitting
selftests/mm: skip test if application doesn't has root privileges
selftests/mm: conform test to TAP format output
selftests: mm: hugepage-mmap: conform to TAP format output
selftests/mm: gup_test: conform test to TAP format output
mm/selftests: hugepage-mremap: conform test to TAP format output
mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING
mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large
mm/memcontrol: remove __mod_lruvec_page_state()
mm/khugepaged: use a folio more in collapse_file()
slub: use a folio in __kmalloc_large_node
slub: use folio APIs in free_large_kmalloc()
slub: use alloc_pages_node() in alloc_slab_page()
mm: remove inc/dec lruvec page state functions
mm: ratelimit stat flush from workingset shrinker
kasan: stop leaking stack trace handles
mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE
mm/mglru: add dummy pmd_dirty()
...
|
||
|
Linus Torvalds
|
c604110e66 |
vfs-6.8.misc
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Merge tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual fses.
Features:
- Add Jan Kara as VFS reviewer
- Show correct device and inode numbers in proc/<pid>/maps for vma
files on stacked filesystems. This is now easily doable thanks to
the backing file work from the last cycles. This comes with
selftests
Cleanups:
- Remove a redundant might_sleep() from wait_on_inode()
- Initialize pointer with NULL, not 0
- Clarify comment on access_override_creds()
- Rework and simplify eventfd_signal() and eventfd_signal_mask()
helpers
- Process aio completions in batches to avoid needless wakeups
- Completely decouple struct mnt_idmap from namespaces. We now only
keep the actual idmapping around and don't stash references to
namespaces
- Reformat maintainer entries to indicate that a given subsystem
belongs to fs/
- Simplify fput() for files that were never opened
- Get rid of various pointless file helpers
- Rename various file helpers
- Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from
last cycle
- Make relatime_need_update() return bool
- Use GFP_KERNEL instead of GFP_USER when allocating superblocks
- Replace deprecated ida_simple_*() calls with their current ida_*()
counterparts
Fixes:
- Fix comments on user namespace id mapping helpers. They aren't
kernel doc comments so they shouldn't be using /**
- s/Retuns/Returns/g in various places
- Add missing parameter documentation on can_move_mount_beneath()
- Rename i_mapping->private_data to i_mapping->i_private_data
- Fix a false-positive lockdep warning in pipe_write() for watch
queues
- Improve __fget_files_rcu() code generation to improve performance
- Only notify writer that pipe resizing has finished after setting
pipe->max_usage otherwise writers are never notified that the pipe
has been resized and hang
- Fix some kernel docs in hfsplus
- s/passs/pass/g in various places
- Fix kernel docs in ntfs
- Fix kcalloc() arguments order reported by gcc 14
- Fix uninitialized value in reiserfs"
* tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits)
reiserfs: fix uninit-value in comp_keys
watch_queue: fix kcalloc() arguments order
ntfs: dir.c: fix kernel-doc function parameter warnings
fs: fix doc comment typo fs tree wide
selftests/overlayfs: verify device and inode numbers in /proc/pid/maps
fs/proc: show correct device and inode numbers in /proc/pid/maps
eventfd: Remove usage of the deprecated ida_simple_xx() API
fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation
fs/hfsplus: wrapper.c: fix kernel-doc warnings
fs: add Jan Kara as reviewer
fs/inode: Make relatime_need_update return bool
pipe: wakeup wr_wait after setting max_usage
file: remove __receive_fd()
file: stop exposing receive_fd_user()
fs: replace f_rcuhead with f_task_work
file: remove pointless wrapper
file: s/close_fd_get_file()/file_close_fd()/g
Improve __fget_files_rcu() code generation (and thus __fget_light())
file: massage cleanup of files that failed to open
fs/pipe: Fix lockdep false-positive in watchqueue pipe_write()
...
|
||
|
Joel Granados
|
9d5b947535 |
fs: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel elements ctl_table struct. Special attention was placed in making sure that an empty directory for fs/verity was created when CONFIG_FS_VERITY_BUILTIN_SIGNATURES is not defined. In this case we use the register sysctl call that expects a size. Signed-off-by: Joel Granados <j.granados@samsung.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
||
Alexander Mikhalitsyn
|
376870aa23
|
fs: fix doc comment typo fs tree wide
Do the replacement: s/simply passs @nop_mnt_idmap/simply pass @nop_mnt_idmap/ in the fs/ tree. Found by chance while working on support for idmapped mounts in fuse. Cc: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: <linux-fsdevel@vger.kernel.org> Cc: <linux-kernel@vger.kernel.org> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/r/20231215130927.136917-1-aleksandr.mikhalitsyn@canonical.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Nhat Pham
|
0a97c01cd2 |
list_lru: allow explicit memcg and NUMA node selection
Patch series "workload-specific and memory pressure-driven zswap writeback", v8. There are currently several issues with zswap writeback: 1. There is only a single global LRU for zswap, making it impossible to perform worload-specific shrinking - an memcg under memory pressure cannot determine which pages in the pool it owns, and often ends up writing pages from other memcgs. This issue has been previously observed in practice and mitigated by simply disabling memcg-initiated shrinking: https://lore.kernel.org/all/20230530232435.3097106-1-nphamcs@gmail.com/T/#u But this solution leaves a lot to be desired, as we still do not have an avenue for an memcg to free up its own memory locked up in the zswap pool. 2. We only shrink the zswap pool when the user-defined limit is hit. This means that if we set the limit too high, cold data that are unlikely to be used again will reside in the pool, wasting precious memory. It is hard to predict how much zswap space will be needed ahead of time, as this depends on the workload (specifically, on factors such as memory access patterns and compressibility of the memory pages). This patch series solves these issues by separating the global zswap LRU into per-memcg and per-NUMA LRUs, and performs workload-specific (i.e memcg- and NUMA-aware) zswap writeback under memory pressure. The new shrinker does not have any parameter that must be tuned by the user, and can be opted in or out on a per-memcg basis. As a proof of concept, we ran the following synthetic benchmark: build the linux kernel in a memory-limited cgroup, and allocate some cold data in tmpfs to see if the shrinker could write them out and improved the overall performance. Depending on the amount of cold data generated, we observe from 14% to 35% reduction in kernel CPU time used in the kernel builds. This patch (of 6): The interface of list_lru is based on the assumption that the list node and the data it represents belong to the same allocated on the correct node/memcg. While this assumption is valid for existing slab objects LRU such as dentries and inodes, it is undocumented, and rather inflexible for certain potential list_lru users (such as the upcoming zswap shrinker and the THP shrinker). It has caused us a lot of issues during our development. This patch changes list_lru interface so that the caller must explicitly specify numa node and memcg when adding and removing objects. The old list_lru_add() and list_lru_del() are renamed to list_lru_add_obj() and list_lru_del_obj(), respectively. It also extends the list_lru API with a new function, list_lru_putback, which undoes a previous list_lru_isolate call. Unlike list_lru_add, it does not increment the LRU node count (as list_lru_isolate does not decrement the node count). list_lru_putback also allows for explicit memcg and NUMA node selection. Link: https://lkml.kernel.org/r/20231130194023.4102148-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20231130194023.4102148-2-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Hao Ge
|
effa1870b2
|
fs/inode: Make relatime_need_update return bool
relatime_need_update should return bool to consistent with the function __atime_needs_update that is caller Signed-off-by: Hao Ge <gehao@kylinos.cn> Link: https://lore.kernel.org/r/20231205064545.332322-1-gehao@kylinos.cn Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Al Viro
|
dbd4540df2 |
kill lock_two_inodes()
There's only one caller left (lock_two_nondirectories()), and it needs less complexity. Fold lock_two_inodes() in there and simplify. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
Matthew Wilcox (Oracle)
|
600f111ef5 |
fs: Rename mapping private members
It is hard to find where mapping->private_lock, mapping->private_list and mapping->private_data are used, due to private_XXX being a relatively common name for variables and structure members in the kernel. To fit with other members of struct address_space, rename them all to have an i_ prefix. Tested with an allmodconfig build. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/20231117215823.2821906-1-willy@infradead.org Acked-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
Christoph Hellwig
|
762321dab9 |
filemap: add a per-mapping stable writes flag
folio_wait_stable waits for writeback to finish before modifying the contents of a folio again, e.g. to support check summing of the data in the block integrity code. Currently this behavior is controlled by the SB_I_STABLE_WRITES flag on the super_block, which means it is uniform for the entire file system. This is wrong for the block device pseudofs which is shared by all block devices, or file systems that can use multiple devices like XFS witht the RT subvolume or btrfs (although btrfs currently reimplements folio_wait_stable anyway). Add a per-address_space AS_STABLE_WRITES flag to control the behavior in a more fine grained way. The existing SB_I_STABLE_WRITES is kept to initialize AS_STABLE_WRITES to the existing default which covers most cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231025141020.192413-2-hch@lst.de Tested-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Linus Torvalds
|
8f6f76a6a2 |
As usual, lots of singleton and doubleton patches all over the tree and
there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- "kdump: use generic functions to simplify crashkernel reservation in
arch", from Baoquan He. This is mainly cleanups and consolidation of
the "crashkernel=" kernel parameter handling.
- After much discussion, David Laight's "minmax: Relax type checks in
min() and max()" is here. Hopefully reduces some typecasting and the
use of min_t() and max_t().
- A group of patches from Oleg Nesterov which clean up and slightly fix
our handling of reads from /proc/PID/task/... and which remove
task_struct.therad_group.
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Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"As usual, lots of singleton and doubleton patches all over the tree
and there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- 'kdump: use generic functions to simplify crashkernel reservation
in arch', from Baoquan He. This is mainly cleanups and
consolidation of the 'crashkernel=' kernel parameter handling
- After much discussion, David Laight's 'minmax: Relax type checks in
min() and max()' is here. Hopefully reduces some typecasting and
the use of min_t() and max_t()
- A group of patches from Oleg Nesterov which clean up and slightly
fix our handling of reads from /proc/PID/task/... and which remove
task_struct.thread_group"
* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
scripts/gdb/vmalloc: disable on no-MMU
scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
.mailmap: add address mapping for Tomeu Vizoso
mailmap: update email address for Claudiu Beznea
tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
.mailmap: map Benjamin Poirier's address
scripts/gdb: add lx_current support for riscv
ocfs2: fix a spelling typo in comment
proc: test ProtectionKey in proc-empty-vm test
proc: fix proc-empty-vm test with vsyscall
fs/proc/base.c: remove unneeded semicolon
do_io_accounting: use sig->stats_lock
do_io_accounting: use __for_each_thread()
ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
ocfs2: fix a typo in a comment
scripts/show_delta: add __main__ judgement before main code
treewide: mark stuff as __ro_after_init
fs: ocfs2: check status values
proc: test /proc/${pid}/statm
compiler.h: move __is_constexpr() to compiler.h
...
|
||
|
Linus Torvalds
|
14ab6d425e |
vfs-6.7.ctime
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZTppYgAKCRCRxhvAZXjc okIHAP9anLz1QDyMLH12ASuHjgBc0Of3jcB6NB97IWGpL4O21gEA46ohaD+vcJuC YkBLU3lXqQ87nfu28ExFAzh10hG2jwM= =m4pB -----END PGP SIGNATURE----- Merge tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs inode time accessor updates from Christian Brauner: "This finishes the conversion of all inode time fields to accessor functions as discussed on list. Changing timestamps manually as we used to do before is error prone. Using accessors function makes this robust. It does not contain the switch of the time fields to discrete 64 bit integers to replace struct timespec and free up space in struct inode. But after this, the switch can be trivially made and the patch should only affect the vfs if we decide to do it" * tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits) fs: rename inode i_atime and i_mtime fields security: convert to new timestamp accessors selinux: convert to new timestamp accessors apparmor: convert to new timestamp accessors sunrpc: convert to new timestamp accessors mm: convert to new timestamp accessors bpf: convert to new timestamp accessors ipc: convert to new timestamp accessors linux: convert to new timestamp accessors zonefs: convert to new timestamp accessors xfs: convert to new timestamp accessors vboxsf: convert to new timestamp accessors ufs: convert to new timestamp accessors udf: convert to new timestamp accessors ubifs: convert to new timestamp accessors tracefs: convert to new timestamp accessors sysv: convert to new timestamp accessors squashfs: convert to new timestamp accessors server: convert to new timestamp accessors client: convert to new timestamp accessors ... |
||
|
Linus Torvalds
|
3b3f874cc1 |
vfs-6.7.misc
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Merge tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual fses.
Features:
- Rename and export helpers that get write access to a mount. They
are used in overlayfs to get write access to the upper mount.
- Print the pretty name of the root device on boot failure. This
helps in scenarios where we would usually only print
"unknown-block(1,2)".
- Add an internal SB_I_NOUMASK flag. This is another part in the
endless POSIX ACL saga in a way.
When POSIX ACLs are enabled via SB_POSIXACL the vfs cannot strip
the umask because if the relevant inode has POSIX ACLs set it might
take the umask from there. But if the inode doesn't have any POSIX
ACLs set then we apply the umask in the filesytem itself. So we end
up with:
(1) no SB_POSIXACL -> strip umask in vfs
(2) SB_POSIXACL -> strip umask in filesystem
The umask semantics associated with SB_POSIXACL allowed filesystems
that don't even support POSIX ACLs at all to raise SB_POSIXACL
purely to avoid umask stripping. That specifically means NFS v4 and
Overlayfs. NFS v4 does it because it delegates this to the server
and Overlayfs because it needs to delegate umask stripping to the
upper filesystem, i.e., the filesystem used as the writable layer.
This went so far that SB_POSIXACL is raised eve on kernels that
don't even have POSIX ACL support at all.
Stop this blatant abuse and add SB_I_NOUMASK which is an internal
superblock flag that filesystems can raise to opt out of umask
handling. That should really only be the two mentioned above. It's
not that we want any filesystems to do this. Ideally we have all
umask handling always in the vfs.
- Make overlayfs use SB_I_NOUMASK too.
- Now that we have SB_I_NOUMASK, stop checking for SB_POSIXACL in
IS_POSIXACL() if the kernel doesn't have support for it. This is a
very old patch but it's only possible to do this now with the wider
cleanup that was done.
- Follow-up work on fake path handling from last cycle. Citing mostly
from Amir:
When overlayfs was first merged, overlayfs files of regular files
and directories, the ones that are installed in file table, had a
"fake" path, namely, f_path is the overlayfs path and f_inode is
the "real" inode on the underlying filesystem.
In v6.5, we took another small step by introducing of the
backing_file container and the file_real_path() helper. This change
allowed vfs and filesystem code to get the "real" path of an
overlayfs backing file. With this change, we were able to make
fsnotify work correctly and report events on the "real" filesystem
objects that were accessed via overlayfs.
This method works fine, but it still leaves the vfs vulnerable to
new code that is not aware of files with fake path. A recent
example is commit
|
||
Alexey Dobriyan
|
68279f9c9f |
treewide: mark stuff as __ro_after_init
__read_mostly predates __ro_after_init. Many variables which are marked __read_mostly should have been __ro_after_init from day 1. Also, mark some stuff as "const" and "__init" while I'm at it. [akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning] [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jeff Layton
|
16a9496523
|
fs: convert core infrastructure to new timestamp accessors
Convert the core vfs code to use the new timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185239.80830-2-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christian Brauner
|
647aa76828
|
Revert "fs: add infrastructure for multigrain timestamps"
This reverts commit
|
||
Amir Goldstein
|
3e15dcf77b
|
fs: rename __mnt_{want,drop}_write*() helpers
Before exporting these helpers to modules, make their names more
meaningful.
The names mnt_{get,put)_write_access*() were chosen, because they rhyme
with the inode {get,put)_write_access() helpers, which have a very close
meaning for the inode object.
Suggested-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230817-anfechtbar-ruhelosigkeit-8c6cca8443fc@brauner/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Message-Id: <20230908132900.2983519-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
||
|
Linus Torvalds
|
511fb5bafe |
v6.6-vfs.super
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Merge tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull superblock updates from Christian Brauner:
"This contains the super rework that was ready for this cycle. The
first part changes the order of how we open block devices and allocate
superblocks, contains various cleanups, simplifications, and a new
mechanism to wait on superblock state changes.
This unblocks work to ultimately limit the number of writers to a
block device. Jan has already scheduled follow-up work that will be
ready for v6.7 and allows us to restrict the number of writers to a
given block device. That series builds on this work right here.
The second part contains filesystem freezing updates.
Overview:
The generic superblock changes are rougly organized as follows
(ignoring additional minor cleanups):
(1) Removal of the bd_super member from struct block_device.
This was a very odd back pointer to struct super_block with
unclear rules. For all relevant places we have other means to get
the same information so just get rid of this.
(2) Simplify rules for superblock cleanup.
Roughly, everything that is allocated during fs_context
initialization and that's stored in fs_context->s_fs_info needs
to be cleaned up by the fs_context->free() implementation before
the superblock allocation function has been called successfully.
After sget_fc() returned fs_context->s_fs_info has been
transferred to sb->s_fs_info at which point sb->kill_sb() if
fully responsible for cleanup. Adhering to these rules means that
cleanup of sb->s_fs_info in fill_super() is to be avoided as it's
brittle and inconsistent.
Cleanup shouldn't be duplicated between sb->put_super() as
sb->put_super() is only called if sb->s_root has been set aka
when the filesystem has been successfully born (SB_BORN). That
complexity should be avoided.
This also means that block devices are to be closed in
sb->kill_sb() instead of sb->put_super(). More details in the
lower section.
(3) Make it possible to lookup or create a superblock before opening
block devices
There's a subtle dependency on (2) as some filesystems did rely
on fill_super() to be called in order to correctly clean up
sb->s_fs_info. All these filesystems have been fixed.
(4) Switch most filesystem to follow the same logic as the generic
mount code now does as outlined in (3).
(5) Use the superblock as the holder of the block device. We can now
easily go back from block device to owning superblock.
(6) Export and extend the generic fs_holder_ops and use them as
holder ops everywhere and remove the filesystem specific holder
ops.
(7) Call from the block layer up into the filesystem layer when the
block device is removed, allowing to shut down the filesystem
without risk of deadlocks.
(8) Get rid of get_super().
We can now easily go back from the block device to owning
superblock and can call up from the block layer into the
filesystem layer when the device is removed. So no need to wade
through all registered superblock to find the owning superblock
anymore"
Link: https://lore.kernel.org/lkml/20230824-prall-intakt-95dbffdee4a0@brauner/
* tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (47 commits)
super: use higher-level helper for {freeze,thaw}
super: wait until we passed kill super
super: wait for nascent superblocks
super: make locking naming consistent
super: use locking helpers
fs: simplify invalidate_inodes
fs: remove get_super
block: call into the file system for ioctl BLKFLSBUF
block: call into the file system for bdev_mark_dead
block: consolidate __invalidate_device and fsync_bdev
block: drop the "busy inodes on changed media" log message
dasd: also call __invalidate_device when setting the device offline
amiflop: don't call fsync_bdev in FDFMTBEG
floppy: call disk_force_media_change when changing the format
block: simplify the disk_force_media_change interface
nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl
xfs use fs_holder_ops for the log and RT devices
xfs: drop s_umount over opening the log and RT devices
ext4: use fs_holder_ops for the log device
ext4: drop s_umount over opening the log device
...
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Linus Torvalds
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615e95831e |
v6.6-vfs.ctime
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Merge tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs timestamp updates from Christian Brauner:
"This adds VFS support for multi-grain timestamps and converts tmpfs,
xfs, ext4, and btrfs to use them. This carries acks from all relevant
filesystems.
The VFS always uses coarse-grained timestamps when updating the ctime
and mtime after a change. This has the benefit of allowing filesystems
to optimize away a lot of metadata updates, down to around 1 per
jiffy, even when a file is under heavy writes.
Unfortunately, this has always been an issue when we're exporting via
NFSv3, which relies on timestamps to validate caches. A lot of changes
can happen in a jiffy, so timestamps aren't sufficient to help the
client decide to invalidate the cache.
Even with NFSv4, a lot of exported filesystems don't properly support
a change attribute and are subject to the same problems with timestamp
granularity. Other applications have similar issues with timestamps
(e.g., backup applications).
If we were to always use fine-grained timestamps, that would improve
the situation, but that becomes rather expensive, as the underlying
filesystem would have to log a lot more metadata updates.
This introduces fine-grained timestamps that are used when they are
actively queried.
This uses the 31st bit of the ctime tv_nsec field to indicate that
something has queried the inode for the mtime or ctime. When this flag
is set, on the next mtime or ctime update, the kernel will fetch a
fine-grained timestamp instead of the usual coarse-grained one.
As POSIX generally mandates that when the mtime changes, the ctime
must also change the kernel always stores normalized ctime values, so
only the first 30 bits of the tv_nsec field are ever used.
Filesytems can opt into this behavior by setting the FS_MGTIME flag in
the fstype. Filesystems that don't set this flag will continue to use
coarse-grained timestamps.
Various preparatory changes, fixes and cleanups are included:
- Fixup all relevant places where POSIX requires updating ctime
together with mtime. This is a wide-range of places and all
maintainers provided necessary Acks.
- Add new accessors for inode->i_ctime directly and change all
callers to rely on them. Plain accesses to inode->i_ctime are now
gone and it is accordingly rename to inode->__i_ctime and commented
as requiring accessors.
- Extend generic_fillattr() to pass in a request mask mirroring in a
sense the statx() uapi. This allows callers to pass in a request
mask to only get a subset of attributes filled in.
- Rework timestamp updates so it's possible to drop the @now
parameter the update_time() inode operation and associated helpers.
- Add inode_update_timestamps() and convert all filesystems to it
removing a bunch of open-coding"
* tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits)
btrfs: convert to multigrain timestamps
ext4: switch to multigrain timestamps
xfs: switch to multigrain timestamps
tmpfs: add support for multigrain timestamps
fs: add infrastructure for multigrain timestamps
fs: drop the timespec64 argument from update_time
xfs: have xfs_vn_update_time gets its own timestamp
fat: make fat_update_time get its own timestamp
fat: remove i_version handling from fat_update_time
ubifs: have ubifs_update_time use inode_update_timestamps
btrfs: have it use inode_update_timestamps
fs: drop the timespec64 arg from generic_update_time
fs: pass the request_mask to generic_fillattr
fs: remove silly warning from current_time
gfs2: fix timestamp handling on quota inodes
fs: rename i_ctime field to __i_ctime
selinux: convert to ctime accessor functions
security: convert to ctime accessor functions
apparmor: convert to ctime accessor functions
sunrpc: convert to ctime accessor functions
...
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Christoph Hellwig
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e127b9bccd |
fs: simplify invalidate_inodes
kill_dirty has always been true for a long time, so hard code it and remove the unused return value. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-18-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Mateusz Guzik
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c8afaa1b0f |
locking: remove spin_lock_prefetch
The only remaining consumer is new_inode, where it showed up in 2001 as
commit c37fa164f793 ("v2.4.9.9 -> v2.4.9.10") in a historical repo [1]
with a changelog which does not mention it.
Since then the line got only touched up to keep compiling.
While it may have been of benefit back in the day, it is guaranteed to
at best not get in the way in the multicore setting -- as the code
performs *a lot* of work between the prefetch and actual lock acquire,
any contention means the cacheline is already invalid by the time the
routine calls spin_lock(). It adds spurious traffic, for short.
On top of it prefetch is notoriously tricky to use for single-threaded
purposes, making it questionable from the get go.
As such, remove it.
I admit upfront I did not see value in benchmarking this change, but I
can do it if that is deemed appropriate.
Removal from new_inode and of the entire thing are in the same patch as
requested by Linus, so whatever weird looks can be directed at that guy.
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/fs/inode.c?id=c37fa164f793735b32aa3f53154ff1a7659e6442 [1]
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jeff Layton
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ffb6cf19e0
|
fs: add infrastructure for multigrain timestamps
The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. What we need is a way to only use fine-grained timestamps when they are being actively queried. POSIX generally mandates that when the the mtime changes, the ctime must also change. The kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Use the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Later patches will convert individual filesystems to use the new infrastructure. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-9-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
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Jeff Layton
|
913e99287b
|
fs: drop the timespec64 argument from update_time
Now that all of the update_time operations are prepared for it, we can drop the timespec64 argument from the update_time operation. Do that and remove it from some associated functions like inode_update_time and inode_needs_update_time. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Jeff Layton
|
541d4c798a |
fs: drop the timespec64 arg from generic_update_time
In future patches we're going to change how the ctime is updated to keep track of when it has been queried. The way that the update_time operation works (and a lot of its callers) make this difficult, since they grab a timestamp early and then pass it down to eventually be copied into the inode. All of the existing update_time callers pass in the result of current_time() in some fashion. Drop the "time" parameter from generic_update_time, and rework it to fetch its own timestamp. This change means that an update_time could fetch a different timestamp than was seen in inode_needs_update_time. update_time is only ever called with one of two flag combinations: Either S_ATIME is set, or S_MTIME|S_CTIME|S_VERSION are set. With this change we now treat the flags argument as an indicator that some value needed to be updated when last checked, rather than an indication to update specific timestamps. Rework the logic for updating the timestamps and put it in a new inode_update_timestamps helper that other update_time routines can use. S_ATIME is as treated as we always have, but if any of the other three are set, then we attempt to update all three. Also, some callers of generic_update_time need to know what timestamps were actually updated. Change it to return an S_* flag mask to indicate that and rework the callers to expect it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-3-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Jeff Layton
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b3030e4f23 |
fs: remove silly warning from current_time
An inode with no superblock? Unpossible! Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-1-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Jeff Layton
|
2276e5ba85 |
fs: convert to ctime accessor functions
In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@kernel.org> Message-Id: <20230705190309.579783-23-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |