In order to switch fuse over to using iomap for buffered writes we need
to be able to have the struct file for the original write, in case we
have to read in the page to make it uptodate. Handle this by using the
existing private field in the iomap_iter, and add the argument to
iomap_file_buffered_write. This will allow us to pass the file in
through the iomap buffered write path, and is flexible for any other
file systems needs.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/7f55c7c32275004ba00cddf862d970e6e633f750.1724755651.git.josef@toxicpanda.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Instead of assuming that PAGE_SHIFT is always higher than the blocklog,
make the calculation generic so that page cache count can be calculated
correctly for LBS.
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-10-kernel@pankajraghav.com
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
For block size larger than page size, the unit of efficient IO is
the block size, not the page size. Leaving stat() to report
PAGE_SIZE as the block size causes test programs like fsx to issue
illegal ranges for operations that require block size alignment
(e.g. fallocate() insert range). Hence update the preferred IO size
to reflect the block size in this case.
This change is based on a patch originally from Dave Chinner.[1]
[1] https://lwn.net/ml/linux-fsdevel/20181107063127.3902-16-david@fromorbit.com/
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240822135018.1931258-9-kernel@pankajraghav.com
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pankaj Raghav reported that when filesystem block size is larger
than page size, the xattr code can use kmalloc() for high order
allocations. This triggers a useless warning in the allocator as it
is a __GFP_NOFAIL allocation here:
static inline
struct page *rmqueue(struct zone *preferred_zone,
struct zone *zone, unsigned int order,
gfp_t gfp_flags, unsigned int alloc_flags,
int migratetype)
{
struct page *page;
/*
* We most definitely don't want callers attempting to
* allocate greater than order-1 page units with __GFP_NOFAIL.
*/
>>>> WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
...
Fix this by changing all these call sites to use kvmalloc(), which
will strip the NOFAIL from the kmalloc attempt and if that fails
will do a __GFP_NOFAIL vmalloc().
This is not an issue that productions systems will see as
filesystems with block size > page size cannot be mounted by the
kernel; Pankaj is developing this functionality right now.
Reported-by: Pankaj Raghav <kernel@pankajraghav.com>
Fixes: f078d4ea82 ("xfs: convert kmem_alloc() to kmalloc()")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-8-kernel@pankajraghav.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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>
* Enable FITRIM on the realtime device.
* Introduce byte-based grant head log reservation tracking instead of
physical log location tracking.
This allows grant head to track a full 64 bit bytes space and hence
overcome the limit of 4GB indexing that has been present until now.
* Fixes
- xfs_flush_unmap_range() and xfs_prepare_shift() should consider RT extents
in the flush unmap range.
- Implement bounds check when traversing log operations during log replay.
- Prevent out of bounds access when traversing a directory data block.
- Prevent incorrect ENOSPC when concurrently performing file creation and
file writes.
- Fix rtalloc rotoring when delalloc is in use
* Cleanups
- Clean up I/O path inode locking helpers and the page fault handler.
- xfs: hoist inode operations to libxfs in anticipation of the metadata
inode directory feature, which maintains a directory tree of metadata
inodes. This will be necessary for further enhancements to the realtime
feature, subvolume support.
- Clean up some warts in the extent freeing log intent code.
- Clean up the refcount and rmap intent code before adding support for
realtime devices.
- Provide the correct email address for sysfs ABI documentation.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.11-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
"Major changes in this release are limited to enabling FITRIM on
realtime devices and Byte-based grant head log reservation tracking.
The remaining changes are limited to fixes and cleanups included in
this pull request.
Core:
- Enable FITRIM on the realtime device
- Introduce byte-based grant head log reservation tracking instead of
physical log location tracking.
This allows grant head to track a full 64 bit bytes space and hence
overcome the limit of 4GB indexing that has been present until now
Fixes:
- xfs_flush_unmap_range() and xfs_prepare_shift() should consider RT
extents in the flush unmap range
- Implement bounds check when traversing log operations during log
replay
- Prevent out of bounds access when traversing a directory data block
- Prevent incorrect ENOSPC when concurrently performing file creation
and file writes
- Fix rtalloc rotoring when delalloc is in use
Cleanups:
- Clean up I/O path inode locking helpers and the page fault handler
- xfs: hoist inode operations to libxfs in anticipation of the
metadata inode directory feature, which maintains a directory tree
of metadata inodes. This will be necessary for further enhancements
to the realtime feature, subvolume support
- Clean up some warts in the extent freeing log intent code
- Clean up the refcount and rmap intent code before adding support
for realtime devices
- Provide the correct email address for sysfs ABI documentation"
* tag 'xfs-6.11-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (80 commits)
xfs: fix rtalloc rotoring when delalloc is in use
xfs: get rid of xfs_ag_resv_rmapbt_alloc
xfs: skip flushing log items during push
xfs: grant heads track byte counts, not LSNs
xfs: pass the full grant head to accounting functions
xfs: track log space pinned by the AIL
xfs: collapse xlog_state_set_callback in caller
xfs: l_last_sync_lsn is really AIL state
xfs: ensure log tail is always up to date
xfs: background AIL push should target physical space
xfs: AIL doesn't need manual pushing
xfs: move and rename xfs_trans_committed_bulk
xfs: fix the contact address for the sysfs ABI documentation
xfs: Avoid races with cnt_btree lastrec updates
xfs: move xfs_refcount_update_defer_add to xfs_refcount_item.c
xfs: simplify usage of the rcur local variable in xfs_refcount_finish_one
xfs: don't bother calling xfs_refcount_finish_one_cleanup in xfs_refcount_finish_one
xfs: reuse xfs_refcount_update_cancel_item
xfs: add a ci_entry helper
xfs: remove xfs_trans_set_refcount_flags
...
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Merge tag 'vfs-6.11.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull iomap updates from Christian Brauner:
"This contains some minor work for the iomap subsystem:
- Add documentation on the design of iomap and how to port to it
- Optimize iomap_read_folio()
- Bring back the change to iomap_write_end() to no increase i_size.
This is accompanied by a change to xfs to reserve blocks for
truncating large realtime inodes to avoid exposing stale data when
iomap_write_end() stops increasing i_size"
* tag 'vfs-6.11.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
iomap: don't increase i_size in iomap_write_end()
xfs: reserve blocks for truncating large realtime inode
Documentation: the design of iomap and how to port
iomap: Optimize iomap_read_folio
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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
If we're trying to allocate real space for a delalloc reservation at
offset 0, we should use the rotor to spread files across the rt volume.
Switch the rtalloc to use the XFS_ALLOC_INITIAL_USER_DATA flag that
is set for any write at startoff to make it match the behavior for
the main data device.
Based on a patch from Darrick J. Wong.
Fixes: 6a94b1acda ("xfs: reinstate delalloc for RT inodes (if sb_rextsize == 1)")
Reported-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The pag in xfs_ag_resv_rmapbt_alloc() is already held when the struct
xfs_btree_cur is initialized in xfs_rmapbt_init_cursor(), so there is no
need to get pag again.
On the other hand, in xfs_rmapbt_free_block(), the similar function
xfs_ag_resv_rmapbt_free() was removed in commit 92a005448f ("xfs: get
rid of unnecessary xfs_perag_{get,put} pairs"), xfs_ag_resv_rmapbt_alloc()
was left because scrub used it, but now scrub has removed it. Therefore,
we could get rid of xfs_ag_resv_rmapbt_alloc() just like the rmap free
block, make the code cleaner.
Signed-off-by: Long Li <leo.lilong@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The AIL pushing code spends a huge amount of time skipping over
items that are already marked as flushing. It is not uncommon to
see hundreds of thousands of items skipped every second due to inode
clustering marking all the inodes in a cluster as flushing when the
first one is flushed.
However, to discover an item is already flushing and should be
skipped we have to call the iop_push() method for it to try to flush
the item. For inodes (where this matters most), we have to first
check that inode is flushable first.
We can optimise this overhead away by tracking whether the log item
is flushing internally. This allows xfsaild_push() to check the log
item directly for flushing state and immediately skip the log item.
Whilst this doesn't remove the CPU cache misses for loading the log
item, it does avoid the overhead of an indirect function call
and the cache misses involved in accessing inode and
backing cluster buffer structures to determine flushing state. When
trying to flush hundreds of thousands of inodes each second, this
CPU overhead saving adds up quickly.
It's so noticeable that the biggest issue with pushing on the AIL on
fast storage becomes the 10ms back-off wait when we hit enough
pinned buffers to break out of the push loop but not enough for the
AIL pushing to be considered stuck. This limits the xfsaild to about
70% total CPU usage, and on fast storage this isn't enough to keep
the storage 100% busy.
The xfsaild will block on IO submission on slow storage and so is
self throttling - it does not need a backoff in the case where we
are really just breaking out of the walk to submit the IO we have
gathered.
Further with no backoff we don't need to gather huge delwri lists to
mitigate the impact of backoffs, so we can submit IO more frequently
and reduce the time log items spend in flushing state by breaking
out of the item push loop once we've gathered enough IO to batch
submission effectively.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The grant heads in the log track the space reserved in the log for
running transactions. They do this by tracking how far ahead of the
tail that the reservation has reached, and the units for doing this
are {cycle,bytes} for the reserve head rather than {cycle,blocks}
which are normal used by LSNs.
This is annoyingly complex because we have to split, crack and
combined these tuples for any calculation we do to determine log
space and targets. This is computationally expensive as well as
difficult to do atomically and locklessly, as well as limiting the
size of the log to 2^32 bytes.
Really, though, all the grant heads are tracking is how much space
is currently available for use in the log. We can track this as a
simply byte count - we just don't care what the actual physical
location in the log the head and tail are at, just how much space we
have remaining before the head and tail overlap.
So, convert the grant heads to track the byte reservations that are
active rather than the current (cycle, offset) tuples. This means an
empty log has zero bytes consumed, and a full log is when the
reservations reach the size of the log minus the space consumed by
the AIL.
This greatly simplifies the accounting and checks for whether there
is space available. We no longer need to crack or combine LSNs to
determine how much space the log has left, nor do we need to look at
the head or tail of the log to determine how close to full we are.
There is, however, a complexity that needs to be handled. We know
how much space is being tracked in the AIL now via log->l_tail_space
and the log tickets track active reservations and return the unused
portions to the grant heads when ungranted. Unfortunately, we don't
track the used portion of the grant, so when we transfer log items
from the CIL to the AIL, the space accounted to the grant heads is
transferred to the log tail space. Hence when we move the AIL head
forwards on item insert, we have to remove that space from the grant
heads.
We also remove the xlog_verify_grant_tail() debug function as it is
no longer useful. The check it performs has been racy since delayed
logging was introduced, but now it is clearly only detecting false
positives so remove it.
The result of this substantially simpler accounting algorithm is an
increase in sustained transaction rate from ~1.3 million
transactions/s to ~1.9 million transactions/s with no increase in
CPU usage. We also remove the 32 bit space limitation on the grant
heads, which will allow us to increase the journal size beyond 2GB
in future.
Note that this renames the sysfs files exposing the log grant space
now that the values are exported in bytes. This allows xfstests
to auto-detect the old or new ABI.
[hch: move xlog_grant_sub_space out of line,
update the xlog_grant_{add,sub}_space prototypes,
rename the sysfs files to allow auto-detection in xfstests]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Because we are going to need them soon. API change only, no logic
changes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Currently we track space used in the log by grant heads.
These store the reserved space as a physical log location and
combine both space reserved for future use with space already used in
the log in a single variable. The amount of space consumed in the
log is then calculated as the distance between the log tail and
the grant head.
The problem with tracking the grant head as a physical location
comes from the fact that it tracks both log cycle count and offset
into the log in bytes in a single 64 bit variable. because the cycle
count on disk is a 32 bit number, this also limits the offset into
the log to 32 bits. ANd because that is in bytes, we are limited to
being able to track only 2GB of log space in the grant head.
Hence to support larger physical logs, we need to track used space
differently in the grant head. We no longer use the grant head for
guiding AIL pushing, so the only thing it is now used for is
determining if we've run out of reservation space via the
calculation in xlog_space_left().
What we really need to do is move the grant heads away from tracking
physical space in the log. The issue here is that space consumed in
the log is not directly tracked by the current mechanism - the
space consumed in the log by grant head reservations gets returned
to the free pool by the tail of the log moving forward. i.e. the
space isn't directly tracked or calculated, but the used grant space
gets "freed" as the physical limits of the log are updated without
actually needing to update the grant heads.
Hence to move away from implicit, zero-update log space tracking we
need to explicitly track the amount of physical space the log
actually consumes separately to the in-memory reservations for
operations that will be committed to the journal. Luckily, we
already track the information we need to calculate this in the AIL
itself.
That is, the space currently consumed by the journal is the maximum
LSN that the AIL has seen minus the current log tail. As we update
both of these items dynamically as the head and tail of the log
moves, we always know exactly how much space the journal consumes.
This means that we also know exactly how much space the currently
active reservations require, and exactly how much free space we have
remaining for new reservations to be made. Most importantly, we know
what these spaces are indepedently of the physical locations of
the head and tail of the log.
Hence by separating out the physical space consumed by the journal,
we can now track reservations in the grant heads purely as a byte
count, and the log can be considered full when the tail space +
reservation space exceeds the size of the log. This means we can use
the full 64 bits of grant head space for reservation space,
completely removing the 32 bit byte count limitation on log size
that they impose.
Hence the first step in this conversion is to track and update the
"log tail space" every time the AIL tail or maximum seen LSN
changes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The function is called from a single place, and it isn't just
setting the iclog state to XLOG_STATE_CALLBACK - it can mark iclogs
clean, which moves them to states after CALLBACK. Hence the function
is now badly named, and should just be folded into the caller where
the iclog completion logic makes a whole lot more sense.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The current implementation of xlog_assign_tail_lsn() assumes that
when the AIL is empty, the log tail matches the LSN of the last
written commit record. This is recorded in xlog_state_set_callback()
as log->l_last_sync_lsn when the iclog state changes to
XLOG_STATE_CALLBACK. This change is then immediately followed by
running the callbacks on the iclog which then insert the log items
into the AIL at the "commit lsn" of that checkpoint.
The AIL tracks log items via the start record LSN of the checkpoint,
not the commit record LSN. This is because we can pipeline multiple
checkpoints, and so the start record of checkpoint N+1 can be
written before the commit record of checkpoint N. i.e:
start N commit N
+-------------+------------+----------------+
start N+1 commit N+1
The tail of the log cannot be moved to the LSN of commit N when all
the items of that checkpoint are written back, because then the
start record for N+1 is no longer in the active portion of the log
and recovery will fail/corrupt the filesystem.
Hence when all the log items in checkpoint N are written back, the
tail of the log most now only move as far forwards as the start LSN
of checkpoint N+1.
Hence we cannot use the maximum start record LSN the AIL sees as a
replacement the pointer to the current head of the on-disk log
records. However, we currently only use the l_last_sync_lsn when the
AIL is empty - when there is no start LSN remaining, the tail of the
log moves to the LSN of the last commit record as this is where
recovery needs to start searching for recoverable records. THe next
checkpoint will have a start record LSN that is higher than
l_last_sync_lsn, and so everything still works correctly when new
checkpoints are written to an otherwise empty log.
l_last_sync_lsn is an atomic variable because it is currently
updated when an iclog with callbacks attached moves to the CALLBACK
state. While we hold the icloglock at this point, we don't hold the
AIL lock. When we assign the log tail, we hold the AIL lock, not the
icloglock because we have to look up the AIL. Hence it is an atomic
variable so it's not bound to a specific lock context.
However, the iclog callbacks are only used for CIL checkpoints. We
don't use callbacks with unmount record writes, so the
l_last_sync_lsn variable only gets updated when we are processing
CIL checkpoint callbacks. And those callbacks run under AIL lock
contexts, not icloglock context. The CIL checkpoint already knows
what the LSN of the iclog the commit record was written to (obtained
when written into the iclog before submission) and so we can update
the l_last_sync_lsn under the AIL lock in this callback. No other
iclog callbacks will run until the currently executing one
completes, and hence we can update the l_last_sync_lsn under the AIL
lock safely.
This means l_last_sync_lsn can move to the AIL as the "ail_head_lsn"
and it can be used to replace the atomic l_last_sync_lsn in the
iclog code. This makes tracking the log tail belong entirely to the
AIL, rather than being smeared across log, iclog and AIL state and
locking.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Whenever we write an iclog, we call xlog_assign_tail_lsn() to update
the current tail before we write it into the iclog header. This
means we have to take the AIL lock on every iclog write just to
check if the tail of the log has moved.
This doesn't avoid races with log tail updates - the log tail could
move immediately after we assign the tail to the iclog header and
hence by the time the iclog reaches stable storage the tail LSN has
moved forward in memory. Hence the log tail LSN in the iclog header
is really just a point in time snapshot of the current state of the
AIL.
With this in mind, if we simply update the in memory log->l_tail_lsn
every time it changes in the AIL, there is no need to update the in
memory value when we are writing it into an iclog - it will already
be up-to-date in memory and checking the AIL again will not change
this. Hence xlog_state_release_iclog() does not need to check the
AIL to update the tail lsn and can just sample it directly without
needing to take the AIL lock.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Currently the AIL attempts to keep 25% of the "log space" free,
where the current used space is tracked by the reserve grant head.
That is, it tracks both physical space used plus the amount reserved
by transactions in progress.
When we start tail pushing, we are trying to make space for new
reservations by writing back older metadata and the log is generally
physically full of dirty metadata, and reservations for modifications
in flight take up whatever space the AIL can physically free up.
Hence we don't really need to take into account the reservation
space that has been used - we just need to keep the log tail moving
as fast as we can to free up space for more reservations to be made.
We know exactly how much physical space the journal is consuming in
the AIL (i.e. max LSN - min LSN) so we can base push thresholds
directly on this state rather than have to look at grant head
reservations to determine how much to physically push out of the
log.
This also allows code that needs to know if log items in the current
transaction need to be pushed or re-logged to simply sample the
current target - they don't need to calculate the current target
themselves. This avoids the need for any locking when doing such
checks.
Further, moving to a physical target means we don't need "push all
until empty semantics" like were introduced in the previous patch.
We can now test and clear the "push all" as a one-shot command to
set the target to the current head of the AIL. This allows the
xfsaild to maximise the use of log space right up to the point where
conditions indicate that the xfsaild is not keeping up with load and
it needs to work harder, and as soon as those constraints go away
(i.e. external code no longer needs everything pushed) the xfsaild
will return to maintaining the normal 25% free space thresholds.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
We have a mechanism that checks the amount of log space remaining
available every time we make a transaction reservation. If the
amount of space is below a threshold (25% free) we push on the AIL
to tell it to do more work. To do this, we end up calculating the
LSN that the AIL needs to push to on every reservation and updating
the push target for the AIL with that new target LSN.
This is silly and expensive. The AIL is perfectly capable of
calculating the push target itself, and it will always be running
when the AIL contains objects.
What the target does is determine if the AIL needs to do
any work before it goes back to sleep. If we haven't run out of
reservation space or memory (or some other push all trigger), it
will simply go back to sleep for a while if there is more than 25%
of the journal space free without doing anything.
If there are items in the AIL at a lower LSN than the target, it
will try to push up to the target or to the point of getting stuck
before going back to sleep and trying again soon after.`
Hence we can modify the AIL to calculate it's own 25% push target
before it starts a push using the same reserve grant head based
calculation as is currently used, and remove all the places where we
ask the AIL to push to a new 25% free target. We can also drop the
minimum free space size of 256BBs from the calculation because the
25% of a minimum sized log is *always going to be larger than
256BBs.
This does still require a manual push in certain circumstances.
These circumstances arise when the AIL is not full, but the
reservation grants consume the entire of the free space in the log.
In this case, we still need to push on the AIL to free up space, so
when we hit this condition (i.e. reservation going to sleep to wait
on log space) we do a single push to tell the AIL it should empty
itself. This will keep the AIL moving as new reservations come in
and want more space, rather than keep queuing them and having to
push the AIL repeatedly.
The reason for using the "push all" when grant space runs out is
that we can run out of grant space when there is more than 25% of
the log free. Small logs are notorious for this, and we have a hack
in the log callback code (xlog_state_set_callback()) where we push
the AIL because the *head* moved) to ensure that we kick the AIL
when we consume space in it because that can push us over the "less
than 25% available" available that starts tail pushing back up
again.
Hence when we run out of grant space and are going to sleep, we have
to consider that the grant space may be consuming almost all the log
space and there is almost nothing in the AIL. In this situation, the
AIL pins the tail and moving the tail forwards is the only way the
grant space will come available, so we have to force the AIL to push
everything to guarantee grant space will eventually be returned.
Hence triggering a "push all" just before sleeping removes all the
nasty corner cases we have in other parts of the code that work
around the "we didn't ask the AIL to push enough to free grant
space" condition that leads to log space hangs...
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Ever since the CIL and delayed logging was introduced,
xfs_trans_committed_bulk() has been a purely CIL checkpoint
completion function and not a transaction commit completion
function. Now that we are adding log specific updates to this
function, it really does not have anything to do with the
transaction subsystem - it is really log and log item level
functionality.
This should be part of the CIL code as it is the callback
that moves log items from the CIL checkpoint to the AIL. Move it
and rename it to xlog_cil_ail_insert().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
A concurrent file creation and little writing could unexpectedly return
-ENOSPC error since there is a race window that the allocator could get
the wrong agf->agf_longest.
Write file process steps:
1) Find the entry that best meets the conditions, then calculate the start
address and length of the remaining part of the entry after allocation.
2) Delete this entry and update the -current- agf->agf_longest.
3) Insert the remaining unused parts of this entry based on the
calculations in 1), and update the agf->agf_longest again if necessary.
Create file process steps:
1) Check whether there are free inodes in the inode chunk.
2) If there is no free inode, check whether there has space for creating
inode chunks, perform the no-lock judgment first.
3) If the judgment succeeds, the judgment is performed again with agf lock
held. Otherwire, an error is returned directly.
If the write process is in step 2) but not go to 3) yet, the create file
process goes to 2) at this time, it may be mistaken for no space,
resulting in the file system still has space but the file creation fails.
We have sent two different commits to the community in order to fix this
problem[1][2]. Unfortunately, both solutions have flaws. In [2], I
discussed with Dave and Darrick, realized that a better solution to this
problem requires the "last cnt record tracking" to be ripped out of the
generic btree code. And surprisingly, Dave directly provided his fix code.
This patch includes appropriate modifications based on his tmp-code to
address this issue.
The entire fix can be roughly divided into two parts:
1) Delete the code related to lastrec-update in the generic btree code.
2) Place the process of updating longest freespace with cntbt separately
to the end of the cntbt modifications. Move the cursor to the rightmost
firstly, and update the longest free extent based on the record.
Note that we can not update the longest with xfs_alloc_get_rec() after
find the longest record, as xfs_verify_agbno() may not pass because
pag->block_count is updated on the outside. Therefore, use
xfs_btree_get_rec() as a replacement.
[1] https://lore.kernel.org/all/20240419061848.1032366-2-yebin10@huawei.com
[2] https://lore.kernel.org/all/20240604071121.3981686-1-wozizhi@huawei.com
Reported by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Move the code that adds the incore xfs_refcount_update_item deferred
work data to a transaction live with the CUI log item code. This means
that the refcount code no longer has to know about the inner workings of
the CUI log items.
As a consequence, we can get rid of the _{get,put}_group helpers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Only update rcur when we know the final *pcur value.
Inspired-by: Christoph Hellwig <hch@lst.de>
[djwong: don't leave the caller with a dangling ref]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In xfs_refcount_finish_one we know the cursor is non-zero when calling
xfs_refcount_finish_one_cleanup and we pass a 0 error variable. This
means xfs_refcount_finish_one_cleanup is just doing a
xfs_btree_del_cursor.
Open code that and move xfs_refcount_finish_one_cleanup to
fs/xfs/xfs_refcount_item.c.
Inspired-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reuse xfs_refcount_update_cancel_item to put the AG/RTG and free the
item in a few places that currently open code the logic.
Inspired-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add a helper to translate from the item list head to the
refcount_intent_item structure and use it so shorten assignments and
avoid the need for extra local variables.
Inspired-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Pass the incore refcount intent structure to the tracepoints instead of
open-coding the argument passing.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Prepare the rest of refcount btree tracepoints for use with realtime
reflink by making them take the btree cursor object as a parameter.
This will save us a lot of trouble later on.
Remove the xfs_refcount_recover_extent tracepoint since it's already
covered by other refcount tracepoints.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The only user of the "ag" tracepoint event classes is the refcount
btree, so rename them to make that obvious and make them take the btree
cursor to simplify the arguments. This will save us a lot of trouble
later on.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Convert all the refcount tracepoints to use the btree error tracepoint
class.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the code that adds the incore xfs_rmap_update_item deferred work
data to a transaction to live with the RUI log item code. This means
that the rmap code no longer has to know about the inner workings of the
RUI log items.
As a consequence, we can get rid of the _{get,put}_group helpers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Only update rcur when we know the final *pcur value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: don't leave the caller with a dangling ref]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
In xfs_rmap_finish_one we known the cursor is non-zero when calling
xfs_rmap_finish_one_cleanup and we pass a 0 error variable. This means
xfs_rmap_finish_one_cleanup is just doing a xfs_btree_del_cursor.
Open code that and move xfs_rmap_finish_one_cleanup to
fs/xfs/xfs_rmap_item.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: minor porting changes]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reuse xfs_rmap_update_cancel_item to put the AG/RTG and free the item in
a few places that currently open code the logic.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Add a helper to translate from the item list head to the
rmap_intent_item structure and use it so shorten assignments
and avoid the need for extra local variables.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Pass the incore rmap structure to the tracepoints instead of open-coding
the argument passing.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Prepare the rmap btree tracepoints for use with realtime rmap btrees by
making them take the btree cursor object as a parameter. This will save
us a lot of trouble later on.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a new tracepoint class for btree-related errors, then convert all
the rmap tracepoints to use it. Also fix the one tracepoint that was
abusing the old class by making it a separate tracepoint.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the code that adds the incore xfs_extent_free_item deferred work
data to a transaction to live with the EFI log item code. This means
that the allocator code no longer has to know about the inner workings
of the EFI log items.
As a consequence, we can get rid of the _{get,put}_group helpers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_free_extent_later can handle the extra AGFL special casing with
very little extra logic.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The bno/len verification is already done by the calls to
xfs_verify_rtbext / xfs_verify_fsbext, and reporting a corruption error
seem like the better handling than tripping an assert anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Factor out a helper to add an extent to and EFD instead of duplicating
the logic in two places.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reuse xfs_extent_free_cancel_item to put the AG/RTG and free the item in
a few places that currently open code the logic.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Add a helper to translate from the item list head to the
xfs_extent_free_item structure and use it so shorten assignments
and avoid the need for extra local variables.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
All callers of xfs_perag_intent_get have a fsbno and need boilerplate
code to turn that into an agno. Just pass the fsbno to
xfs_perag_intent_get and look up the agno there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Convert the boolean to skip discard on free into a proper flags field so
that we can add more flags in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Pass the incore EFI structure to the tracepoints instead of open-coding
the argument passing. This cleans up the call sites a bit.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
