writeback: fix calculations in trace_balance_dirty_pages() for cgwb

In the commit dcc25ae76eb7 ("writeback: move global_dirty_limit into
wb_domain") of the cgroup writeback backpressure propagation

writeback: fix calculations in trace_balance_dirty_pages() for cgwb

In the commit dcc25ae76eb7 ("writeback: move global_dirty_limit into
wb_domain") of the cgroup writeback backpressure propagation patchset,
Tejun made some adaptations to trace_balance_dirty_pages() for cgroup
writeback. However, this adaptation was incomplete and Tejun missed
further adaptation in the subsequent patches.

In the cgroup writeback scenario, if sdtc in balance_dirty_pages() is
assigned to mdtc, then upon entering trace_balance_dirty_pages(),
__entry->limit should be assigned based on the dirty_limit of the
corresponding memcg's wb_domain, rather than global_wb_domain.

To address this issue and simplify the implementation, introduce a 'limit'
field in struct dirty_throttle_control to store the hard_limit value
computed in wb_position_ratio() by calling hard_dirty_limit(). This field
will then be used in trace_balance_dirty_pages() to assign the value to
__entry->limit.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: dcc25ae76eb7 ("writeback: move global_dirty_limit into wb_domain")
Signed-off-by: Tang Yizhou <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: "Masami Hiramatsu (Google)" <[email protected]>
Cc: Matthew Wilcow (Oracle) <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

writeback: let trace_balance_dirty_pages() take struct dtc as parameter

Patch series "Fix calculations in trace_balance_dirty_pages() for cgwb", v2.

In my experiment, I found that the output of tra

writeback: let trace_balance_dirty_pages() take struct dtc as parameter

Patch series "Fix calculations in trace_balance_dirty_pages() for cgwb", v2.

In my experiment, I found that the output of trace_balance_dirty_pages()
in the cgroup writeback scenario was strange because
trace_balance_dirty_pages() always uses global_wb_domain.dirty_limit for
related calculations instead of the dirty_limit of the corresponding
memcg's wb_domain.

The basic idea of the fix is to store the hard dirty limit value computed
in wb_position_ratio() into struct dirty_throttle_control and use it for
calculations in trace_balance_dirty_pages().


This patch (of 3):

Currently, trace_balance_dirty_pages() already has 12 parameters. In the
patch #3, I initially attempted to introduce an additional parameter.
However, in include/linux/trace_events.h, bpf_trace_run12() only supports
up to 12 parameters and bpf_trace_run13() does not exist.

To reduce the number of parameters in trace_balance_dirty_pages(), we can
make it accept a pointer to struct dirty_throttle_control as a parameter.
To achieve this, we need to move the definition of struct
dirty_throttle_control from mm/page-writeback.c to
include/linux/writeback.h.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Tang Yizhou <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: "Masami Hiramatsu (Google)" <[email protected]>
Cc: Matthew Wilcow (Oracle) <[email protected]>
Cc: Tang Yizhou <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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fs: fs-writeback: move sysctl to fs/fs-writeback.c

The dirtytime_expire_interval belongs to fs/fs-writeback.c, move it to
fs/fs-writeback.c from /kernel/sysctl.c. And remove the useless extern
varia

fs: fs-writeback: move sysctl to fs/fs-writeback.c

The dirtytime_expire_interval belongs to fs/fs-writeback.c, move it to
fs/fs-writeback.c from /kernel/sysctl.c. And remove the useless extern
variable declaration and the function declaration from
include/linux/writeback.h

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

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writeback: wbc_attach_fdatawrite_inode out of line

This allows exporting this high-level interface only while keeping
wbc_attach_and_unlock_inode private in fs-writeback.c and unexporting
__inode_at

writeback: wbc_attach_fdatawrite_inode out of line

This allows exporting this high-level interface only while keeping
wbc_attach_and_unlock_inode private in fs-writeback.c and unexporting
__inode_attach_wb.

Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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fs/writeback: convert wbc_account_cgroup_owner to take a folio

Most of the callers of wbc_account_cgroup_owner() are converting a folio
to page before calling the function. wbc_account_cgroup_owner(

fs/writeback: convert wbc_account_cgroup_owner to take a folio

Most of the callers of wbc_account_cgroup_owner() are converting a folio
to page before calling the function. wbc_account_cgroup_owner() is
converting the page back to a folio to call mem_cgroup_css_from_folio().

Convert wbc_account_cgroup_owner() to take a folio instead of a page,
and convert all callers to pass a folio directly except f2fs.

Convert the page to folio for all the callers from f2fs as they were the
only callers calling wbc_account_cgroup_owner() with a page. As f2fs is
already in the process of converting to folios, these call sites might
also soon be calling wbc_account_cgroup_owner() with a folio directly in
the future.

No functional changes. Only compile tested.

Signed-off-by: Pankaj Raghav <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: David Sterba <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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mm: shmem: support large folio swap out

Shmem will support large folio allocation [1] [2] to get a better
performance, however, the memory reclaim still splits the precious large
folios when trying

mm: shmem: support large folio swap out

Shmem will support large folio allocation [1] [2] to get a better
performance, however, the memory reclaim still splits the precious large
folios when trying to swap out shmem, which may lead to the memory
fragmentation issue and can not take advantage of the large folio for
shmeme.

Moreover, the swap code already supports for swapping out large folio
without split, hence this patch set supports the large folio swap out for
shmem.

Note the i915_gem_shmem driver still need to be split when swapping, thus
add a new flag 'split_large_folio' for writeback_control to indicate
spliting the large folio.

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/

[[email protected]: shmem_writepage() split folio at EOF before swapout]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: remove the wbc->split_large_folio per Hugh]
Link: https://lkml.kernel.org/r/1236a002daa301b3b9ba73d6c0fab348427cf295.1724833399.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/d80c21abd20e1b0f5ca66b330f074060fb2f082d.1723434324.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Chris Li <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Pankaj Raghav <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

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/[email protected]
Reviewed-by: Josef

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/[email protected]
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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fs: don't flush in-flight wb switches for superblocks without cgroup writeback

When deactivating any type of superblock, it had to wait for the in-flight
wb switches to be completed. wb switches are

fs: don't flush in-flight wb switches for superblocks without cgroup writeback

When deactivating any type of superblock, it had to wait for the in-flight
wb switches to be completed. wb switches are executed in inode_switch_wbs_work_fn()
which needs to acquire the wb_switch_rwsem and races against sync_inodes_sb().
If there are too much dirty data in the superblock, the waiting time may increase
significantly.

For superblocks without cgroup writeback such as tmpfs, they have nothing to
do with the wb swithes, so the flushing can be avoided.

Signed-off-by: Haifeng Xu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jan Kara <[email protected]>
Suggested-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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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 ct

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 <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Co-developed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

writeback: support retrieving per group debug writeback stats of bdi

Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats
of bdi.

Following domain hierarchy is tested:

writeback: support retrieving per group debug writeback stats of bdi

Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats
of bdi.

Following domain hierarchy is tested:
global domain (320G)
/ \
cgroup domain1(10G) cgroup domain2(10G)
| |
bdi wb1 wb2

/* per wb writeback info of bdi is collected */
cat wb_stats
WbCgIno: 1
WbWriteback: 0 kB
WbReclaimable: 0 kB
WbDirtyThresh: 0 kB
WbDirtied: 0 kB
WbWritten: 0 kB
WbWriteBandwidth: 102400 kBps
b_dirty: 0
b_io: 0
b_more_io: 0
b_dirty_time: 0
state: 1

WbCgIno: 4091
WbWriteback: 1792 kB
WbReclaimable: 820512 kB
WbDirtyThresh: 6004692 kB
WbDirtied: 1820448 kB
WbWritten: 999488 kB
WbWriteBandwidth: 169020 kBps
b_dirty: 0
b_io: 0
b_more_io: 1
b_dirty_time: 0
state: 5

WbCgIno: 4131
WbWriteback: 1120 kB
WbReclaimable: 820064 kB
WbDirtyThresh: 6004728 kB
WbDirtied: 1822688 kB
WbWritten: 1002400 kB
WbWriteBandwidth: 153520 kBps
b_dirty: 0
b_io: 0
b_more_io: 1
b_dirty_time: 0
state: 5

[[email protected]: fix build problems]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kemeng Shi <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: David Howells <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Mateusz Guzik <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

writeback: add a writeback iterator

Refactor the code left in write_cache_pages into an iterator that the file
system can call to get the next folio for a writeback operation:

struct folio *folio

writeback: add a writeback iterator

Refactor the code left in write_cache_pages into an iterator that the file
system can call to get the next folio for a writeback operation:

struct folio *folio = NULL;

while ((folio = writeback_iter(mapping, wbc, folio, &error))) {
error = <do per-folio writeback>;
}

The twist here is that the error value is passed by reference, so that the
iterator can restore it when breaking out of the loop.

Handling of the magic AOP_WRITEPAGE_ACTIVATE value stays outside the
iterator and needs is just kept in the write_cache_pages legacy wrapper.
in preparation for eventually killing it off.

Heavily based on a for_each* based iterator from Matthew Wilcox.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Brian Foster <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: David Howells <[email protected]>
Cc: "Matthew Wilcox (Oracle)" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

writeback: factor writeback_get_batch() out of write_cache_pages()

This simple helper will be the basis of the writeback iterator. To make
this work, we need to remember the current index and end p

writeback: factor writeback_get_batch() out of write_cache_pages()

This simple helper will be the basis of the writeback iterator. To make
this work, we need to remember the current index and end positions in
writeback_control.

[[email protected]: heavily rebased, add helpers to get the tag and end index, don't keep the end index in struct writeback_control]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Brian Foster <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Acked-by: Dave Chinner <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

writeback: remove a duplicate prototype for tag_pages_for_writeback

[[email protected]: split from a larger patch]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christo

writeback: remove a duplicate prototype for tag_pages_for_writeback

[[email protected]: split from a larger patch]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Brian Foster <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Acked-by: Dave Chinner <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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netfs: Move pinning-for-writeback from fscache to netfs

Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have

netfs: Move pinning-for-writeback from fscache to netfs

Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have dirty
pages on the netfs inode in the pagecache such that VM writeback will be
able to reach it.

Whilst we're at it, switch the parameters of netfs_unpin_writeback() to
match ->write_inode() so that it can be used for that directly.

Note that this mechanism could be more generically useful than that for
network filesystems. Quite often they have to keep around other resources
(e.g. authentication tokens or network connections) until the writeback is
complete.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]

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vfs: remove a redundant might_sleep in wait_on_inode

wait_on_bit already does it.

Signed-off-by: Mateusz Guzik <[email protected]>
Link: https://lore.kernel.org/r/20231104221117.2584708-1-mjguzik@g

vfs: remove a redundant might_sleep in wait_on_inode

wait_on_bit already does it.

Signed-off-by: Mateusz Guzik <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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mm: remove folio_account_redirty

Fold folio_account_redirty into folio_redirty_for_writepage now
that all other users except for the also unused account_page_redirty
wrapper are gone.

Reviewed-by:

mm: remove folio_account_redirty

Fold folio_account_redirty into folio_redirty_for_writepage now
that all other users except for the also unused account_page_redirty
wrapper are gone.

Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

show more ...

btrfs, mm: remove the punt_to_cgroup field in struct writeback_control

punt_to_cgroup is only used by extent_write_locked_range, but that
function also directly controls the bio flags for the actual

btrfs, mm: remove the punt_to_cgroup field in struct writeback_control

punt_to_cgroup is only used by extent_write_locked_range, but that
function also directly controls the bio flags for the actual submission.
Remove th punt_to_cgroup field, and just set REQ_CGROUP_PUNT directly
in extent_write_locked_range.

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: David Sterba <[email protected]>

show more ...

fs: convert writepage_t callback to pass a folio

Patch series "Convert writepage_t to use a folio".

More folioisation. I split out the mpage work from everything else
because it completely dominat

fs: convert writepage_t callback to pass a folio

Patch series "Convert writepage_t to use a folio".

More folioisation. I split out the mpage work from everything else
because it completely dominated the patch, but some implementations I just
converted outright.


This patch (of 2):

We always write back an entire folio, but that's currently passed as the
head page. Convert all filesystems that use write_cache_pages() to expect
a folio instead of a page.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/fs: convert inode_attach_wb() to take a folio

Patch series "Writeback folio conversions".

Remove more calls to compound_head() by passing folios around instead of
pages.


This patch (of 2):

Th

mm/fs: convert inode_attach_wb() to take a folio

Patch series "Writeback folio conversions".

Remove more calls to compound_head() by passing folios around instead of
pages.


This patch (of 2):

The only caller of inode_attach_wb() which doesn't pass NULL already has a
folio, so convert the whole call-chain to take folios.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: remove generic_writepages

Now that all external callers are gone, just fold it into do_writepages.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph He

mm: remove generic_writepages

Now that all external callers are gone, just fold it into do_writepages.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Joseph Qi <[email protected]>
Cc: Konstantin Komarov <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

writeback: remove unused macro DIRTY_FULL_SCOPE

It's introduced but never used. Remove it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <lin

writeback: remove unused macro DIRTY_FULL_SCOPE

It's introduced but never used. Remove it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Acked-by: Jens Axboe <[email protected]>
Cc: Bart Van Assche <[email protected]>
Cc: David Howells <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: zhanglianjie <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: Add balance_dirty_pages_ratelimited_flags() function

This adds the helper function balance_dirty_pages_ratelimited_flags().
It adds the parameter flags to balance_dirty_pages_ratelimited().
The

mm: Add balance_dirty_pages_ratelimited_flags() function

This adds the helper function balance_dirty_pages_ratelimited_flags().
It adds the parameter flags to balance_dirty_pages_ratelimited().
The flags parameter is passed to balance_dirty_pages(). For async
buffered writes the flag value will be BDP_ASYNC.

If balance_dirty_pages() gets called for async buffered write, we don't
want to wait. Instead we need to indicate to the caller that throttling
is needed so that it can stop writing and offload the rest of the write
to a context that can block.

The new helper function is also used by balance_dirty_pages_ratelimited().

Signed-off-by: Jan Kara <[email protected]>
Signed-off-by: Stefan Roesch <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[axboe: fix kerneltest bot 'ret' issue]
Signed-off-by: Jens Axboe <[email protected]>

show more ...

mm: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for block
layer request flags.

Cc: Andrew Morton <[email protected]>
Cc: Christoph Hellwig <hch@l

mm: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for block
layer request flags.

Cc: Andrew Morton <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Stefan Roesch <[email protected]>
Cc: NeilBrown <[email protected]>
Signed-off-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

show more ...

mm: submit multipage write for SWP_FS_OPS swap-space

swap_writepage() is given one page at a time, but may be called repeatedly
in succession.

For block-device swapspace, the blk_plug functionality

mm: submit multipage write for SWP_FS_OPS swap-space

swap_writepage() is given one page at a time, but may be called repeatedly
in succession.

For block-device swapspace, the blk_plug functionality allows the multiple
pages to be combined together at lower layers. That cannot be used for
SWP_FS_OPS as blk_plug may not exist - it is only active when
CONFIG_BLOCK=y. Consequently all swap reads over NFS are single page
reads.

With this patch we pass a pointer-to-pointer via the wbc. swap_writepage
can store state between calls - much like the pointer passed explicitly to
swap_readpage. After calling swap_writepage() some number of times, the
state will be passed to swap_write_unplug() which can submit the combined
request.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: NeilBrown <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Tested-by: David Howells <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Miaohe Lin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm: move page-writeback sysctls to their own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance

mm: move page-writeback sysctls to their own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong. The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we just
care about the core logic.

So move the page-writeback sysctls to its own file.

[[email protected]: coding-style cleanups]

[email protected]: fix CONFIG_SYSCTL=n warnings]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: zhanglianjie <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Iurii Zaikin <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

show more ...