<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/f2fs/segment.c, branch v5.17</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux</title>
<updated>2022-01-23T04:20:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-01-23T04:20:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3689f9f8b0c52dfd8f5995e4b58917f8f3ac3ee3'/>
<id>3689f9f8b0c52dfd8f5995e4b58917f8f3ac3ee3</id>
<content type='text'>
Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs</title>
<updated>2022-01-19T09:50:20+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-01-19T09:50:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1d1df41c5a33359a00e919d54eaebfb789711fdc'/>
<id>1d1df41c5a33359a00e919d54eaebfb789711fdc</id>
<content type='text'>
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've tried to address some performance issues in
  f2fs_checkpoint and direct IO flows. Also, there was a work to enhance
  the page cache management used for compression. Other than them, we've
  done typical work including sysfs, code clean-ups, tracepoint, sanity
  check, in addition to bug fixes on corner cases.

  Enhancements:
   - use iomap for direct IO
   - try to avoid lock contention to improve f2fs_ckpt speed
   - avoid unnecessary memory allocation in compression flow
   - POSIX_FADV_DONTNEED drops the page cache containing compression
     pages
   - add some sysfs entries (gc_urgent_high_remaining, pending_discard)

  Bug fixes:
   - try not to expose unwritten blocks to user by DIO (this was added
     to avoid merge conflict; another patch is coming to address other
     missing case)
   - relax minor error condition for file pinning feature used in
     Android OTA
   - fix potential deadlock case in compression flow
   - should not truncate any block on pinned file

  In addition, we've done some code clean-ups and tracepoint/sanity
  check improvement"

* tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits)
  f2fs: do not allow partial truncation on pinned file
  f2fs: remove redunant invalidate compress pages
  f2fs: Simplify bool conversion
  f2fs: don't drop compressed page cache in .{invalidate,release}page
  f2fs: fix to reserve space for IO align feature
  f2fs: fix to check available space of CP area correctly in update_ckpt_flags()
  f2fs: support fault injection to f2fs_trylock_op()
  f2fs: clean up __find_inline_xattr() with __find_xattr()
  f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
  f2fs: do not bother checkpoint by f2fs_get_node_info
  f2fs: avoid down_write on nat_tree_lock during checkpoint
  f2fs: compress: fix potential deadlock of compress file
  f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file
  f2fs: add gc_urgent_high_remaining sysfs node
  f2fs: fix to do sanity check in is_alive()
  f2fs: fix to avoid panic in is_alive() if metadata is inconsistent
  f2fs: fix to do sanity check on inode type during garbage collection
  f2fs: avoid duplicate call of mark_inode_dirty
  f2fs: show number of pending discard commands
  f2fs: support POSIX_FADV_DONTNEED drop compressed page cache
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've tried to address some performance issues in
  f2fs_checkpoint and direct IO flows. Also, there was a work to enhance
  the page cache management used for compression. Other than them, we've
  done typical work including sysfs, code clean-ups, tracepoint, sanity
  check, in addition to bug fixes on corner cases.

  Enhancements:
   - use iomap for direct IO
   - try to avoid lock contention to improve f2fs_ckpt speed
   - avoid unnecessary memory allocation in compression flow
   - POSIX_FADV_DONTNEED drops the page cache containing compression
     pages
   - add some sysfs entries (gc_urgent_high_remaining, pending_discard)

  Bug fixes:
   - try not to expose unwritten blocks to user by DIO (this was added
     to avoid merge conflict; another patch is coming to address other
     missing case)
   - relax minor error condition for file pinning feature used in
     Android OTA
   - fix potential deadlock case in compression flow
   - should not truncate any block on pinned file

  In addition, we've done some code clean-ups and tracepoint/sanity
  check improvement"

* tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits)
  f2fs: do not allow partial truncation on pinned file
  f2fs: remove redunant invalidate compress pages
  f2fs: Simplify bool conversion
  f2fs: don't drop compressed page cache in .{invalidate,release}page
  f2fs: fix to reserve space for IO align feature
  f2fs: fix to check available space of CP area correctly in update_ckpt_flags()
  f2fs: support fault injection to f2fs_trylock_op()
  f2fs: clean up __find_inline_xattr() with __find_xattr()
  f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
  f2fs: do not bother checkpoint by f2fs_get_node_info
  f2fs: avoid down_write on nat_tree_lock during checkpoint
  f2fs: compress: fix potential deadlock of compress file
  f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file
  f2fs: add gc_urgent_high_remaining sysfs node
  f2fs: fix to do sanity check in is_alive()
  f2fs: fix to avoid panic in is_alive() if metadata is inconsistent
  f2fs: fix to do sanity check on inode type during garbage collection
  f2fs: avoid duplicate call of mark_inode_dirty
  f2fs: show number of pending discard commands
  f2fs: support POSIX_FADV_DONTNEED drop compressed page cache
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate</title>
<updated>2022-01-15T16:47:31+00:00</updated>
<author>
<name>Yury Norov</name>
<email>yury.norov@gmail.com</email>
</author>
<published>2021-08-14T21:17:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b5c7e7ec7d3418af2544452b45cc67297c857a86'/>
<id>b5c7e7ec7d3418af2544452b45cc67297c857a86</id>
<content type='text'>
find_first{,_zero}_bit is a more effective analogue of 'next' version if
start == 0. This patch replaces 'next' with 'first' where things look
trivial.

Signed-off-by: Yury Norov &lt;yury.norov@gmail.com&gt;
Tested-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
find_first{,_zero}_bit is a more effective analogue of 'next' version if
start == 0. This patch replaces 'next' with 'first' where things look
trivial.

Signed-off-by: Yury Norov &lt;yury.norov@gmail.com&gt;
Tested-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: introduce memalloc_retry_wait()</title>
<updated>2022-01-15T14:30:29+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2022-01-14T22:07:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4034247a0d6ab281ba3293798ce67af494d86129'/>
<id>4034247a0d6ab281ba3293798ce67af494d86129</id>
<content type='text'>
Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying.  Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:

 - a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
 - a need to check for the process being signalled between failures
 - the possibility that other recovery actions could be performed
 - the allocation is quite deep in support code, and passing down an
   extra flag to say if __GFP_NOFAIL is wanted would be clumsy.

Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.

It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.

This patch introduces memalloc_retry_wait() with takes on that
responsibility.  Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used.  It will wait
however is appropriate.

For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests.  If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing.  So there is no need for much
further waiting.  memalloc_retry_wait() will wait until the current
jiffie ends.  If this condition is not met, then alloc_page() won't have
waited much if at all.  In that case memalloc_retry_wait() waits about
200ms.  This is the delay that most current loops uses.

linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.

Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Cc: Dave Chinner &lt;david@fromorbit.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
Cc: Chao Yu &lt;chao@kernel.org&gt;
Cc: Darrick J. Wong &lt;djwong@kernel.org&gt;
Cc: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying.  Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:

 - a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
 - a need to check for the process being signalled between failures
 - the possibility that other recovery actions could be performed
 - the allocation is quite deep in support code, and passing down an
   extra flag to say if __GFP_NOFAIL is wanted would be clumsy.

Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.

It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.

This patch introduces memalloc_retry_wait() with takes on that
responsibility.  Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used.  It will wait
however is appropriate.

For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests.  If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing.  So there is no need for much
further waiting.  memalloc_retry_wait() will wait until the current
jiffie ends.  If this condition is not met, then alloc_page() won't have
waited much if at all.  In that case memalloc_retry_wait() waits about
200ms.  This is the delay that most current loops uses.

linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.

Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Cc: Dave Chinner &lt;david@fromorbit.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
Cc: Chao Yu &lt;chao@kernel.org&gt;
Cc: Darrick J. Wong &lt;djwong@kernel.org&gt;
Cc: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: do not bother checkpoint by f2fs_get_node_info</title>
<updated>2022-01-04T21:20:49+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk@kernel.org</email>
</author>
<published>2021-12-13T22:16:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a9419b63bf414775e8aeee95d8c4a5e0df690748'/>
<id>a9419b63bf414775e8aeee95d8c4a5e0df690748</id>
<content type='text'>
This patch tries to mitigate lock contention between f2fs_write_checkpoint and
f2fs_get_node_info along with nat_tree_lock.

The idea is, if checkpoint is currently running, other threads that try to grab
nat_tree_lock would be better to wait for checkpoint.

Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch tries to mitigate lock contention between f2fs_write_checkpoint and
f2fs_get_node_info along with nat_tree_lock.

The idea is, if checkpoint is currently running, other threads that try to grab
nat_tree_lock would be better to wait for checkpoint.

Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: invalidate META_MAPPING before IPU/DIO write</title>
<updated>2021-11-09T16:16:34+00:00</updated>
<author>
<name>Hyeong-Jun Kim</name>
<email>hj514.kim@samsung.com</email>
</author>
<published>2021-11-02T07:10:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e3b49ea36802053f312013fd4ccb6e59920a9f76'/>
<id>e3b49ea36802053f312013fd4ccb6e59920a9f76</id>
<content type='text'>
Encrypted pages during GC are read and cached in META_MAPPING.
However, due to cached pages in META_MAPPING, there is an issue where
newly written pages are lost by IPU or DIO writes.

Thread A - f2fs_gc()            Thread B
/* phase 3 */
down_write(i_gc_rwsem)
ra_data_block()       ---- (a)
up_write(i_gc_rwsem)
                                f2fs_direct_IO() :
                                 - down_read(i_gc_rwsem)
                                 - __blockdev_direct_io()
                                 - get_data_block_dio_write()
                                 - f2fs_dio_submit_bio()  ---- (b)
                                 - up_read(i_gc_rwsem)
/* phase 4 */
down_write(i_gc_rwsem)
move_data_block()     ---- (c)
up_write(i_gc_rwsem)

(a) In phase 3 of f2fs_gc(), up-to-date page is read from storage and
    cached in META_MAPPING.
(b) In thread B, writing new data by IPU or DIO write on same blkaddr as
    read in (a). cached page in META_MAPPING become out-dated.
(c) In phase 4 of f2fs_gc(), out-dated page in META_MAPPING is copied to
    new blkaddr. In conclusion, the newly written data in (b) is lost.

To address this issue, invalidating pages in META_MAPPING before IPU or
DIO write.

Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC")
Signed-off-by: Hyeong-Jun Kim &lt;hj514.kim@samsung.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Encrypted pages during GC are read and cached in META_MAPPING.
However, due to cached pages in META_MAPPING, there is an issue where
newly written pages are lost by IPU or DIO writes.

Thread A - f2fs_gc()            Thread B
/* phase 3 */
down_write(i_gc_rwsem)
ra_data_block()       ---- (a)
up_write(i_gc_rwsem)
                                f2fs_direct_IO() :
                                 - down_read(i_gc_rwsem)
                                 - __blockdev_direct_io()
                                 - get_data_block_dio_write()
                                 - f2fs_dio_submit_bio()  ---- (b)
                                 - up_read(i_gc_rwsem)
/* phase 4 */
down_write(i_gc_rwsem)
move_data_block()     ---- (c)
up_write(i_gc_rwsem)

(a) In phase 3 of f2fs_gc(), up-to-date page is read from storage and
    cached in META_MAPPING.
(b) In thread B, writing new data by IPU or DIO write on same blkaddr as
    read in (a). cached page in META_MAPPING become out-dated.
(c) In phase 4 of f2fs_gc(), out-dated page in META_MAPPING is copied to
    new blkaddr. In conclusion, the newly written data in (b) is lost.

To address this issue, invalidating pages in META_MAPPING before IPU or
DIO write.

Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC")
Signed-off-by: Hyeong-Jun Kim &lt;hj514.kim@samsung.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: multidevice: support direct IO</title>
<updated>2021-10-26T21:04:30+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2021-09-01T06:39:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=71f2c8206202584c644eef5ca7efe91fc8305c1f'/>
<id>71f2c8206202584c644eef5ca7efe91fc8305c1f</id>
<content type='text'>
Commit 3c62be17d4f5 ("f2fs: support multiple devices") missed
to support direct IO for multiple device feature, this patch
adds to support the missing part of multidevice feature.

In addition, for multiple device image, we should be aware of
any issued direct write IO rather than just buffered write IO,
so that fsync and syncfs can issue a preflush command to the
device where direct write IO goes, to persist user data for
posix compliant.

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 3c62be17d4f5 ("f2fs: support multiple devices") missed
to support direct IO for multiple device feature, this patch
adds to support the missing part of multidevice feature.

In addition, for multiple device image, we should be aware of
any issued direct write IO rather than just buffered write IO,
so that fsync and syncfs can issue a preflush command to the
device where direct write IO goes, to persist user data for
posix compliant.

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: introduce fragment allocation mode mount option</title>
<updated>2021-10-26T21:04:30+00:00</updated>
<author>
<name>Daeho Jeong</name>
<email>daehojeong@google.com</email>
</author>
<published>2021-09-29T18:12:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6691d940b0e09dd1564130e7a354d6deaf05d009'/>
<id>6691d940b0e09dd1564130e7a354d6deaf05d009</id>
<content type='text'>
Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.

"fragment:segment": f2fs allocates a new segment in ramdom position.
		With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
		"max_fragment_chunk" and "max_fragment_hole" sysfs
		nodes. f2fs will allocate 1..&lt;max_fragment_chunk&gt;
		blocks in a chunk and make a hole in the length of
		1..&lt;max_fragment_hole&gt; by turns	in a newly allocated
		free segment. Plus, this mode implicitly enables
		"fragment:segment" option for more randomness.

Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.

"fragment:segment": f2fs allocates a new segment in ramdom position.
		With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
		"max_fragment_chunk" and "max_fragment_hole" sysfs
		nodes. f2fs will allocate 1..&lt;max_fragment_chunk&gt;
		blocks in a chunk and make a hole in the length of
		1..&lt;max_fragment_hole&gt; by turns	in a newly allocated
		free segment. Plus, this mode implicitly enables
		"fragment:segment" option for more randomness.

Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix wrong condition to trigger background checkpoint correctly</title>
<updated>2021-10-11T23:15:23+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2021-09-28T19:19:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cd6d697a6e2013a0a85f8b261b16c8cfd50c1f5f'/>
<id>cd6d697a6e2013a0a85f8b261b16c8cfd50c1f5f</id>
<content type='text'>
In f2fs_balance_fs_bg(), it needs to check both NAT_ENTRIES and INO_ENTRIES
memory usage to decide whether we should skip background checkpoint, otherwise
we may always skip checking INO_ENTRIES memory usage, so that INO_ENTRIES may
potentially cause high memory footprint.

Fixes: 493720a48543 ("f2fs: fix to avoid REQ_TIME and CP_TIME collision")
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In f2fs_balance_fs_bg(), it needs to check both NAT_ENTRIES and INO_ENTRIES
memory usage to decide whether we should skip background checkpoint, otherwise
we may always skip checking INO_ENTRIES memory usage, so that INO_ENTRIES may
potentially cause high memory footprint.

Fixes: 493720a48543 ("f2fs: fix to avoid REQ_TIME and CP_TIME collision")
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: introduce excess_dirty_threshold()</title>
<updated>2021-09-20T23:12:51+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2021-09-16T09:09:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=287b1406dde2bc80f468c73708e7f7a87be390ea'/>
<id>287b1406dde2bc80f468c73708e7f7a87be390ea</id>
<content type='text'>
This patch enables f2fs_balance_fs_bg() to check all metadatas' dirty
threshold rather than just checking node block's, so that checkpoint()
from background can be triggered more frequently to avoid heaping up
too much dirty metadatas.

Threshold value by default:
race with foreground ops	single type	global
No				16MB		24MB
Yes				24MB		36MB

In addtion, let f2fs_balance_fs_bg() be aware of roll-forward sapce
as well as fsync().

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch enables f2fs_balance_fs_bg() to check all metadatas' dirty
threshold rather than just checking node block's, so that checkpoint()
from background can be triggered more frequently to avoid heaping up
too much dirty metadatas.

Threshold value by default:
race with foreground ops	single type	global
No				16MB		24MB
Yes				24MB		36MB

In addtion, let f2fs_balance_fs_bg() be aware of roll-forward sapce
as well as fsync().

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
