<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/trace/events/ext4.h, branch linux-6.16.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ext4: enhance tracepoints during the folios writeback</title>
<updated>2025-08-23T14:49:41+00:00</updated>
<author>
<name>Zhang Yi</name>
<email>yi.zhang@huawei.com</email>
</author>
<published>2025-07-07T14:08:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7fe61ac002623a3a7232a33e1439fbbcb4fe8f2a'/>
<id>7fe61ac002623a3a7232a33e1439fbbcb4fe8f2a</id>
<content type='text'>
commit 6b132759b0fe78e518abafb62190c294100db6d6 upstream.

After mpage_map_and_submit_extent() supports restarting handle if
credits are insufficient during allocating blocks, it is more likely to
exit the current mapping iteration and continue to process the current
processing partially mapped folio again. The existing tracepoints are
not sufficient to track this situation, so enhance the tracepoints to
track the writeback position and the return value before and after
submitting the folios.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20250707140814.542883-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6b132759b0fe78e518abafb62190c294100db6d6 upstream.

After mpage_map_and_submit_extent() supports restarting handle if
credits are insufficient during allocating blocks, it is more likely to
exit the current mapping iteration and continue to process the current
processing partially mapped folio again. The existing tracepoints are
not sufficient to track this situation, so enhance the tracepoints to
track the writeback position and the return value before and after
submitting the folios.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20250707140814.542883-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: process folios writeback in bytes</title>
<updated>2025-08-23T14:49:41+00:00</updated>
<author>
<name>Zhang Yi</name>
<email>yi.zhang@huawei.com</email>
</author>
<published>2025-07-07T14:08:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc3588c04debe4cfe026797c43b830bd65a8a3ba'/>
<id>dc3588c04debe4cfe026797c43b830bd65a8a3ba</id>
<content type='text'>
commit 1bfe6354e0975fe89c3d25e81b6546d205556a4b upstream.

Since ext4 supports large folios, processing writebacks in pages is no
longer appropriate, it can be modified to process writebacks in bytes.

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20250707140814.542883-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1bfe6354e0975fe89c3d25e81b6546d205556a4b upstream.

Since ext4 supports large folios, processing writebacks in pages is no
longer appropriate, it can be modified to process writebacks in bytes.

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20250707140814.542883-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: remove tracing for FALLOC_FL_NO_HIDE_STALE</title>
<updated>2024-08-28T14:53:57+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2024-08-27T06:50:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f951171044762a0d179caf9f1addcdbc7cb533bf'/>
<id>f951171044762a0d179caf9f1addcdbc7cb533bf</id>
<content type='text'>
FALLOC_FL_NO_HIDE_STALE can't make it past vfs_fallocate (and if the
flag does what the name implies that's a good thing as it would be
highly dangerous).  Remove the dead tracing code for it.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240827065123.1762168-3-hch@lst.de
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
FALLOC_FL_NO_HIDE_STALE can't make it past vfs_fallocate (and if the
flag does what the name implies that's a good thing as it would be
highly dangerous).  Remove the dead tracing code for it.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240827065123.1762168-3-hch@lst.de
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: make ext4_da_reserve_space() reserve multi-clusters</title>
<updated>2024-06-27T22:04:50+00:00</updated>
<author>
<name>Zhang Yi</name>
<email>yi.zhang@huawei.com</email>
</author>
<published>2024-05-17T12:40:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0d66b23d79c750276f791411d81a524549a64852'/>
<id>0d66b23d79c750276f791411d81a524549a64852</id>
<content type='text'>
Add 'nr_resv' parameter to ext4_da_reserve_space(), which indicates the
number of clusters wants to reserve, make it reserve multiple clusters
at a time.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20240517124005.347221-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add 'nr_resv' parameter to ext4_da_reserve_space(), which indicates the
number of clusters wants to reserve, make it reserve multiple clusters
at a time.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20240517124005.347221-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: make ext4_es_insert_delayed_block() insert multi-blocks</title>
<updated>2024-06-27T22:04:49+00:00</updated>
<author>
<name>Zhang Yi</name>
<email>yi.zhang@huawei.com</email>
</author>
<published>2024-05-17T12:40:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=12eba993b94c9186e44a01f46e38b3ab3c635f2d'/>
<id>12eba993b94c9186e44a01f46e38b3ab3c635f2d</id>
<content type='text'>
Rename ext4_es_insert_delayed_block() to ext4_es_insert_delayed_extent()
and pass length parameter to make it insert multiple delalloc blocks at
a time. For the case of bigalloc, split the allocated parameter to
lclu_allocated and end_allocated. lclu_allocated indicates the
allocation state of the cluster which is containing the lblk,
end_allocated indicates the allocation state of the extent end, clusters
in the middle of delay allocated extent must be unallocated.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20240517124005.347221-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename ext4_es_insert_delayed_block() to ext4_es_insert_delayed_extent()
and pass length parameter to make it insert multiple delalloc blocks at
a time. For the case of bigalloc, split the allocated parameter to
lclu_allocated and end_allocated. lclu_allocated indicates the
allocation state of the cluster which is containing the lblk,
end_allocated indicates the allocation state of the extent end, clusters
in the middle of delay allocated extent must be unallocated.

Signed-off-by: Zhang Yi &lt;yi.zhang@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://patch.msgid.link/20240517124005.347221-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: remove 'needed' in trace_ext4_discard_preallocations</title>
<updated>2024-01-18T15:52:45+00:00</updated>
<author>
<name>Kemeng Shi</name>
<email>shikemeng@huaweicloud.com</email>
</author>
<published>2024-01-05T09:21:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f0e54b6087de9571ec61c189d6c378b81edbe3b2'/>
<id>f0e54b6087de9571ec61c189d6c378b81edbe3b2</id>
<content type='text'>
As 'needed' to trace_ext4_discard_preallocations is always 0 which
is meaningless. Just remove it.

Signed-off-by: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20240105092102.496631-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As 'needed' to trace_ext4_discard_preallocations is always 0 which
is meaningless. Just remove it.

Signed-off-by: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20240105092102.496631-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: Give symbolic names to mballoc criterias</title>
<updated>2023-06-26T23:34:56+00:00</updated>
<author>
<name>Ojaswin Mujoo</name>
<email>ojaswin@linux.ibm.com</email>
</author>
<published>2023-05-30T12:33:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f52f3d2b9fbab73c776f4d3386393e9bbc83b87d'/>
<id>f52f3d2b9fbab73c776f4d3386393e9bbc83b87d</id>
<content type='text'>
mballoc criterias have historically been called by numbers
like CR0, CR1... however this makes it confusing to understand
what each criteria is about.

Change these criterias from numbers to symbolic names and add
relevant comments. While we are at it, also reformat and add some
comments to ext4_seq_mb_stats_show() for better readability.

Additionally, define CR_FAST which signifies the criteria
below which we can make quicker decisions like:
  * quitting early if (free block &lt; requested len)
  * avoiding to scan free extents smaller than required len.
  * avoiding to initialize buddy cache and work with existing cache
  * limiting prefetches

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/a2dc6ec5aea5e5e68cf8e788c2a964ffead9c8b0.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
mballoc criterias have historically been called by numbers
like CR0, CR1... however this makes it confusing to understand
what each criteria is about.

Change these criterias from numbers to symbolic names and add
relevant comments. While we are at it, also reformat and add some
comments to ext4_seq_mb_stats_show() for better readability.

Additionally, define CR_FAST which signifies the criteria
below which we can make quicker decisions like:
  * quitting early if (free block &lt; requested len)
  * avoiding to scan free extents smaller than required len.
  * avoiding to initialize buddy cache and work with existing cache
  * limiting prefetches

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/a2dc6ec5aea5e5e68cf8e788c2a964ffead9c8b0.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: Add allocation criteria 1.5 (CR1_5)</title>
<updated>2023-06-26T23:34:56+00:00</updated>
<author>
<name>Ojaswin Mujoo</name>
<email>ojaswin@linux.ibm.com</email>
</author>
<published>2023-05-30T12:33:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7e170922f06bf46effa7c57f6035fc463d6edc7e'/>
<id>7e170922f06bf46effa7c57f6035fc463d6edc7e</id>
<content type='text'>
CR1_5 aims to optimize allocations which can't be satisfied in CR1. The
fact that we couldn't find a group in CR1 suggests that it would be
difficult to find a continuous extent to compleltely satisfy our
allocations. So before falling to the slower CR2, in CR1.5 we
proactively trim the the preallocations so we can find a group with
(free / fragments) big enough.  This speeds up our allocation at the
cost of slightly reduced preallocation.

The patch also adds a new sysfs tunable:

* /sys/fs/ext4/&lt;partition&gt;/mb_cr1_5_max_trim_order

This controls how much CR1.5 can trim a request before falling to CR2.
For example, for a request of order 7 and max trim order 2, CR1.5 can
trim this upto order 5.

Suggested-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/150fdf65c8e4cc4dba71e020ce0859bcf636a5ff.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
CR1_5 aims to optimize allocations which can't be satisfied in CR1. The
fact that we couldn't find a group in CR1 suggests that it would be
difficult to find a continuous extent to compleltely satisfy our
allocations. So before falling to the slower CR2, in CR1.5 we
proactively trim the the preallocations so we can find a group with
(free / fragments) big enough.  This speeds up our allocation at the
cost of slightly reduced preallocation.

The patch also adds a new sysfs tunable:

* /sys/fs/ext4/&lt;partition&gt;/mb_cr1_5_max_trim_order

This controls how much CR1.5 can trim a request before falling to CR2.
For example, for a request of order 7 and max trim order 2, CR1.5 can
trim this upto order 5.

Suggested-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/150fdf65c8e4cc4dba71e020ce0859bcf636a5ff.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: Convert mballoc cr (criteria) to enum</title>
<updated>2023-06-26T23:34:56+00:00</updated>
<author>
<name>Ojaswin Mujoo</name>
<email>ojaswin@linux.ibm.com</email>
</author>
<published>2023-05-30T12:33:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4eb7a4a1a33bdaf259fca8528f2546c90ad18f0d'/>
<id>4eb7a4a1a33bdaf259fca8528f2546c90ad18f0d</id>
<content type='text'>
Convert criteria to be an enum so it easier to maintain and
update the tracefiles to use enum names. This change also makes
it easier to insert new criterias in the future.

There is no functional change in this patch.

Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/5d82fd467bdf70ea45bdaef810af3b146013946c.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Convert criteria to be an enum so it easier to maintain and
update the tracefiles to use enum names. This change also makes
it easier to insert new criterias in the future.

There is no functional change in this patch.

Signed-off-by: Ojaswin Mujoo &lt;ojaswin@linux.ibm.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/5d82fd467bdf70ea45bdaef810af3b146013946c.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: Change remaining tracepoints to use folio</title>
<updated>2023-06-15T04:02:10+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>ritesh.list@gmail.com</email>
</author>
<published>2023-05-15T10:40:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36c9b4504088089185f7743433c914935b518ab2'/>
<id>36c9b4504088089185f7743433c914935b518ab2</id>
<content type='text'>
ext4_readpage() is converted to ext4_read_folio() hence change the
related tracepoint from trace_ext4_readpage(page) to
trace_ext4_read_folio(folio). Do the same for
trace_ext4_releasepage(page) to trace_ext4_release_folio(folio)

As a minor bit of optimization to avoid an extra dereferencing,
since both of the above functions already were dereferencing
folio-&gt;mapping-&gt;host, hence change the tracepoint argument to take
(inode, folio).

Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/caba2b3c0147bed4ea7706767dc1d19cd0e29ab0.1684122756.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ext4_readpage() is converted to ext4_read_folio() hence change the
related tracepoint from trace_ext4_readpage(page) to
trace_ext4_read_folio(folio). Do the same for
trace_ext4_releasepage(page) to trace_ext4_release_folio(folio)

As a minor bit of optimization to avoid an extra dereferencing,
since both of the above functions already were dereferencing
folio-&gt;mapping-&gt;host, hence change the tracepoint argument to take
(inode, folio).

Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/caba2b3c0147bed4ea7706767dc1d19cd0e29ab0.1684122756.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
</feed>
