<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/ext4/ioctl.c, branch v6.0</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>ext4: add ioctls to get/set the ext4 superblock uuid</title>
<updated>2022-08-03T03:56:26+00:00</updated>
<author>
<name>Jeremy Bongio</name>
<email>bongiojp@gmail.com</email>
</author>
<published>2022-07-21T22:44:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d95efb14c0b81b684deb32ba10cdb78b4178ae5b'/>
<id>d95efb14c0b81b684deb32ba10cdb78b4178ae5b</id>
<content type='text'>
This fixes a race between changing the ext4 superblock uuid and operations
like mounting, resizing, changing features, etc.

Reviewed-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Jeremy Bongio &lt;bongiojp@gmail.com&gt;
Link: https://lore.kernel.org/r/20220721224422.438351-1-bongiojp@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>
This fixes a race between changing the ext4 superblock uuid and operations
like mounting, resizing, changing features, etc.

Reviewed-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Jeremy Bongio &lt;bongiojp@gmail.com&gt;
Link: https://lore.kernel.org/r/20220721224422.438351-1-bongiojp@gmail.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: update the s_overhead_clusters in the backup sb's when resizing</title>
<updated>2022-08-03T03:52:19+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2022-06-29T04:00:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=827891a38accfb4e04dbcdefe710f8746c6ad16d'/>
<id>827891a38accfb4e04dbcdefe710f8746c6ad16d</id>
<content type='text'>
When the EXT4_IOC_RESIZE_FS ioctl is complete, update the backup
superblocks.  We don't do this for the old-style resize ioctls since
they are quite ancient, and only used by very old versions of
resize2fs --- and we don't want to update the backup superblocks every
time EXT4_IOC_GROUP_ADD is called, since it might get called a lot.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Andreas Dilger &lt;adilger@dilger.ca&gt;
Link: https://lore.kernel.org/r/20220629040026.112371-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the EXT4_IOC_RESIZE_FS ioctl is complete, update the backup
superblocks.  We don't do this for the old-style resize ioctls since
they are quite ancient, and only used by very old versions of
resize2fs --- and we don't want to update the backup superblocks every
time EXT4_IOC_GROUP_ADD is called, since it might get called a lot.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Andreas Dilger &lt;adilger@dilger.ca&gt;
Link: https://lore.kernel.org/r/20220629040026.112371-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4</title>
<updated>2022-05-25T02:04:46+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-25T02:04:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fea3043314f30a87ca04fd1219661810600e256f'/>
<id>fea3043314f30a87ca04fd1219661810600e256f</id>
<content type='text'>
Pull ext4 updates from Ted Ts'o:
 "Various bug fixes and cleanups for ext4.

  In particular, move the crypto related fucntions from fs/ext4/super.c
  into a new fs/ext4/crypto.c, and fix a number of bugs found by fuzzers
  and error injection tools"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: only allow test_dummy_encryption when supported
  ext4: fix bug_on in __es_tree_search
  ext4: avoid cycles in directory h-tree
  ext4: verify dir block before splitting it
  ext4: filter out EXT4_FC_REPLAY from on-disk superblock field s_state
  ext4: fix bug_on in ext4_writepages
  ext4: refactor and move ext4_ioctl_get_encryption_pwsalt()
  ext4: cleanup function defs from ext4.h into crypto.c
  ext4: move ext4 crypto code to its own file crypto.c
  ext4: fix memory leak in parse_apply_sb_mount_options()
  ext4: reject the 'commit' option on ext2 filesystems
  ext4: remove duplicated #include of dax.h in inode.c
  ext4: fix race condition between ext4_write and ext4_convert_inline_data
  ext4: convert symlink external data block mapping to bdev
  ext4: add nowait mode for ext4_getblk()
  ext4: fix journal_ioprio mount option handling
  ext4: mark group as trimmed only if it was fully scanned
  ext4: fix use-after-free in ext4_rename_dir_prepare
  ext4: add unmount filesystem message
  ext4: remove unnecessary conditionals
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ext4 updates from Ted Ts'o:
 "Various bug fixes and cleanups for ext4.

  In particular, move the crypto related fucntions from fs/ext4/super.c
  into a new fs/ext4/crypto.c, and fix a number of bugs found by fuzzers
  and error injection tools"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: only allow test_dummy_encryption when supported
  ext4: fix bug_on in __es_tree_search
  ext4: avoid cycles in directory h-tree
  ext4: verify dir block before splitting it
  ext4: filter out EXT4_FC_REPLAY from on-disk superblock field s_state
  ext4: fix bug_on in ext4_writepages
  ext4: refactor and move ext4_ioctl_get_encryption_pwsalt()
  ext4: cleanup function defs from ext4.h into crypto.c
  ext4: move ext4 crypto code to its own file crypto.c
  ext4: fix memory leak in parse_apply_sb_mount_options()
  ext4: reject the 'commit' option on ext2 filesystems
  ext4: remove duplicated #include of dax.h in inode.c
  ext4: fix race condition between ext4_write and ext4_convert_inline_data
  ext4: convert symlink external data block mapping to bdev
  ext4: add nowait mode for ext4_getblk()
  ext4: fix journal_ioprio mount option handling
  ext4: mark group as trimmed only if it was fully scanned
  ext4: fix use-after-free in ext4_rename_dir_prepare
  ext4: add unmount filesystem message
  ext4: remove unnecessary conditionals
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-block</title>
<updated>2022-05-23T20:56:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-23T20:56:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=115cd47132d71bd7e4aa1093e15d861a59e73a94'/>
<id>115cd47132d71bd7e4aa1093e15d861a59e73a94</id>
<content type='text'>
Pull block updates from Jens Axboe:
 "Here are the core block changes for 5.19. This contains:

   - blk-throttle accounting fix (Laibin)

   - Series removing redundant assignments (Michal)

   - Expose bio cache via the bio_set, so that DM can use it (Mike)

   - Finish off the bio allocation interface cleanups by dealing with
     the weirdest member of the family. bio_kmalloc combines a kmalloc
     for the bio and bio_vecs with a hidden bio_init call and magic
     cleanup semantics (Christoph)

   - Clean up the block layer API so that APIs consumed by file systems
     are (almost) only struct block_device based, so that file systems
     don't have to poke into block layer internals like the
     request_queue (Christoph)

   - Clean up the blk_execute_rq* API (Christoph)

   - Clean up various lose end in the blk-cgroup code to make it easier
     to follow in preparation of reworking the blkcg assignment for bios
     (Christoph)

   - Fix use-after-free issues in BFQ when processes with merged queues
     get moved to different cgroups (Jan)

   - BFQ fixes (Jan)

   - Various fixes and cleanups (Bart, Chengming, Fanjun, Julia, Ming,
     Wolfgang, me)"

* tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-block: (83 commits)
  blk-mq: fix typo in comment
  bfq: Remove bfq_requeue_request_body()
  bfq: Remove superfluous conversion from RQ_BIC()
  bfq: Allow current waker to defend against a tentative one
  bfq: Relax waker detection for shared queues
  blk-cgroup: delete rcu_read_lock_held() WARN_ON_ONCE()
  blk-throttle: Set BIO_THROTTLED when bio has been throttled
  blk-cgroup: Remove unnecessary rcu_read_lock/unlock()
  blk-cgroup: always terminate io.stat lines
  block, bfq: make bfq_has_work() more accurate
  block, bfq: protect 'bfqd-&gt;queued' by 'bfqd-&gt;lock'
  block: cleanup the VM accounting in submit_bio
  block: Fix the bio.bi_opf comment
  block: reorder the REQ_ flags
  blk-iocost: combine local_stat and desc_stat to stat
  block: improve the error message from bio_check_eod
  block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone
  block: remove superfluous calls to blkcg_bio_issue_init
  kthread: unexport kthread_blkcg
  blk-cgroup: cleanup blkcg_maybe_throttle_current
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block updates from Jens Axboe:
 "Here are the core block changes for 5.19. This contains:

   - blk-throttle accounting fix (Laibin)

   - Series removing redundant assignments (Michal)

   - Expose bio cache via the bio_set, so that DM can use it (Mike)

   - Finish off the bio allocation interface cleanups by dealing with
     the weirdest member of the family. bio_kmalloc combines a kmalloc
     for the bio and bio_vecs with a hidden bio_init call and magic
     cleanup semantics (Christoph)

   - Clean up the block layer API so that APIs consumed by file systems
     are (almost) only struct block_device based, so that file systems
     don't have to poke into block layer internals like the
     request_queue (Christoph)

   - Clean up the blk_execute_rq* API (Christoph)

   - Clean up various lose end in the blk-cgroup code to make it easier
     to follow in preparation of reworking the blkcg assignment for bios
     (Christoph)

   - Fix use-after-free issues in BFQ when processes with merged queues
     get moved to different cgroups (Jan)

   - BFQ fixes (Jan)

   - Various fixes and cleanups (Bart, Chengming, Fanjun, Julia, Ming,
     Wolfgang, me)"

* tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-block: (83 commits)
  blk-mq: fix typo in comment
  bfq: Remove bfq_requeue_request_body()
  bfq: Remove superfluous conversion from RQ_BIC()
  bfq: Allow current waker to defend against a tentative one
  bfq: Relax waker detection for shared queues
  blk-cgroup: delete rcu_read_lock_held() WARN_ON_ONCE()
  blk-throttle: Set BIO_THROTTLED when bio has been throttled
  blk-cgroup: Remove unnecessary rcu_read_lock/unlock()
  blk-cgroup: always terminate io.stat lines
  block, bfq: make bfq_has_work() more accurate
  block, bfq: protect 'bfqd-&gt;queued' by 'bfqd-&gt;lock'
  block: cleanup the VM accounting in submit_bio
  block: Fix the bio.bi_opf comment
  block: reorder the REQ_ flags
  blk-iocost: combine local_stat and desc_stat to stat
  block: improve the error message from bio_check_eod
  block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone
  block: remove superfluous calls to blkcg_bio_issue_init
  kthread: unexport kthread_blkcg
  blk-cgroup: cleanup blkcg_maybe_throttle_current
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: refactor and move ext4_ioctl_get_encryption_pwsalt()</title>
<updated>2022-05-22T02:24:24+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>ritesh.list@gmail.com</email>
</author>
<published>2022-05-15T06:37:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=72f63f4a770310233dba3bff8fc6e41660ebaa27'/>
<id>72f63f4a770310233dba3bff8fc6e41660ebaa27</id>
<content type='text'>
This patch move code for FS_IOC_GET_ENCRYPTION_PWSALT case into
ext4's crypto.c file, i.e. ext4_ioctl_get_encryption_pwsalt()
and uuid_is_zero(). This is mostly refactoring logic and should
not affect any functionality change.

Suggested-by: Eric Biggers &lt;ebiggers@google.com&gt;
Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Ritesh Harjani &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/5af98b17152a96b245b4f7d2dfb8607fc93e36aa.1652595565.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>
This patch move code for FS_IOC_GET_ENCRYPTION_PWSALT case into
ext4's crypto.c file, i.e. ext4_ioctl_get_encryption_pwsalt()
and uuid_is_zero(). This is mostly refactoring logic and should
not affect any functionality change.

Suggested-by: Eric Biggers &lt;ebiggers@google.com&gt;
Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Ritesh Harjani &lt;ritesh.list@gmail.com&gt;
Link: https://lore.kernel.org/r/5af98b17152a96b245b4f7d2dfb8607fc93e36aa.1652595565.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: remove QUEUE_FLAG_DISCARD</title>
<updated>2022-04-18T01:49:59+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2022-04-15T04:52:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=70200574cc229f6ba038259e8142af2aa09e6976'/>
<id>70200574cc229f6ba038259e8142af2aa09e6976</id>
<content type='text'>
Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Acked-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt; [drbd]
Acked-by: Jan Höppner &lt;hoeppner@linux.ibm.com&gt; [s390]
Acked-by: Coly Li &lt;colyli@suse.de&gt; [bcache]
Acked-by: David Sterba &lt;dsterba@suse.com&gt; [btrfs]
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Acked-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt; [drbd]
Acked-by: Jan Höppner &lt;hoeppner@linux.ibm.com&gt; [s390]
Acked-by: Coly Li &lt;colyli@suse.de&gt; [bcache]
Acked-by: David Sterba &lt;dsterba@suse.com&gt; [btrfs]
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: update the cached overhead value in the superblock</title>
<updated>2022-04-15T02:39:00+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2022-04-15T02:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eb7054212eac8b451d727bf079eae3db8c88f9d3'/>
<id>eb7054212eac8b451d727bf079eae3db8c88f9d3</id>
<content type='text'>
If we (re-)calculate the file system overhead amount and it's
different from the on-disk s_overhead_clusters value, update the
on-disk version since this can take potentially quite a while on
bigalloc file systems.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If we (re-)calculate the file system overhead amount and it's
different from the on-disk s_overhead_clusters value, update the
on-disk version since this can take potentially quite a while on
bigalloc file systems.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix kernel doc warnings</title>
<updated>2022-03-15T21:45:36+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2022-03-13T02:39:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=919adbfec29d5b89b3e45620653cbeeb0d42e6fd'/>
<id>919adbfec29d5b89b3e45620653cbeeb0d42e6fd</id>
<content type='text'>
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fast commit may not fallback for ineligible commit</title>
<updated>2022-02-03T15:56:39+00:00</updated>
<author>
<name>Xin Yin</name>
<email>yinxin.x@bytedance.com</email>
</author>
<published>2022-01-17T09:36:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e85c81ba8859a4c839bcd69c5d83b32954133a5b'/>
<id>e85c81ba8859a4c839bcd69c5d83b32954133a5b</id>
<content type='text'>
For the follow scenario:
1. jbd start commit transaction n
2. task A get new handle for transaction n+1
3. task A do some ineligible actions and mark FC_INELIGIBLE
4. jbd complete transaction n and clean FC_INELIGIBLE
5. task A call fsync

In this case fast commit will not fallback to full commit and
transaction n+1 also not handled by jbd.

Make ext4_fc_mark_ineligible() also record transaction tid for
latest ineligible case, when call ext4_fc_cleanup() check
current transaction tid, if small than latest ineligible tid
do not clear the EXT4_MF_FC_INELIGIBLE.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Reported-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Suggested-by: Harshad Shirwadkar &lt;harshadshirwadkar@gmail.com&gt;
Signed-off-by: Xin Yin &lt;yinxin.x@bytedance.com&gt;
Link: https://lore.kernel.org/r/20220117093655.35160-2-yinxin.x@bytedance.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For the follow scenario:
1. jbd start commit transaction n
2. task A get new handle for transaction n+1
3. task A do some ineligible actions and mark FC_INELIGIBLE
4. jbd complete transaction n and clean FC_INELIGIBLE
5. task A call fsync

In this case fast commit will not fallback to full commit and
transaction n+1 also not handled by jbd.

Make ext4_fc_mark_ineligible() also record transaction tid for
latest ineligible case, when call ext4_fc_cleanup() check
current transaction tid, if small than latest ineligible tid
do not clear the EXT4_MF_FC_INELIGIBLE.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Reported-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Suggested-by: Harshad Shirwadkar &lt;harshadshirwadkar@gmail.com&gt;
Signed-off-by: Xin Yin &lt;yinxin.x@bytedance.com&gt;
Link: https://lore.kernel.org/r/20220117093655.35160-2-yinxin.x@bytedance.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: implement support for get/set fs label</title>
<updated>2022-01-10T18:25:55+00:00</updated>
<author>
<name>Lukas Czerner</name>
<email>lczerner@redhat.com</email>
</author>
<published>2021-12-13T13:56:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bbc605cdb1e15aafaec899fedc385dc75dddac0e'/>
<id>bbc605cdb1e15aafaec899fedc385dc75dddac0e</id>
<content type='text'>
Implement support for FS_IOC_GETFSLABEL and FS_IOC_SETFSLABEL ioctls for
online reading and setting of file system label.

ext4_ioctl_getlabel() is simple, just get the label from the primary
superblock. This might not be the first sb on the file system if
'sb=' mount option is used.

In ext4_ioctl_setlabel() we update what ext4 currently views as a
primary superblock and then proceed to update backup superblocks. There
are two caveats:
 - the primary superblock might not be the first superblock and so it
   might not be the one used by userspace tools if read directly
   off the disk.
 - because the primary superblock might not be the first superblock we
   potentialy have to update it as part of backup superblock update.
   However the first sb location is a bit more complicated than the rest
   so we have to account for that.

The superblock modification is created generic enough so the
infrastructure can be used for other potential superblock modification
operations, such as chaning UUID.

Tested with generic/492 with various configurations. I also checked the
behavior with 'sb=' mount options, including very large file systems
with and without sparse_super/sparse_super2.

Signed-off-by: Lukas Czerner &lt;lczerner@redhat.com&gt;
Link: https://lore.kernel.org/r/20211213135618.43303-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Implement support for FS_IOC_GETFSLABEL and FS_IOC_SETFSLABEL ioctls for
online reading and setting of file system label.

ext4_ioctl_getlabel() is simple, just get the label from the primary
superblock. This might not be the first sb on the file system if
'sb=' mount option is used.

In ext4_ioctl_setlabel() we update what ext4 currently views as a
primary superblock and then proceed to update backup superblocks. There
are two caveats:
 - the primary superblock might not be the first superblock and so it
   might not be the one used by userspace tools if read directly
   off the disk.
 - because the primary superblock might not be the first superblock we
   potentialy have to update it as part of backup superblock update.
   However the first sb location is a bit more complicated than the rest
   so we have to account for that.

The superblock modification is created generic enough so the
infrastructure can be used for other potential superblock modification
operations, such as chaning UUID.

Tested with generic/492 with various configurations. I also checked the
behavior with 'sb=' mount options, including very large file systems
with and without sparse_super/sparse_super2.

Signed-off-by: Lukas Czerner &lt;lczerner@redhat.com&gt;
Link: https://lore.kernel.org/r/20211213135618.43303-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
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