mm/migrate: fix sleep in atomic for large folios and buffer heads

The large folio + buffer head noref migration scenarios are
being naughty and blocking while holding a spinlock.

As a consequence o

mm/migrate: fix sleep in atomic for large folios and buffer heads

The large folio + buffer head noref migration scenarios are
being naughty and blocking while holding a spinlock.

As a consequence of the pagecache lookup path taking the
folio lock this serializes against migration paths, so
they can wait for each other. For the private_lock
atomic case, a new BH_Migrate flag is introduced which
enables the lookup to bail.

This allows the critical region of the private_lock on
the migration path to be reduced to the way it was before
ebdf4de5642fb6 ("mm: migrate: fix reference check race
between __find_get_block() and migration"), that is covering
the count checks.

The scope is always noref migration.

Reported-by: kernel test robot <[email protected]>
Reported-by: [email protected]
Closes: https://lore.kernel.org/oe-lkp/[email protected]
Fixes: 3c20917120ce61 ("block/bdev: enable large folio support for large logical block sizes")
Reviewed-by: Jan Kara <[email protected]>
Co-developed-by: Luis Chamberlain <[email protected]>
Signed-off-by: Davidlohr Bueso <[email protected]>
Link: https://kdevops.org/ext4/v6.15-rc2.html # [0]
Link: https://lore.kernel.org/all/[email protected]/ # [1]
Link: https://lore.kernel.org/[email protected]
Tested-by: [email protected] # [0] [1]
Reviewed-by: Luis Chamberlain <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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ext4: remove redundant function ext4_has_metadata_csum

Since commit f2b4fa19647e ("ext4: switch to using the crc32c library"),
ext4_has_metadata_csum() is just an alias for
ext4_has_feature_metadata

ext4: remove redundant function ext4_has_metadata_csum

Since commit f2b4fa19647e ("ext4: switch to using the crc32c library"),
ext4_has_metadata_csum() is just an alias for
ext4_has_feature_metadata_csum(). ext4_has_feature_metadata_csum() is
generated by EXT4_FEATURE_RO_COMPAT_FUNCS and uses the regular naming
convention for checking a single ext4 feature. Therefore, remove
ext4_has_metadata_csum() and update all its callers to use
ext4_has_feature_metadata_csum() directly.

Signed-off-by: Eric Biggers <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: add ext4_emergency_state() helper function

Since both SHUTDOWN and EMERGENCY_RO are emergency states of the ext4 file
system, and they are checked in similar locations, we have added a helper

ext4: add ext4_emergency_state() helper function

Since both SHUTDOWN and EMERGENCY_RO are emergency states of the ext4 file
system, and they are checked in similar locations, we have added a helper
function, ext4_emergency_state(), to determine whether the current file
system is in one of these two emergency states.

Then, replace calls to ext4_forced_shutdown() with ext4_emergency_state()
in those functions that could potentially trigger write operations.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Zhang Yi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: Don't set EXT4_STATE_MAY_INLINE_DATA for ea inodes

Setting the EXT4_STATE_MAY_INLINE_DATA flag for ea inodes
is meaningless because ea inodes do not use functions
like ext4_write_begin().

Sig

ext4: Don't set EXT4_STATE_MAY_INLINE_DATA for ea inodes

Setting the EXT4_STATE_MAY_INLINE_DATA flag for ea inodes
is meaningless because ea inodes do not use functions
like ext4_write_begin().

Signed-off-by: Julian Sun <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: fix race in buffer_head read fault injection

When I enabled ext4 debug for fault injection testing, I encountered the
following warning:

EXT4-fs error (device sda): ext4_read_inode_bitmap:2

ext4: fix race in buffer_head read fault injection

When I enabled ext4 debug for fault injection testing, I encountered the
following warning:

EXT4-fs error (device sda): ext4_read_inode_bitmap:201: comm fsstress:
Cannot read inode bitmap - block_group = 8, inode_bitmap = 1051
WARNING: CPU: 0 PID: 511 at fs/buffer.c:1181 mark_buffer_dirty+0x1b3/0x1d0

The root cause of the issue lies in the improper implementation of ext4's
buffer_head read fault injection. The actual completion of buffer_head
read and the buffer_head fault injection are not atomic, which can lead
to the uptodate flag being cleared on normally used buffer_heads in race
conditions.

[CPU0] [CPU1] [CPU2]
ext4_read_inode_bitmap
ext4_read_bh()
<bh read complete>
ext4_read_inode_bitmap
if (buffer_uptodate(bh))
return bh
jbd2_journal_commit_transaction
__jbd2_journal_refile_buffer
__jbd2_journal_unfile_buffer
__jbd2_journal_temp_unlink_buffer
ext4_simulate_fail_bh()
clear_buffer_uptodate
mark_buffer_dirty
<report warning>
WARN_ON_ONCE(!buffer_uptodate(bh))

The best approach would be to perform fault injection in the IO completion
callback function, rather than after IO completion. However, the IO
completion callback function cannot get the fault injection code in sb.

Fix it by passing the result of fault injection into the bh read function,
we simulate faults within the bh read function itself. This requires adding
an extra parameter to the bh read functions that need fault injection.

Fixes: 46f870d690fe ("ext4: simulate various I/O and checksum errors when reading metadata")
Signed-off-by: Long Li <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: check buffer_verified in advance to avoid unneeded ext4_get_group_info()

Check buffer_verified in advance to avoid unneeded ext4_get_group_info().
This could be a simple cleanup as compiler ma

ext4: check buffer_verified in advance to avoid unneeded ext4_get_group_info()

Check buffer_verified in advance to avoid unneeded ext4_get_group_info().
This could be a simple cleanup as compiler may handle this.

Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: remove unneeded NULL check of buffer_head in ext4_mark_inode_used()

If gdp from ext4_get_group_desc() is not NULL, then returned group_desc_bh
won't be NULL either. Remove check of group_desc_

ext4: remove unneeded NULL check of buffer_head in ext4_mark_inode_used()

If gdp from ext4_get_group_desc() is not NULL, then returned group_desc_bh
won't be NULL either. Remove check of group_desc_bh and only check
returned gdp from ext4_get_group_desc() like how other callers do.

Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: move checksum length calculation of inode bitmap into ext4_inode_bitmap_csum_[verify/set]() functions

There are some little improve:
1. remove repeat code to calculate checksum length of inode

ext4: move checksum length calculation of inode bitmap into ext4_inode_bitmap_csum_[verify/set]() functions

There are some little improve:
1. remove repeat code to calculate checksum length of inode bitmap
2. remove unnecessary checksum length calculation if checksum is not
enabled.
3. use more efficient bit shift operation instead of div opreation.

Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: remove dead check in __ext4_new_inode()

If we can't grab any inode, the prvious find_inode_bit() will set ino
to be >= EXT4_INODES_PER_GROUP(sb). So the check of need to repeat
in the same gro

ext4: remove dead check in __ext4_new_inode()

If we can't grab any inode, the prvious find_inode_bit() will set ino
to be >= EXT4_INODES_PER_GROUP(sb). So the check of need to repeat
in the same group is not needed.

Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: avoid negative min_clusters in find_group_orlov()

min_clusters is signed integer and will be converted to unsigned
integer when compared with unsigned number stats.free_clusters.
If min_cluste

ext4: avoid negative min_clusters in find_group_orlov()

min_clusters is signed integer and will be converted to unsigned
integer when compared with unsigned number stats.free_clusters.
If min_clusters is negative, it will be converted to a huge unsigned
value in which case all groups may not meet the actual desired free
clusters.
Set negative min_clusters to 0 to avoid unexpected behavior.

Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: avoid potential buffer_head leak in __ext4_new_inode()

If a group is marked EXT4_GROUP_INFO_IBITMAP_CORRUPT after it's inode
bitmap buffer_head was successfully verified, then __ext4_new_inode

ext4: avoid potential buffer_head leak in __ext4_new_inode()

If a group is marked EXT4_GROUP_INFO_IBITMAP_CORRUPT after it's inode
bitmap buffer_head was successfully verified, then __ext4_new_inode()
will get a valid inode_bitmap_bh of a corrupted group from
ext4_read_inode_bitmap() in which case inode_bitmap_bh misses a release.
Hnadle "IS_ERR(inode_bitmap_bh)" and group corruption separately like
how ext4_free_inode() does to avoid buffer_head leak.

Fixes: 9008a58e5dce ("ext4: make the bitmap read routines return real error codes")
Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: avoid buffer_head leak in ext4_mark_inode_used()

Release inode_bitmap_bh from ext4_read_inode_bitmap() in
ext4_mark_inode_used() to avoid buffer_head leak.
By the way, remove unneeded goto for

ext4: avoid buffer_head leak in ext4_mark_inode_used()

Release inode_bitmap_bh from ext4_read_inode_bitmap() in
ext4_mark_inode_used() to avoid buffer_head leak.
By the way, remove unneeded goto for invalid ino when inode_bitmap_bh
is NULL.

Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Signed-off-by: Kemeng Shi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: use ext4_update_inode_fsync_trans() helper in inode creation

Call helper function ext4_update_inode_fsync_trans() instead of open
coding it in __ext4_new_inode(). This helper checks both that

ext4: use ext4_update_inode_fsync_trans() helper in inode creation

Call helper function ext4_update_inode_fsync_trans() instead of open
coding it in __ext4_new_inode(). This helper checks both that the handle
is valid *and* that it hasn't been aborted due to some fatal error in the
journalling layer, using is_handle_aborted().

Signed-off-by: Luis Henriques (SUSE) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <[email protected]>
Link: https://lore.kernel.org/r/20231004185347.

ext4: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

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

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ext4: drop read-only check in ext4_init_inode_table()

We better should not be initializing inode tables on read-only
filesystem. The following transaction start will warn us and make the
function ba

ext4: drop read-only check in ext4_init_inode_table()

We better should not be initializing inode tables on read-only
filesystem. The following transaction start will warn us and make the
function bail anyway so drop the pointless check.

Signed-off-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: make ext4_forced_shutdown() take struct super_block

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most
callers need to get it from struct super_block anyway. So just pass in
s

ext4: make ext4_forced_shutdown() take struct super_block

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most
callers need to get it from struct super_block anyway. So just pass in
struct super_block to save all callers from some boilerplate code. No
functional changes.

Signed-off-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

ext4: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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ext4: allow ext4_get_group_info() to fail

Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen. However, if a
malicious attaker (or

ext4: allow ext4_get_group_info() to fail

Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen. However, if a
malicious attaker (or fuzzer) modifies the superblock via the block
device while it is the file system is mounted, it is possible for
s_first_data_block to get set to a very large number. In that case,
when calculating the block group of some block number (such as the
starting block of a preallocation region), could result in an
underflow and very large block group number. Then the BUG_ON check in
ext4_get_group_info() would fire, resutling in a denial of service
attack that can be triggered by root or someone with write access to
the block device.

For a quality of implementation perspective, it's best that even if
the system administrator does something that they shouldn't, that it
will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info()
will call ext4_error and return NULL. We also add fallback code in
all of the callers of ext4_get_group_info() that it might NULL.

Also, since ext4_get_group_info() was already borderline to be an
inline function, un-inline it. The results in a next reduction of the
compiled text size of ext4 by roughly 2k.

Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Reported-by: [email protected]
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <[email protected]>
Reviewed-by: Jan Kara <[email protected]>

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ext4: remove unused group parameter in ext4_block_bitmap_csum_set

Remove unused group parameter in ext4_block_bitmap_csum_set. After this,
group parameter in ext4_set_bitmap_checksums is also not us

ext4: remove unused group parameter in ext4_block_bitmap_csum_set

Remove unused group parameter in ext4_block_bitmap_csum_set. After this,
group parameter in ext4_set_bitmap_checksums is also not used, just
remove it too.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: remove unused group parameter in ext4_inode_bitmap_csum_set

Remove unused group parameter in ext4_inode_bitmap_csum_set.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Jan

ext4: remove unused group parameter in ext4_inode_bitmap_csum_set

Remove unused group parameter in ext4_inode_bitmap_csum_set.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: remove unused group parameter in ext4_inode_bitmap_csum_verify

Remove unused group parameter in ext4_inode_bitmap_csum_verify.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-b

ext4: remove unused group parameter in ext4_inode_bitmap_csum_verify

Remove unused group parameter in ext4_inode_bitmap_csum_verify.

Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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fs: port fs{g,u}id helpers to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is jus

fs: port fs{g,u}id helpers to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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fs: port inode_init_owner() to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is ju

fs: port inode_init_owner() to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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ext4: split ext4_journal_start trace for debug

we might want to know why jbd2 thread using high io for detail,
split ext4_journal_start trace to ext4_journal_start_sb and
ext4_journal_start_inode, s

ext4: split ext4_journal_start trace for debug

we might want to know why jbd2 thread using high io for detail,
split ext4_journal_start trace to ext4_journal_start_sb and
ext4_journal_start_inode, show ino and handle type when possible.

Signed-off-by: changfengnan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Darrick J. Wong <[email protected]> # for xfs
Reviewed-by: SeongJae Park <[email protected]> # for damon
Reviewed-by: Jason Gunthorpe <[email protected]> # for infiniband
Reviewed-by: Russell King (Oracle) <[email protected]> # for arm
Acked-by: Ulf Hansson <[email protected]> # for mmc
Signed-off-by: Jason A. Donenfeld <[email protected]>

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