kernel.git/fs/ext4/ext4.h, branch linux-6.15.y

ext4: factor out ext4_get_maxbytes()

2025-06-27T10:13:03Z

commit dbe27f06fa38b9bfc598f8864ae1c5d5831d9992 upstream. There are several locations that get the correct maxbytes value based on the inode's block type. It would be beneficial to extract a common helper function to make the code more clear. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: Make sb update interval tunable

2025-03-21T05:12:33Z

Currently, outside error paths, we auto commit the super block after 1 hour has passed and 16MB worth of updates have been written since last commit. This is a policy decision so make this tunable while keeping the defaults same. This is useful if user wants to tweak the superblock behavior or for debugging the codepath by allowing to trigger it more frequently. We can now tweak the super block update using sb_update_sec and sb_update_kb files in /sys/fs/ext4// Reviewed-by: Jan Kara Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Baokun Li Signed-off-by: Ojaswin Mujoo Link: https://patch.msgid.link/950fb8c9b2905620e16f02a3b9eeea5a5b6cb87e.1742279837.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: avoid journaling sb update on error if journal is destroying

2025-03-21T05:12:33Z

Presently we always BUG_ON if trying to start a transaction on a journal marked with JBD2_UNMOUNT, since this should never happen. However, while ltp running stress tests, it was observed that in case of some error handling paths, it is possible for update_super_work to start a transaction after the journal is destroyed eg: (umount) ext4_kill_sb kill_block_super generic_shutdown_super sync_filesystem /* commits all txns */ evict_inodes /* might start a new txn */ ext4_put_super flush_work(&sbi->s_sb_upd_work) /* flush the workqueue */ jbd2_journal_destroy journal_kill_thread journal->j_flags |= JBD2_UNMOUNT; jbd2_journal_commit_transaction jbd2_journal_get_descriptor_buffer jbd2_journal_bmap ext4_journal_bmap ext4_map_blocks ... ext4_inode_error ext4_handle_error schedule_work(&sbi->s_sb_upd_work) /* work queue kicks in */ update_super_work jbd2_journal_start start_this_handle BUG_ON(journal->j_flags & JBD2_UNMOUNT) Hence, introduce a new mount flag to indicate journal is destroying and only do a journaled (and deferred) update of sb if this flag is not set. Otherwise, just fallback to an un-journaled commit. Further, in the journal destroy path, we have the following sequence: 1. Set mount flag indicating journal is destroying 2. force a commit and wait for it 3. flush pending sb updates This sequence is important as it ensures that, after this point, there is no sb update that might be journaled so it is safe to update the sb outside the journal. (To avoid race discussed in 2d01ddc86606) Also, we don't need a similar check in ext4_grp_locked_error since it is only called from mballoc and AFAICT it would be always valid to schedule work here. Fixes: 2d01ddc86606 ("ext4: save error info to sb through journal if available") Reported-by: Mahesh Kumar Signed-off-by: Ojaswin Mujoo Reviewed-by: Jan Kara Link: https://patch.msgid.link/9613c465d6ff00cd315602f99283d5f24018c3f7.1742279837.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: remove redundant function ext4_has_metadata_csum

2025-03-17T15:19:41Z

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 Reviewed-by: Darrick J. Wong Link: https://patch.msgid.link/20250207031335.42637-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: remove unused input "inode" in ext4_find_dest_de

2025-03-17T02:41:17Z

Remove unused input "inode" in ext4_find_dest_de. Signed-off-by: Kemeng Shi Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250123162050.2114499-4-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: add ext4_emergency_state() helper function

2025-03-13T14:16:34Z

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 Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122114130.229709-4-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: add EXT4_FLAGS_EMERGENCY_RO bit

2025-03-13T14:16:34Z

EXT4_FLAGS_EMERGENCY_RO Indicates that the current file system has become read-only due to some error. Compared to SB_RDONLY, setting it does not require a lock because we won't clear it, which avoids over-coupling with vfs freeze. Also, add a helper function ext4_emergency_ro() to check if the bit is set. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122114130.229709-3-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: convert EXT4_FLAGS_* defines to enum

2025-03-13T14:16:34Z

Do away with the defines and use an enum as it's cleaner. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122114130.229709-2-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: pack holes in ext4_inode_info

2025-03-13T14:08:09Z

When CONFIG_DEBUG_SPINLOCK is not enabled (general case), there are four 4 bytes holes and one 2 bytes hole in struct ext4_inode_info. Move the members to pack the four 4 bytes holes. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122110533.4116662-10-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: remove unused member 'i_unwritten' from 'ext4_inode_info'

2025-03-13T14:08:09Z

After commit 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure"), no one cares about the value of i_unwritten, so there is no need to maintain this variable, remove it, and clean up the associated logic. Suggested-by: Zhang Yi Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122110533.4116662-9-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o