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| author | Ojaswin Mujoo <ojaswin@linux.ibm.com> | 2023-03-25 13:43:40 +0530 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-04-06 01:13:13 -0400 |
| commit | a8e38fd37cff911638ac288adb138265f71e50c0 (patch) | |
| tree | 06f3f5a748e05949344efd129a6e5b479b322080 /fs/ext4/mballoc.h | |
| parent | 93cdf49f6eca5e23f6546b8f28457b2e6a6961d9 (diff) | |
| download | lwn-a8e38fd37cff911638ac288adb138265f71e50c0.tar.gz lwn-a8e38fd37cff911638ac288adb138265f71e50c0.zip | |
ext4: Convert pa->pa_inode_list and pa->pa_obj_lock into a union
** Splitting pa->pa_inode_list **
Currently, we use the same pa->pa_inode_list to add a pa to either
the inode preallocation list or the locality group preallocation list.
For better clarity, split this list into a union of 2 list_heads and use
either of the them based on the type of pa.
** Splitting pa->pa_obj_lock **
Currently, pa->pa_obj_lock is either assigned &ei->i_prealloc_lock for
inode PAs or lg_prealloc_lock for lg PAs, and is then used to lock the
lists containing these PAs. Make the distinction between the 2 PA types
clear by changing this lock to a union of 2 locks. Explicitly use the
pa_lock_node.inode_lock for inode PAs and pa_lock_node.lg_lock for lg
PAs.
This patch is required so that the locality group preallocation code
remains the same as in upcoming patches we are going to make changes to
inode preallocation code to move from list to rbtree based
implementation. This patch also makes it easier to review the upcoming
patches.
There are no functional changes in this patch.
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1d7ac0557e998c3fc7eef422b52e4bc67bdef2b0.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.h')
| -rw-r--r-- | fs/ext4/mballoc.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h index dcda2a943cee..398a6688c341 100644 --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -114,7 +114,10 @@ struct ext4_free_data { }; struct ext4_prealloc_space { - struct list_head pa_inode_list; + union { + struct list_head inode_list; /* for inode PAs */ + struct list_head lg_list; /* for lg PAs */ + } pa_node; struct list_head pa_group_list; union { struct list_head pa_tmp_list; @@ -128,7 +131,10 @@ struct ext4_prealloc_space { ext4_grpblk_t pa_len; /* len of preallocated chunk */ ext4_grpblk_t pa_free; /* how many blocks are free */ unsigned short pa_type; /* pa type. inode or group */ - spinlock_t *pa_obj_lock; + union { + spinlock_t *inode_lock; /* locks the inode list holding this PA */ + spinlock_t *lg_lock; /* locks the lg list holding this PA */ + } pa_node_lock; struct inode *pa_inode; /* hack, for history only */ }; |