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| author |   Al Viro <viro@zeniv.linux.org.uk> | 2019-04-10 14:43:44 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-05-01 22:37:39 -0400 |
| commit | fdb0da89f4ba0c74d7d3b9e6f471e96a5766820b (patch) | |
| tree | 3c82eb1fe04568315a76d03ec86617e206b12a41 /Documentation/filesystems/Locking | |
| parent | Merge branch 'fixes' into work.icache (diff) | |
| download | linux-dev-fdb0da89f4ba0c74d7d3b9e6f471e96a5766820b.tar.xz linux-dev-fdb0da89f4ba0c74d7d3b9e6f471e96a5766820b.zip | |
new inode method: ->free_inode()
A lot of ->destroy_inode() instances end with call_rcu() of a callback
that does RCU-delayed part of freeing. Introduce a new method for
doing just that, with saner signature.
Rules:
->destroy_inode ->free_inode
f g immediate call of f(),
RCU-delayed call of g()
f NULL immediate call of f(),
no RCU-delayed calls
NULL g RCU-delayed call of g()
NULL NULL RCU-delayed default freeing
IOW, NULL ->free_inode gives the same behaviour as now.
Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could
mandate the latter form, but that would have very little benefit beyond
making rules a bit more symmetric. It would break backwards compatibility,
require extra boilerplate and expected semantics for (NULL, NULL) pair
would have no use whatsoever...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation/filesystems/Locking')
| -rw-r--r-- | Documentation/filesystems/Locking | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index efea228ccd8a..7b20c385cc02 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -118,6 +118,7 @@ set: exclusive --------------------------- super_operations --------------------------- prototypes: struct inode *(*alloc_inode)(struct super_block *sb); + void (*free_inode)(struct inode *); void (*destroy_inode)(struct inode *); void (*dirty_inode) (struct inode *, int flags); int (*write_inode) (struct inode *, struct writeback_control *wbc); @@ -139,6 +140,7 @@ locking rules: All may block [not true, see below] s_umount alloc_inode: +free_inode: called from RCU callback destroy_inode: dirty_inode: write_inode: |