diff options
Diffstat (limited to 'Documentation/filesystems/porting.rst')
| -rw-r--r-- | Documentation/filesystems/porting.rst | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index da8073b592ff..d890ef07a9fd 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -1078,3 +1078,20 @@ by compiler. ->d_delete() instances are now called for dentries with ->d_lock held and refcount equal to 0. They are not permitted to drop/regain ->d_lock. None of in-tree instances did anything of that sort. Make sure yours do not... + +-- + +**mandatory** + +->d_prune() instances are now called without ->d_lock held on the parent. +->d_lock on dentry itself is still held; if you need per-parent exclusions (none +of the in-tree instances did), use your own spinlock. + +->d_iput() and ->d_release() are called with victim dentry still in the +list of parent's children. It is still unhashed, marked killed, etc., just not +removed from parent's ->d_children yet. + +Anyone iterating through the list of children needs to be aware of the +half-killed dentries that might be seen there; taking ->d_lock on those will +see them negative, unhashed and with negative refcount, which means that most +of the in-kernel users would've done the right thing anyway without any adjustment. |