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Diffstat (limited to 'Documentation/filesystems/porting.rst')
| -rw-r--r-- | Documentation/filesystems/porting.rst | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index c549fb2fc3ba..1be76ef117b3 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -1091,6 +1091,40 @@ would need to do so. --- +**mandatory** + +The list of children anchored in parent dentry got turned into hlist now. +Field names got changed (->d_children/->d_sib instead of ->d_subdirs/->d_child +for anchor/entries resp.), so any affected places will be immediately caught +by compiler. + +--- + +**mandatory** + +->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. + +--- + **recommended** Block device freezing and thawing have been moved to holder operations. |