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Diffstat (limited to 'Documentation/filesystems/porting')
| -rw-r--r-- | Documentation/filesystems/porting | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 1567a53857bd..12c57abdaac9 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -557,3 +557,21 @@ in your dentry operations instead. will not happen in parallel ("same" in the sense of your ->d_compare()). Lookups on different names in the same directory can and do happen in parallel now. +-- +[recommended] + ->iterate_shared() is added; it's a parallel variant of ->iterate(). + Exclusion on struct file level is still provided (as well as that + between it and lseek on the same struct file), but if your directory + has been opened several times, you can get these called in parallel. + Exclusion between that method and all directory-modifying ones is + still provided, of course. + + Often enough ->iterate() can serve as ->iterate_shared() without any + changes - it is a read-only operation, after all. If you have any + per-inode or per-dentry in-core data structures modified by ->iterate(), + you might need something to serialize the access to them. If you + do dcache pre-seeding, you'll need to switch to d_alloc_parallel() for + that; look for in-tree examples. + + Old method is only used if the new one is absent; eventually it will + be removed. Switch while you still can; the old one won't stay. |