This adds a d_prune dentry operation that is called by the VFS prior to pruning (i.e. unhashing and killing) a hashed dentry from the dcache. This will be used by Ceph to maintain a flag indicating whether the complete contents of a directory are contained in the dcache, allowing it to satisfy lookups and readdir without addition server communication.
Signed-off-by: Sage Weil <[email protected]> --- Documentation/filesystems/Locking | 1 + fs/dcache.c | 8 ++++++++ include/linux/dcache.h | 3 +++ 3 files changed, 12 insertions(+), 0 deletions(-) diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 57d827d..b3fa7c8 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -29,6 +29,7 @@ d_hash no no no maybe d_compare: yes no no maybe d_delete: no yes no no d_release: no no yes no +d_prune: no yes no no d_iput: no no yes no d_dname: no no no no d_automount: no no yes no diff --git a/fs/dcache.c b/fs/dcache.c index fbdcbca..84e1756 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -673,6 +673,8 @@ static void try_prune_one_dentry(struct dentry *dentry) spin_unlock(&dentry->d_lock); return; } + if (dentry->d_flags & DCACHE_OP_PRUNE) + dentry->d_op->d_prune(dentry); dentry = dentry_kill(dentry, 1); } } @@ -879,6 +881,8 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) /* detach this root from the system */ spin_lock(&dentry->d_lock); + if (dentry->d_flags & DCACHE_OP_PRUNE) + dentry->d_op->d_prune(dentry); dentry_lru_del(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); @@ -895,6 +899,8 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) d_u.d_child) { spin_lock_nested(&loop->d_lock, DENTRY_D_LOCK_NESTED); + if (dentry->d_flags & DCACHE_OP_PRUNE) + dentry->d_op->d_prune(dentry); dentry_lru_del(loop); __d_drop(loop); spin_unlock(&loop->d_lock); @@ -1363,6 +1369,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) dentry->d_flags |= DCACHE_OP_REVALIDATE; if (op->d_delete) dentry->d_flags |= DCACHE_OP_DELETE; + if (op->d_prune) + dentry->d_flags |= DCACHE_OP_PRUNE; } EXPORT_SYMBOL(d_set_d_op); diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 19d90a5..681f46f 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -165,6 +165,7 @@ struct dentry_operations { unsigned int, const char *, const struct qstr *); int (*d_delete)(const struct dentry *); void (*d_release)(struct dentry *); + void (*d_prune)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)(struct dentry *, char *, int); struct vfsmount *(*d_automount)(struct path *); @@ -219,6 +220,8 @@ struct dentry_operations { #define DCACHE_MANAGED_DENTRY \ (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT) +#define DCACHE_OP_PRUNE 0x80000 + extern seqlock_t rename_lock; static inline int dname_external(struct dentry *dentry) -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
