diff options
| -rw-r--r-- | Documentation/filesystems/porting | 5 | ||||
| -rw-r--r-- | fs/dcache.c | 24 | ||||
| -rw-r--r-- | fs/nsfs.c | 3 | ||||
| -rw-r--r-- | include/linux/dcache.h | 2 |
4 files changed, 20 insertions, 14 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 7b7b845c490a..32b5186be412 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -622,3 +622,8 @@ in your dentry operations instead. alloc_file_clone(file, flags, ops) does not affect any caller's references. On success you get a new struct file sharing the mount/dentry with the original, on failure - ERR_PTR(). +-- +[mandatory] + DCACHE_RCUACCESS is gone; having an RCU delay on dentry freeing is the + default. DCACHE_NORCU opts out, and only d_alloc_pseudo() has any + business doing so. diff --git a/fs/dcache.c b/fs/dcache.c index cb515f183482..6e0022326afe 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -344,7 +344,7 @@ static void dentry_free(struct dentry *dentry) } } /* if dentry was never visible to RCU, immediate free is OK */ - if (!(dentry->d_flags & DCACHE_RCUACCESS)) + if (dentry->d_flags & DCACHE_NORCU) __d_free(&dentry->d_u.d_rcu); else call_rcu(&dentry->d_u.d_rcu, __d_free); @@ -1694,7 +1694,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) struct dentry *dentry = __d_alloc(parent->d_sb, name); if (!dentry) return NULL; - dentry->d_flags |= DCACHE_RCUACCESS; spin_lock(&parent->d_lock); /* * don't need child lock because it is not subject @@ -1719,7 +1718,7 @@ struct dentry *d_alloc_cursor(struct dentry * parent) { struct dentry *dentry = d_alloc_anon(parent->d_sb); if (dentry) { - dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR; + dentry->d_flags |= DCACHE_DENTRY_CURSOR; dentry->d_parent = dget(parent); } return dentry; @@ -1732,10 +1731,17 @@ struct dentry *d_alloc_cursor(struct dentry * parent) * * For a filesystem that just pins its dentries in memory and never * performs lookups at all, return an unhashed IS_ROOT dentry. + * This is used for pipes, sockets et.al. - the stuff that should + * never be anyone's children or parents. Unlike all other + * dentries, these will not have RCU delay between dropping the + * last reference and freeing them. */ struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name) { - return __d_alloc(sb, name); + struct dentry *dentry = __d_alloc(sb, name); + if (likely(dentry)) + dentry->d_flags |= DCACHE_NORCU; + return dentry; } EXPORT_SYMBOL(d_alloc_pseudo); @@ -1899,12 +1905,10 @@ struct dentry *d_make_root(struct inode *root_inode) if (root_inode) { res = d_alloc_anon(root_inode->i_sb); - if (res) { - res->d_flags |= DCACHE_RCUACCESS; + if (res) d_instantiate(res, root_inode); - } else { + else iput(root_inode); - } } return res; } @@ -2769,9 +2773,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target, copy_name(dentry, target); target->d_hash.pprev = NULL; dentry->d_parent->d_lockref.count++; - if (dentry == old_parent) - dentry->d_flags |= DCACHE_RCUACCESS; - else + if (dentry != old_parent) /* wasn't IS_ROOT */ WARN_ON(!--old_parent->d_lockref.count); } else { target->d_parent = old_parent; diff --git a/fs/nsfs.c b/fs/nsfs.c index 60702d677bd4..30d150a4f0c6 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -85,13 +85,12 @@ slow: inode->i_fop = &ns_file_operations; inode->i_private = ns; - dentry = d_alloc_pseudo(mnt->mnt_sb, &empty_name); + dentry = d_alloc_anon(mnt->mnt_sb); if (!dentry) { iput(inode); return ERR_PTR(-ENOMEM); } d_instantiate(dentry, inode); - dentry->d_flags |= DCACHE_RCUACCESS; dentry->d_fsdata = (void *)ns->ops; d = atomic_long_cmpxchg(&ns->stashed, 0, (unsigned long)dentry); if (d) { diff --git a/include/linux/dcache.h b/include/linux/dcache.h index ef4b70f64f33..0880baefd85f 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -175,7 +175,6 @@ struct dentry_operations { * typically using d_splice_alias. */ #define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */ -#define DCACHE_RCUACCESS 0x00000080 /* Entry has ever been RCU-visible */ #define DCACHE_CANT_MOUNT 0x00000100 #define DCACHE_GENOCIDE 0x00000200 @@ -216,6 +215,7 @@ struct dentry_operations { #define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */ #define DCACHE_DENTRY_CURSOR 0x20000000 +#define DCACHE_NORCU 0x40000000 /* No RCU delay for freeing */ extern seqlock_t rename_lock; |