diff options
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 1162 |
1 files changed, 365 insertions, 797 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index f90141387f01..86d2de63461e 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -14,7 +14,7 @@ * the dcache entry is deleted or garbage collected. */ -#include <linux/syscalls.h> +#include <linux/ratelimit.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/fs.h> @@ -24,22 +24,12 @@ #include <linux/hash.h> #include <linux/cache.h> #include <linux/export.h> -#include <linux/mount.h> -#include <linux/file.h> -#include <linux/uaccess.h> #include <linux/security.h> #include <linux/seqlock.h> -#include <linux/swap.h> #include <linux/bootmem.h> -#include <linux/fs_struct.h> -#include <linux/hardirq.h> #include <linux/bit_spinlock.h> #include <linux/rculist_bl.h> -#include <linux/prefetch.h> -#include <linux/ratelimit.h> #include <linux/list_lru.h> -#include <linux/kasan.h> - #include "internal.h" #include "mount.h" @@ -49,8 +39,8 @@ * - i_dentry, d_u.d_alias, d_inode of aliases * dcache_hash_bucket lock protects: * - the dcache hash table - * s_anon bl list spinlock protects: - * - the s_anon list (see __d_drop) + * s_roots bl list spinlock protects: + * - the s_roots list (see __d_drop) * dentry->d_sb->s_dentry_lru_lock protects: * - the dcache lru lists and counters * d_lock protects: @@ -68,7 +58,7 @@ * dentry->d_lock * dentry->d_sb->s_dentry_lru_lock * dcache_hash_bucket lock - * s_anon lock + * s_roots lock * * If there is an ancestor relationship: * dentry->d_parent->...->d_parent->d_lock @@ -77,9 +67,7 @@ * dentry->d_lock * * If no ancestor relationship: - * if (dentry1 < dentry2) - * dentry1->d_lock - * dentry2->d_lock + * arbitrary, since it's serialized on rename_lock */ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); @@ -104,14 +92,13 @@ EXPORT_SYMBOL(slash_name); * information, yet avoid using a prime hash-size or similar. */ -static unsigned int d_hash_mask __read_mostly; static unsigned int d_hash_shift __read_mostly; static struct hlist_bl_head *dentry_hashtable __read_mostly; static inline struct hlist_bl_head *d_hash(unsigned int hash) { - return dentry_hashtable + (hash >> (32 - d_hash_shift)); + return dentry_hashtable + (hash >> d_hash_shift); } #define IN_LOOKUP_SHIFT 10 @@ -195,7 +182,7 @@ static inline int dentry_string_cmp(const unsigned char *cs, const unsigned char unsigned long a,b,mask; for (;;) { - a = *(unsigned long *)cs; + a = read_word_at_a_time(cs); b = load_unaligned_zeropad(ct); if (tcount < sizeof(unsigned long)) break; @@ -231,7 +218,7 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c { /* * Be careful about RCU walk racing with rename: - * use 'lockless_dereference' to fetch the name pointer. + * use 'READ_ONCE' to fetch the name pointer. * * NOTE! Even if a rename will mean that the length * was not loaded atomically, we don't care. The @@ -245,7 +232,7 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c * early because the data cannot match (there can * be no NUL in the ct/tcount data) */ - const unsigned char *cs = lockless_dereference(dentry->d_name.name); + const unsigned char *cs = READ_ONCE(dentry->d_name.name); return dentry_string_cmp(cs, ct, tcount); } @@ -270,11 +257,25 @@ static void __d_free(struct rcu_head *head) kmem_cache_free(dentry_cache, dentry); } +static void __d_free_external_name(struct rcu_head *head) +{ + struct external_name *name = container_of(head, struct external_name, + u.head); + + mod_node_page_state(page_pgdat(virt_to_page(name)), + NR_INDIRECTLY_RECLAIMABLE_BYTES, + -ksize(name)); + + kfree(name); +} + static void __d_free_external(struct rcu_head *head) { struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu); - kfree(external_name(dentry)); - kmem_cache_free(dentry_cache, dentry); + + __d_free_external_name(&external_name(dentry)->u.head); + + kmem_cache_free(dentry_cache, dentry); } static inline int dname_external(const struct dentry *dentry) @@ -304,7 +305,7 @@ void release_dentry_name_snapshot(struct name_snapshot *name) struct external_name *p; p = container_of(name->name, struct external_name, name[0]); if (unlikely(atomic_dec_and_test(&p->u.count))) - kfree_rcu(p, u.head); + call_rcu(&p->u.head, __d_free_external_name); } } EXPORT_SYMBOL(release_dentry_name_snapshot); @@ -444,17 +445,6 @@ static void d_lru_shrink_move(struct list_lru_one *lru, struct dentry *dentry, list_lru_isolate_move(lru, &dentry->d_lru, list); } -/* - * dentry_lru_(add|del)_list) must be called with d_lock held. - */ -static void dentry_lru_add(struct dentry *dentry) -{ - if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) - d_lru_add(dentry); - else if (unlikely(!(dentry->d_flags & DCACHE_REFERENCED))) - dentry->d_flags |= DCACHE_REFERENCED; -} - /** * d_drop - drop a dentry * @dentry: dentry to drop @@ -468,27 +458,33 @@ static void dentry_lru_add(struct dentry *dentry) * d_drop() is used mainly for stuff that wants to invalidate a dentry for some * reason (NFS timeouts or autofs deletes). * - * __d_drop requires dentry->d_lock. + * __d_drop requires dentry->d_lock + * ___d_drop doesn't mark dentry as "unhashed" + * (dentry->d_hash.pprev will be LIST_POISON2, not NULL). */ +static void ___d_drop(struct dentry *dentry) +{ + struct hlist_bl_head *b; + /* + * Hashed dentries are normally on the dentry hashtable, + * with the exception of those newly allocated by + * d_obtain_root, which are always IS_ROOT: + */ + if (unlikely(IS_ROOT(dentry))) + b = &dentry->d_sb->s_roots; + else + b = d_hash(dentry->d_name.hash); + + hlist_bl_lock(b); + __hlist_bl_del(&dentry->d_hash); + hlist_bl_unlock(b); +} + void __d_drop(struct dentry *dentry) { if (!d_unhashed(dentry)) { - struct hlist_bl_head *b; - /* - * Hashed dentries are normally on the dentry hashtable, - * with the exception of those newly allocated by - * d_obtain_alias, which are always IS_ROOT: - */ - if (unlikely(IS_ROOT(dentry))) - b = &dentry->d_sb->s_anon; - else - b = d_hash(dentry->d_name.hash); - - hlist_bl_lock(b); - __hlist_bl_del(&dentry->d_hash); + ___d_drop(dentry); dentry->d_hash.pprev = NULL; - hlist_bl_unlock(b); - /* After this call, in-progress rcu-walk path lookup will fail. */ write_seqcount_invalidate(&dentry->d_seq); } } @@ -586,10 +582,71 @@ static void __dentry_kill(struct dentry *dentry) dentry_free(dentry); } +static struct dentry *__lock_parent(struct dentry *dentry) +{ + struct dentry *parent; + rcu_read_lock(); + spin_unlock(&dentry->d_lock); +again: + parent = READ_ONCE(dentry->d_parent); + spin_lock(&parent->d_lock); + /* + * We can't blindly lock dentry until we are sure + * that we won't violate the locking order. + * Any changes of dentry->d_parent must have + * been done with parent->d_lock held, so + * spin_lock() above is enough of a barrier + * for checking if it's still our child. + */ + if (unlikely(parent != dentry->d_parent)) { + spin_unlock(&parent->d_lock); + goto again; + } + rcu_read_unlock(); + if (parent != dentry) + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + else + parent = NULL; + return parent; +} + +static inline struct dentry *lock_parent(struct dentry *dentry) +{ + struct dentry *parent = dentry->d_parent; + if (IS_ROOT(dentry)) + return NULL; + if (likely(spin_trylock(&parent->d_lock))) + return parent; + return __lock_parent(dentry); +} + +static inline bool retain_dentry(struct dentry *dentry) +{ + WARN_ON(d_in_lookup(dentry)); + + /* Unreachable? Get rid of it */ + if (unlikely(d_unhashed(dentry))) + return false; + + if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) + return false; + + if (unlikely(dentry->d_flags & DCACHE_OP_DELETE)) { + if (dentry->d_op->d_delete(dentry)) + return false; + } + /* retain; LRU fodder */ + dentry->d_lockref.count--; + if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) + d_lru_add(dentry); + else if (unlikely(!(dentry->d_flags & DCACHE_REFERENCED))) + dentry->d_flags |= DCACHE_REFERENCED; + return true; +} + /* * Finish off a dentry we've decided to kill. * dentry->d_lock must be held, returns with it unlocked. - * If ref is non-zero, then decrement the refcount too. * Returns dentry requiring refcount drop, or NULL if we're done. */ static struct dentry *dentry_kill(struct dentry *dentry) @@ -599,57 +656,43 @@ static struct dentry *dentry_kill(struct dentry *dentry) struct dentry *parent = NULL; if (inode && unlikely(!spin_trylock(&inode->i_lock))) - goto failed; + goto slow_positive; if (!IS_ROOT(dentry)) { parent = dentry->d_parent; if (unlikely(!spin_trylock(&parent->d_lock))) { - if (inode) - spin_unlock(&inode->i_lock); - goto failed; + parent = __lock_parent(dentry); + if (likely(inode || !dentry->d_inode)) + goto got_locks; + /* negative that became positive */ + if (parent) + spin_unlock(&parent->d_lock); + inode = dentry->d_inode; + goto slow_positive; } } - __dentry_kill(dentry); return parent; -failed: +slow_positive: spin_unlock(&dentry->d_lock); - return dentry; /* try again with same dentry */ -} - -static inline struct dentry *lock_parent(struct dentry *dentry) -{ - struct dentry *parent = dentry->d_parent; - if (IS_ROOT(dentry)) - return NULL; - if (unlikely(dentry->d_lockref.count < 0)) - return NULL; - if (likely(spin_trylock(&parent->d_lock))) + spin_lock(&inode->i_lock); + spin_lock(&dentry->d_lock); + parent = lock_parent(dentry); +got_locks: + if (unlikely(dentry->d_lockref.count != 1)) { + dentry->d_lockref.count--; + } else if (likely(!retain_dentry(dentry))) { + __dentry_kill(dentry); return parent; - rcu_read_lock(); - spin_unlock(&dentry->d_lock); -again: - parent = ACCESS_ONCE(dentry->d_parent); - spin_lock(&parent->d_lock); - /* - * We can't blindly lock dentry until we are sure - * that we won't violate the locking order. - * Any changes of dentry->d_parent must have - * been done with parent->d_lock held, so - * spin_lock() above is enough of a barrier - * for checking if it's still our child. - */ - if (unlikely(parent != dentry->d_parent)) { - spin_unlock(&parent->d_lock); - goto again; } - rcu_read_unlock(); - if (parent != dentry) - spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); - else - parent = NULL; - return parent; + /* we are keeping it, after all */ + if (inode) + spin_unlock(&inode->i_lock); + if (parent) + spin_unlock(&parent->d_lock); + spin_unlock(&dentry->d_lock); + return NULL; } /* @@ -721,7 +764,7 @@ static inline bool fast_dput(struct dentry *dentry) * around with a zero refcount. */ smp_rmb(); - d_flags = ACCESS_ONCE(dentry->d_flags); + d_flags = READ_ONCE(dentry->d_flags); d_flags &= DCACHE_REFERENCED | DCACHE_LRU_LIST | DCACHE_DISCONNECTED; /* Nothing to do? Dropping the reference was all we needed? */ @@ -799,27 +842,11 @@ repeat: /* Slow case: now with the dentry lock held */ rcu_read_unlock(); - WARN_ON(d_in_lookup(dentry)); - - /* Unreachable? Get rid of it */ - if (unlikely(d_unhashed(dentry))) - goto kill_it; - - if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) - goto kill_it; - - if (unlikely(dentry->d_flags & DCACHE_OP_DELETE)) { - if (dentry->d_op->d_delete(dentry)) - goto kill_it; + if (likely(retain_dentry(dentry))) { + spin_unlock(&dentry->d_lock); + return; } - dentry_lru_add(dentry); - - dentry->d_lockref.count--; - spin_unlock(&dentry->d_lock); - return; - -kill_it: dentry = dentry_kill(dentry); if (dentry) { cond_resched(); @@ -850,11 +877,11 @@ struct dentry *dget_parent(struct dentry *dentry) * locking. */ rcu_read_lock(); - ret = ACCESS_ONCE(dentry->d_parent); + ret = READ_ONCE(dentry->d_parent); gotref = lockref_get_not_zero(&ret->d_lockref); rcu_read_unlock(); if (likely(gotref)) { - if (likely(ret == ACCESS_ONCE(dentry->d_parent))) + if (likely(ret == READ_ONCE(dentry->d_parent))) return ret; dput(ret); } @@ -968,56 +995,85 @@ restart: } EXPORT_SYMBOL(d_prune_aliases); -static void shrink_dentry_list(struct list_head *list) +/* + * Lock a dentry from shrink list. + * Called under rcu_read_lock() and dentry->d_lock; the former + * guarantees that nothing we access will be freed under us. + * Note that dentry is *not* protected from concurrent dentry_kill(), + * d_delete(), etc. + * + * Return false if dentry has been disrupted or grabbed, leaving + * the caller to kick it off-list. Otherwise, return true and have + * that dentry's inode and parent both locked. + */ +static bool shrink_lock_dentry(struct dentry *dentry) { - struct dentry *dentry, *parent; + struct inode *inode; + struct dentry *parent; - while (!list_empty(list)) { - struct inode *inode; - dentry = list_entry(list->prev, struct dentry, d_lru); + if (dentry->d_lockref.count) + return false; + + inode = dentry->d_inode; + if (inode && unlikely(!spin_trylock(&inode->i_lock))) { + spin_unlock(&dentry->d_lock); + spin_lock(&inode->i_lock); spin_lock(&dentry->d_lock); - parent = lock_parent(dentry); + if (unlikely(dentry->d_lockref.count)) + goto out; + /* changed inode means that somebody had grabbed it */ + if (unlikely(inode != dentry->d_inode)) + goto out; + } - /* - * The dispose list is isolated and dentries are not accounted - * to the LRU here, so we can simply remove it from the list - * here regardless of whether it is referenced or not. - */ - d_shrink_del(dentry); + parent = dentry->d_parent; + if (IS_ROOT(dentry) || likely(spin_trylock(&parent->d_lock))) + return true; - /* - * We found an inuse dentry which was not removed from - * the LRU because of laziness during lookup. Do not free it. - */ - if (dentry->d_lockref.count > 0) { - spin_unlock(&dentry->d_lock); - if (parent) - spin_unlock(&parent->d_lock); - continue; - } + spin_unlock(&dentry->d_lock); + spin_lock(&parent->d_lock); + if (unlikely(parent != dentry->d_parent)) { + spin_unlock(&parent->d_lock); + spin_lock(&dentry->d_lock); + goto out; + } + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + if (likely(!dentry->d_lockref.count)) + return true; + spin_unlock(&parent->d_lock); +out: + if (inode) + spin_unlock(&inode->i_lock); + return false; +} + +static void shrink_dentry_list(struct list_head *list) +{ + while (!list_empty(list)) { + struct dentry *dentry, *parent; + cond_resched(); - if (unlikely(dentry->d_flags & DCACHE_DENTRY_KILLED)) { - bool can_free = dentry->d_flags & DCACHE_MAY_FREE; + dentry = list_entry(list->prev, struct dentry, d_lru); + spin_lock(&dentry->d_lock); + rcu_read_lock(); + if (!shrink_lock_dentry(dentry)) { + bool can_free = false; + rcu_read_unlock(); + d_shrink_del(dentry); + if (dentry->d_lockref.count < 0) + can_free = dentry->d_flags & DCACHE_MAY_FREE; spin_unlock(&dentry->d_lock); - if (parent) - spin_unlock(&parent->d_lock); if (can_free) dentry_free(dentry); continue; } - - inode = dentry->d_inode; - if (inode && unlikely(!spin_trylock(&inode->i_lock))) { - d_shrink_add(dentry, list); - spin_unlock(&dentry->d_lock); - if (parent) - spin_unlock(&parent->d_lock); - continue; - } - + rcu_read_unlock(); + d_shrink_del(dentry); + parent = dentry->d_parent; __dentry_kill(dentry); - + if (parent == dentry) + continue; /* * We need to prune ancestors too. This is necessary to prevent * quadratic behavior of shrink_dcache_parent(), but is also @@ -1025,26 +1081,8 @@ static void shrink_dentry_list(struct list_head *list) * fragmentation. */ dentry = parent; - while (dentry && !lockref_put_or_lock(&dentry->d_lockref)) { - parent = lock_parent(dentry); - if (dentry->d_lockref.count != 1) { - dentry->d_lockref.count--; - spin_unlock(&dentry->d_lock); - if (parent) - spin_unlock(&parent->d_lock); - break; - } - inode = dentry->d_inode; /* can't be NULL */ - if (unlikely(!spin_trylock(&inode->i_lock))) { - spin_unlock(&dentry->d_lock); - if (parent) - spin_unlock(&parent->d_lock); - cpu_relax(); - continue; - } - __dentry_kill(dentry); - dentry = parent; - } + while (dentry && !lockref_put_or_lock(&dentry->d_lockref)) + dentry = dentry_kill(dentry); } } @@ -1169,7 +1207,6 @@ void shrink_dcache_sb(struct super_block *sb) this_cpu_sub(nr_dentry_unused, freed); shrink_dentry_list(&dispose); - cond_resched(); } while (list_lru_count(&sb->s_dentry_lru) > 0); } EXPORT_SYMBOL(shrink_dcache_sb); @@ -1451,7 +1488,6 @@ void shrink_dcache_parent(struct dentry *parent) break; shrink_dentry_list(&data.dispose); - cond_resched(); } } EXPORT_SYMBOL(shrink_dcache_parent); @@ -1500,8 +1536,8 @@ void shrink_dcache_for_umount(struct super_block *sb) sb->s_root = NULL; do_one_tree(dentry); - while (!hlist_bl_empty(&sb->s_anon)) { - dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash)); + while (!hlist_bl_empty(&sb->s_roots)) { + dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_roots), struct dentry, d_hash)); do_one_tree(dentry); } } @@ -1578,7 +1614,6 @@ void d_invalidate(struct dentry *dentry) detach_mounts(data.mountpoint); dput(data.mountpoint); } - cond_resched(); } } EXPORT_SYMBOL(d_invalidate); @@ -1595,6 +1630,7 @@ EXPORT_SYMBOL(d_invalidate); struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) { + struct external_name *ext = NULL; struct dentry *dentry; char *dname; int err; @@ -1615,17 +1651,14 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) dname = dentry->d_iname; } else if (name->len > DNAME_INLINE_LEN-1) { size_t size = offsetof(struct external_name, name[1]); - struct external_name *p = kmalloc(size + name->len, - GFP_KERNEL_ACCOUNT); - if (!p) { + + ext = kmalloc(size + name->len, GFP_KERNEL_ACCOUNT); + if (!ext) { kmem_cache_free(dentry_cache, dentry); return NULL; } - atomic_set(&p->u.count, 1); - dname = p->name; - if (IS_ENABLED(CONFIG_DCACHE_WORD_ACCESS)) - kasan_unpoison_shadow(dname, - round_up(name->len + 1, sizeof(unsigned long))); + atomic_set(&ext->u.count, 1); + dname = ext->name; } else { dname = dentry->d_iname; } @@ -1636,8 +1669,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) dname[name->len] = 0; /* Make sure we always see the terminating NUL character */ - smp_wmb(); - dentry->d_name.name = dname; + smp_store_release(&dentry->d_name.name, dname); /* ^^^ */ dentry->d_lockref.count = 1; dentry->d_flags = 0; @@ -1665,6 +1697,12 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) } } + if (unlikely(ext)) { + pg_data_t *pgdat = page_pgdat(virt_to_page(ext)); + mod_node_page_state(pgdat, NR_INDIRECTLY_RECLAIMABLE_BYTES, + ksize(ext)); + } + this_cpu_inc(nr_dentry); return dentry; @@ -1699,9 +1737,15 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) } EXPORT_SYMBOL(d_alloc); +struct dentry *d_alloc_anon(struct super_block *sb) +{ + return __d_alloc(sb, NULL); +} +EXPORT_SYMBOL(d_alloc_anon); + struct dentry *d_alloc_cursor(struct dentry * parent) { - struct dentry *dentry = __d_alloc(parent->d_sb, NULL); + struct dentry *dentry = d_alloc_anon(parent->d_sb); if (dentry) { dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR; dentry->d_parent = dget(parent); @@ -1887,7 +1931,7 @@ struct dentry *d_make_root(struct inode *root_inode) struct dentry *res = NULL; if (root_inode) { - res = __d_alloc(root_inode->i_sb, NULL); + res = d_alloc_anon(root_inode->i_sb); if (res) d_instantiate(res, root_inode); else @@ -1926,33 +1970,19 @@ struct dentry *d_find_any_alias(struct inode *inode) } EXPORT_SYMBOL(d_find_any_alias); -static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) +static struct dentry *__d_instantiate_anon(struct dentry *dentry, + struct inode *inode, + bool disconnected) { - struct dentry *tmp; struct dentry *res; unsigned add_flags; - if (!inode) - return ERR_PTR(-ESTALE); - if (IS_ERR(inode)) - return ERR_CAST(inode); - - res = d_find_any_alias(inode); - if (res) - goto out_iput; - - tmp = __d_alloc(inode->i_sb, NULL); - if (!tmp) { - res = ERR_PTR(-ENOMEM); - goto out_iput; - } - - security_d_instantiate(tmp, inode); + security_d_instantiate(dentry, inode); spin_lock(&inode->i_lock); res = __d_find_any_alias(inode); if (res) { spin_unlock(&inode->i_lock); - dput(tmp); + dput(dentry); goto out_iput; } @@ -1962,22 +1992,57 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) if (disconnected) add_flags |= DCACHE_DISCONNECTED; - spin_lock(&tmp->d_lock); - __d_set_inode_and_type(tmp, inode, add_flags); - hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry); - hlist_bl_lock(&tmp->d_sb->s_anon); - hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon); - hlist_bl_unlock(&tmp->d_sb->s_anon); - spin_unlock(&tmp->d_lock); + spin_lock(&dentry->d_lock); + __d_set_inode_and_type(dentry, inode, add_flags); + hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); + if (!disconnected) { + hlist_bl_lock(&dentry->d_sb->s_roots); + hlist_bl_add_head(&dentry->d_hash, &dentry->d_sb->s_roots); + hlist_bl_unlock(&dentry->d_sb->s_roots); + } + spin_unlock(&dentry->d_lock); spin_unlock(&inode->i_lock); - return tmp; + return dentry; out_iput: iput(inode); return res; } +struct dentry *d_instantiate_anon(struct dentry *dentry, struct inode *inode) +{ + return __d_instantiate_anon(dentry, inode, true); +} +EXPORT_SYMBOL(d_instantiate_anon); + +static struct dentry *__d_obtain_alias(struct inode *inode, bool disconnected) +{ + struct dentry *tmp; + struct dentry *res; + + if (!inode) + return ERR_PTR(-ESTALE); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + res = d_find_any_alias(inode); + if (res) + goto out_iput; + + tmp = d_alloc_anon(inode->i_sb); + if (!tmp) { + res = ERR_PTR(-ENOMEM); + goto out_iput; + } + + return __d_instantiate_anon(tmp, inode, disconnected); + +out_iput: + iput(inode); + return res; +} + /** * d_obtain_alias - find or allocate a DISCONNECTED dentry for a given inode * @inode: inode to allocate the dentry for @@ -1998,7 +2063,7 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) */ struct dentry *d_obtain_alias(struct inode *inode) { - return __d_obtain_alias(inode, 1); + return __d_obtain_alias(inode, true); } EXPORT_SYMBOL(d_obtain_alias); @@ -2019,7 +2084,7 @@ EXPORT_SYMBOL(d_obtain_alias); */ struct dentry *d_obtain_root(struct inode *inode) { - return __d_obtain_alias(inode, 0); + return __d_obtain_alias(inode, false); } EXPORT_SYMBOL(d_obtain_root); @@ -2348,32 +2413,22 @@ EXPORT_SYMBOL(d_hash_and_lookup); void d_delete(struct dentry * dentry) { - struct inode *inode; - int isdir = 0; + struct inode *inode = dentry->d_inode; + int isdir = d_is_dir(dentry); + + spin_lock(&inode->i_lock); + spin_lock(&dentry->d_lock); /* * Are we the only user? */ -again: - spin_lock(&dentry->d_lock); - inode = dentry->d_inode; - isdir = S_ISDIR(inode->i_mode); if (dentry->d_lockref.count == 1) { - if (!spin_trylock(&inode->i_lock)) { - spin_unlock(&dentry->d_lock); - cpu_relax(); - goto again; - } dentry->d_flags &= ~DCACHE_CANT_MOUNT; dentry_unlink_inode(dentry); - fsnotify_nameremove(dentry, isdir); - return; - } - - if (!d_unhashed(dentry)) + } else { __d_drop(dentry); - - spin_unlock(&dentry->d_lock); - + spin_unlock(&dentry->d_lock); + spin_unlock(&inode->i_lock); + } fsnotify_nameremove(dentry, isdir); } EXPORT_SYMBOL(d_delete); @@ -2381,7 +2436,7 @@ EXPORT_SYMBOL(d_delete); static void __d_rehash(struct dentry *entry) { struct hlist_bl_head *b = d_hash(entry->d_name.hash); - BUG_ON(!d_unhashed(entry)); + hlist_bl_lock(b); hlist_bl_add_head_rcu(&entry->d_hash, b); hlist_bl_unlock(b); @@ -2448,7 +2503,7 @@ struct dentry *d_alloc_parallel(struct dentry *parent, retry: rcu_read_lock(); - seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1; + seq = smp_load_acquire(&parent->d_inode->i_dir_seq); r_seq = read_seqbegin(&rename_lock); dentry = __d_lookup_rcu(parent, name, &d_seq); if (unlikely(dentry)) { @@ -2469,8 +2524,14 @@ retry: rcu_read_unlock(); goto retry; } + + if (unlikely(seq & 1)) { + rcu_read_unlock(); + goto retry; + } + hlist_bl_lock(b); - if (unlikely(parent->d_inode->i_dir_seq != seq)) { + if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) { hlist_bl_unlock(b); rcu_read_unlock(); goto retry; @@ -2705,8 +2766,6 @@ static void swap_names(struct dentry *dentry, struct dentry *target) */ unsigned int i; BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long))); - kmemcheck_mark_initialized(dentry->d_iname, DNAME_INLINE_LEN); - kmemcheck_mark_initialized(target->d_iname, DNAME_INLINE_LEN); for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) { swap(((long *) &dentry->d_iname)[i], ((long *) &target->d_iname)[i]); @@ -2731,61 +2790,10 @@ static void copy_name(struct dentry *dentry, struct dentry *target) dentry->d_name.hash_len = target->d_name.hash_len; } if (old_name && likely(atomic_dec_and_test(&old_name->u.count))) - kfree_rcu(old_name, u.head); -} - -static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target) -{ - /* - * XXXX: do we really need to take target->d_lock? - */ - if (IS_ROOT(dentry) || dentry->d_parent == target->d_parent) - spin_lock(&target->d_parent->d_lock); - else { - if (d_ancestor(dentry->d_parent, target->d_parent)) { - spin_lock(&dentry->d_parent->d_lock); - spin_lock_nested(&target->d_parent->d_lock, - DENTRY_D_LOCK_NESTED); - } else { - spin_lock(&target->d_parent->d_lock); - spin_lock_nested(&dentry->d_parent->d_lock, - DENTRY_D_LOCK_NESTED); - } - } - if (target < dentry) { - spin_lock_nested(&target->d_lock, 2); - spin_lock_nested(&dentry->d_lock, 3); - } else { - spin_lock_nested(&dentry->d_lock, 2); - spin_lock_nested(&target->d_lock, 3); - } -} - -static void dentry_unlock_for_move(struct dentry *dentry, struct dentry *target) -{ - if (target->d_parent != dentry->d_parent) - spin_unlock(&dentry->d_parent->d_lock); - if (target->d_parent != target) - spin_unlock(&target->d_parent->d_lock); - spin_unlock(&target->d_lock); - spin_unlock(&dentry->d_lock); + call_rcu(&old_name->u.head, __d_free_external_name); } /* - * When switching names, the actual string doesn't strictly have to - * be preserved in the target - because we're dropping the target - * anyway. As such, we can just do a simple memcpy() to copy over - * the new name before we switch, unless we are going to rehash - * it. Note that if we *do* unhash the target, we are not allowed - * to rehash it without giving it a new name/hash key - whether - * we swap or overwrite the names here, resulting name won't match - * the reality in filesystem; it's only there for d_path() purposes. - * Note that all of this is happening under rename_lock, so the - * any hash lookup seeing it in the middle of manipulations will - * be discarded anyway. So we do not care what happens to the hash - * key in that case. - */ -/* * __d_move - move a dentry * @dentry: entry to move * @target: new dentry @@ -2799,15 +2807,34 @@ static void dentry_unlock_for_move(struct dentry *dentry, struct dentry *target) static void __d_move(struct dentry *dentry, struct dentry *target, bool exchange) { + struct dentry *old_parent, *p; struct inode *dir = NULL; unsigned n; - if (!dentry->d_inode) - printk(KERN_WARNING "VFS: moving negative dcache entry\n"); - BUG_ON(d_ancestor(dentry, target)); + WARN_ON(!dentry->d_inode); + if (WARN_ON(dentry == target)) + return; + BUG_ON(d_ancestor(target, dentry)); + old_parent = dentry->d_parent; + p = d_ancestor(old_parent, target); + if (IS_ROOT(dentry)) { + BUG_ON(p); + spin_lock(&target->d_parent->d_lock); + } else if (!p) { + /* target is not a descendent of dentry->d_parent */ + spin_lock(&target->d_parent->d_lock); + spin_lock_nested(&old_parent->d_lock, DENTRY_D_LOCK_NESTED); + } else { + BUG_ON(p == dentry); + spin_lock(&old_parent->d_lock); + if (p != target) + spin_lock_nested(&target->d_parent->d_lock, + DENTRY_D_LOCK_NESTED); + } + spin_lock_nested(&dentry->d_lock, 2); + spin_lock_nested(&target->d_lock, 3); - dentry_lock_for_move(dentry, target); if (unlikely(d_in_lookup(target))) { dir = target->d_parent->d_inode; n = start_dir_add(dir); @@ -2818,45 +2845,44 @@ static void __d_move(struct dentry *dentry, struct dentry *target, write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED); /* unhash both */ - /* __d_drop does write_seqcount_barrier, but they're OK to nest. */ - __d_drop(dentry); - __d_drop(target); - - /* Switch the names.. */ - if (exchange) - swap_names(dentry, target); - else - copy_name(dentry, target); - - /* rehash in new place(s) */ - __d_rehash(dentry); - if (exchange) - __d_rehash(target); + if (!d_unhashed(dentry)) + ___d_drop(dentry); + if (!d_unhashed(target)) + ___d_drop(target); /* ... and switch them in the tree */ - if (IS_ROOT(dentry)) { - /* splicing a tree */ - dentry->d_flags |= DCACHE_RCUACCESS; - dentry->d_parent = target->d_parent; - target->d_parent = target; - list_del_init(&target->d_child); - list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); + dentry->d_parent = target->d_parent; + if (!exchange) { + 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 + WARN_ON(!--old_parent->d_lockref.count); } else { - /* swapping two dentries */ - swap(dentry->d_parent, target->d_parent); + target->d_parent = old_parent; + swap_names(dentry, target); list_move(&target->d_child, &target->d_parent->d_subdirs); - list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); - if (exchange) - fsnotify_update_flags(target); - fsnotify_update_flags(dentry); + __d_rehash(target); + fsnotify_update_flags(target); } + list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); + __d_rehash(dentry); + fsnotify_update_flags(dentry); write_seqcount_end(&target->d_seq); write_seqcount_end(&dentry->d_seq); if (dir) end_dir_add(dir, n); - dentry_unlock_for_move(dentry, target); + + if (dentry->d_parent != old_parent) + spin_unlock(&dentry->d_parent->d_lock); + if (dentry != old_parent) + spin_unlock(&old_parent->d_lock); + spin_unlock(&target->d_lock); + spin_unlock(&dentry->d_lock); } /* @@ -3004,12 +3030,14 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) inode->i_sb->s_type->name, inode->i_sb->s_id); } else if (!IS_ROOT(new)) { + struct dentry *old_parent = dget(new->d_parent); int err = __d_unalias(inode, dentry, new); write_sequnlock(&rename_lock); if (err) { dput(new); new = ERR_PTR(err); } + dput(old_parent); } else { __d_move(new, dentry, false); write_sequnlock(&rename_lock); @@ -3024,470 +3052,6 @@ out: } EXPORT_SYMBOL(d_splice_alias); -static int prepend(char **buffer, int *buflen, const char *str, int namelen) -{ - *buflen -= namelen; - if (*buflen < 0) - return -ENAMETOOLONG; - *buffer -= namelen; - memcpy(*buffer, str, namelen); - return 0; -} - -/** - * prepend_name - prepend a pathname in front of current buffer pointer - * @buffer: buffer pointer - * @buflen: allocated length of the buffer - * @name: name string and length qstr structure - * - * With RCU path tracing, it may race with d_move(). Use ACCESS_ONCE() to - * make sure that either the old or the new name pointer and length are - * fetched. However, there may be mismatch between length and pointer. - * The length cannot be trusted, we need to copy it byte-by-byte until - * the length is reached or a null byte is found. It also prepends "/" at - * the beginning of the name. The sequence number check at the caller will - * retry it again when a d_move() does happen. So any garbage in the buffer - * due to mismatched pointer and length will be discarded. - * - * Data dependency barrier is needed to make sure that we see that terminating - * NUL. Alpha strikes again, film at 11... - */ -static int prepend_name(char **buffer, int *buflen, const struct qstr *name) -{ - const char *dname = ACCESS_ONCE(name->name); - u32 dlen = ACCESS_ONCE(name->len); - char *p; - - smp_read_barrier_depends(); - - *buflen -= dlen + 1; - if (*buflen < 0) - return -ENAMETOOLONG; - p = *buffer -= dlen + 1; - *p++ = '/'; - while (dlen--) { - char c = *dname++; - if (!c) - break; - *p++ = c; - } - return 0; -} - -/** - * prepend_path - Prepend path string to a buffer - * @path: the dentry/vfsmount to report - * @root: root vfsmnt/dentry - * @buffer: pointer to the end of the buffer - * @buflen: pointer to buffer length - * - * The function will first try to write out the pathname without taking any - * lock other than the RCU read lock to make sure that dentries won't go away. - * It only checks the sequence number of the global rename_lock as any change - * in the dentry's d_seq will be preceded by changes in the rename_lock - * sequence number. If the sequence number had been changed, it will restart - * the whole pathname back-tracing sequence again by taking the rename_lock. - * In this case, there is no need to take the RCU read lock as the recursive - * parent pointer references will keep the dentry chain alive as long as no - * rename operation is performed. - */ -static int prepend_path(const struct path *path, - const struct path *root, - char **buffer, int *buflen) -{ - struct dentry *dentry; - struct vfsmount *vfsmnt; - struct mount *mnt; - int error = 0; - unsigned seq, m_seq = 0; - char *bptr; - int blen; - - rcu_read_lock(); -restart_mnt: - read_seqbegin_or_lock(&mount_lock, &m_seq); - seq = 0; - rcu_read_lock(); -restart: - bptr = *buffer; - blen = *buflen; - error = 0; - dentry = path->dentry; - vfsmnt = path->mnt; - mnt = real_mount(vfsmnt); - read_seqbegin_or_lock(&rename_lock, &seq); - while (dentry != root->dentry || vfsmnt != root->mnt) { - struct dentry * parent; - - if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { - struct mount *parent = ACCESS_ONCE(mnt->mnt_parent); - /* Escaped? */ - if (dentry != vfsmnt->mnt_root) { - bptr = *buffer; - blen = *buflen; - error = 3; - break; - } - /* Global root? */ - if (mnt != parent) { - dentry = ACCESS_ONCE(mnt->mnt_mountpoint); - mnt = parent; - vfsmnt = &mnt->mnt; - continue; - } - if (!error) - error = is_mounted(vfsmnt) ? 1 : 2; - break; - } - parent = dentry->d_parent; - prefetch(parent); - error = prepend_name(&bptr, &blen, &dentry->d_name); - if (error) - break; - - dentry = parent; - } - if (!(seq & 1)) - rcu_read_unlock(); - if (need_seqretry(&rename_lock, seq)) { - seq = 1; - goto restart; - } - done_seqretry(&rename_lock, seq); - - if (!(m_seq & 1)) - rcu_read_unlock(); - if (need_seqretry(&mount_lock, m_seq)) { - m_seq = 1; - goto restart_mnt; - } - done_seqretry(&mount_lock, m_seq); - - if (error >= 0 && bptr == *buffer) { - if (--blen < 0) - error = -ENAMETOOLONG; - else - *--bptr = '/'; - } - *buffer = bptr; - *buflen = blen; - return error; -} - -/** - * __d_path - return the path of a dentry - * @path: the dentry/vfsmount to report - * @root: root vfsmnt/dentry - * @buf: buffer to return value in - * @buflen: buffer length - * - * Convert a dentry into an ASCII path name. - * - * Returns a pointer into the buffer or an error code if the - * path was too long. - * - * "buflen" should be positive. - * - * If the path is not reachable from the supplied root, return %NULL. - */ -char *__d_path(const struct path *path, - const struct path *root, - char *buf, int buflen) -{ - char *res = buf + buflen; - int error; - - prepend(&res, &buflen, "\0", 1); - error = prepend_path(path, root, &res, &buflen); - - if (error < 0) - return ERR_PTR(error); - if (error > 0) - return NULL; - return res; -} - -char *d_absolute_path(const struct path *path, - char *buf, int buflen) -{ - struct path root = {}; - char *res = buf + buflen; - int error; - - prepend(&res, &buflen, "\0", 1); - error = prepend_path(path, &root, &res, &buflen); - - if (error > 1) - error = -EINVAL; - if (error < 0) - return ERR_PTR(error); - return res; -} - -/* - * same as __d_path but appends "(deleted)" for unlinked files. - */ -static int path_with_deleted(const struct path *path, - const struct path *root, - char **buf, int *buflen) -{ - prepend(buf, buflen, "\0", 1); - if (d_unlinked(path->dentry)) { - int error = prepend(buf, buflen, " (deleted)", 10); - if (error) - return error; - } - - return prepend_path(path, root, buf, buflen); -} - -static int prepend_unreachable(char **buffer, int *buflen) -{ - return prepend(buffer, buflen, "(unreachable)", 13); -} - -static void get_fs_root_rcu(struct fs_struct *fs, struct path *root) -{ - unsigned seq; - - do { - seq = read_seqcount_begin(&fs->seq); - *root = fs->root; - } while (read_seqcount_retry(&fs->seq, seq)); -} - -/** - * d_path - return the path of a dentry - * @path: path to report - * @buf: buffer to return value in - * @buflen: buffer length - * - * Convert a dentry into an ASCII path name. If the entry has been deleted - * the string " (deleted)" is appended. Note that this is ambiguous. - * - * Returns a pointer into the buffer or an error code if the path was - * too long. Note: Callers should use the returned pointer, not the passed - * in buffer, to use the name! The implementation often starts at an offset - * into the buffer, and may leave 0 bytes at the start. - * - * "buflen" should be positive. - */ -char *d_path(const struct path *path, char *buf, int buflen) -{ - char *res = buf + buflen; - struct path root; - int error; - - /* - * We have various synthetic filesystems that never get mounted. On - * these filesystems dentries are never used for lookup purposes, and - * thus don't need to be hashed. They also don't need a name until a - * user wants to identify the object in /proc/pid/fd/. The little hack - * below allows us to generate a name for these objects on demand: - * - * Some pseudo inodes are mountable. When they are mounted - * path->dentry == path->mnt->mnt_root. In that case don't call d_dname - * and instead have d_path return the mounted path. - */ - if (path->dentry->d_op && path->dentry->d_op->d_dname && - (!IS_ROOT(path->dentry) || path->dentry != path->mnt->mnt_root)) - return path->dentry->d_op->d_dname(path->dentry, buf, buflen); - - rcu_read_lock(); - get_fs_root_rcu(current->fs, &root); - error = path_with_deleted(path, &root, &res, &buflen); - rcu_read_unlock(); - - if (error < 0) - res = ERR_PTR(error); - return res; -} -EXPORT_SYMBOL(d_path); - -/* - * Helper function for dentry_operations.d_dname() members - */ -char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen, - const char *fmt, ...) -{ - va_list args; - char temp[64]; - int sz; - - va_start(args, fmt); - sz = vsnprintf(temp, sizeof(temp), fmt, args) + 1; - va_end(args); - - if (sz > sizeof(temp) || sz > buflen) - return ERR_PTR(-ENAMETOOLONG); - - buffer += buflen - sz; - return memcpy(buffer, temp, sz); -} - -char *simple_dname(struct dentry *dentry, char *buffer, int buflen) -{ - char *end = buffer + buflen; - /* these dentries are never renamed, so d_lock is not needed */ - if (prepend(&end, &buflen, " (deleted)", 11) || - prepend(&end, &buflen, dentry->d_name.name, dentry->d_name.len) || - prepend(&end, &buflen, "/", 1)) - end = ERR_PTR(-ENAMETOOLONG); - return end; -} -EXPORT_SYMBOL(simple_dname); - -/* - * Write full pathname from the root of the filesystem into the buffer. - */ -static char *__dentry_path(struct dentry *d, char *buf, int buflen) -{ - struct dentry *dentry; - char *end, *retval; - int len, seq = 0; - int error = 0; - - if (buflen < 2) - goto Elong; - - rcu_read_lock(); -restart: - dentry = d; - end = buf + buflen; - len = buflen; - prepend(&end, &len, "\0", 1); - /* Get '/' right */ - retval = end-1; - *retval = '/'; - read_seqbegin_or_lock(&rename_lock, &seq); - while (!IS_ROOT(dentry)) { - struct dentry *parent = dentry->d_parent; - - prefetch(parent); - error = prepend_name(&end, &len, &dentry->d_name); - if (error) - break; - - retval = end; - dentry = parent; - } - if (!(seq & 1)) - rcu_read_unlock(); - if (need_seqretry(&rename_lock, seq)) { - seq = 1; - goto restart; - } - done_seqretry(&rename_lock, seq); - if (error) - goto Elong; - return retval; -Elong: - return ERR_PTR(-ENAMETOOLONG); -} - -char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen) -{ - return __dentry_path(dentry, buf, buflen); -} -EXPORT_SYMBOL(dentry_path_raw); - -char *dentry_path(struct dentry *dentry, char *buf, int buflen) -{ - char *p = NULL; - char *retval; - - if (d_unlinked(dentry)) { - p = buf + buflen; - if (prepend(&p, &buflen, "//deleted", 10) != 0) - goto Elong; - buflen++; - } - retval = __dentry_path(dentry, buf, buflen); - if (!IS_ERR(retval) && p) - *p = '/'; /* restore '/' overriden with '\0' */ - return retval; -Elong: - return ERR_PTR(-ENAMETOOLONG); -} - -static void get_fs_root_and_pwd_rcu(struct fs_struct *fs, struct path *root, - struct path *pwd) -{ - unsigned seq; - - do { - seq = read_seqcount_begin(&fs->seq); - *root = fs->root; - *pwd = fs->pwd; - } while (read_seqcount_retry(&fs->seq, seq)); -} - -/* - * NOTE! The user-level library version returns a - * character pointer. The kernel system call just - * returns the length of the buffer filled (which - * includes the ending '\0' character), or a negative - * error value. So libc would do something like - * - * char *getcwd(char * buf, size_t size) - * { - * int retval; - * - * retval = sys_getcwd(buf, size); - * if (retval >= 0) - * return buf; - * errno = -retval; - * return NULL; - * } - */ -SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) -{ - int error; - struct path pwd, root; - char *page = __getname(); - - if (!page) - return -ENOMEM; - - rcu_read_lock(); - get_fs_root_and_pwd_rcu(current->fs, &root, &pwd); - - error = -ENOENT; - if (!d_unlinked(pwd.dentry)) { - unsigned long len; - char *cwd = page + PATH_MAX; - int buflen = PATH_MAX; - - prepend(&cwd, &buflen, "\0", 1); - error = prepend_path(&pwd, &root, &cwd, &buflen); - rcu_read_unlock(); - - if (error < 0) - goto out; - - /* Unreachable from current root */ - if (error > 0) { - error = prepend_unreachable(&cwd, &buflen); - if (error) - goto out; - } - - error = -ERANGE; - len = PATH_MAX + page - cwd; - if (len <= size) { - error = len; - if (copy_to_user(buf, cwd, len)) - error = -EFAULT; - } - } else { - rcu_read_unlock(); - } - -out: - __putname(page); - return error; -} - /* * Test whether new_dentry is a subdirectory of old_dentry. * @@ -3529,6 +3093,7 @@ bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) return result; } +EXPORT_SYMBOL(is_subdir); static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry) { @@ -3550,6 +3115,8 @@ void d_genocide(struct dentry *parent) d_walk(parent, parent, d_genocide_kill, NULL); } +EXPORT_SYMBOL(d_genocide); + void d_tmpfile(struct dentry *dentry, struct inode *inode) { inode_dec_link_count(inode); @@ -3591,9 +3158,10 @@ static void __init dcache_init_early(void) 13, HASH_EARLY | HASH_ZERO, &d_hash_shift, - &d_hash_mask, + NULL, 0, 0); + d_hash_shift = 32 - d_hash_shift; } static void __init dcache_init(void) @@ -3603,8 +3171,9 @@ static void __init dcache_init(void) * but it is probably not worth it because of the cache nature * of the dcache. */ - dentry_cache = KMEM_CACHE(dentry, - SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD|SLAB_ACCOUNT); + dentry_cache = KMEM_CACHE_USERCOPY(dentry, + SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD|SLAB_ACCOUNT, + d_iname); /* Hash may have been set up in dcache_init_early */ if (!hashdist) @@ -3617,17 +3186,16 @@ static void __init dcache_init(void) 13, HASH_ZERO, &d_hash_shift, - &d_hash_mask, + NULL, 0, 0); + d_hash_shift = 32 - d_hash_shift; } /* SLAB cache for __getname() consumers */ struct kmem_cache *names_cachep __read_mostly; EXPORT_SYMBOL(names_cachep); -EXPORT_SYMBOL(d_genocide); - void __init vfs_caches_init_early(void) { int i; @@ -3641,8 +3209,8 @@ void __init vfs_caches_init_early(void) void __init vfs_caches_init(void) { - names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0, - SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + names_cachep = kmem_cache_create_usercopy("names_cache", PATH_MAX, 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, 0, PATH_MAX, NULL); dcache_init(); inode_init(); |