diff options
| -rw-r--r-- | fs/nfsd/Kconfig | 1 | ||||
| -rw-r--r-- | fs/nfsd/Makefile | 3 | ||||
| -rw-r--r-- | fs/nfsd/export.c | 13 | ||||
| -rw-r--r-- | fs/nfsd/filecache.c | 885 | ||||
| -rw-r--r-- | fs/nfsd/filecache.h | 60 | ||||
| -rw-r--r-- | fs/nfsd/nfssvc.c | 9 | ||||
| -rw-r--r-- | fs/nfsd/trace.h | 140 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 65 | ||||
| -rw-r--r-- | fs/nfsd/vfs.h | 3 |
9 files changed, 1155 insertions, 24 deletions
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig index d25f6bbe7006..bff8456220e0 100644 --- a/fs/nfsd/Kconfig +++ b/fs/nfsd/Kconfig @@ -3,6 +3,7 @@ config NFSD tristate "NFS server support" depends on INET depends on FILE_LOCKING + depends on FSNOTIFY select LOCKD select SUNRPC select EXPORTFS diff --git a/fs/nfsd/Makefile b/fs/nfsd/Makefile index 2bfb58eefad1..6a40b1afe703 100644 --- a/fs/nfsd/Makefile +++ b/fs/nfsd/Makefile @@ -11,7 +11,8 @@ obj-$(CONFIG_NFSD) += nfsd.o nfsd-y += trace.o nfsd-y += nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \ - export.o auth.o lockd.o nfscache.o nfsxdr.o stats.o + export.o auth.o lockd.o nfscache.o nfsxdr.o \ + stats.o filecache.o nfsd-$(CONFIG_NFSD_FAULT_INJECTION) += fault_inject.o nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o nfsd-$(CONFIG_NFSD_V3) += nfs3proc.o nfs3xdr.o diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index baa01956a5b3..052fac64b578 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -22,6 +22,7 @@ #include "nfsfh.h" #include "netns.h" #include "pnfs.h" +#include "filecache.h" #define NFSDDBG_FACILITY NFSDDBG_EXPORT @@ -232,6 +233,17 @@ static struct cache_head *expkey_alloc(void) return NULL; } +static void expkey_flush(void) +{ + /* + * Take the nfsd_mutex here to ensure that the file cache is not + * destroyed while we're in the middle of flushing. + */ + mutex_lock(&nfsd_mutex); + nfsd_file_cache_purge(); + mutex_unlock(&nfsd_mutex); +} + static const struct cache_detail svc_expkey_cache_template = { .owner = THIS_MODULE, .hash_size = EXPKEY_HASHMAX, @@ -244,6 +256,7 @@ static const struct cache_detail svc_expkey_cache_template = { .init = expkey_init, .update = expkey_update, .alloc = expkey_alloc, + .flush = expkey_flush, }; static int diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c new file mode 100644 index 000000000000..a2fcb251d2f6 --- /dev/null +++ b/fs/nfsd/filecache.c @@ -0,0 +1,885 @@ +/* + * Open file cache. + * + * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com> + */ + +#include <linux/hash.h> +#include <linux/slab.h> +#include <linux/hash.h> +#include <linux/file.h> +#include <linux/sched.h> +#include <linux/list_lru.h> +#include <linux/fsnotify_backend.h> +#include <linux/fsnotify.h> +#include <linux/seq_file.h> + +#include "vfs.h" +#include "nfsd.h" +#include "nfsfh.h" +#include "filecache.h" +#include "trace.h" + +#define NFSDDBG_FACILITY NFSDDBG_FH + +/* FIXME: dynamically size this for the machine somehow? */ +#define NFSD_FILE_HASH_BITS 12 +#define NFSD_FILE_HASH_SIZE (1 << NFSD_FILE_HASH_BITS) +#define NFSD_LAUNDRETTE_DELAY (2 * HZ) + +#define NFSD_FILE_LRU_RESCAN (0) +#define NFSD_FILE_SHUTDOWN (1) +#define NFSD_FILE_LRU_THRESHOLD (4096UL) +#define NFSD_FILE_LRU_LIMIT (NFSD_FILE_LRU_THRESHOLD << 2) + +/* We only care about NFSD_MAY_READ/WRITE for this cache */ +#define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE) + +struct nfsd_fcache_bucket { + struct hlist_head nfb_head; + spinlock_t nfb_lock; + unsigned int nfb_count; + unsigned int nfb_maxcount; +}; + +static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); + +static struct kmem_cache *nfsd_file_slab; +static struct kmem_cache *nfsd_file_mark_slab; +static struct nfsd_fcache_bucket *nfsd_file_hashtbl; +static struct list_lru nfsd_file_lru; +static long nfsd_file_lru_flags; +static struct fsnotify_group *nfsd_file_fsnotify_group; +static atomic_long_t nfsd_filecache_count; +static struct delayed_work nfsd_filecache_laundrette; + +enum nfsd_file_laundrette_ctl { + NFSD_FILE_LAUNDRETTE_NOFLUSH = 0, + NFSD_FILE_LAUNDRETTE_MAY_FLUSH +}; + +static void +nfsd_file_schedule_laundrette(enum nfsd_file_laundrette_ctl ctl) +{ + long count = atomic_long_read(&nfsd_filecache_count); + + if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags)) + return; + + /* Be more aggressive about scanning if over the threshold */ + if (count > NFSD_FILE_LRU_THRESHOLD) + mod_delayed_work(system_wq, &nfsd_filecache_laundrette, 0); + else + schedule_delayed_work(&nfsd_filecache_laundrette, NFSD_LAUNDRETTE_DELAY); + + if (ctl == NFSD_FILE_LAUNDRETTE_NOFLUSH) + return; + + /* ...and don't delay flushing if we're out of control */ + if (count >= NFSD_FILE_LRU_LIMIT) + flush_delayed_work(&nfsd_filecache_laundrette); +} + +static void +nfsd_file_slab_free(struct rcu_head *rcu) +{ + struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu); + + put_cred(nf->nf_cred); + kmem_cache_free(nfsd_file_slab, nf); +} + +static void +nfsd_file_mark_free(struct fsnotify_mark *mark) +{ + struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark, + nfm_mark); + + kmem_cache_free(nfsd_file_mark_slab, nfm); +} + +static struct nfsd_file_mark * +nfsd_file_mark_get(struct nfsd_file_mark *nfm) +{ + if (!atomic_inc_not_zero(&nfm->nfm_ref)) + return NULL; + return nfm; +} + +static void +nfsd_file_mark_put(struct nfsd_file_mark *nfm) +{ + if (atomic_dec_and_test(&nfm->nfm_ref)) { + + fsnotify_destroy_mark(&nfm->nfm_mark, nfsd_file_fsnotify_group); + fsnotify_put_mark(&nfm->nfm_mark); + } +} + +static struct nfsd_file_mark * +nfsd_file_mark_find_or_create(struct nfsd_file *nf) +{ + int err; + struct fsnotify_mark *mark; + struct nfsd_file_mark *nfm = NULL, *new; + struct inode *inode = nf->nf_inode; + + do { + mutex_lock(&nfsd_file_fsnotify_group->mark_mutex); + mark = fsnotify_find_mark(&inode->i_fsnotify_marks, + nfsd_file_fsnotify_group); + if (mark) { + nfm = nfsd_file_mark_get(container_of(mark, + struct nfsd_file_mark, + nfm_mark)); + mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); + fsnotify_put_mark(mark); + if (likely(nfm)) + break; + } else + mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); + + /* allocate a new nfm */ + new = kmem_cache_alloc(nfsd_file_mark_slab, GFP_KERNEL); + if (!new) + return NULL; + fsnotify_init_mark(&new->nfm_mark, nfsd_file_fsnotify_group); + new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF; + atomic_set(&new->nfm_ref, 1); + + err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0); + + /* + * If the add was successful, then return the object. + * Otherwise, we need to put the reference we hold on the + * nfm_mark. The fsnotify code will take a reference and put + * it on failure, so we can't just free it directly. It's also + * not safe to call fsnotify_destroy_mark on it as the + * mark->group will be NULL. Thus, we can't let the nfm_ref + * counter drive the destruction at this point. + */ + if (likely(!err)) + nfm = new; + else + fsnotify_put_mark(&new->nfm_mark); + } while (unlikely(err == -EEXIST)); + + return nfm; +} + +static struct nfsd_file * +nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval) +{ + struct nfsd_file *nf; + + nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL); + if (nf) { + INIT_HLIST_NODE(&nf->nf_node); + INIT_LIST_HEAD(&nf->nf_lru); + nf->nf_file = NULL; + nf->nf_cred = get_current_cred(); + nf->nf_flags = 0; + nf->nf_inode = inode; + nf->nf_hashval = hashval; + atomic_set(&nf->nf_ref, 1); + nf->nf_may = may & NFSD_FILE_MAY_MASK; + if (may & NFSD_MAY_NOT_BREAK_LEASE) { + if (may & NFSD_MAY_WRITE) + __set_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags); + if (may & NFSD_MAY_READ) + __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); + } + nf->nf_mark = NULL; + trace_nfsd_file_alloc(nf); + } + return nf; +} + +static bool +nfsd_file_free(struct nfsd_file *nf) +{ + bool flush = false; + + trace_nfsd_file_put_final(nf); + if (nf->nf_mark) + nfsd_file_mark_put(nf->nf_mark); + if (nf->nf_file) { + get_file(nf->nf_file); + filp_close(nf->nf_file, NULL); + fput(nf->nf_file); + flush = true; + } + call_rcu(&nf->nf_rcu, nfsd_file_slab_free); + return flush; +} + +static void +nfsd_file_do_unhash(struct nfsd_file *nf) +{ + lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + + trace_nfsd_file_unhash(nf); + + --nfsd_file_hashtbl[nf->nf_hashval].nfb_count; + hlist_del_rcu(&nf->nf_node); + if (!list_empty(&nf->nf_lru)) + list_lru_del(&nfsd_file_lru, &nf->nf_lru); + atomic_long_dec(&nfsd_filecache_count); +} + +static bool +nfsd_file_unhash(struct nfsd_file *nf) +{ + if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { + nfsd_file_do_unhash(nf); + return true; + } + return false; +} + +/* + * Return true if the file was unhashed. + */ +static bool +nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *dispose) +{ + lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + + trace_nfsd_file_unhash_and_release_locked(nf); + if (!nfsd_file_unhash(nf)) + return false; + /* keep final reference for nfsd_file_lru_dispose */ + if (atomic_add_unless(&nf->nf_ref, -1, 1)) + return true; + + list_add(&nf->nf_lru, dispose); + return true; +} + +static int +nfsd_file_put_noref(struct nfsd_file *nf) +{ + int count; + trace_nfsd_file_put(nf); + + count = atomic_dec_return(&nf->nf_ref); + if (!count) { + WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags)); + nfsd_file_free(nf); + } + return count; +} + +void +nfsd_file_put(struct nfsd_file *nf) +{ + bool is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; + + set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); + if (nfsd_file_put_noref(nf) == 1 && is_hashed) + nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_MAY_FLUSH); +} + +struct nfsd_file * +nfsd_file_get(struct nfsd_file *nf) +{ + if (likely(atomic_inc_not_zero(&nf->nf_ref))) + return nf; + return NULL; +} + +static void +nfsd_file_dispose_list(struct list_head *dispose) +{ + struct nfsd_file *nf; + + while(!list_empty(dispose)) { + nf = list_first_entry(dispose, struct nfsd_file, nf_lru); + list_del(&nf->nf_lru); + nfsd_file_put_noref(nf); + } +} + +static void +nfsd_file_dispose_list_sync(struct list_head *dispose) +{ + bool flush = false; + struct nfsd_file *nf; + + while(!list_empty(dispose)) { + nf = list_first_entry(dispose, struct nfsd_file, nf_lru); + list_del(&nf->nf_lru); + if (!atomic_dec_and_test(&nf->nf_ref)) + continue; + if (nfsd_file_free(nf)) + flush = true; + } + if (flush) + flush_delayed_fput(); +} + +/* + * Note this can deadlock with nfsd_file_cache_purge. + */ +static enum lru_status +nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, + spinlock_t *lock, void *arg) + __releases(lock) + __acquires(lock) +{ + struct list_head *head = arg; + struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru); + + /* + * Do a lockless refcount check. The hashtable holds one reference, so + * we look to see if anything else has a reference, or if any have + * been put since the shrinker last ran. Those don't get unhashed and + * released. + * + * Note that in the put path, we set the flag and then decrement the + * counter. Here we check the counter and then test and clear the flag. + * That order is deliberate to ensure that we can do this locklessly. + */ + if (atomic_read(&nf->nf_ref) > 1) + goto out_skip; + if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) + goto out_rescan; + + if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) + goto out_skip; + + list_lru_isolate_move(lru, &nf->nf_lru, head); + return LRU_REMOVED; +out_rescan: + set_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags); +out_skip: + return LRU_SKIP; +} + +static void +nfsd_file_lru_dispose(struct list_head *head) +{ + while(!list_empty(head)) { + struct nfsd_file *nf = list_first_entry(head, + struct nfsd_file, nf_lru); + list_del_init(&nf->nf_lru); + spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + nfsd_file_do_unhash(nf); + spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + nfsd_file_put_noref(nf); + } +} + +static unsigned long +nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc) +{ + return list_lru_count(&nfsd_file_lru); +} + +static unsigned long +nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc) +{ + LIST_HEAD(head); + unsigned long ret; + + ret = list_lru_shrink_walk(&nfsd_file_lru, sc, nfsd_file_lru_cb, &head); + nfsd_file_lru_dispose(&head); + return ret; +} + +static struct shrinker nfsd_file_shrinker = { + .scan_objects = nfsd_file_lru_scan, + .count_objects = nfsd_file_lru_count, + .seeks = 1, +}; + +static void +__nfsd_file_close_inode(struct inode *inode, unsigned int hashval, + struct list_head *dispose) +{ + struct nfsd_file *nf; + struct hlist_node *tmp; + + spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); + hlist_for_each_entry_safe(nf, tmp, &nfsd_file_hashtbl[hashval].nfb_head, nf_node) { + if (inode == nf->nf_inode) + nfsd_file_unhash_and_release_locked(nf, dispose); + } + spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); +} + +/** + * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file + * @inode: inode of the file to attempt to remove + * + * Walk the whole hash bucket, looking for any files that correspond to "inode". + * If any do, then unhash them and put the hashtable reference to them and + * destroy any that had their last reference put. Also ensure that any of the + * fputs also have their final __fput done as well. + */ +void +nfsd_file_close_inode_sync(struct inode *inode) +{ + unsigned int hashval = (unsigned int)hash_long(inode->i_ino, + NFSD_FILE_HASH_BITS); + LIST_HEAD(dispose); + + __nfsd_file_close_inode(inode, hashval, &dispose); + trace_nfsd_file_close_inode_sync(inode, hashval, !list_empty(&dispose)); + nfsd_file_dispose_list_sync(&dispose); +} + +/** + * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file + * @inode: inode of the file to attempt to remove + * + * Walk the whole hash bucket, looking for any files that correspond to "inode". + * If any do, then unhash them and put the hashtable reference to them and + * destroy any that had their last reference put. + */ +static void +nfsd_file_close_inode(struct inode *inode) +{ + unsigned int hashval = (unsigned int)hash_long(inode->i_ino, + NFSD_FILE_HASH_BITS); + LIST_HEAD(dispose); + + __nfsd_file_close_inode(inode, hashval, &dispose); + trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose)); + nfsd_file_dispose_list(&dispose); +} + +/** + * nfsd_file_delayed_close - close unused nfsd_files + * @work: dummy + * + * Walk the LRU list and close any entries that have not been used since + * the last scan. + * + * Note this can deadlock with nfsd_file_cache_purge. + */ +static void +nfsd_file_delayed_close(struct work_struct *work) +{ + LIST_HEAD(head); + + list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, &head, LONG_MAX); + + if (test_and_clear_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags)) + nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_NOFLUSH); + + if (!list_empty(&head)) { + nfsd_file_lru_dispose(&head); + flush_delayed_fput(); + } +} + +static int +nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg, + void *data) +{ + struct file_lock *fl = data; + + /* Only close files for F_SETLEASE leases */ + if (fl->fl_flags & FL_LEASE) + nfsd_file_close_inode_sync(file_inode(fl->fl_file)); + return 0; +} + +static struct notifier_block nfsd_file_lease_notifier = { + .notifier_call = nfsd_file_lease_notifier_call, +}; + +static int +nfsd_file_fsnotify_handle_event(struct fsnotify_group *group, + struct inode *inode, + u32 mask, const void *data, int data_type, + const struct qstr *file_name, u32 cookie, + struct fsnotify_iter_info *iter_info) +{ + trace_nfsd_file_fsnotify_handle_event(inode, mask); + + /* Should be no marks on non-regular files */ + if (!S_ISREG(inode->i_mode)) { + WARN_ON_ONCE(1); + return 0; + } + + /* don't close files if this was not the last link */ + if (mask & FS_ATTRIB) { + if (inode->i_nlink) + return 0; + } + + nfsd_file_close_inode(inode); + return 0; +} + + +static const struct fsnotify_ops nfsd_file_fsnotify_ops = { + .handle_event = nfsd_file_fsnotify_handle_event, + .free_mark = nfsd_file_mark_free, +}; + +int +nfsd_file_cache_init(void) +{ + int ret = -ENOMEM; + unsigned int i; + + clear_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags); + + if (nfsd_file_hashtbl) + return 0; + + nfsd_file_hashtbl = kcalloc(NFSD_FILE_HASH_SIZE, + sizeof(*nfsd_file_hashtbl), GFP_KERNEL); + if (!nfsd_file_hashtbl) { + pr_err("nfsd: unable to allocate nfsd_file_hashtbl\n"); + goto out_err; + } + + nfsd_file_slab = kmem_cache_create("nfsd_file", + sizeof(struct nfsd_file), 0, 0, NULL); + if (!nfsd_file_slab) { + pr_err("nfsd: unable to create nfsd_file_slab\n"); + goto out_err; + } + + nfsd_file_mark_slab = kmem_cache_create("nfsd_file_mark", + sizeof(struct nfsd_file_mark), 0, 0, NULL); + if (!nfsd_file_mark_slab) { + pr_err("nfsd: unable to create nfsd_file_mark_slab\n"); + goto out_err; + } + + + ret = list_lru_init(&nfsd_file_lru); + if (ret) { + pr_err("nfsd: failed to init nfsd_file_lru: %d\n", ret); + goto out_err; + } + + ret = register_shrinker(&nfsd_file_shrinker); + if (ret) { + pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret); + goto out_lru; + } + + ret = lease_register_notifier(&nfsd_file_lease_notifier); + if (ret) { + pr_err("nfsd: unable to register lease notifier: %d\n", ret); + goto out_shrinker; + } + + nfsd_file_fsnotify_group = fsnotify_alloc_group(&nfsd_file_fsnotify_ops); + if (IS_ERR(nfsd_file_fsnotify_group)) { + pr_err("nfsd: unable to create fsnotify group: %ld\n", + PTR_ERR(nfsd_file_fsnotify_group)); + nfsd_file_fsnotify_group = NULL; + goto out_notifier; + } + + for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { + INIT_HLIST_HEAD(&nfsd_file_hashtbl[i].nfb_head); + spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock); + } + + INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_delayed_close); +out: + return ret; +out_notifier: + lease_unregister_notifier(&nfsd_file_lease_notifier); +out_shrinker: + unregister_shrinker(&nfsd_file_shrinker); +out_lru: + list_lru_destroy(&nfsd_file_lru); +out_err: + kmem_cache_destroy(nfsd_file_slab); + nfsd_file_slab = NULL; + kmem_cache_destroy(nfsd_file_mark_slab); + nfsd_file_mark_slab = NULL; + kfree(nfsd_file_hashtbl); + nfsd_file_hashtbl = NULL; + goto out; +} + +/* + * Note this can deadlock with nfsd_file_lru_cb. + */ +void +nfsd_file_cache_purge(void) +{ + unsigned int i; + struct nfsd_file *nf; + LIST_HEAD(dispose); + bool del; + + if (!nfsd_file_hashtbl) + return; + + for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { + spin_lock(&nfsd_file_hashtbl[i].nfb_lock); + while(!hlist_empty(&nfsd_file_hashtbl[i].nfb_head)) { + nf = hlist_entry(nfsd_file_hashtbl[i].nfb_head.first, + struct nfsd_file, nf_node); + del = nfsd_file_unhash_and_release_locked(nf, &dispose); + + /* + * Deadlock detected! Something marked this entry as + * unhased, but hasn't removed it from the hash list. + */ + WARN_ON_ONCE(!del); + } + spin_unlock(&nfsd_file_hashtbl[i].nfb_lock); + nfsd_file_dispose_list(&dispose); + } +} + +void +nfsd_file_cache_shutdown(void) +{ + LIST_HEAD(dispose); + + set_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags); + + lease_unregister_notifier(&nfsd_file_lease_notifier); + unregister_shrinker(&nfsd_file_shrinker); + /* + * make sure all callers of nfsd_file_lru_cb are done before + * calling nfsd_file_cache_purge + */ + cancel_delayed_work_sync(&nfsd_filecache_laundrette); + nfsd_file_cache_purge(); + list_lru_destroy(&nfsd_file_lru); + rcu_barrier(); + fsnotify_put_group(nfsd_file_fsnotify_group); + nfsd_file_fsnotify_group = NULL; + kmem_cache_destroy(nfsd_file_slab); + nfsd_file_slab = NULL; + fsnotify_wait_marks_destroyed(); + kmem_cache_destroy(nfsd_file_mark_slab); + nfsd_file_mark_slab = NULL; + kfree(nfsd_file_hashtbl); + nfsd_file_hashtbl = NULL; +} + +static bool +nfsd_match_cred(const struct cred *c1, const struct cred *c2) +{ + int i; + + if (!uid_eq(c1->fsuid, c2->fsuid)) + return false; + if (!gid_eq(c1->fsgid, c2->fsgid)) + return false; + if (c1->group_info == NULL || c2->group_info == NULL) + return c1->group_info == c2->group_info; + if (c1->group_info->ngroups != c2->group_info->ngroups) + return false; + for (i = 0; i < c1->group_info->ngroups; i++) { + if (!gid_eq(c1->group_info->gid[i], c2->group_info->gid[i])) + return false; + } + return true; +} + +static struct nfsd_file * +nfsd_file_find_locked(struct inode *inode, unsigned int may_flags, + unsigned int hashval) +{ + struct nfsd_file *nf; + unsigned char need = may_flags & NFSD_FILE_MAY_MASK; + + hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head, + nf_node) { + if ((need & nf->nf_may) != need) + continue; + if (nf->nf_inode != inode) + continue; + if (!nfsd_match_cred(nf->nf_cred, current_cred())) + continue; + if (nfsd_file_get(nf) != NULL) + return nf; + } + return NULL; +} + +/** + * nfsd_file_is_cached - are there any cached open files for this fh? + * @inode: inode of the file to check + * + * Scan the hashtable for open files that match this fh. Returns true if there + * are any, and false if not. + */ +bool +nfsd_file_is_cached(struct inode *inode) +{ + bool ret = false; + struct nfsd_file *nf; + unsigned int hashval; + + hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS); + + rcu_read_lock(); + hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head, + nf_node) { + if (inode == nf->nf_inode) { + ret = true; + break; + } + } + rcu_read_unlock(); + trace_nfsd_file_is_cached(inode, hashval, (int)ret); + return ret; +} + +__be32 +nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, + unsigned int may_flags, struct nfsd_file **pnf) +{ + __be32 status; + struct nfsd_file *nf, *new; + struct inode *inode; + unsigned int hashval; + + /* FIXME: skip this if fh_dentry is already set? */ + status = fh_verify(rqstp, fhp, S_IFREG, + may_flags|NFSD_MAY_OWNER_OVERRIDE); + if (status != nfs_ok) + return status; + + inode = d_inode(fhp->fh_dentry); + hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS); +retry: + rcu_read_lock(); + nf = nfsd_file_find_locked(inode, may_flags, hashval); + rcu_read_unlock(); + if (nf) + goto wait_for_construction; + + new = nfsd_file_alloc(inode, may_flags, hashval); + if (!new) { + trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags, + NULL, nfserr_jukebox); + return nfserr_jukebox; + } + + spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); + nf = nfsd_file_find_locked(inode, may_flags, hashval); + if (nf == NULL) + goto open_file; + spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); + nfsd_file_slab_free(&new->nf_rcu); + +wait_for_construction: + wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE); + + /* Did construction of this file fail? */ + if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { + nfsd_file_put_noref(nf); + goto retry; + } + + this_cpu_inc(nfsd_file_cache_hits); + + if (!(may_flags & NFSD_MAY_NOT_BREAK_LEASE)) { + bool write = (may_flags & NFSD_MAY_WRITE); + + if (test_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags) || + (test_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags) && write)) { + status = nfserrno(nfsd_open_break_lease( + file_inode(nf->nf_file), may_flags)); + if (status == nfs_ok) { + clear_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); + if (write) + clear_bit(NFSD_FILE_BREAK_WRITE, + &nf->nf_flags); + } + } + } +out: + if (status == nfs_ok) { + *pnf = nf; + } else { + nfsd_file_put(nf); + nf = NULL; + } + + trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags, nf, status); + return status; +open_file: + nf = new; + /* Take reference for the hashtable */ + atomic_inc(&nf->nf_ref); + __set_bit(NFSD_FILE_HASHED, &nf->nf_flags); + __set_bit(NFSD_FILE_PENDING, &nf->nf_flags); + list_lru_add(&nfsd_file_lru, &nf->nf_lru); + hlist_add_head_rcu(&nf->nf_node, &nfsd_file_hashtbl[hashval].nfb_head); + ++nfsd_file_hashtbl[hashval].nfb_count; + nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount, + nfsd_file_hashtbl[hashval].nfb_count); + spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); + atomic_long_inc(&nfsd_filecache_count); + + nf->nf_mark = nfsd_file_mark_find_or_create(nf); + if (nf->nf_mark) + status = nfsd_open_verified(rqstp, fhp, S_IFREG, + may_flags, &nf->nf_file); + else + status = nfserr_jukebox; + /* + * If construction failed, or we raced with a call to unlink() + * then unhash. + */ + if (status != nfs_ok || inode->i_nlink == 0) { + bool do_free; + spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); + do_free = nfsd_file_unhash(nf); + spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); + if (do_free) + nfsd_file_put_noref(nf); + } + clear_bit_unlock(NFSD_FILE_PENDING, &nf->nf_flags); + smp_mb__after_atomic(); + wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING); + goto out; +} + +/* + * Note that fields may be added, removed or reordered in the future. Programs + * scraping this file for info should test the labels to ensure they're + * getting the correct field. + */ +static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) +{ + unsigned int i, count = 0, longest = 0; + unsigned long hits = 0; + + /* + * No need for spinlocks here since we're not terribly interested in + * accuracy. We do take the nfsd_mutex simply to ensure that we + * don't end up racing with server shutdown + */ + mutex_lock(&nfsd_mutex); + if (nfsd_file_hashtbl) { + for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { + count += nfsd_file_hashtbl[i].nfb_count; + longest = max(longest, nfsd_file_hashtbl[i].nfb_count); + } + } + mutex_unlock(&nfsd_mutex); + + for_each_possible_cpu(i) + hits += per_cpu(nfsd_file_cache_hits, i); + + seq_printf(m, "total entries: %u\n", count); + seq_printf(m, "longest chain: %u\n", longest); + seq_printf(m, "cache hits: %lu\n", hits); + return 0; +} + +int nfsd_file_cache_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, nfsd_file_cache_stats_show, NULL); +} diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h new file mode 100644 index 000000000000..0c0c67166b87 --- /dev/null +++ b/fs/nfsd/filecache.h @@ -0,0 +1,60 @@ +#ifndef _FS_NFSD_FILECACHE_H +#define _FS_NFSD_FILECACHE_H + +#include <linux/fsnotify_backend.h> + +/* + * This is the fsnotify_mark container that nfsd attaches to the files that it + * is holding open. Note that we have a separate refcount here aside from the + * one in the fsnotify_mark. We only want a single fsnotify_mark attached to + * the inode, and for each nfsd_file to hold a reference to it. + * + * The fsnotify_mark is itself refcounted, but that's not sufficient to tell us + * how to put that reference. If there are still outstanding nfsd_files that + * reference the mark, then we would want to call fsnotify_put_mark on it. + * If there were not, then we'd need to call fsnotify_destroy_mark. Since we + * can't really tell the difference, we use the nfm_mark to keep track of how + * many nfsd_files hold references to the mark. When that counter goes to zero + * then we know to call fsnotify_destroy_mark on it. + */ +struct nfsd_file_mark { + struct fsnotify_mark nfm_mark; + atomic_t nfm_ref; +}; + +/* + * A representation of a file that has been opened by knfsd. These are hashed + * in the hashtable by inode pointer value. Note that this object doesn't + * hold a reference to the inode by itself, so the nf_inode pointer should + * never be dereferenced, only used for comparison. + */ +struct nfsd_file { + struct hlist_node nf_node; + struct list_head nf_lru; + struct rcu_head nf_rcu; + struct file *nf_file; + const struct cred *nf_cred; +#define NFSD_FILE_HASHED (0) +#define NFSD_FILE_PENDING (1) +#define NFSD_FILE_BREAK_READ (2) +#define NFSD_FILE_BREAK_WRITE (3) +#define NFSD_FILE_REFERENCED (4) + unsigned long nf_flags; + struct inode *nf_inode; + unsigned int nf_hashval; + atomic_t nf_ref; + unsigned char nf_may; + struct nfsd_file_mark *nf_mark; +}; + +int nfsd_file_cache_init(void); +void nfsd_file_cache_purge(void); +void nfsd_file_cache_shutdown(void); +void nfsd_file_put(struct nfsd_file *nf); +struct nfsd_file *nfsd_file_get(struct nfsd_file *nf); +void nfsd_file_close_inode_sync(struct inode *inode); +bool nfsd_file_is_cached(struct inode *inode); +__be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, + unsigned int may_flags, struct nfsd_file **nfp); +int nfsd_file_cache_stats_open(struct inode *, struct file *); +#endif /* _FS_NFSD_FILECACHE_H */ diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 18d94ea984ba..a6b1eab7b722 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -27,6 +27,7 @@ #include "cache.h" #include "vfs.h" #include "netns.h" +#include "filecache.h" #define NFSDDBG_FACILITY NFSDDBG_SVC @@ -313,6 +314,9 @@ static int nfsd_startup_generic(int nrservs) if (nfsd_users++) return 0; + ret = nfsd_file_cache_init(); + if (ret) + goto dec_users; /* * Readahead param cache - will no-op if it already exists. * (Note therefore results will be suboptimal if number of @@ -320,7 +324,7 @@ static int nfsd_startup_generic(int nrservs) */ ret = nfsd_racache_init(2*nrservs); if (ret) - goto dec_users; + goto out_file_cache; ret = nfs4_state_start(); if (ret) @@ -329,6 +333,8 @@ static int nfsd_startup_generic(int nrservs) out_racache: nfsd_racache_shutdown(); +out_file_cache: + nfsd_file_cache_shutdown(); dec_users: nfsd_users--; return ret; @@ -340,6 +346,7 @@ static void nfsd_shutdown_generic(void) return; nfs4_state_shutdown(); + nfsd_file_cache_shutdown(); nfsd_racache_shutdown(); } diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index 80933e4334d8..ffc78a0e28b2 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -126,6 +126,8 @@ DEFINE_NFSD_ERR_EVENT(read_err); DEFINE_NFSD_ERR_EVENT(write_err); #include "state.h" +#include "filecache.h" +#include "vfs.h" DECLARE_EVENT_CLASS(nfsd_stateid_class, TP_PROTO(stateid_t *stp), @@ -164,6 +166,144 @@ DEFINE_STATEID_EVENT(layout_recall_done); DEFINE_STATEID_EVENT(layout_recall_fail); DEFINE_STATEID_EVENT(layout_recall_release); +#define show_nf_flags(val) \ + __print_flags(val, "|", \ + { 1 << NFSD_FILE_HASHED, "HASHED" }, \ + { 1 << NFSD_FILE_PENDING, "PENDING" }, \ + { 1 << NFSD_FILE_BREAK_READ, "BREAK_READ" }, \ + { 1 << NFSD_FILE_BREAK_WRITE, "BREAK_WRITE" }, \ + { 1 << NFSD_FILE_REFERENCED, "REFERENCED"}) + +/* FIXME: This should probably be fleshed out in the future. */ +#define show_nf_may(val) \ + __print_flags(val, "|", \ + { NFSD_MAY_READ, "READ" }, \ + { NFSD_MAY_WRITE, "WRITE" }, \ + { NFSD_MAY_NOT_BREAK_LEASE, "NOT_BREAK_LEASE" }) + +DECLARE_EVENT_CLASS(nfsd_file_class, + TP_PROTO(struct nfsd_file *nf), + TP_ARGS(nf), + TP_STRUCT__entry( + __field(unsigned int, nf_hashval) + __field(void *, nf_inode) + __field(int, nf_ref) + __field(unsigned long, nf_flags) + __field(unsigned char, nf_may) + __field(struct file *, nf_file) + ), + TP_fast_assign( + __entry->nf_hashval = nf->nf_hashval; + __entry->nf_inode = nf->nf_inode; + __entry->nf_ref = atomic_read(&nf->nf_ref); + __entry->nf_flags = nf->nf_flags; + __entry->nf_may = nf->nf_may; + __entry->nf_file = nf->nf_file; + ), + TP_printk("hash=0x%x inode=0x%p ref=%d flags=%s may=%s file=%p", + __entry->nf_hashval, + __entry->nf_inode, + __entry->nf_ref, + show_nf_flags(__entry->nf_flags), + show_nf_may(__entry->nf_may), + __entry->nf_file) +) + +#define DEFINE_NFSD_FILE_EVENT(name) \ +DEFINE_EVENT(nfsd_file_class, name, \ + TP_PROTO(struct nfsd_file *nf), \ + TP_ARGS(nf)) + +DEFINE_NFSD_FILE_EVENT(nfsd_file_alloc); +DEFINE_NFSD_FILE_EVENT(nfsd_file_put_final); +DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash); +DEFINE_NFSD_FILE_EVENT(nfsd_file_put); +DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_release_locked); + +TRACE_EVENT(nfsd_file_acquire, + TP_PROTO(struct svc_rqst *rqstp, unsigned int hash, + struct inode *inode, unsigned int may_flags, + struct nfsd_file *nf, __be32 status), + + TP_ARGS(rqstp, hash, inode, may_flags, nf, status), + + TP_STRUCT__entry( + __field(__be32, xid) + __field(unsigned int, hash) + __field(void *, inode) + __field(unsigned int, may_flags) + __field(int, nf_ref) + __field(unsigned long, nf_flags) + __field(unsigned char, nf_may) + __field(struct file *, nf_file) + __field(__be32, status) + ), + + TP_fast_assign( + __entry->xid = rqstp->rq_xid; + __entry->hash = hash; + __entry->inode = inode; + __entry->may_flags = may_flags; + __entry->nf_ref = nf ? atomic_read(&nf->nf_ref) : 0; + __entry->nf_flags = nf ? nf->nf_flags : 0; + __entry->nf_may = nf ? nf->nf_may : 0; + __entry->nf_file = nf ? nf->nf_file : NULL; + __entry->status = status; + ), + + TP_printk("xid=0x%x hash=0x%x inode=0x%p may_flags=%s ref=%d nf_flags=%s nf_may=%s nf_file=0x%p status=%u", + be32_to_cpu(__entry->xid), __entry->hash, __entry->inode, + show_nf_may(__entry->may_flags), __entry->nf_ref, + show_nf_flags(__entry->nf_flags), + show_nf_may(__entry->nf_may), __entry->nf_file, + be32_to_cpu(__entry->status)) +); + +DECLARE_EVENT_CLASS(nfsd_file_search_class, + TP_PROTO(struct inode *inode, unsigned int hash, int found), + TP_ARGS(inode, hash, found), + TP_STRUCT__entry( + __field(struct inode *, inode) + __field(unsigned int, hash) + __field(int, found) + ), + TP_fast_assign( + __entry->inode = inode; + __entry->hash = hash; + __entry->found = found; + ), + TP_printk("hash=0x%x inode=0x%p found=%d", __entry->hash, + __entry->inode, __entry->found) +); + +#define DEFINE_NFSD_FILE_SEARCH_EVENT(name) \ +DEFINE_EVENT(nfsd_file_search_class, name, \ + TP_PROTO(struct inode *inode, unsigned int hash, int found), \ + TP_ARGS(inode, hash, found)) + +DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode_sync); +DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode); +DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_is_cached); + +TRACE_EVENT(nfsd_file_fsnotify_handle_event, + TP_PROTO(struct inode *inode, u32 mask), + TP_ARGS(inode, mask), + TP_STRUCT__entry( + __field(struct inode *, inode) + __field(unsigned int, nlink) + __field(umode_t, mode) + __field(u32, mask) + ), + TP_fast_assign( + __entry->inode = inode; + __entry->nlink = inode->i_nlink; + __entry->mode = inode->i_mode; + __entry->mask = mask; + ), + TP_printk("inode=0x%p nlink=%u mode=0%ho mask=0x%x", __entry->inode, + __entry->nlink, __entry->mode, __entry->mask) +); + #endif /* _NFSD_TRACE_H */ #undef TRACE_INCLUDE_PATH diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index c85783e536d5..5983206ab036 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -699,7 +699,7 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *suppor } #endif /* CONFIG_NFSD_V3 */ -static int nfsd_open_break_lease(struct inode *inode, int access) +int nfsd_open_break_lease(struct inode *inode, int access) { unsigned int mode; @@ -715,8 +715,8 @@ static int nfsd_open_break_lease(struct inode *inode, int access) * and additional flags. * N.B. After this call fhp needs an fh_put */ -__be32 -nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, +static __be32 +__nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int may_flags, struct file **filp) { struct path path; @@ -726,25 +726,6 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, __be32 err; int host_err = 0; - validate_process_creds(); - - /* - * If we get here, then the client has already done an "open", - * and (hopefully) checked permission - so allow OWNER_OVERRIDE - * in case a chmod has now revoked permission. - * - * Arguably we should also allow the owner override for - * directories, but we never have and it doesn't seem to have - * caused anyone a problem. If we were to change this, note - * also that our filldir callbacks would need a variant of - * lookup_one_len that doesn't check permissions. - */ - if (type == S_IFREG) - may_flags |= NFSD_MAY_OWNER_OVERRIDE; - err = fh_verify(rqstp, fhp, type, may_flags); - if (err) - goto out; - path.mnt = fhp->fh_export->ex_path.mnt; path.dentry = fhp->fh_dentry; inode = d_inode(path.dentry); @@ -798,10 +779,50 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, out_nfserr: err = nfserrno(host_err); out: + return err; +} + +__be32 +nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, + int may_flags, struct file **filp) +{ + __be32 err; + + validate_process_creds(); + /* + * If we get here, then the client has already done an "open", + * and (hopefully) checked permission - so allow OWNER_OVERRIDE + * in case a chmod has now revoked permission. + * + * Arguably we should also allow the owner override for + * directories, but we never have and it doesn't seem to have + * caused anyone a problem. If we were to change this, note + * also that our filldir callbacks would need a variant of + * lookup_one_len that doesn't check permissions. + */ + if (type == S_IFREG) + may_flags |= NFSD_MAY_OWNER_OVERRIDE; + err = fh_verify(rqstp, fhp, type, may_flags); + if (!err) + err = __nfsd_open(rqstp, fhp, type, may_flags, filp); + validate_process_creds(); + return err; +} + +__be32 +nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, + int may_flags, struct file **filp) +{ + __be32 err; + + validate_process_creds(); + err = __nfsd_open(rqstp, fhp, type, may_flags, filp); validate_process_creds(); return err; } + + struct raparms * nfsd_init_raparms(struct file *file) { diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index db351247892d..31fdae34e028 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -75,8 +75,11 @@ __be32 do_nfsd_create(struct svc_rqst *, struct svc_fh *, __be32 nfsd_commit(struct svc_rqst *, struct svc_fh *, loff_t, unsigned long); #endif /* CONFIG_NFSD_V3 */ +int nfsd_open_break_lease(struct inode *, int); __be32 nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t, int, struct file **); +__be32 nfsd_open_verified(struct svc_rqst *, struct svc_fh *, umode_t, + int, struct file **); struct raparms; __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, |