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1094 lines
27 KiB
1094 lines
27 KiB
/* |
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* Open file cache. |
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* |
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* (c) 2015 - Jeff Layton <[email protected]> |
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*/ |
|
|
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#include <linux/hash.h> |
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#include <linux/slab.h> |
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#include <linux/file.h> |
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#include <linux/sched.h> |
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#include <linux/list_lru.h> |
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#include <linux/fsnotify_backend.h> |
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#include <linux/fsnotify.h> |
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#include <linux/seq_file.h> |
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|
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#include "vfs.h" |
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#include "nfsd.h" |
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#include "nfsfh.h" |
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#include "netns.h" |
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#include "filecache.h" |
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#include "trace.h" |
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|
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#define NFSDDBG_FACILITY NFSDDBG_FH |
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|
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/* FIXME: dynamically size this for the machine somehow? */ |
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#define NFSD_FILE_HASH_BITS 12 |
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#define NFSD_FILE_HASH_SIZE (1 << NFSD_FILE_HASH_BITS) |
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#define NFSD_LAUNDRETTE_DELAY (2 * HZ) |
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|
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#define NFSD_FILE_SHUTDOWN (1) |
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#define NFSD_FILE_LRU_THRESHOLD (4096UL) |
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#define NFSD_FILE_LRU_LIMIT (NFSD_FILE_LRU_THRESHOLD << 2) |
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|
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/* We only care about NFSD_MAY_READ/WRITE for this cache */ |
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#define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE) |
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|
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struct nfsd_fcache_bucket { |
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struct hlist_head nfb_head; |
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spinlock_t nfb_lock; |
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unsigned int nfb_count; |
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unsigned int nfb_maxcount; |
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}; |
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|
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static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); |
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|
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struct nfsd_fcache_disposal { |
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struct list_head list; |
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struct work_struct work; |
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struct net *net; |
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spinlock_t lock; |
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struct list_head freeme; |
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struct rcu_head rcu; |
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}; |
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|
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static struct workqueue_struct *nfsd_filecache_wq __read_mostly; |
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|
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static struct kmem_cache *nfsd_file_slab; |
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static struct kmem_cache *nfsd_file_mark_slab; |
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static struct nfsd_fcache_bucket *nfsd_file_hashtbl; |
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static struct list_lru nfsd_file_lru; |
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static long nfsd_file_lru_flags; |
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static struct fsnotify_group *nfsd_file_fsnotify_group; |
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static atomic_long_t nfsd_filecache_count; |
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static struct delayed_work nfsd_filecache_laundrette; |
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static DEFINE_SPINLOCK(laundrette_lock); |
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static LIST_HEAD(laundrettes); |
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|
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static void nfsd_file_gc(void); |
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|
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static void |
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nfsd_file_schedule_laundrette(void) |
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{ |
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long count = atomic_long_read(&nfsd_filecache_count); |
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|
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if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags)) |
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return; |
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|
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queue_delayed_work(system_wq, &nfsd_filecache_laundrette, |
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NFSD_LAUNDRETTE_DELAY); |
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} |
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|
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static void |
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nfsd_file_slab_free(struct rcu_head *rcu) |
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{ |
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struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu); |
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|
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put_cred(nf->nf_cred); |
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kmem_cache_free(nfsd_file_slab, nf); |
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} |
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|
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static void |
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nfsd_file_mark_free(struct fsnotify_mark *mark) |
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{ |
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struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark, |
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nfm_mark); |
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|
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kmem_cache_free(nfsd_file_mark_slab, nfm); |
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} |
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|
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static struct nfsd_file_mark * |
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nfsd_file_mark_get(struct nfsd_file_mark *nfm) |
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{ |
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if (!refcount_inc_not_zero(&nfm->nfm_ref)) |
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return NULL; |
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return nfm; |
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} |
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|
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static void |
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nfsd_file_mark_put(struct nfsd_file_mark *nfm) |
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{ |
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if (refcount_dec_and_test(&nfm->nfm_ref)) { |
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fsnotify_destroy_mark(&nfm->nfm_mark, nfsd_file_fsnotify_group); |
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fsnotify_put_mark(&nfm->nfm_mark); |
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} |
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} |
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|
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static struct nfsd_file_mark * |
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nfsd_file_mark_find_or_create(struct nfsd_file *nf) |
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{ |
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int err; |
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struct fsnotify_mark *mark; |
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struct nfsd_file_mark *nfm = NULL, *new; |
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struct inode *inode = nf->nf_inode; |
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|
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do { |
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mutex_lock(&nfsd_file_fsnotify_group->mark_mutex); |
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mark = fsnotify_find_mark(&inode->i_fsnotify_marks, |
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nfsd_file_fsnotify_group); |
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if (mark) { |
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nfm = nfsd_file_mark_get(container_of(mark, |
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struct nfsd_file_mark, |
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nfm_mark)); |
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mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); |
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if (nfm) { |
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fsnotify_put_mark(mark); |
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break; |
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} |
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/* Avoid soft lockup race with nfsd_file_mark_put() */ |
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fsnotify_destroy_mark(mark, nfsd_file_fsnotify_group); |
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fsnotify_put_mark(mark); |
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} else |
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mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); |
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|
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/* allocate a new nfm */ |
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new = kmem_cache_alloc(nfsd_file_mark_slab, GFP_KERNEL); |
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if (!new) |
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return NULL; |
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fsnotify_init_mark(&new->nfm_mark, nfsd_file_fsnotify_group); |
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new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF; |
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refcount_set(&new->nfm_ref, 1); |
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|
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err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0); |
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|
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/* |
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* If the add was successful, then return the object. |
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* Otherwise, we need to put the reference we hold on the |
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* nfm_mark. The fsnotify code will take a reference and put |
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* it on failure, so we can't just free it directly. It's also |
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* not safe to call fsnotify_destroy_mark on it as the |
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* mark->group will be NULL. Thus, we can't let the nfm_ref |
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* counter drive the destruction at this point. |
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*/ |
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if (likely(!err)) |
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nfm = new; |
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else |
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fsnotify_put_mark(&new->nfm_mark); |
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} while (unlikely(err == -EEXIST)); |
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|
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return nfm; |
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} |
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|
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static struct nfsd_file * |
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nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, |
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struct net *net) |
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{ |
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struct nfsd_file *nf; |
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|
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nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL); |
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if (nf) { |
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INIT_HLIST_NODE(&nf->nf_node); |
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INIT_LIST_HEAD(&nf->nf_lru); |
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nf->nf_file = NULL; |
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nf->nf_cred = get_current_cred(); |
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nf->nf_net = net; |
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nf->nf_flags = 0; |
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nf->nf_inode = inode; |
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nf->nf_hashval = hashval; |
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refcount_set(&nf->nf_ref, 1); |
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nf->nf_may = may & NFSD_FILE_MAY_MASK; |
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if (may & NFSD_MAY_NOT_BREAK_LEASE) { |
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if (may & NFSD_MAY_WRITE) |
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__set_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags); |
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if (may & NFSD_MAY_READ) |
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__set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); |
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} |
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nf->nf_mark = NULL; |
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init_rwsem(&nf->nf_rwsem); |
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trace_nfsd_file_alloc(nf); |
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} |
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return nf; |
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} |
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|
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static bool |
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nfsd_file_free(struct nfsd_file *nf) |
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{ |
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bool flush = false; |
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|
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trace_nfsd_file_put_final(nf); |
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if (nf->nf_mark) |
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nfsd_file_mark_put(nf->nf_mark); |
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if (nf->nf_file) { |
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get_file(nf->nf_file); |
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filp_close(nf->nf_file, NULL); |
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fput(nf->nf_file); |
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flush = true; |
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} |
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call_rcu(&nf->nf_rcu, nfsd_file_slab_free); |
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return flush; |
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} |
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|
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static bool |
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nfsd_file_check_writeback(struct nfsd_file *nf) |
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{ |
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struct file *file = nf->nf_file; |
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struct address_space *mapping; |
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|
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if (!file || !(file->f_mode & FMODE_WRITE)) |
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return false; |
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mapping = file->f_mapping; |
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return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || |
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mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); |
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} |
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|
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static int |
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nfsd_file_check_write_error(struct nfsd_file *nf) |
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{ |
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struct file *file = nf->nf_file; |
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|
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if (!file || !(file->f_mode & FMODE_WRITE)) |
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return 0; |
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return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)); |
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} |
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|
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static void |
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nfsd_file_do_unhash(struct nfsd_file *nf) |
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{ |
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lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); |
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|
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trace_nfsd_file_unhash(nf); |
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|
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if (nfsd_file_check_write_error(nf)) |
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nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); |
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--nfsd_file_hashtbl[nf->nf_hashval].nfb_count; |
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hlist_del_rcu(&nf->nf_node); |
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atomic_long_dec(&nfsd_filecache_count); |
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} |
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|
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static bool |
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nfsd_file_unhash(struct nfsd_file *nf) |
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{ |
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if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { |
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nfsd_file_do_unhash(nf); |
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if (!list_empty(&nf->nf_lru)) |
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list_lru_del(&nfsd_file_lru, &nf->nf_lru); |
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return true; |
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} |
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return false; |
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} |
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|
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/* |
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* Return true if the file was unhashed. |
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*/ |
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static bool |
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nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *dispose) |
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{ |
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lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); |
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|
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trace_nfsd_file_unhash_and_release_locked(nf); |
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if (!nfsd_file_unhash(nf)) |
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return false; |
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/* keep final reference for nfsd_file_lru_dispose */ |
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if (refcount_dec_not_one(&nf->nf_ref)) |
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return true; |
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|
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list_add(&nf->nf_lru, dispose); |
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return true; |
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} |
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|
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static void |
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nfsd_file_put_noref(struct nfsd_file *nf) |
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{ |
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trace_nfsd_file_put(nf); |
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|
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if (refcount_dec_and_test(&nf->nf_ref)) { |
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WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags)); |
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nfsd_file_free(nf); |
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} |
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} |
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|
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void |
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nfsd_file_put(struct nfsd_file *nf) |
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{ |
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bool is_hashed; |
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|
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set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); |
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if (refcount_read(&nf->nf_ref) > 2 || !nf->nf_file) { |
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nfsd_file_put_noref(nf); |
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return; |
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} |
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|
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filemap_flush(nf->nf_file->f_mapping); |
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is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; |
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nfsd_file_put_noref(nf); |
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if (is_hashed) |
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nfsd_file_schedule_laundrette(); |
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if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT) |
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nfsd_file_gc(); |
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} |
|
|
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struct nfsd_file * |
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nfsd_file_get(struct nfsd_file *nf) |
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{ |
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if (likely(refcount_inc_not_zero(&nf->nf_ref))) |
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return nf; |
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return NULL; |
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} |
|
|
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static void |
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nfsd_file_dispose_list(struct list_head *dispose) |
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{ |
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struct nfsd_file *nf; |
|
|
|
while(!list_empty(dispose)) { |
|
nf = list_first_entry(dispose, struct nfsd_file, nf_lru); |
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list_del(&nf->nf_lru); |
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nfsd_file_put_noref(nf); |
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} |
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} |
|
|
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static void |
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nfsd_file_dispose_list_sync(struct list_head *dispose) |
|
{ |
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bool flush = false; |
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struct nfsd_file *nf; |
|
|
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while(!list_empty(dispose)) { |
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nf = list_first_entry(dispose, struct nfsd_file, nf_lru); |
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list_del(&nf->nf_lru); |
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if (!refcount_dec_and_test(&nf->nf_ref)) |
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continue; |
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if (nfsd_file_free(nf)) |
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flush = true; |
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} |
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if (flush) |
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flush_delayed_fput(); |
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} |
|
|
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static void |
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nfsd_file_list_remove_disposal(struct list_head *dst, |
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struct nfsd_fcache_disposal *l) |
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{ |
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spin_lock(&l->lock); |
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list_splice_init(&l->freeme, dst); |
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spin_unlock(&l->lock); |
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} |
|
|
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static void |
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nfsd_file_list_add_disposal(struct list_head *files, struct net *net) |
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{ |
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struct nfsd_fcache_disposal *l; |
|
|
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rcu_read_lock(); |
|
list_for_each_entry_rcu(l, &laundrettes, list) { |
|
if (l->net == net) { |
|
spin_lock(&l->lock); |
|
list_splice_tail_init(files, &l->freeme); |
|
spin_unlock(&l->lock); |
|
queue_work(nfsd_filecache_wq, &l->work); |
|
break; |
|
} |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
static void |
|
nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src, |
|
struct net *net) |
|
{ |
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struct nfsd_file *nf, *tmp; |
|
|
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list_for_each_entry_safe(nf, tmp, src, nf_lru) { |
|
if (nf->nf_net == net) |
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list_move_tail(&nf->nf_lru, dst); |
|
} |
|
} |
|
|
|
static void |
|
nfsd_file_dispose_list_delayed(struct list_head *dispose) |
|
{ |
|
LIST_HEAD(list); |
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struct nfsd_file *nf; |
|
|
|
while(!list_empty(dispose)) { |
|
nf = list_first_entry(dispose, struct nfsd_file, nf_lru); |
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nfsd_file_list_add_pernet(&list, dispose, nf->nf_net); |
|
nfsd_file_list_add_disposal(&list, nf->nf_net); |
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} |
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} |
|
|
|
/* |
|
* 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) |
|
{ |
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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 (refcount_read(&nf->nf_ref) > 1) |
|
goto out_skip; |
|
|
|
/* |
|
* Don't throw out files that are still undergoing I/O or |
|
* that have uncleared errors pending. |
|
*/ |
|
if (nfsd_file_check_writeback(nf)) |
|
goto out_skip; |
|
|
|
if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) |
|
goto out_skip; |
|
|
|
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_skip: |
|
return LRU_SKIP; |
|
} |
|
|
|
static unsigned long |
|
nfsd_file_lru_walk_list(struct shrink_control *sc) |
|
{ |
|
LIST_HEAD(head); |
|
struct nfsd_file *nf; |
|
unsigned long ret; |
|
|
|
if (sc) |
|
ret = list_lru_shrink_walk(&nfsd_file_lru, sc, |
|
nfsd_file_lru_cb, &head); |
|
else |
|
ret = list_lru_walk(&nfsd_file_lru, |
|
nfsd_file_lru_cb, |
|
&head, LONG_MAX); |
|
list_for_each_entry(nf, &head, 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_dispose_list_delayed(&head); |
|
return ret; |
|
} |
|
|
|
static void |
|
nfsd_file_gc(void) |
|
{ |
|
nfsd_file_lru_walk_list(NULL); |
|
} |
|
|
|
static void |
|
nfsd_file_gc_worker(struct work_struct *work) |
|
{ |
|
nfsd_file_gc(); |
|
nfsd_file_schedule_laundrette(); |
|
} |
|
|
|
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) |
|
{ |
|
return nfsd_file_lru_walk_list(sc); |
|
} |
|
|
|
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 - attempt a delayed close of 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_delayed(&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); |
|
struct nfsd_fcache_disposal *l = container_of(work, |
|
struct nfsd_fcache_disposal, work); |
|
|
|
nfsd_file_list_remove_disposal(&head, l); |
|
nfsd_file_dispose_list(&head); |
|
} |
|
|
|
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_mark *mark, u32 mask, |
|
struct inode *inode, struct inode *dir, |
|
const struct qstr *name, u32 cookie) |
|
{ |
|
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_inode_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_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0); |
|
if (!nfsd_filecache_wq) |
|
goto out; |
|
|
|
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)); |
|
ret = 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_gc_worker); |
|
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; |
|
destroy_workqueue(nfsd_filecache_wq); |
|
nfsd_filecache_wq = NULL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Note this can deadlock with nfsd_file_lru_cb. |
|
*/ |
|
void |
|
nfsd_file_cache_purge(struct net *net) |
|
{ |
|
unsigned int i; |
|
struct nfsd_file *nf; |
|
struct hlist_node *next; |
|
LIST_HEAD(dispose); |
|
bool del; |
|
|
|
if (!nfsd_file_hashtbl) |
|
return; |
|
|
|
for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { |
|
struct nfsd_fcache_bucket *nfb = &nfsd_file_hashtbl[i]; |
|
|
|
spin_lock(&nfb->nfb_lock); |
|
hlist_for_each_entry_safe(nf, next, &nfb->nfb_head, nf_node) { |
|
if (net && nf->nf_net != net) |
|
continue; |
|
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(&nfb->nfb_lock); |
|
nfsd_file_dispose_list(&dispose); |
|
} |
|
} |
|
|
|
static struct nfsd_fcache_disposal * |
|
nfsd_alloc_fcache_disposal(struct net *net) |
|
{ |
|
struct nfsd_fcache_disposal *l; |
|
|
|
l = kmalloc(sizeof(*l), GFP_KERNEL); |
|
if (!l) |
|
return NULL; |
|
INIT_WORK(&l->work, nfsd_file_delayed_close); |
|
l->net = net; |
|
spin_lock_init(&l->lock); |
|
INIT_LIST_HEAD(&l->freeme); |
|
return l; |
|
} |
|
|
|
static void |
|
nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l) |
|
{ |
|
rcu_assign_pointer(l->net, NULL); |
|
cancel_work_sync(&l->work); |
|
nfsd_file_dispose_list(&l->freeme); |
|
kfree_rcu(l, rcu); |
|
} |
|
|
|
static void |
|
nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l) |
|
{ |
|
spin_lock(&laundrette_lock); |
|
list_add_tail_rcu(&l->list, &laundrettes); |
|
spin_unlock(&laundrette_lock); |
|
} |
|
|
|
static void |
|
nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l) |
|
{ |
|
spin_lock(&laundrette_lock); |
|
list_del_rcu(&l->list); |
|
spin_unlock(&laundrette_lock); |
|
} |
|
|
|
static int |
|
nfsd_alloc_fcache_disposal_net(struct net *net) |
|
{ |
|
struct nfsd_fcache_disposal *l; |
|
|
|
l = nfsd_alloc_fcache_disposal(net); |
|
if (!l) |
|
return -ENOMEM; |
|
nfsd_add_fcache_disposal(l); |
|
return 0; |
|
} |
|
|
|
static void |
|
nfsd_free_fcache_disposal_net(struct net *net) |
|
{ |
|
struct nfsd_fcache_disposal *l; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(l, &laundrettes, list) { |
|
if (l->net != net) |
|
continue; |
|
nfsd_del_fcache_disposal(l); |
|
rcu_read_unlock(); |
|
nfsd_free_fcache_disposal(l); |
|
return; |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
int |
|
nfsd_file_cache_start_net(struct net *net) |
|
{ |
|
return nfsd_alloc_fcache_disposal_net(net); |
|
} |
|
|
|
void |
|
nfsd_file_cache_shutdown_net(struct net *net) |
|
{ |
|
nfsd_file_cache_purge(net); |
|
nfsd_free_fcache_disposal_net(net); |
|
} |
|
|
|
void |
|
nfsd_file_cache_shutdown(void) |
|
{ |
|
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(NULL); |
|
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; |
|
destroy_workqueue(nfsd_filecache_wq); |
|
nfsd_filecache_wq = 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 net *net) |
|
{ |
|
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, lockdep_is_held(&nfsd_file_hashtbl[hashval].nfb_lock)) { |
|
if (nf->nf_may != need) |
|
continue; |
|
if (nf->nf_inode != inode) |
|
continue; |
|
if (nf->nf_net != net) |
|
continue; |
|
if (!nfsd_match_cred(nf->nf_cred, current_cred())) |
|
continue; |
|
if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) |
|
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 net *net = SVC_NET(rqstp); |
|
struct nfsd_file *nf, *new; |
|
struct inode *inode; |
|
unsigned int hashval; |
|
bool retry = true; |
|
|
|
/* 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, net); |
|
rcu_read_unlock(); |
|
if (nf) |
|
goto wait_for_construction; |
|
|
|
new = nfsd_file_alloc(inode, may_flags, hashval, net); |
|
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, net); |
|
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)) { |
|
if (!retry) { |
|
status = nfserr_jukebox; |
|
goto out; |
|
} |
|
retry = false; |
|
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 */ |
|
refcount_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); |
|
if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD) |
|
nfsd_file_gc(); |
|
|
|
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); |
|
}
|
|
|