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-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAl/bPRMACgkQnJ2qBz9k QNmktwf7BE+H0PEgm3VfEs8uKUnmgr/TTBd9rhuKVa8NeYrT1YlX2ocCykawaLSW ppyXkr2rWKwvRO5P9hZPUsMbjvp7ucz14imBHlhiQpPyfh8cqMazPJLySqbAI/M+ Eo8WIl74EqQ4VIgCGgfIVD073yjA4FWvO+5/CITYR44Pc2WzyCdU/1oKGBrs4+Cg OZAsHvg+2uKiEVeaBwbII+X/jChCJwEfHEYry3A8oRL427HrDir7Jc9i3SNGTDnc SE6DPj9X5HWOfoXjVrMratnaz654isvdRdP6GRAFKX8rJlNPGLMZbQ3DTzLGTYKL 7r9KylGD5nCkL1SXjUOLCqHgVRrgpg== =xcC/ -----END PGP SIGNATURE----- Merge tag 'fsnotify_for_v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "A few fsnotify fixes from Amir fixing fallout from big fsnotify overhaul a few months back and an improvement of defaults limiting maximum number of inotify watches from Waiman" * tag 'fsnotify_for_v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: fix events reported to watching parent and child inotify: convert to handle_inode_event() interface fsnotify: generalize handle_inode_event() inotify: Increase default inotify.max_user_watches limit to 1048576
1092 lines
27 KiB
C
1092 lines
27 KiB
C
/*
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* Open file cache.
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*
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* (c) 2015 - Jeff Layton <jeff.layton@primarydata.com>
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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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#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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#define NFSDDBG_FACILITY NFSDDBG_FH
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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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#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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/* 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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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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static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
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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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static struct workqueue_struct *nfsd_filecache_wq __read_mostly;
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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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static void nfsd_file_gc(void);
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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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if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags))
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return;
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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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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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put_cred(nf->nf_cred);
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kmem_cache_free(nfsd_file_slab, nf);
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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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kmem_cache_free(nfsd_file_mark_slab, nfm);
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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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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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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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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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/* 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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err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0);
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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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return nfm;
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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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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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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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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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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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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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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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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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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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trace_nfsd_file_unhash(nf);
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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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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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* 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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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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list_add(&nf->nf_lru, dispose);
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return true;
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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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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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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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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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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;
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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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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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{
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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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|
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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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|
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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();
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list_for_each_entry_rcu(l, &laundrettes, list) {
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if (l->net == net) {
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spin_lock(&l->lock);
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list_splice_tail_init(files, &l->freeme);
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spin_unlock(&l->lock);
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queue_work(nfsd_filecache_wq, &l->work);
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break;
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}
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}
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rcu_read_unlock();
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}
|
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|
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static void
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nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src,
|
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struct net *net)
|
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{
|
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struct nfsd_file *nf, *tmp;
|
|
|
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list_for_each_entry_safe(nf, tmp, src, nf_lru) {
|
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if (nf->nf_net == net)
|
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list_move_tail(&nf->nf_lru, dst);
|
|
}
|
|
}
|
|
|
|
static void
|
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nfsd_file_dispose_list_delayed(struct list_head *dispose)
|
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{
|
|
LIST_HEAD(list);
|
|
struct nfsd_file *nf;
|
|
|
|
while(!list_empty(dispose)) {
|
|
nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
|
|
nfsd_file_list_add_pernet(&list, dispose, nf->nf_net);
|
|
nfsd_file_list_add_disposal(&list, nf->nf_net);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 (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_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_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 (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);
|
|
}
|