[PATCH] nfsd4: reference count struct nfs4_file
Add a struct kref to each nfs4_file and take a reference to it from each
stateid and delegation that refers to it. The atomicity guarantees are
overkill given that all this stuff is done under the single nfsd4 state lock,
but a) we'd like finer-grained locking some day, and b) this simplifies the
cleanup of the structures a bit, something that has previously been a bit
complicated and bug-prone.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a84a80e..6ba428a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -111,7 +111,6 @@
/* forward declarations */
static void release_stateowner(struct nfs4_stateowner *sop);
static void release_stateid(struct nfs4_stateid *stp, int flags);
-static void release_file(struct nfs4_file *fp);
/*
* Delegation state
@@ -121,6 +120,27 @@
spinlock_t recall_lock;
static struct list_head del_recall_lru;
+static void
+free_nfs4_file(struct kref *kref)
+{
+ struct nfs4_file *fp = container_of(kref, struct nfs4_file, fi_ref);
+ list_del(&fp->fi_hash);
+ iput(fp->fi_inode);
+ kmem_cache_free(file_slab, fp);
+}
+
+static inline void
+put_nfs4_file(struct nfs4_file *fi)
+{
+ kref_put(&fi->fi_ref, free_nfs4_file);
+}
+
+static inline void
+get_nfs4_file(struct nfs4_file *fi)
+{
+ kref_get(&fi->fi_ref);
+}
+
static struct nfs4_delegation *
alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_fh *current_fh, u32 type)
{
@@ -136,6 +156,7 @@
INIT_LIST_HEAD(&dp->dl_del_perclnt);
INIT_LIST_HEAD(&dp->dl_recall_lru);
dp->dl_client = clp;
+ get_nfs4_file(fp);
dp->dl_file = fp;
dp->dl_flock = NULL;
get_file(stp->st_vfs_file);
@@ -163,6 +184,7 @@
{
if (atomic_dec_and_test(&dp->dl_count)) {
dprintk("NFSD: freeing dp %p\n",dp);
+ put_nfs4_file(dp->dl_file);
kmem_cache_free(deleg_slab, dp);
}
}
@@ -953,6 +975,7 @@
fp = kmem_cache_alloc(file_slab, GFP_KERNEL);
if (fp) {
+ kref_init(&fp->fi_ref);
INIT_LIST_HEAD(&fp->fi_hash);
INIT_LIST_HEAD(&fp->fi_stateids);
INIT_LIST_HEAD(&fp->fi_delegations);
@@ -965,24 +988,6 @@
}
static void
-release_all_files(void)
-{
- int i;
- struct nfs4_file *fp;
-
- for (i=0;i<FILE_HASH_SIZE;i++) {
- while (!list_empty(&file_hashtbl[i])) {
- fp = list_entry(file_hashtbl[i].next, struct nfs4_file, fi_hash);
- /* this should never be more than once... */
- if (!list_empty(&fp->fi_stateids) || !list_empty(&fp->fi_delegations)) {
- printk("ERROR: release_all_files: file %p is open, creating dangling state !!!\n",fp);
- }
- release_file(fp);
- }
- }
-}
-
-static void
nfsd4_free_slab(kmem_cache_t **slab)
{
int status;
@@ -1141,6 +1146,7 @@
list_add(&stp->st_perfilestate, &sop->so_perfilestate);
list_add(&stp->st_perfile, &fp->fi_stateids);
stp->st_stateowner = sop;
+ get_nfs4_file(fp);
stp->st_file = fp;
stp->st_stateid.si_boot = boot_time;
stp->st_stateid.si_stateownerid = sop->so_id;
@@ -1166,18 +1172,11 @@
nfsd_close(filp);
} else if (flags & LOCK_STATE)
locks_remove_posix(filp, (fl_owner_t) stp->st_stateowner);
+ put_nfs4_file(stp->st_file);
kmem_cache_free(stateid_slab, stp);
stp = NULL;
}
-static void
-release_file(struct nfs4_file *fp)
-{
- list_del(&fp->fi_hash);
- iput(fp->fi_inode);
- kmem_cache_free(file_slab, fp);
-}
-
void
move_to_close_lru(struct nfs4_stateowner *sop)
{
@@ -1192,7 +1191,6 @@
release_state_owner(struct nfs4_stateid *stp, int flag)
{
struct nfs4_stateowner *sop = stp->st_stateowner;
- struct nfs4_file *fp = stp->st_file;
dprintk("NFSD: release_state_owner\n");
release_stateid(stp, flag);
@@ -1203,10 +1201,6 @@
*/
if (sop->so_confirmed && list_empty(&sop->so_perfilestate))
move_to_close_lru(sop);
- /* unused nfs4_file's are releseed. XXX slab cache? */
- if (list_empty(&fp->fi_stateids) && list_empty(&fp->fi_delegations)) {
- release_file(fp);
- }
}
static int
@@ -1236,8 +1230,10 @@
struct nfs4_file *fp;
list_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
- if (fp->fi_inode == ino)
+ if (fp->fi_inode == ino) {
+ get_nfs4_file(fp);
return fp;
+ }
}
return NULL;
}
@@ -1288,19 +1284,24 @@
struct inode *ino = current_fh->fh_dentry->d_inode;
struct nfs4_file *fp;
struct nfs4_stateid *stp;
+ int ret;
dprintk("NFSD: nfs4_share_conflict\n");
fp = find_file(ino);
- if (fp) {
+ if (!fp)
+ return nfs_ok;
+ ret = nfserr_share_denied;
/* Search for conflicting share reservations */
- list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
- if (test_bit(deny_type, &stp->st_deny_bmap) ||
- test_bit(NFS4_SHARE_DENY_BOTH, &stp->st_deny_bmap))
- return nfserr_share_denied;
- }
+ list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
+ if (test_bit(deny_type, &stp->st_deny_bmap) ||
+ test_bit(NFS4_SHARE_DENY_BOTH, &stp->st_deny_bmap))
+ goto out;
}
- return nfs_ok;
+ ret = nfs_ok;
+out:
+ put_nfs4_file(fp);
+ return ret;
}
static inline void
@@ -1829,10 +1830,8 @@
stp->st_stateid.si_boot, stp->st_stateid.si_stateownerid,
stp->st_stateid.si_fileid, stp->st_stateid.si_generation);
out:
- /* take the opportunity to clean up unused state */
- if (fp && list_empty(&fp->fi_stateids) && list_empty(&fp->fi_delegations))
- release_file(fp);
-
+ if (fp)
+ put_nfs4_file(fp);
/* CLAIM_PREVIOUS has different error returns */
nfs4_set_claim_prev(open, &status);
/*
@@ -2480,16 +2479,19 @@
static struct nfs4_delegation *
find_delegation_stateid(struct inode *ino, stateid_t *stid)
{
- struct nfs4_file *fp = NULL;
+ struct nfs4_file *fp;
+ struct nfs4_delegation *dl;
dprintk("NFSD:find_delegation_stateid stateid=(%08x/%08x/%08x/%08x)\n",
stid->si_boot, stid->si_stateownerid,
stid->si_fileid, stid->si_generation);
fp = find_file(ino);
- if (fp)
- return find_delegation_file(fp, stid);
- return NULL;
+ if (!fp)
+ return NULL;
+ dl = find_delegation_file(fp, stid);
+ put_nfs4_file(fp);
+ return dl;
}
/*
@@ -2636,6 +2638,7 @@
list_add(&stp->st_perfile, &fp->fi_stateids);
list_add(&stp->st_perfilestate, &sop->so_perfilestate);
stp->st_stateowner = sop;
+ get_nfs4_file(fp);
stp->st_file = fp;
stp->st_stateid.si_boot = boot_time;
stp->st_stateid.si_stateownerid = sop->so_id;
@@ -3287,7 +3290,6 @@
unhash_delegation(dp);
}
- release_all_files();
cancel_delayed_work(&laundromat_work);
flush_scheduled_work();
nfs4_init = 0;