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[PATCH] nfsd4: reference count struct nfs4_file
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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>
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NeilBrown authored and Linus Torvalds committed Jun 24, 2005
1 parent 8beefa2 commit 13cd218
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Showing 2 changed files with 52 additions and 49 deletions.
100 changes: 51 additions & 49 deletions fs/nfsd/nfs4state.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,7 +111,6 @@ opaque_hashval(const void *ptr, int nbytes)
/* 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
Expand All @@ -121,6 +120,27 @@ static void release_file(struct nfs4_file *fp);
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)
{
Expand All @@ -136,6 +156,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
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);
Expand Down Expand Up @@ -163,6 +184,7 @@ nfs4_put_delegation(struct nfs4_delegation *dp)
{
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);
}
}
Expand Down Expand Up @@ -953,6 +975,7 @@ alloc_init_file(struct inode *ino)

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);
Expand All @@ -964,24 +987,6 @@ alloc_init_file(struct inode *ino)
return NULL;
}

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)
{
Expand Down Expand Up @@ -1141,6 +1146,7 @@ init_stateid(struct nfs4_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *
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;
Expand All @@ -1166,18 +1172,11 @@ release_stateid(struct nfs4_stateid *stp, int flags)
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)
{
Expand All @@ -1192,7 +1191,6 @@ void
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);
Expand All @@ -1203,10 +1201,6 @@ release_state_owner(struct nfs4_stateid *stp, int flag)
*/
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
Expand Down Expand Up @@ -1236,8 +1230,10 @@ find_file(struct inode *ino)
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;
}
Expand Down Expand Up @@ -1288,19 +1284,24 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
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
Expand Down Expand Up @@ -1829,10 +1830,8 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
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);
/*
Expand Down Expand Up @@ -2480,16 +2479,19 @@ find_stateid(stateid_t *stid, int flags)
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;
}

/*
Expand Down Expand Up @@ -2636,6 +2638,7 @@ alloc_init_lock_stateid(struct nfs4_stateowner *sop, struct nfs4_file *fp, struc
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;
Expand Down Expand Up @@ -3287,7 +3290,6 @@ __nfs4_state_shutdown(void)
unhash_delegation(dp);
}

release_all_files();
cancel_delayed_work(&laundromat_work);
flush_scheduled_work();
nfs4_init = 0;
Expand Down
1 change: 1 addition & 0 deletions include/linux/nfsd/state.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,7 @@ struct nfs4_stateowner {
* share_acces, share_deny on the file.
*/
struct nfs4_file {
struct kref fi_ref;
struct list_head fi_hash; /* hash by "struct inode *" */
struct list_head fi_stateids;
struct list_head fi_delegations;
Expand Down

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