knfsd: don't allocate file_locks on the stack

struct file_lock is pretty large and really ought not live on the stack.
On my x86_64 machine, they're almost 200 bytes each.

    (gdb) p sizeof(struct file_lock)
    $1 = 192

...allocate them dynamically instead.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 123b471..5f1a91a 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4046,8 +4046,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        struct nfs4_lockowner *lock_sop = NULL;
        struct nfs4_ol_stateid *lock_stp;
        struct file *filp = NULL;
-       struct file_lock file_lock;
-       struct file_lock conflock;
+       struct file_lock *file_lock = NULL;
+       struct file_lock *conflock = NULL;
        __be32 status = 0;
        bool new_state = false;
        int lkflg;
@@ -4117,21 +4117,28 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        if (!locks_in_grace(SVC_NET(rqstp)) && lock->lk_reclaim)
                goto out;
 
-       locks_init_lock(&file_lock);
+       file_lock = locks_alloc_lock();
+       if (!file_lock) {
+               dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+               status = nfserr_jukebox;
+               goto out;
+       }
+
+       locks_init_lock(file_lock);
        switch (lock->lk_type) {
                case NFS4_READ_LT:
                case NFS4_READW_LT:
                        filp = find_readable_file(lock_stp->st_file);
                        if (filp)
                                get_lock_access(lock_stp, NFS4_SHARE_ACCESS_READ);
-                       file_lock.fl_type = F_RDLCK;
+                       file_lock->fl_type = F_RDLCK;
                        break;
                case NFS4_WRITE_LT:
                case NFS4_WRITEW_LT:
                        filp = find_writeable_file(lock_stp->st_file);
                        if (filp)
                                get_lock_access(lock_stp, NFS4_SHARE_ACCESS_WRITE);
-                       file_lock.fl_type = F_WRLCK;
+                       file_lock->fl_type = F_WRLCK;
                        break;
                default:
                        status = nfserr_inval;
@@ -4141,17 +4148,23 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                status = nfserr_openmode;
                goto out;
        }
-       file_lock.fl_owner = (fl_owner_t)lock_sop;
-       file_lock.fl_pid = current->tgid;
-       file_lock.fl_file = filp;
-       file_lock.fl_flags = FL_POSIX;
-       file_lock.fl_lmops = &nfsd_posix_mng_ops;
-
-       file_lock.fl_start = lock->lk_offset;
-       file_lock.fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
-       nfs4_transform_lock_offset(&file_lock);
+       file_lock->fl_owner = (fl_owner_t)lock_sop;
+       file_lock->fl_pid = current->tgid;
+       file_lock->fl_file = filp;
+       file_lock->fl_flags = FL_POSIX;
+       file_lock->fl_lmops = &nfsd_posix_mng_ops;
+       file_lock->fl_start = lock->lk_offset;
+       file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
+       nfs4_transform_lock_offset(file_lock);
+
+       conflock = locks_alloc_lock();
+       if (!conflock) {
+               dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+               status = nfserr_jukebox;
+               goto out;
+       }
 
-       err = vfs_lock_file(filp, F_SETLK, &file_lock, &conflock);
+       err = vfs_lock_file(filp, F_SETLK, file_lock, conflock);
        switch (-err) {
        case 0: /* success! */
                update_stateid(&lock_stp->st_stid.sc_stateid);
@@ -4162,7 +4175,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        case (EAGAIN):          /* conflock holds conflicting lock */
                status = nfserr_denied;
                dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
-               nfs4_set_lock_denied(&conflock, &lock->lk_denied);
+               nfs4_set_lock_denied(conflock, &lock->lk_denied);
                break;
        case (EDEADLK):
                status = nfserr_deadlock;
@@ -4177,6 +4190,10 @@ out:
                release_lockowner(lock_sop);
        if (!cstate->replay_owner)
                nfs4_unlock_state();
+       if (file_lock)
+               locks_free_lock(file_lock);
+       if (conflock)
+               locks_free_lock(conflock);
        return status;
 }
 
@@ -4205,7 +4222,7 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            struct nfsd4_lockt *lockt)
 {
        struct inode *inode;
-       struct file_lock file_lock;
+       struct file_lock *file_lock = NULL;
        struct nfs4_lockowner *lo;
        __be32 status;
        struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
@@ -4226,15 +4243,21 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                goto out;
 
        inode = cstate->current_fh.fh_dentry->d_inode;
-       locks_init_lock(&file_lock);
+       file_lock = locks_alloc_lock();
+       if (!file_lock) {
+               dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+               status = nfserr_jukebox;
+               goto out;
+       }
+       locks_init_lock(file_lock);
        switch (lockt->lt_type) {
                case NFS4_READ_LT:
                case NFS4_READW_LT:
-                       file_lock.fl_type = F_RDLCK;
+                       file_lock->fl_type = F_RDLCK;
                break;
                case NFS4_WRITE_LT:
                case NFS4_WRITEW_LT:
-                       file_lock.fl_type = F_WRLCK;
+                       file_lock->fl_type = F_WRLCK;
                break;
                default:
                        dprintk("NFSD: nfs4_lockt: bad lock type!\n");
@@ -4244,25 +4267,27 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
        lo = find_lockowner_str(inode, &lockt->lt_clientid, &lockt->lt_owner);
        if (lo)
-               file_lock.fl_owner = (fl_owner_t)lo;
-       file_lock.fl_pid = current->tgid;
-       file_lock.fl_flags = FL_POSIX;
+               file_lock->fl_owner = (fl_owner_t)lo;
+       file_lock->fl_pid = current->tgid;
+       file_lock->fl_flags = FL_POSIX;
 
-       file_lock.fl_start = lockt->lt_offset;
-       file_lock.fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
+       file_lock->fl_start = lockt->lt_offset;
+       file_lock->fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
 
-       nfs4_transform_lock_offset(&file_lock);
+       nfs4_transform_lock_offset(file_lock);
 
-       status = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock);
+       status = nfsd_test_lock(rqstp, &cstate->current_fh, file_lock);
        if (status)
                goto out;
 
-       if (file_lock.fl_type != F_UNLCK) {
+       if (file_lock->fl_type != F_UNLCK) {
                status = nfserr_denied;
-               nfs4_set_lock_denied(&file_lock, &lockt->lt_denied);
+               nfs4_set_lock_denied(file_lock, &lockt->lt_denied);
        }
 out:
        nfs4_unlock_state();
+       if (file_lock)
+               locks_free_lock(file_lock);
        return status;
 }
 
@@ -4272,7 +4297,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 {
        struct nfs4_ol_stateid *stp;
        struct file *filp = NULL;
-       struct file_lock file_lock;
+       struct file_lock *file_lock = NULL;
        __be32 status;
        int err;
                                                        
@@ -4294,22 +4319,29 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                status = nfserr_lock_range;
                goto out;
        }
-       locks_init_lock(&file_lock);
-       file_lock.fl_type = F_UNLCK;
-       file_lock.fl_owner = (fl_owner_t)lockowner(stp->st_stateowner);
-       file_lock.fl_pid = current->tgid;
-       file_lock.fl_file = filp;
-       file_lock.fl_flags = FL_POSIX; 
-       file_lock.fl_lmops = &nfsd_posix_mng_ops;
-       file_lock.fl_start = locku->lu_offset;
-
-       file_lock.fl_end = last_byte_offset(locku->lu_offset, locku->lu_length);
-       nfs4_transform_lock_offset(&file_lock);
+       file_lock = locks_alloc_lock();
+       if (!file_lock) {
+               dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+               status = nfserr_jukebox;
+               goto out;
+       }
+       locks_init_lock(file_lock);
+       file_lock->fl_type = F_UNLCK;
+       file_lock->fl_owner = (fl_owner_t)lockowner(stp->st_stateowner);
+       file_lock->fl_pid = current->tgid;
+       file_lock->fl_file = filp;
+       file_lock->fl_flags = FL_POSIX;
+       file_lock->fl_lmops = &nfsd_posix_mng_ops;
+       file_lock->fl_start = locku->lu_offset;
+
+       file_lock->fl_end = last_byte_offset(locku->lu_offset,
+                                               locku->lu_length);
+       nfs4_transform_lock_offset(file_lock);
 
        /*
        *  Try to unlock the file in the VFS.
        */
-       err = vfs_lock_file(filp, F_SETLK, &file_lock, NULL);
+       err = vfs_lock_file(filp, F_SETLK, file_lock, NULL);
        if (err) {
                dprintk("NFSD: nfs4_locku: vfs_lock_file failed!\n");
                goto out_nfserr;
@@ -4323,6 +4355,8 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 out:
        if (!cstate->replay_owner)
                nfs4_unlock_state();
+       if (file_lock)
+               locks_free_lock(file_lock);
        return status;
 
 out_nfserr: