From f475ae957db66650db66916c62604ac27409d884 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 29 Jun 2006 16:38:32 -0400 Subject: [PATCH 1/5] VFS: Allow caller to determine if BSD or posix locks were actually freed Change posix_lock_file_conf(), and flock_lock_file() so that if called with an F_UNLCK argument, and the FL_EXISTS flag they will indicate whether or not any locks were actually freed by returning 0 or -ENOENT. Signed-off-by: Trond Myklebust --- fs/locks.c | 18 ++++++++++++++++-- include/linux/fs.h | 1 + 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 1ad29c9b6252..50cb0a2b74d9 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -725,6 +725,10 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks * at the head of the list, but that's secret knowledge known only to * flock_lock_file and posix_lock_file. + * + * Note that if called with an FL_EXISTS argument, the caller may determine + * whether or not a lock was successfully freed by testing the return + * value for -ENOENT. */ static int flock_lock_file(struct file *filp, struct file_lock *request) { @@ -750,8 +754,11 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) break; } - if (request->fl_type == F_UNLCK) + if (request->fl_type == F_UNLCK) { + if ((request->fl_flags & FL_EXISTS) && !found) + error = -ENOENT; goto out; + } error = -ENOMEM; new_fl = locks_alloc_lock(); @@ -948,8 +955,11 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request error = 0; if (!added) { - if (request->fl_type == F_UNLCK) + if (request->fl_type == F_UNLCK) { + if (request->fl_flags & FL_EXISTS) + error = -ENOENT; goto out; + } if (!new_fl) { error = -ENOLCK; @@ -996,6 +1006,10 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request * Add a POSIX style lock to a file. * We merge adjacent & overlapping locks whenever possible. * POSIX locks are sorted by owner task, then by starting address + * + * Note that if called with an FL_EXISTS argument, the caller may determine + * whether or not a lock was successfully freed by testing the return + * value for -ENOENT. */ int posix_lock_file(struct file *filp, struct file_lock *fl) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 134b32068246..43aef9b230fd 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -716,6 +716,7 @@ extern spinlock_t files_lock; #define FL_POSIX 1 #define FL_FLOCK 2 #define FL_ACCESS 8 /* not trying to lock, just looking */ +#define FL_EXISTS 16 /* when unlocking, test for existence */ #define FL_LEASE 32 /* lease held on this file */ #define FL_CLOSE 64 /* unlock on close */ #define FL_SLEEP 128 /* A blocking lock */ From 9b07357490e5c7a1c3c2b6f4679d7ee4b4185ecd Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 29 Jun 2006 16:38:34 -0400 Subject: [PATCH 2/5] NLM,NFSv4: Don't put UNLOCK requests on the wire unless we hold a lock Use the new behaviour of {flock,posix}_file_lock(F_UNLCK) to determine if we held a lock, and only send the RPC request to the server if this was the case. Signed-off-by: Trond Myklebust --- fs/lockd/clntproc.c | 18 ++++++++++-------- fs/nfs/nfs4proc.c | 31 ++++++++++++------------------- 2 files changed, 22 insertions(+), 27 deletions(-) diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c index 5980c45998cc..24c691f5480e 100644 --- a/fs/lockd/clntproc.c +++ b/fs/lockd/clntproc.c @@ -454,7 +454,7 @@ static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *ho fl->fl_ops = &nlmclnt_lock_ops; } -static void do_vfs_lock(struct file_lock *fl) +static int do_vfs_lock(struct file_lock *fl) { int res = 0; switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { @@ -467,9 +467,7 @@ static void do_vfs_lock(struct file_lock *fl) default: BUG(); } - if (res < 0) - printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", - __FUNCTION__); + return res; } /* @@ -541,7 +539,8 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) } fl->fl_flags |= FL_SLEEP; /* Ensure the resulting lock will get added to granted list */ - do_vfs_lock(fl); + if (do_vfs_lock(fl) < 0) + printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); up_read(&host->h_rwsem); } status = nlm_stat_to_errno(resp->status); @@ -606,15 +605,19 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) { struct nlm_host *host = req->a_host; struct nlm_res *resp = &req->a_res; - int status; + int status = 0; /* * Note: the server is supposed to either grant us the unlock * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either * case, we want to unlock. */ + fl->fl_flags |= FL_EXISTS; down_read(&host->h_rwsem); - do_vfs_lock(fl); + if (do_vfs_lock(fl) == -ENOENT) { + up_read(&host->h_rwsem); + goto out; + } up_read(&host->h_rwsem); if (req->a_flags & RPC_TASK_ASYNC) @@ -624,7 +627,6 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) if (status < 0) goto out; - status = 0; if (resp->status == NLM_LCK_GRANTED) goto out; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b4916b092194..b8c63757f039 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3144,9 +3144,6 @@ static int do_vfs_lock(struct file *file, struct file_lock *fl) default: BUG(); } - if (res < 0) - printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", - __FUNCTION__); return res; } @@ -3258,8 +3255,6 @@ static struct rpc_task *nfs4_do_unlck(struct file_lock *fl, return ERR_PTR(-ENOMEM); } - /* Unlock _before_ we do the RPC call */ - do_vfs_lock(fl->fl_file, fl); return rpc_run_task(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data); } @@ -3270,30 +3265,28 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock * struct rpc_task *task; int status = 0; + status = nfs4_set_lock_state(state, request); + /* Unlock _before_ we do the RPC call */ + request->fl_flags |= FL_EXISTS; + if (do_vfs_lock(request->fl_file, request) == -ENOENT) + goto out; + if (status != 0) + goto out; /* Is this a delegated lock? */ if (test_bit(NFS_DELEGATED_STATE, &state->flags)) - goto out_unlock; - /* Is this open_owner holding any locks on the server? */ - if (test_bit(LK_STATE_IN_USE, &state->flags) == 0) - goto out_unlock; - - status = nfs4_set_lock_state(state, request); - if (status != 0) - goto out_unlock; + goto out; lsp = request->fl_u.nfs4_fl.owner; - status = -ENOMEM; seqid = nfs_alloc_seqid(&lsp->ls_seqid); + status = -ENOMEM; if (seqid == NULL) - goto out_unlock; + goto out; task = nfs4_do_unlck(request, request->fl_file->private_data, lsp, seqid); status = PTR_ERR(task); if (IS_ERR(task)) - goto out_unlock; + goto out; status = nfs4_wait_for_completion_rpc_task(task); rpc_release_task(task); - return status; -out_unlock: - do_vfs_lock(request->fl_file, request); +out: return status; } From 42a2d13eee3c895d22e9d1a52b96d15ca49adabc Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 29 Jun 2006 16:38:36 -0400 Subject: [PATCH 3/5] NFSv4: Ensure nfs4_lock_expired() caches delegated locks Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b8c63757f039..8bdfe3ff7925 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3454,10 +3454,10 @@ static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request struct nfs4_exception exception = { }; int err; - /* Cache the lock if possible... */ - if (test_bit(NFS_DELEGATED_STATE, &state->flags)) - return 0; do { + /* Cache the lock if possible... */ + if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0) + return 0; err = _nfs4_do_setlk(state, F_SETLK, request, 1); if (err != -NFS4ERR_DELAY) break; @@ -3476,6 +3476,8 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request if (err != 0) return err; do { + if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0) + return 0; err = _nfs4_do_setlk(state, F_SETLK, request, 0); if (err != -NFS4ERR_DELAY) break; From f07f18dd6f29f11887b8d9cf7ecb736bf2f7dc62 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 29 Jun 2006 16:38:37 -0400 Subject: [PATCH 4/5] VFS: Add support for the FL_ACCESS flag to flock_lock_file() Signed-off-by: Trond Myklebust --- fs/locks.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/locks.c b/fs/locks.c index 50cb0a2b74d9..b0b41a64e10b 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -739,6 +739,8 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) int found = 0; lock_kernel(); + if (request->fl_flags & FL_ACCESS) + goto find_conflict; for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) @@ -771,6 +773,7 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) if (found) cond_resched(); +find_conflict: for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) @@ -784,6 +787,8 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) locks_insert_block(fl, request); goto out; } + if (request->fl_flags & FL_ACCESS) + goto out; locks_copy_lock(new_fl, request); locks_insert_lock(&inode->i_flock, new_fl); new_fl = NULL; From 01c3b861cd77b28565a2d18c7caa3ce7f938e35c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 29 Jun 2006 16:38:39 -0400 Subject: [PATCH 5/5] NLM,NFSv4: Wait on local locks before we put RPC calls on the wire Use FL_ACCESS flag to test and/or wait for local locks before we try requesting a lock from the server Signed-off-by: Trond Myklebust --- fs/lockd/clntproc.c | 8 +++++++- fs/nfs/nfs4proc.c | 35 ++++++++++++++++++++++++----------- 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c index 24c691f5480e..89ba0df14c22 100644 --- a/fs/lockd/clntproc.c +++ b/fs/lockd/clntproc.c @@ -496,6 +496,7 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) struct nlm_host *host = req->a_host; struct nlm_res *resp = &req->a_res; struct nlm_wait *block = NULL; + unsigned char fl_flags = fl->fl_flags; int status = -ENOLCK; if (!host->h_monitored && nsm_monitor(host) < 0) { @@ -503,6 +504,10 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) host->h_name); goto out; } + fl->fl_flags |= FL_ACCESS; + status = do_vfs_lock(fl); + if (status < 0) + goto out; block = nlmclnt_prepare_block(host, fl); again: @@ -537,8 +542,8 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) up_read(&host->h_rwsem); goto again; } - fl->fl_flags |= FL_SLEEP; /* Ensure the resulting lock will get added to granted list */ + fl->fl_flags = fl_flags | FL_SLEEP; if (do_vfs_lock(fl) < 0) printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); up_read(&host->h_rwsem); @@ -551,6 +556,7 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) nlmclnt_cancel(host, req->a_args.block, fl); out: nlm_release_call(req); + fl->fl_flags = fl_flags; return status; } diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 8bdfe3ff7925..e6ee97f19d81 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3489,29 +3489,42 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request) { struct nfs4_client *clp = state->owner->so_client; + unsigned char fl_flags = request->fl_flags; int status; /* Is this a delegated open? */ - if (NFS_I(state->inode)->delegation_state != 0) { - /* Yes: cache locks! */ - status = do_vfs_lock(request->fl_file, request); - /* ...but avoid races with delegation recall... */ - if (status < 0 || test_bit(NFS_DELEGATED_STATE, &state->flags)) - return status; - } - down_read(&clp->cl_sem); status = nfs4_set_lock_state(state, request); if (status != 0) goto out; + request->fl_flags |= FL_ACCESS; + status = do_vfs_lock(request->fl_file, request); + if (status < 0) + goto out; + down_read(&clp->cl_sem); + if (test_bit(NFS_DELEGATED_STATE, &state->flags)) { + struct nfs_inode *nfsi = NFS_I(state->inode); + /* Yes: cache locks! */ + down_read(&nfsi->rwsem); + /* ...but avoid races with delegation recall... */ + if (test_bit(NFS_DELEGATED_STATE, &state->flags)) { + request->fl_flags = fl_flags & ~FL_SLEEP; + status = do_vfs_lock(request->fl_file, request); + up_read(&nfsi->rwsem); + goto out_unlock; + } + up_read(&nfsi->rwsem); + } status = _nfs4_do_setlk(state, cmd, request, 0); if (status != 0) - goto out; + goto out_unlock; /* Note: we always want to sleep here! */ - request->fl_flags |= FL_SLEEP; + request->fl_flags = fl_flags | FL_SLEEP; if (do_vfs_lock(request->fl_file, request) < 0) printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); -out: +out_unlock: up_read(&clp->cl_sem); +out: + request->fl_flags = fl_flags; return status; }