From 150b393456e5a23513cace286a019e87151e47f0 Mon Sep 17 00:00:00 2001 From: Marc Eshel Date: Thu, 18 Jan 2007 16:15:35 -0500 Subject: [PATCH] locks: allow {vfs,posix}_lock_file to return conflicting lock The nfsv4 protocol's lock operation, in the case of a conflict, returns information about the conflicting lock. It's unclear how clients can use this, so for now we're not going so far as to add a filesystem method that can return a conflicting lock, but we may as well return something in the local case when it's easy to. Signed-off-by: Marc Eshel Signed-off-by: "J. Bruce Fields" --- fs/lockd/svclock.c | 6 +++--- fs/lockd/svcsubs.c | 2 +- fs/locks.c | 45 ++++++++++++++++++++------------------------- fs/nfsd/nfs4state.c | 10 ++++++---- include/linux/fs.h | 5 ++--- 5 files changed, 32 insertions(+), 36 deletions(-) diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index 97b0160ef10f..3b0e7a4b817b 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -363,7 +363,7 @@ again: } else lock = &block->b_call->a_args.lock; - error = posix_lock_file(file->f_file, &lock->fl); + error = posix_lock_file(file->f_file, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP; dprintk("lockd: posix_lock_file returned %d\n", error); @@ -467,7 +467,7 @@ nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) nlmsvc_cancel_blocked(file, lock); lock->fl.fl_type = F_UNLCK; - error = posix_lock_file(file->f_file, &lock->fl); + error = posix_lock_file(file->f_file, &lock->fl, NULL); return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; } @@ -569,7 +569,7 @@ nlmsvc_grant_blocked(struct nlm_block *block) /* Try the lock operation again */ lock->fl.fl_flags |= FL_SLEEP; - error = posix_lock_file(file->f_file, &lock->fl); + error = posix_lock_file(file->f_file, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP; switch (error) { diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c index c0df00c74ce3..50957089be1f 100644 --- a/fs/lockd/svcsubs.c +++ b/fs/lockd/svcsubs.c @@ -182,7 +182,7 @@ again: lock.fl_type = F_UNLCK; lock.fl_start = 0; lock.fl_end = OFFSET_MAX; - if (posix_lock_file(file->f_file, &lock) < 0) { + if (posix_lock_file(file->f_file, &lock, NULL) < 0) { printk("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__); return 1; diff --git a/fs/locks.c b/fs/locks.c index f4fd1515b6e2..ee46584c1a40 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -801,7 +801,7 @@ out: return error; } -static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock) +static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock) { struct file_lock *fl; struct file_lock *new_fl = NULL; @@ -1007,6 +1007,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request * posix_lock_file - Apply a POSIX-style lock to a file * @filp: The file to apply the lock to * @fl: The lock to be applied + * @conflock: Place to return a copy of the conflicting lock, if found. * * Add a POSIX style lock to a file. * We merge adjacent & overlapping locks whenever possible. @@ -1016,26 +1017,12 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request * 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) -{ - return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, NULL); -} -EXPORT_SYMBOL(posix_lock_file); - -/** - * posix_lock_file_conf - Apply a POSIX-style lock to a file - * @filp: The file to apply the lock to - * @fl: The lock to be applied - * @conflock: Place to return a copy of the conflicting lock, if found. - * - * Except for the conflock parameter, acts just like posix_lock_file. - */ -int posix_lock_file_conf(struct file *filp, struct file_lock *fl, +int posix_lock_file(struct file *filp, struct file_lock *fl, struct file_lock *conflock) { - return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, conflock); + return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock); } -EXPORT_SYMBOL(posix_lock_file_conf); +EXPORT_SYMBOL(posix_lock_file); /** * posix_lock_file_wait - Apply a POSIX-style lock to a file @@ -1051,7 +1038,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) int error; might_sleep (); for (;;) { - error = posix_lock_file(filp, fl); + error = posix_lock_file(filp, fl, NULL); if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP)) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); @@ -1123,7 +1110,7 @@ int locks_mandatory_area(int read_write, struct inode *inode, fl.fl_end = offset + count - 1; for (;;) { - error = __posix_lock_file_conf(inode, &fl, NULL); + error = __posix_lock_file(inode, &fl, NULL); if (error != -EAGAIN) break; if (!(fl.fl_flags & FL_SLEEP)) @@ -1703,13 +1690,21 @@ out: * @filp: The file to apply the lock to * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.) * @fl: The lock to be applied + * @conf: Place to return a copy of the conflicting lock, if found. + * + * A caller that doesn't care about the conflicting lock may pass NULL + * as the final argument. + * + * If the filesystem defines a private ->lock() method, then @conf will + * be left unchanged; so a caller that cares should initialize it to + * some acceptable default. */ -int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl) +int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf) { if (filp->f_op && filp->f_op->lock) return filp->f_op->lock(filp, cmd, fl); else - return posix_lock_file(filp, fl); + return posix_lock_file(filp, fl, conf); } EXPORT_SYMBOL_GPL(vfs_lock_file); @@ -1776,7 +1771,7 @@ again: goto out; for (;;) { - error = vfs_lock_file(filp, cmd, file_lock); + error = vfs_lock_file(filp, cmd, file_lock, NULL); if (error != -EAGAIN || cmd == F_SETLK) break; error = wait_event_interruptible(file_lock->fl_wait, @@ -1902,7 +1897,7 @@ again: goto out; for (;;) { - error = vfs_lock_file(filp, cmd, file_lock); + error = vfs_lock_file(filp, cmd, file_lock, NULL); if (error != -EAGAIN || cmd == F_SETLK64) break; error = wait_event_interruptible(file_lock->fl_wait, @@ -1956,7 +1951,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner) lock.fl_ops = NULL; lock.fl_lmops = NULL; - vfs_lock_file(filp, F_SETLK, &lock); + vfs_lock_file(filp, F_SETLK, &lock, NULL); if (lock.fl_ops && lock.fl_ops->fl_release_private) lock.fl_ops->fl_release_private(&lock); diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e42c7a0eb6fa..03b0578781cb 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2657,6 +2657,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct file_lock conflock; __be32 status = 0; unsigned int strhashval; + unsigned int cmd; int err; dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n", @@ -2739,10 +2740,12 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, case NFS4_READ_LT: case NFS4_READW_LT: file_lock.fl_type = F_RDLCK; + cmd = F_SETLK; break; case NFS4_WRITE_LT: case NFS4_WRITEW_LT: file_lock.fl_type = F_WRLCK; + cmd = F_SETLK; break; default: status = nfserr_inval; @@ -2769,9 +2772,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, /* XXX?: Just to divert the locks_release_private at the start of * locks_copy_lock: */ - conflock.fl_ops = NULL; - conflock.fl_lmops = NULL; - err = posix_lock_file_conf(filp, &file_lock, &conflock); + locks_init_lock(&conflock); + err = posix_lock_file(filp, &file_lock, &conflock); switch (-err) { case 0: /* success! */ update_stateid(&lock_stp->st_stateid); @@ -2933,7 +2935,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, /* * Try to unlock the file in the VFS. */ - err = posix_lock_file(filp, &file_lock); + err = posix_lock_file(filp, &file_lock, NULL); if (err) { dprintk("NFSD: nfs4_locku: posix_lock_file failed!\n"); goto out_nfserr; diff --git a/include/linux/fs.h b/include/linux/fs.h index 1d5ccdd7c68d..c92d0bdff39f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -852,12 +852,11 @@ extern void locks_copy_lock(struct file_lock *, struct file_lock *); extern void locks_remove_posix(struct file *, fl_owner_t); extern void locks_remove_flock(struct file *); extern int posix_test_lock(struct file *, struct file_lock *); -extern int posix_lock_file_conf(struct file *, struct file_lock *, struct file_lock *); -extern int posix_lock_file(struct file *, struct file_lock *); +extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *); extern int posix_lock_file_wait(struct file *, struct file_lock *); extern int posix_unblock_lock(struct file *, struct file_lock *); extern int vfs_test_lock(struct file *, struct file_lock *); -extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *); +extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl); extern int __break_lease(struct inode *inode, unsigned int flags); extern void lease_get_mtime(struct inode *, struct timespec *time);