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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:34:24 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:34:24 -0700 |
commit | 2d56d3c43cc97ae48586745556f5a5b564d61582 (patch) | |
tree | 28f2edc1e69b79e94d99023041dd0358861b6956 /fs/locks.c | |
parent | 0f9008ef38d5a6305d94bbdd8f20d68fc75c63b6 (diff) | |
parent | 586759f03e2e9031ac5589912a51a909ed53c30a (diff) | |
download | kernel_samsung_espresso10-2d56d3c43cc97ae48586745556f5a5b564d61582.zip kernel_samsung_espresso10-2d56d3c43cc97ae48586745556f5a5b564d61582.tar.gz kernel_samsung_espresso10-2d56d3c43cc97ae48586745556f5a5b564d61582.tar.bz2 |
Merge branch 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux
* 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux:
gfs2: nfs lock support for gfs2
lockd: add code to handle deferred lock requests
lockd: always preallocate block in nlmsvc_lock()
lockd: handle test_lock deferrals
lockd: pass cookie in nlmsvc_testlock
lockd: handle fl_grant callbacks
lockd: save lock state on deferral
locks: add fl_grant callback for asynchronous lock return
nfsd4: Convert NFSv4 to new lock interface
locks: add lock cancel command
locks: allow {vfs,posix}_lock_file to return conflicting lock
locks: factor out generic/filesystem switch from setlock code
locks: factor out generic/filesystem switch from test_lock
locks: give posix_test_lock same interface as ->lock
locks: make ->lock release private data before returning in GETLK case
locks: create posix-to-flock helper functions
locks: trivial removal of unnecessary parentheses
Diffstat (limited to 'fs/locks.c')
-rw-r--r-- | fs/locks.c | 264 |
1 files changed, 156 insertions, 108 deletions
@@ -665,11 +665,11 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w } int -posix_test_lock(struct file *filp, struct file_lock *fl, - struct file_lock *conflock) +posix_test_lock(struct file *filp, struct file_lock *fl) { struct file_lock *cfl; + fl->fl_type = F_UNLCK; lock_kernel(); for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) { if (!IS_POSIX(cfl)) @@ -678,7 +678,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl, break; } if (cfl) { - __locks_copy_lock(conflock, cfl); + __locks_copy_lock(fl, cfl); unlock_kernel(); return 1; } @@ -800,7 +800,7 @@ 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; @@ -1006,6 +1006,7 @@ 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. @@ -1015,26 +1016,12 @@ 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 @@ -1050,7 +1037,7 @@ 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); @@ -1122,7 +1109,7 @@ 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)) @@ -1610,12 +1597,62 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd) return error; } +/** + * vfs_test_lock - test file byte range lock + * @filp: The file to test lock for + * @fl: The lock to test + * @conf: Place to return a copy of the conflicting lock, if found + * + * Returns -ERRNO on failure. Indicates presence of conflicting lock by + * setting conf->fl_type to something other than F_UNLCK. + */ +int vfs_test_lock(struct file *filp, struct file_lock *fl) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, F_GETLK, fl); + posix_test_lock(filp, fl); + return 0; +} +EXPORT_SYMBOL_GPL(vfs_test_lock); + +static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) +{ + flock->l_pid = fl->fl_pid; +#if BITS_PER_LONG == 32 + /* + * Make sure we can represent the posix lock via + * legacy 32bit flock. + */ + if (fl->fl_start > OFFT_OFFSET_MAX) + return -EOVERFLOW; + if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX) + return -EOVERFLOW; +#endif + flock->l_start = fl->fl_start; + flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : + fl->fl_end - fl->fl_start + 1; + flock->l_whence = 0; + return 0; +} + +#if BITS_PER_LONG == 32 +static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) +{ + flock->l_pid = fl->fl_pid; + flock->l_start = fl->fl_start; + flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : + fl->fl_end - fl->fl_start + 1; + flock->l_whence = 0; + flock->l_type = fl->fl_type; +} +#endif + /* Report the first existing lock that would conflict with l. * This implements the F_GETLK command of fcntl(). */ int fcntl_getlk(struct file *filp, struct flock __user *l) { - struct file_lock *fl, cfl, file_lock; + struct file_lock file_lock; struct flock flock; int error; @@ -1630,38 +1667,15 @@ int fcntl_getlk(struct file *filp, struct flock __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock) { - error = filp->f_op->lock(filp, F_GETLK, &file_lock); - if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) - file_lock.fl_ops->fl_release_private(&file_lock); - if (error < 0) - goto out; - else - fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); - } else { - fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); - } + error = vfs_test_lock(filp, &file_lock); + if (error) + goto out; - flock.l_type = F_UNLCK; - if (fl != NULL) { - flock.l_pid = fl->fl_pid; -#if BITS_PER_LONG == 32 - /* - * Make sure we can represent the posix lock via - * legacy 32bit flock. - */ - error = -EOVERFLOW; - if (fl->fl_start > OFFT_OFFSET_MAX) - goto out; - if ((fl->fl_end != OFFSET_MAX) - && (fl->fl_end > OFFT_OFFSET_MAX)) + flock.l_type = file_lock.fl_type; + if (file_lock.fl_type != F_UNLCK) { + error = posix_lock_to_flock(&flock, &file_lock); + if (error) goto out; -#endif - flock.l_start = fl->fl_start; - flock.l_len = fl->fl_end == OFFSET_MAX ? 0 : - fl->fl_end - fl->fl_start + 1; - flock.l_whence = 0; - flock.l_type = fl->fl_type; } error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) @@ -1670,6 +1684,48 @@ out: return error; } +/** + * vfs_lock_file - file byte range lock + * @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. + * + * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX + * locks, the ->lock() interface may return asynchronously, before the lock has + * been granted or denied by the underlying filesystem, if (and only if) + * fl_grant is set. Callers expecting ->lock() to return asynchronously + * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) + * the request is for a blocking lock. When ->lock() does return asynchronously, + * it must return -EINPROGRESS, and call ->fl_grant() when the lock + * request completes. + * If the request is for non-blocking lock the file system should return + * -EINPROGRESS then try to get the lock and call the callback routine with + * the result. If the request timed out the callback routine will return a + * nonzero return code and the file system should release the lock. The file + * system is also responsible to keep a corresponding posix lock when it + * grants a lock so the VFS can find out which locks are locally held and do + * the correct lock cleanup when required. + * The underlying filesystem must not drop the kernel lock or call + * ->fl_grant() before returning to the caller with a -EINPROGRESS + * return code. + */ +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, conf); +} +EXPORT_SYMBOL_GPL(vfs_lock_file); + /* Apply the lock described by l to an open file descriptor. * This implements both the F_SETLK and F_SETLKW commands of fcntl(). */ @@ -1732,21 +1788,17 @@ again: if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) - error = filp->f_op->lock(filp, cmd, file_lock); - else { - for (;;) { - error = posix_lock_file(filp, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK)) - break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; - - locks_delete_block(file_lock); + for (;;) { + error = vfs_lock_file(filp, cmd, file_lock, NULL); + if (error != -EAGAIN || cmd == F_SETLK) break; - } + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; + + locks_delete_block(file_lock); + break; } /* @@ -1769,7 +1821,7 @@ out: */ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) { - struct file_lock *fl, cfl, file_lock; + struct file_lock file_lock; struct flock64 flock; int error; @@ -1784,27 +1836,14 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l) if (error) goto out; - if (filp->f_op && filp->f_op->lock) { - error = filp->f_op->lock(filp, F_GETLK, &file_lock); - if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private) - file_lock.fl_ops->fl_release_private(&file_lock); - if (error < 0) - goto out; - else - fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock); - } else { - fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL); - } - - flock.l_type = F_UNLCK; - if (fl != NULL) { - flock.l_pid = fl->fl_pid; - flock.l_start = fl->fl_start; - flock.l_len = fl->fl_end == OFFSET_MAX ? 0 : - fl->fl_end - fl->fl_start + 1; - flock.l_whence = 0; - flock.l_type = fl->fl_type; - } + error = vfs_test_lock(filp, &file_lock); + if (error) + goto out; + + flock.l_type = file_lock.fl_type; + if (file_lock.fl_type != F_UNLCK) + posix_lock_to_flock64(&flock, &file_lock); + error = -EFAULT; if (!copy_to_user(l, &flock, sizeof(flock))) error = 0; @@ -1875,21 +1914,17 @@ again: if (error) goto out; - if (filp->f_op && filp->f_op->lock != NULL) - error = filp->f_op->lock(filp, cmd, file_lock); - else { - for (;;) { - error = posix_lock_file(filp, file_lock); - if ((error != -EAGAIN) || (cmd == F_SETLK64)) - break; - error = wait_event_interruptible(file_lock->fl_wait, - !file_lock->fl_next); - if (!error) - continue; - - locks_delete_block(file_lock); + for (;;) { + error = vfs_lock_file(filp, cmd, file_lock, NULL); + if (error != -EAGAIN || cmd == F_SETLK64) break; - } + error = wait_event_interruptible(file_lock->fl_wait, + !file_lock->fl_next); + if (!error) + continue; + + locks_delete_block(file_lock); + break; } /* @@ -1934,10 +1969,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner) lock.fl_ops = NULL; lock.fl_lmops = NULL; - if (filp->f_op && filp->f_op->lock != NULL) - filp->f_op->lock(filp, F_SETLK, &lock); - else - posix_lock_file(filp, &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); @@ -2014,6 +2046,22 @@ posix_unblock_lock(struct file *filp, struct file_lock *waiter) EXPORT_SYMBOL(posix_unblock_lock); +/** + * vfs_cancel_lock - file byte range unblock lock + * @filp: The file to apply the unblock to + * @fl: The lock to be unblocked + * + * Used by lock managers to cancel blocked requests + */ +int vfs_cancel_lock(struct file *filp, struct file_lock *fl) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, F_CANCELLK, fl); + return 0; +} + +EXPORT_SYMBOL_GPL(vfs_cancel_lock); + static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx) { struct inode *inode = NULL; |