| #include <linux/ceph/ceph_debug.h> |
| |
| #include <linux/file.h> |
| #include <linux/namei.h> |
| |
| #include "super.h" |
| #include "mds_client.h" |
| #include <linux/ceph/pagelist.h> |
| |
| /** |
| * Implement fcntl and flock locking functions. |
| */ |
| static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, |
| int cmd, u8 wait, struct file_lock *fl) |
| { |
| struct inode *inode = file_inode(file); |
| struct ceph_mds_client *mdsc = |
| ceph_sb_to_client(inode->i_sb)->mdsc; |
| struct ceph_mds_request *req; |
| int err; |
| u64 length = 0; |
| |
| req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| req->r_inode = inode; |
| ihold(inode); |
| |
| /* mds requires start and length rather than start and end */ |
| if (LLONG_MAX == fl->fl_end) |
| length = 0; |
| else |
| length = fl->fl_end - fl->fl_start + 1; |
| |
| dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " |
| "length: %llu, wait: %d, type: %d", (int)lock_type, |
| (int)operation, (u64)fl->fl_pid, fl->fl_start, |
| length, wait, fl->fl_type); |
| |
| req->r_args.filelock_change.rule = lock_type; |
| req->r_args.filelock_change.type = cmd; |
| req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); |
| /* This should be adjusted, but I'm not sure if |
| namespaces actually get id numbers*/ |
| req->r_args.filelock_change.pid_namespace = |
| cpu_to_le64((u64)(unsigned long)fl->fl_nspid); |
| req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); |
| req->r_args.filelock_change.length = cpu_to_le64(length); |
| req->r_args.filelock_change.wait = wait; |
| |
| err = ceph_mdsc_do_request(mdsc, inode, req); |
| |
| if ( operation == CEPH_MDS_OP_GETFILELOCK){ |
| fl->fl_pid = le64_to_cpu(req->r_reply_info.filelock_reply->pid); |
| if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) |
| fl->fl_type = F_RDLCK; |
| else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) |
| fl->fl_type = F_WRLCK; |
| else |
| fl->fl_type = F_UNLCK; |
| |
| fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); |
| length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + |
| le64_to_cpu(req->r_reply_info.filelock_reply->length); |
| if (length >= 1) |
| fl->fl_end = length -1; |
| else |
| fl->fl_end = 0; |
| |
| } |
| ceph_mdsc_put_request(req); |
| dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " |
| "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type, |
| (int)operation, (u64)fl->fl_pid, fl->fl_start, |
| length, wait, fl->fl_type, err); |
| return err; |
| } |
| |
| /** |
| * Attempt to set an fcntl lock. |
| * For now, this just goes away to the server. Later it may be more awesome. |
| */ |
| int ceph_lock(struct file *file, int cmd, struct file_lock *fl) |
| { |
| u8 lock_cmd; |
| int err; |
| u8 wait = 0; |
| u16 op = CEPH_MDS_OP_SETFILELOCK; |
| |
| fl->fl_nspid = get_pid(task_tgid(current)); |
| dout("ceph_lock, fl_pid:%d", fl->fl_pid); |
| |
| /* set wait bit as appropriate, then make command as Ceph expects it*/ |
| if (F_SETLKW == cmd) |
| wait = 1; |
| if (F_GETLK == cmd) |
| op = CEPH_MDS_OP_GETFILELOCK; |
| |
| if (F_RDLCK == fl->fl_type) |
| lock_cmd = CEPH_LOCK_SHARED; |
| else if (F_WRLCK == fl->fl_type) |
| lock_cmd = CEPH_LOCK_EXCL; |
| else |
| lock_cmd = CEPH_LOCK_UNLOCK; |
| |
| err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file, lock_cmd, wait, fl); |
| if (!err) { |
| if ( op != CEPH_MDS_OP_GETFILELOCK ){ |
| dout("mds locked, locking locally"); |
| err = posix_lock_file(file, fl, NULL); |
| if (err && (CEPH_MDS_OP_SETFILELOCK == op)) { |
| /* undo! This should only happen if |
| * the kernel detects local |
| * deadlock. */ |
| ceph_lock_message(CEPH_LOCK_FCNTL, op, file, |
| CEPH_LOCK_UNLOCK, 0, fl); |
| dout("got %d on posix_lock_file, undid lock", |
| err); |
| } |
| } |
| |
| } else if (err == -ERESTARTSYS) { |
| dout("undoing lock\n"); |
| ceph_lock_message(CEPH_LOCK_FCNTL, op, file, |
| CEPH_LOCK_UNLOCK, 0, fl); |
| } |
| return err; |
| } |
| |
| int ceph_flock(struct file *file, int cmd, struct file_lock *fl) |
| { |
| u8 lock_cmd; |
| int err; |
| u8 wait = 1; |
| |
| fl->fl_nspid = get_pid(task_tgid(current)); |
| dout("ceph_flock, fl_pid:%d", fl->fl_pid); |
| |
| /* set wait bit, then clear it out of cmd*/ |
| if (cmd & LOCK_NB) |
| wait = 0; |
| cmd = cmd & (LOCK_SH | LOCK_EX | LOCK_UN); |
| /* set command sequence that Ceph wants to see: |
| shared lock, exclusive lock, or unlock */ |
| if (LOCK_SH == cmd) |
| lock_cmd = CEPH_LOCK_SHARED; |
| else if (LOCK_EX == cmd) |
| lock_cmd = CEPH_LOCK_EXCL; |
| else |
| lock_cmd = CEPH_LOCK_UNLOCK; |
| |
| err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, |
| file, lock_cmd, wait, fl); |
| if (!err) { |
| err = flock_lock_file_wait(file, fl); |
| if (err) { |
| ceph_lock_message(CEPH_LOCK_FLOCK, |
| CEPH_MDS_OP_SETFILELOCK, |
| file, CEPH_LOCK_UNLOCK, 0, fl); |
| dout("got %d on flock_lock_file_wait, undid lock", err); |
| } |
| } else if (err == -ERESTARTSYS) { |
| dout("undoing lock\n"); |
| ceph_lock_message(CEPH_LOCK_FLOCK, |
| CEPH_MDS_OP_SETFILELOCK, |
| file, CEPH_LOCK_UNLOCK, 0, fl); |
| } |
| return err; |
| } |
| |
| /** |
| * Must be called with lock_flocks() already held. Fills in the passed |
| * counter variables, so you can prepare pagelist metadata before calling |
| * ceph_encode_locks. |
| */ |
| void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) |
| { |
| struct file_lock *lock; |
| |
| *fcntl_count = 0; |
| *flock_count = 0; |
| |
| for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { |
| if (lock->fl_flags & FL_POSIX) |
| ++(*fcntl_count); |
| else if (lock->fl_flags & FL_FLOCK) |
| ++(*flock_count); |
| } |
| dout("counted %d flock locks and %d fcntl locks", |
| *flock_count, *fcntl_count); |
| } |
| |
| /** |
| * Encode the flock and fcntl locks for the given inode into the ceph_filelock |
| * array. Must be called with lock_flocks() already held. |
| * If we encounter more of a specific lock type than expected, return -ENOSPC. |
| */ |
| int ceph_encode_locks_to_buffer(struct inode *inode, |
| struct ceph_filelock *flocks, |
| int num_fcntl_locks, int num_flock_locks) |
| { |
| struct file_lock *lock; |
| int err = 0; |
| int seen_fcntl = 0; |
| int seen_flock = 0; |
| int l = 0; |
| |
| dout("encoding %d flock and %d fcntl locks", num_flock_locks, |
| num_fcntl_locks); |
| |
| for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { |
| if (lock->fl_flags & FL_POSIX) { |
| ++seen_fcntl; |
| if (seen_fcntl > num_fcntl_locks) { |
| err = -ENOSPC; |
| goto fail; |
| } |
| err = lock_to_ceph_filelock(lock, &flocks[l]); |
| if (err) |
| goto fail; |
| ++l; |
| } |
| } |
| for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { |
| if (lock->fl_flags & FL_FLOCK) { |
| ++seen_flock; |
| if (seen_flock > num_flock_locks) { |
| err = -ENOSPC; |
| goto fail; |
| } |
| err = lock_to_ceph_filelock(lock, &flocks[l]); |
| if (err) |
| goto fail; |
| ++l; |
| } |
| } |
| fail: |
| return err; |
| } |
| |
| /** |
| * Copy the encoded flock and fcntl locks into the pagelist. |
| * Format is: #fcntl locks, sequential fcntl locks, #flock locks, |
| * sequential flock locks. |
| * Returns zero on success. |
| */ |
| int ceph_locks_to_pagelist(struct ceph_filelock *flocks, |
| struct ceph_pagelist *pagelist, |
| int num_fcntl_locks, int num_flock_locks) |
| { |
| int err = 0; |
| __le32 nlocks; |
| |
| nlocks = cpu_to_le32(num_fcntl_locks); |
| err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); |
| if (err) |
| goto out_fail; |
| |
| err = ceph_pagelist_append(pagelist, flocks, |
| num_fcntl_locks * sizeof(*flocks)); |
| if (err) |
| goto out_fail; |
| |
| nlocks = cpu_to_le32(num_flock_locks); |
| err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); |
| if (err) |
| goto out_fail; |
| |
| err = ceph_pagelist_append(pagelist, |
| &flocks[num_fcntl_locks], |
| num_flock_locks * sizeof(*flocks)); |
| out_fail: |
| return err; |
| } |
| |
| /* |
| * Given a pointer to a lock, convert it to a ceph filelock |
| */ |
| int lock_to_ceph_filelock(struct file_lock *lock, |
| struct ceph_filelock *cephlock) |
| { |
| int err = 0; |
| |
| cephlock->start = cpu_to_le64(lock->fl_start); |
| cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); |
| cephlock->client = cpu_to_le64(0); |
| cephlock->pid = cpu_to_le64(lock->fl_pid); |
| cephlock->pid_namespace = |
| cpu_to_le64((u64)(unsigned long)lock->fl_nspid); |
| |
| switch (lock->fl_type) { |
| case F_RDLCK: |
| cephlock->type = CEPH_LOCK_SHARED; |
| break; |
| case F_WRLCK: |
| cephlock->type = CEPH_LOCK_EXCL; |
| break; |
| case F_UNLCK: |
| cephlock->type = CEPH_LOCK_UNLOCK; |
| break; |
| default: |
| dout("Have unknown lock type %d", lock->fl_type); |
| err = -EINVAL; |
| } |
| |
| return err; |
| } |