| #include <linux/ceph/ceph_debug.h> |
| |
| #include <linux/file.h> |
| #include <linux/namei.h> |
| #include <linux/random.h> |
| |
| #include "super.h" |
| #include "mds_client.h" |
| #include <linux/ceph/pagelist.h> |
| |
| static u64 lock_secret; |
| static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, |
| struct ceph_mds_request *req); |
| |
| static inline u64 secure_addr(void *addr) |
| { |
| u64 v = lock_secret ^ (u64)(unsigned long)addr; |
| /* |
| * Set the most significant bit, so that MDS knows the 'owner' |
| * is sufficient to identify the owner of lock. (old code uses |
| * both 'owner' and 'pid') |
| */ |
| v |= (1ULL << 63); |
| return v; |
| } |
| |
| void __init ceph_flock_init(void) |
| { |
| get_random_bytes(&lock_secret, sizeof(lock_secret)); |
| } |
| |
| /** |
| * 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; |
| u64 owner; |
| |
| if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK) |
| wait = 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); |
| req->r_num_caps = 1; |
| |
| /* 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; |
| |
| owner = secure_addr(fl->fl_owner); |
| |
| dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, " |
| "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type, |
| (int)operation, owner, (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.owner = cpu_to_le64(owner); |
| req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); |
| 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; |
| |
| if (wait) |
| req->r_wait_for_completion = ceph_lock_wait_for_completion; |
| |
| 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; |
| } |
| |
| static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, |
| struct ceph_mds_request *req) |
| { |
| struct ceph_mds_request *intr_req; |
| struct inode *inode = req->r_inode; |
| int err, lock_type; |
| |
| BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); |
| if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) |
| lock_type = CEPH_LOCK_FCNTL_INTR; |
| else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) |
| lock_type = CEPH_LOCK_FLOCK_INTR; |
| else |
| BUG_ON(1); |
| BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); |
| |
| err = wait_for_completion_interruptible(&req->r_completion); |
| if (!err) |
| return 0; |
| |
| dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", |
| req->r_tid); |
| |
| intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, |
| USE_AUTH_MDS); |
| if (IS_ERR(intr_req)) |
| return PTR_ERR(intr_req); |
| |
| intr_req->r_inode = inode; |
| ihold(inode); |
| intr_req->r_num_caps = 1; |
| |
| intr_req->r_args.filelock_change = req->r_args.filelock_change; |
| intr_req->r_args.filelock_change.rule = lock_type; |
| intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; |
| |
| err = ceph_mdsc_do_request(mdsc, inode, intr_req); |
| ceph_mdsc_put_request(intr_req); |
| |
| if (err && err != -ERESTARTSYS) |
| return err; |
| |
| wait_for_completion(&req->r_completion); |
| return 0; |
| } |
| |
| /** |
| * 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; |
| |
| if (!(fl->fl_flags & FL_POSIX)) |
| return -ENOLCK; |
| /* No mandatory locks */ |
| if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) |
| return -ENOLCK; |
| |
| dout("ceph_lock, fl_owner: %p", fl->fl_owner); |
| |
| /* set wait bit as appropriate, then make command as Ceph expects it*/ |
| if (IS_GETLK(cmd)) |
| op = CEPH_MDS_OP_GETFILELOCK; |
| else if (IS_SETLKW(cmd)) |
| wait = 1; |
| |
| 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); |
| } |
| } |
| } |
| return err; |
| } |
| |
| int ceph_flock(struct file *file, int cmd, struct file_lock *fl) |
| { |
| u8 lock_cmd; |
| int err; |
| u8 wait = 0; |
| |
| if (!(fl->fl_flags & FL_FLOCK)) |
| return -ENOLCK; |
| /* No mandatory locks */ |
| if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) |
| return -ENOLCK; |
| |
| dout("ceph_flock, fl_file: %p", fl->fl_file); |
| |
| if (IS_SETLKW(cmd)) |
| wait = 1; |
| |
| 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_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); |
| } |
| } |
| 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 inode->i_lock 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((u64)lock->fl_pid); |
| cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); |
| |
| 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; |
| } |