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497 lines
13 KiB
497 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/ceph/ceph_debug.h> |
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#include <linux/file.h> |
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#include <linux/namei.h> |
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#include <linux/random.h> |
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#include "super.h" |
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#include "mds_client.h" |
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#include <linux/ceph/pagelist.h> |
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static u64 lock_secret; |
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static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, |
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struct ceph_mds_request *req); |
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static inline u64 secure_addr(void *addr) |
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{ |
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u64 v = lock_secret ^ (u64)(unsigned long)addr; |
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/* |
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* Set the most significant bit, so that MDS knows the 'owner' |
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* is sufficient to identify the owner of lock. (old code uses |
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* both 'owner' and 'pid') |
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*/ |
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v |= (1ULL << 63); |
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return v; |
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} |
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void __init ceph_flock_init(void) |
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{ |
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get_random_bytes(&lock_secret, sizeof(lock_secret)); |
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} |
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static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) |
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{ |
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struct ceph_file_info *fi = dst->fl_file->private_data; |
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struct inode *inode = file_inode(dst->fl_file); |
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atomic_inc(&ceph_inode(inode)->i_filelock_ref); |
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atomic_inc(&fi->num_locks); |
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} |
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static void ceph_fl_release_lock(struct file_lock *fl) |
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{ |
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struct ceph_file_info *fi = fl->fl_file->private_data; |
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struct inode *inode = file_inode(fl->fl_file); |
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struct ceph_inode_info *ci = ceph_inode(inode); |
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atomic_dec(&fi->num_locks); |
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if (atomic_dec_and_test(&ci->i_filelock_ref)) { |
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/* clear error when all locks are released */ |
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spin_lock(&ci->i_ceph_lock); |
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ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; |
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spin_unlock(&ci->i_ceph_lock); |
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} |
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} |
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static const struct file_lock_operations ceph_fl_lock_ops = { |
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.fl_copy_lock = ceph_fl_copy_lock, |
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.fl_release_private = ceph_fl_release_lock, |
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}; |
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/* |
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* Implement fcntl and flock locking functions. |
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*/ |
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static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, |
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int cmd, u8 wait, struct file_lock *fl) |
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{ |
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struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb); |
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struct ceph_mds_request *req; |
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int err; |
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u64 length = 0; |
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u64 owner; |
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if (operation == CEPH_MDS_OP_SETFILELOCK) { |
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/* |
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* increasing i_filelock_ref closes race window between |
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* handling request reply and adding file_lock struct to |
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* inode. Otherwise, auth caps may get trimmed in the |
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* window. Caller function will decrease the counter. |
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*/ |
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fl->fl_ops = &ceph_fl_lock_ops; |
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fl->fl_ops->fl_copy_lock(fl, NULL); |
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} |
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if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK) |
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wait = 0; |
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req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); |
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if (IS_ERR(req)) |
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return PTR_ERR(req); |
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req->r_inode = inode; |
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ihold(inode); |
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req->r_num_caps = 1; |
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/* mds requires start and length rather than start and end */ |
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if (LLONG_MAX == fl->fl_end) |
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length = 0; |
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else |
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length = fl->fl_end - fl->fl_start + 1; |
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owner = secure_addr(fl->fl_owner); |
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dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, " |
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"start: %llu, length: %llu, wait: %d, type: %d\n", (int)lock_type, |
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(int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length, |
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wait, fl->fl_type); |
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req->r_args.filelock_change.rule = lock_type; |
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req->r_args.filelock_change.type = cmd; |
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req->r_args.filelock_change.owner = cpu_to_le64(owner); |
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req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); |
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req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); |
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req->r_args.filelock_change.length = cpu_to_le64(length); |
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req->r_args.filelock_change.wait = wait; |
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err = ceph_mdsc_submit_request(mdsc, inode, req); |
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if (!err) |
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err = ceph_mdsc_wait_request(mdsc, req, wait ? |
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ceph_lock_wait_for_completion : NULL); |
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if (!err && operation == CEPH_MDS_OP_GETFILELOCK) { |
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fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid); |
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if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) |
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fl->fl_type = F_RDLCK; |
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else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) |
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fl->fl_type = F_WRLCK; |
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else |
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fl->fl_type = F_UNLCK; |
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fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); |
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length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + |
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le64_to_cpu(req->r_reply_info.filelock_reply->length); |
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if (length >= 1) |
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fl->fl_end = length -1; |
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else |
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fl->fl_end = 0; |
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} |
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ceph_mdsc_put_request(req); |
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dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " |
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"length: %llu, wait: %d, type: %d, err code %d\n", (int)lock_type, |
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(int)operation, (u64)fl->fl_pid, fl->fl_start, |
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length, wait, fl->fl_type, err); |
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return err; |
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} |
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static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, |
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struct ceph_mds_request *req) |
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{ |
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struct ceph_mds_request *intr_req; |
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struct inode *inode = req->r_inode; |
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int err, lock_type; |
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BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); |
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if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) |
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lock_type = CEPH_LOCK_FCNTL_INTR; |
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else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) |
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lock_type = CEPH_LOCK_FLOCK_INTR; |
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else |
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BUG_ON(1); |
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BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); |
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err = wait_for_completion_interruptible(&req->r_completion); |
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if (!err) |
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return 0; |
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dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", |
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req->r_tid); |
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mutex_lock(&mdsc->mutex); |
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if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { |
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err = 0; |
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} else { |
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/* |
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* ensure we aren't running concurrently with |
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* ceph_fill_trace or ceph_readdir_prepopulate, which |
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* rely on locks (dir mutex) held by our caller. |
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*/ |
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mutex_lock(&req->r_fill_mutex); |
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req->r_err = err; |
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set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); |
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mutex_unlock(&req->r_fill_mutex); |
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if (!req->r_session) { |
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// haven't sent the request |
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err = 0; |
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} |
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} |
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mutex_unlock(&mdsc->mutex); |
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if (!err) |
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return 0; |
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intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, |
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USE_AUTH_MDS); |
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if (IS_ERR(intr_req)) |
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return PTR_ERR(intr_req); |
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intr_req->r_inode = inode; |
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ihold(inode); |
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intr_req->r_num_caps = 1; |
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intr_req->r_args.filelock_change = req->r_args.filelock_change; |
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intr_req->r_args.filelock_change.rule = lock_type; |
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intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; |
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err = ceph_mdsc_do_request(mdsc, inode, intr_req); |
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ceph_mdsc_put_request(intr_req); |
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if (err && err != -ERESTARTSYS) |
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return err; |
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wait_for_completion_killable(&req->r_safe_completion); |
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return 0; |
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} |
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static int try_unlock_file(struct file *file, struct file_lock *fl) |
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{ |
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int err; |
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unsigned int orig_flags = fl->fl_flags; |
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fl->fl_flags |= FL_EXISTS; |
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err = locks_lock_file_wait(file, fl); |
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fl->fl_flags = orig_flags; |
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if (err == -ENOENT) { |
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if (!(orig_flags & FL_EXISTS)) |
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err = 0; |
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return err; |
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} |
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return 1; |
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} |
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/* |
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* Attempt to set an fcntl lock. |
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* For now, this just goes away to the server. Later it may be more awesome. |
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*/ |
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int ceph_lock(struct file *file, int cmd, struct file_lock *fl) |
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{ |
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struct inode *inode = file_inode(file); |
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struct ceph_inode_info *ci = ceph_inode(inode); |
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int err = 0; |
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u16 op = CEPH_MDS_OP_SETFILELOCK; |
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u8 wait = 0; |
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u8 lock_cmd; |
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if (!(fl->fl_flags & FL_POSIX)) |
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return -ENOLCK; |
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if (ceph_inode_is_shutdown(inode)) |
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return -ESTALE; |
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dout("ceph_lock, fl_owner: %p\n", fl->fl_owner); |
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/* set wait bit as appropriate, then make command as Ceph expects it*/ |
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if (IS_GETLK(cmd)) |
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op = CEPH_MDS_OP_GETFILELOCK; |
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else if (IS_SETLKW(cmd)) |
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wait = 1; |
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spin_lock(&ci->i_ceph_lock); |
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if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { |
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err = -EIO; |
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} |
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spin_unlock(&ci->i_ceph_lock); |
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if (err < 0) { |
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if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) |
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posix_lock_file(file, fl, NULL); |
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return err; |
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} |
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if (F_RDLCK == fl->fl_type) |
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lock_cmd = CEPH_LOCK_SHARED; |
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else if (F_WRLCK == fl->fl_type) |
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lock_cmd = CEPH_LOCK_EXCL; |
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else |
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lock_cmd = CEPH_LOCK_UNLOCK; |
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if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) { |
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err = try_unlock_file(file, fl); |
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if (err <= 0) |
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return err; |
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} |
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err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); |
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if (!err) { |
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if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK != fl->fl_type) { |
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dout("mds locked, locking locally\n"); |
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err = posix_lock_file(file, fl, NULL); |
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if (err) { |
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/* undo! This should only happen if |
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* the kernel detects local |
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* deadlock. */ |
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ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, |
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CEPH_LOCK_UNLOCK, 0, fl); |
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dout("got %d on posix_lock_file, undid lock\n", |
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err); |
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} |
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} |
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} |
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return err; |
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} |
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int ceph_flock(struct file *file, int cmd, struct file_lock *fl) |
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{ |
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struct inode *inode = file_inode(file); |
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struct ceph_inode_info *ci = ceph_inode(inode); |
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int err = 0; |
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u8 wait = 0; |
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u8 lock_cmd; |
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if (!(fl->fl_flags & FL_FLOCK)) |
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return -ENOLCK; |
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if (ceph_inode_is_shutdown(inode)) |
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return -ESTALE; |
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dout("ceph_flock, fl_file: %p\n", fl->fl_file); |
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spin_lock(&ci->i_ceph_lock); |
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if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { |
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err = -EIO; |
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} |
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spin_unlock(&ci->i_ceph_lock); |
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if (err < 0) { |
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if (F_UNLCK == fl->fl_type) |
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locks_lock_file_wait(file, fl); |
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return err; |
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} |
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if (IS_SETLKW(cmd)) |
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wait = 1; |
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if (F_RDLCK == fl->fl_type) |
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lock_cmd = CEPH_LOCK_SHARED; |
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else if (F_WRLCK == fl->fl_type) |
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lock_cmd = CEPH_LOCK_EXCL; |
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else |
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lock_cmd = CEPH_LOCK_UNLOCK; |
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if (F_UNLCK == fl->fl_type) { |
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err = try_unlock_file(file, fl); |
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if (err <= 0) |
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return err; |
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} |
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err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, |
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inode, lock_cmd, wait, fl); |
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if (!err && F_UNLCK != fl->fl_type) { |
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err = locks_lock_file_wait(file, fl); |
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if (err) { |
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ceph_lock_message(CEPH_LOCK_FLOCK, |
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CEPH_MDS_OP_SETFILELOCK, |
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inode, CEPH_LOCK_UNLOCK, 0, fl); |
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dout("got %d on locks_lock_file_wait, undid lock\n", err); |
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} |
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} |
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return err; |
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} |
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/* |
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* Fills in the passed counter variables, so you can prepare pagelist metadata |
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* before calling ceph_encode_locks. |
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*/ |
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void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) |
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{ |
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struct file_lock *lock; |
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struct file_lock_context *ctx; |
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*fcntl_count = 0; |
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*flock_count = 0; |
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ctx = inode->i_flctx; |
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if (ctx) { |
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spin_lock(&ctx->flc_lock); |
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list_for_each_entry(lock, &ctx->flc_posix, fl_list) |
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++(*fcntl_count); |
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list_for_each_entry(lock, &ctx->flc_flock, fl_list) |
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++(*flock_count); |
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spin_unlock(&ctx->flc_lock); |
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} |
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dout("counted %d flock locks and %d fcntl locks\n", |
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*flock_count, *fcntl_count); |
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} |
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/* |
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* Given a pointer to a lock, convert it to a ceph filelock |
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*/ |
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static int lock_to_ceph_filelock(struct file_lock *lock, |
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struct ceph_filelock *cephlock) |
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{ |
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int err = 0; |
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cephlock->start = cpu_to_le64(lock->fl_start); |
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cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); |
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cephlock->client = cpu_to_le64(0); |
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cephlock->pid = cpu_to_le64((u64)lock->fl_pid); |
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cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); |
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switch (lock->fl_type) { |
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case F_RDLCK: |
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cephlock->type = CEPH_LOCK_SHARED; |
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break; |
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case F_WRLCK: |
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cephlock->type = CEPH_LOCK_EXCL; |
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break; |
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case F_UNLCK: |
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cephlock->type = CEPH_LOCK_UNLOCK; |
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break; |
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default: |
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dout("Have unknown lock type %d\n", lock->fl_type); |
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err = -EINVAL; |
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} |
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return err; |
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} |
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/* |
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* Encode the flock and fcntl locks for the given inode into the ceph_filelock |
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* array. Must be called with inode->i_lock already held. |
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* If we encounter more of a specific lock type than expected, return -ENOSPC. |
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*/ |
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int ceph_encode_locks_to_buffer(struct inode *inode, |
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struct ceph_filelock *flocks, |
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int num_fcntl_locks, int num_flock_locks) |
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{ |
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struct file_lock *lock; |
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struct file_lock_context *ctx = inode->i_flctx; |
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int err = 0; |
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int seen_fcntl = 0; |
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int seen_flock = 0; |
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int l = 0; |
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dout("encoding %d flock and %d fcntl locks\n", num_flock_locks, |
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num_fcntl_locks); |
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if (!ctx) |
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return 0; |
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spin_lock(&ctx->flc_lock); |
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list_for_each_entry(lock, &ctx->flc_posix, fl_list) { |
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++seen_fcntl; |
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if (seen_fcntl > num_fcntl_locks) { |
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err = -ENOSPC; |
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goto fail; |
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} |
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err = lock_to_ceph_filelock(lock, &flocks[l]); |
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if (err) |
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goto fail; |
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++l; |
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} |
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list_for_each_entry(lock, &ctx->flc_flock, fl_list) { |
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++seen_flock; |
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if (seen_flock > num_flock_locks) { |
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err = -ENOSPC; |
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goto fail; |
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} |
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err = lock_to_ceph_filelock(lock, &flocks[l]); |
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if (err) |
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goto fail; |
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++l; |
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} |
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fail: |
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spin_unlock(&ctx->flc_lock); |
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return err; |
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} |
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/* |
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* Copy the encoded flock and fcntl locks into the pagelist. |
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* Format is: #fcntl locks, sequential fcntl locks, #flock locks, |
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* sequential flock locks. |
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* Returns zero on success. |
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*/ |
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int ceph_locks_to_pagelist(struct ceph_filelock *flocks, |
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struct ceph_pagelist *pagelist, |
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int num_fcntl_locks, int num_flock_locks) |
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{ |
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int err = 0; |
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__le32 nlocks; |
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nlocks = cpu_to_le32(num_fcntl_locks); |
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err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); |
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if (err) |
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goto out_fail; |
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if (num_fcntl_locks > 0) { |
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err = ceph_pagelist_append(pagelist, flocks, |
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num_fcntl_locks * sizeof(*flocks)); |
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if (err) |
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goto out_fail; |
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} |
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nlocks = cpu_to_le32(num_flock_locks); |
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err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); |
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if (err) |
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goto out_fail; |
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if (num_flock_locks > 0) { |
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err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], |
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num_flock_locks * sizeof(*flocks)); |
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} |
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out_fail: |
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return err; |
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}
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