--- /dev/null
+#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;
+}
+
+/*
+ * 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;
+ struct file_lock_context *ctx;
+
+ *fcntl_count = 0;
+ *flock_count = 0;
+
+ ctx = inode->i_flctx;
+ if (ctx) {
+ spin_lock(&ctx->flc_lock);
+ list_for_each_entry(lock, &ctx->flc_posix, fl_list)
+ ++(*fcntl_count);
+ list_for_each_entry(lock, &ctx->flc_flock, fl_list)
+ ++(*flock_count);
+ spin_unlock(&ctx->flc_lock);
+ }
+ 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;
+ struct file_lock_context *ctx = inode->i_flctx;
+ 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);
+
+ if (!ctx)
+ return 0;
+
+ spin_lock(&ctx->flc_lock);
+ list_for_each_entry(lock, &ctx->flc_flock, fl_list) {
+ ++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;
+ }
+ list_for_each_entry(lock, &ctx->flc_flock, fl_list) {
+ ++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:
+ spin_unlock(&ctx->flc_lock);
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff