From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- fs/ceph/locks.c | 479 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 479 insertions(+) create mode 100644 fs/ceph/locks.c (limited to 'fs/ceph/locks.c') diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c new file mode 100644 index 000000000..6a8f4a995 --- /dev/null +++ b/fs/ceph/locks.c @@ -0,0 +1,479 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +#include +#include +#include + +#include "super.h" +#include "mds_client.h" +#include + +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)); +} + +static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) +{ + struct inode *inode = file_inode(src->fl_file); + atomic_inc(&ceph_inode(inode)->i_filelock_ref); +} + +static void ceph_fl_release_lock(struct file_lock *fl) +{ + struct inode *inode = file_inode(fl->fl_file); + struct ceph_inode_info *ci = ceph_inode(inode); + if (atomic_dec_and_test(&ci->i_filelock_ref)) { + /* clear error when all locks are released */ + spin_lock(&ci->i_ceph_lock); + ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; + spin_unlock(&ci->i_ceph_lock); + } +} + +static const struct file_lock_operations ceph_fl_lock_ops = { + .fl_copy_lock = ceph_fl_copy_lock, + .fl_release_private = ceph_fl_release_lock, +}; + +/** + * Implement fcntl and flock locking functions. + */ +static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, + int cmd, u8 wait, struct file_lock *fl) +{ + 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) { + /* + * increasing i_filelock_ref closes race window between + * handling request reply and adding file_lock struct to + * inode. Otherwise, auth caps may get trimmed in the + * window. Caller function will decrease the counter. + */ + fl->fl_ops = &ceph_fl_lock_ops; + atomic_inc(&ceph_inode(inode)->i_filelock_ref); + } + + 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\n", (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 (!err && 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\n", (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); + + mutex_lock(&mdsc->mutex); + if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { + err = 0; + } else { + /* + * ensure we aren't running concurrently with + * ceph_fill_trace or ceph_readdir_prepopulate, which + * rely on locks (dir mutex) held by our caller. + */ + mutex_lock(&req->r_fill_mutex); + req->r_err = err; + set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); + mutex_unlock(&req->r_fill_mutex); + + if (!req->r_session) { + // haven't sent the request + err = 0; + } + } + mutex_unlock(&mdsc->mutex); + if (!err) + return 0; + + 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_killable(&req->r_safe_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) +{ + struct inode *inode = file_inode(file); + struct ceph_inode_info *ci = ceph_inode(inode); + int err = 0; + u16 op = CEPH_MDS_OP_SETFILELOCK; + u8 wait = 0; + u8 lock_cmd; + + 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\n", 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; + + spin_lock(&ci->i_ceph_lock); + if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { + err = -EIO; + } else if (op == CEPH_MDS_OP_SETFILELOCK) { + /* + * increasing i_filelock_ref closes race window between + * handling request reply and adding file_lock struct to + * inode. Otherwise, i_auth_cap may get trimmed in the + * window. Caller function will decrease the counter. + */ + fl->fl_ops = &ceph_fl_lock_ops; + atomic_inc(&ci->i_filelock_ref); + } + spin_unlock(&ci->i_ceph_lock); + if (err < 0) { + if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) + posix_lock_file(file, fl, NULL); + return err; + } + + 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, inode, lock_cmd, wait, fl); + if (!err) { + if (op == CEPH_MDS_OP_SETFILELOCK) { + dout("mds locked, locking locally\n"); + err = posix_lock_file(file, fl, NULL); + if (err) { + /* undo! This should only happen if + * the kernel detects local + * deadlock. */ + ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, + CEPH_LOCK_UNLOCK, 0, fl); + dout("got %d on posix_lock_file, undid lock\n", + err); + } + } + } + return err; +} + +int ceph_flock(struct file *file, int cmd, struct file_lock *fl) +{ + struct inode *inode = file_inode(file); + struct ceph_inode_info *ci = ceph_inode(inode); + int err = 0; + u8 wait = 0; + u8 lock_cmd; + + if (!(fl->fl_flags & FL_FLOCK)) + return -ENOLCK; + /* No mandatory locks */ + if (fl->fl_type & LOCK_MAND) + return -EOPNOTSUPP; + + dout("ceph_flock, fl_file: %p\n", fl->fl_file); + + spin_lock(&ci->i_ceph_lock); + if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { + err = -EIO; + } else { + /* see comment in ceph_lock */ + fl->fl_ops = &ceph_fl_lock_ops; + atomic_inc(&ci->i_filelock_ref); + } + spin_unlock(&ci->i_ceph_lock); + if (err < 0) { + if (F_UNLCK == fl->fl_type) + locks_lock_file_wait(file, fl); + return err; + } + + 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, + inode, lock_cmd, wait, fl); + if (!err) { + err = locks_lock_file_wait(file, fl); + if (err) { + ceph_lock_message(CEPH_LOCK_FLOCK, + CEPH_MDS_OP_SETFILELOCK, + inode, CEPH_LOCK_UNLOCK, 0, fl); + dout("got %d on locks_lock_file_wait, undid lock\n", 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\n", + *flock_count, *fcntl_count); +} + +/* + * Given a pointer to a lock, convert it to a ceph filelock + */ +static 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\n", lock->fl_type); + err = -EINVAL; + } + + return err; +} + +/** + * 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\n", num_flock_locks, + num_fcntl_locks); + + if (!ctx) + return 0; + + spin_lock(&ctx->flc_lock); + list_for_each_entry(lock, &ctx->flc_posix, 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; + + if (num_fcntl_locks > 0) { + 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; + + if (num_flock_locks > 0) { + err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], + num_flock_locks * sizeof(*flocks)); + } +out_fail: + return err; +} -- cgit v1.2.3