diff options
Diffstat (limited to 'fs/ceph/locks.c')
| -rw-r--r-- | fs/ceph/locks.c | 507 |
1 files changed, 362 insertions, 145 deletions
diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c index ae6d14e82b0f..dd764f9c64b9 100644 --- a/fs/ceph/locks.c +++ b/fs/ceph/locks.c @@ -1,30 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 #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/filelock.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)); +} + +static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) +{ + struct inode *inode = file_inode(dst->c.flc_file); + atomic_inc(&ceph_inode(inode)->i_filelock_ref); + dst->fl_u.ceph.inode = igrab(inode); +} + +/* + * Do not use the 'fl->fl_file' in release function, which + * is possibly already released by another thread. + */ +static void ceph_fl_release_lock(struct file_lock *fl) +{ + struct inode *inode = fl->fl_u.ceph.inode; + struct ceph_inode_info *ci; + + /* + * If inode is NULL it should be a request file_lock, + * nothing we can do. + */ + if (!inode) + return; + + 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); + } + fl->fl_u.ceph.inode = NULL; + iput(inode); +} + +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 file *file, +static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, 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_client *mdsc = ceph_sb_to_mdsc(inode->i_sb); + struct ceph_client *cl = mdsc->fsc->client; 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; + fl->fl_ops->fl_copy_lock(fl, NULL); + } + + 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) @@ -32,32 +110,34 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, 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); + owner = secure_addr(fl->c.flc_owner); + + doutc(cl, "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->c.flc_pid, + fl->fl_start, length, wait, fl->c.flc_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.owner = cpu_to_le64(owner); + req->r_args.filelock_change.pid = cpu_to_le64((u64) fl->c.flc_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; - 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); + err = ceph_mdsc_submit_request(mdsc, inode, req); + if (!err) + err = ceph_mdsc_wait_request(mdsc, req, wait ? + ceph_lock_wait_for_completion : NULL); + if (!err && operation == CEPH_MDS_OP_GETFILELOCK) { + fl->c.flc_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; + fl->c.flc_type = F_RDLCK; else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) - fl->fl_type = F_WRLCK; + fl->c.flc_type = F_WRLCK; else - fl->fl_type = F_UNLCK; + fl->c.flc_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) + @@ -69,128 +149,292 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, } 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); + doutc(cl, "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->c.flc_pid, + fl->fl_start, length, wait, fl->c.flc_type, err); return err; } -/** +static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + struct ceph_client *cl = mdsc->fsc->client; + 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; + + doutc(cl, "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; + + err = wait_for_completion_killable(&req->r_safe_completion); + if (err) + return err; + + return 0; +} + +static int try_unlock_file(struct file *file, struct file_lock *fl) +{ + int err; + unsigned int orig_flags = fl->c.flc_flags; + fl->c.flc_flags |= FL_EXISTS; + err = locks_lock_file_wait(file, fl); + fl->c.flc_flags = orig_flags; + if (err == -ENOENT) { + if (!(orig_flags & FL_EXISTS)) + err = 0; + return err; + } + return 1; +} + +/* * 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; + struct inode *inode = file_inode(file); + struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_client *cl = ceph_inode_to_client(inode); + int err = 0; u16 op = CEPH_MDS_OP_SETFILELOCK; + u8 wait = 0; + u8 lock_cmd; + + if (!(fl->c.flc_flags & FL_POSIX)) + return -ENOLCK; - fl->fl_nspid = get_pid(task_tgid(current)); - dout("ceph_lock, fl_pid:%d", fl->fl_pid); + if (ceph_inode_is_shutdown(inode)) + return -ESTALE; + + doutc(cl, "fl_owner: %p\n", fl->c.flc_owner); /* set wait bit as appropriate, then make command as Ceph expects it*/ - if (F_SETLKW == cmd) - wait = 1; - if (F_GETLK == cmd) + if (IS_GETLK(cmd)) op = CEPH_MDS_OP_GETFILELOCK; + else if (IS_SETLKW(cmd)) + wait = 1; - if (F_RDLCK == fl->fl_type) + spin_lock(&ci->i_ceph_lock); + if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { + err = -EIO; + } + spin_unlock(&ci->i_ceph_lock); + if (err < 0) { + if (op == CEPH_MDS_OP_SETFILELOCK && lock_is_unlock(fl)) + posix_lock_file(file, fl, NULL); + return err; + } + + if (lock_is_read(fl)) lock_cmd = CEPH_LOCK_SHARED; - else if (F_WRLCK == fl->fl_type) + else if (lock_is_write(fl)) 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 (op == CEPH_MDS_OP_SETFILELOCK && lock_is_unlock(fl)) { + err = try_unlock_file(file, fl); + if (err <= 0) + return err; + } + + err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); if (!err) { - if ( op != CEPH_MDS_OP_GETFILELOCK ){ - dout("mds locked, locking locally"); + if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK != fl->c.flc_type) { + doutc(cl, "locking locally\n"); err = posix_lock_file(file, fl, NULL); - if (err && (CEPH_MDS_OP_SETFILELOCK == op)) { + if (err) { /* undo! This should only happen if * the kernel detects local * deadlock. */ - ceph_lock_message(CEPH_LOCK_FCNTL, op, file, + ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, CEPH_LOCK_UNLOCK, 0, fl); - dout("got %d on posix_lock_file, undid lock", - err); + doutc(cl, "got %d on posix_lock_file, undid lock\n", + 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) { + struct inode *inode = file_inode(file); + struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_client *cl = ceph_inode_to_client(inode); + int err = 0; + u8 wait = 0; 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); + if (!(fl->c.flc_flags & FL_FLOCK)) + return -ENOLCK; - /* 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) + if (ceph_inode_is_shutdown(inode)) + return -ESTALE; + + doutc(cl, "fl_file: %p\n", fl->c.flc_file); + + spin_lock(&ci->i_ceph_lock); + if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { + err = -EIO; + } + spin_unlock(&ci->i_ceph_lock); + if (err < 0) { + if (lock_is_unlock(fl)) + locks_lock_file_wait(file, fl); + return err; + } + + if (IS_SETLKW(cmd)) + wait = 1; + + if (lock_is_read(fl)) lock_cmd = CEPH_LOCK_SHARED; - else if (LOCK_EX == cmd) + else if (lock_is_write(fl)) lock_cmd = CEPH_LOCK_EXCL; else lock_cmd = CEPH_LOCK_UNLOCK; + if (lock_is_unlock(fl)) { + err = try_unlock_file(file, fl); + if (err <= 0) + return err; + } + 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); + inode, lock_cmd, wait, fl); + if (!err && F_UNLCK != fl->c.flc_type) { + err = locks_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); + inode, CEPH_LOCK_UNLOCK, 0, fl); + doutc(cl, "got %d on locks_lock_file_wait, undid lock\n", + 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. +/* + * 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 ceph_client *cl = ceph_inode_to_client(inode); struct file_lock *lock; + struct file_lock_context *ctx; *fcntl_count = 0; *flock_count = 0; - for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { - if (lock->fl_flags & FL_POSIX) + ctx = locks_inode_context(inode); + if (ctx) { + spin_lock(&ctx->flc_lock); + for_each_file_lock(lock, &ctx->flc_posix) ++(*fcntl_count); - else if (lock->fl_flags & FL_FLOCK) + for_each_file_lock(lock, &ctx->flc_flock) ++(*flock_count); + spin_unlock(&ctx->flc_lock); } - dout("counted %d flock locks and %d fcntl locks", - *flock_count, *fcntl_count); + doutc(cl, "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 inode *inode, + struct file_lock *lock, + struct ceph_filelock *cephlock) +{ + struct ceph_client *cl = ceph_inode_to_client(inode); + 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->c.flc_pid); + cephlock->owner = cpu_to_le64(secure_addr(lock->c.flc_owner)); + + switch (lock->c.flc_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: + doutc(cl, "Have unknown lock type %d\n", + lock->c.flc_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. @@ -200,45 +444,48 @@ int ceph_encode_locks_to_buffer(struct inode *inode, int num_fcntl_locks, int num_flock_locks) { struct file_lock *lock; + struct file_lock_context *ctx = locks_inode_context(inode); + struct ceph_client *cl = ceph_inode_to_client(inode); 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); + doutc(cl, "encoding %d flock and %d fcntl locks\n", 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; + if (!ctx) + return 0; + + spin_lock(&ctx->flc_lock); + for_each_file_lock(lock, &ctx->flc_posix) { + ++seen_fcntl; + if (seen_fcntl > num_fcntl_locks) { + err = -ENOSPC; + goto fail; } + err = lock_to_ceph_filelock(inode, 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; + for_each_file_lock(lock, &ctx->flc_flock) { + ++seen_flock; + if (seen_flock > num_flock_locks) { + err = -ENOSPC; + goto fail; } + err = lock_to_ceph_filelock(inode, 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. @@ -256,52 +503,22 @@ int ceph_locks_to_pagelist(struct ceph_filelock *flocks, if (err) goto out_fail; - err = ceph_pagelist_append(pagelist, flocks, - num_fcntl_locks * sizeof(*flocks)); - 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; - 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; + if (num_flock_locks > 0) { + err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], + num_flock_locks * sizeof(*flocks)); } - +out_fail: return err; } |
