1
0
Fork 0

ceph: add flock/fcntl lock support

Implement flock inode operation to support advisory file locking.  All
lock/unlock operations are synchronous with the MDS.  Lock state is
sent when reconnecting to a recovering MDS to restore the shared lock
state.

Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
hifive-unleashed-5.1
Greg Farnum 2010-08-02 15:34:23 -07:00 committed by Sage Weil
parent fbaad9797a
commit 40819f6fb2
5 changed files with 284 additions and 2 deletions

View File

@ -6,7 +6,7 @@ ifneq ($(KERNELRELEASE),)
obj-$(CONFIG_CEPH_FS) += ceph.o
ceph-objs := super.o inode.o dir.o file.o addr.o ioctl.o \
ceph-objs := super.o inode.o dir.o file.o locks.o addr.o ioctl.o \
export.o caps.o snap.o xattr.o \
messenger.o msgpool.o buffer.o pagelist.o \
mds_client.o mdsmap.o \

View File

@ -938,6 +938,8 @@ const struct file_operations ceph_file_fops = {
.aio_write = ceph_aio_write,
.mmap = ceph_mmap,
.fsync = ceph_fsync,
.lock = ceph_lock,
.flock = ceph_flock,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.unlocked_ioctl = ceph_ioctl,

256
fs/ceph/locks.c 100644
View File

@ -0,0 +1,256 @@
#include "ceph_debug.h"
#include <linux/file.h>
#include <linux/namei.h>
#include "super.h"
#include "mds_client.h"
#include "pagelist.h"
/**
* Implement fcntl and flock locking functions.
*/
static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
u64 pid, u64 pid_ns,
int cmd, u64 start, u64 length, u8 wait)
{
struct inode *inode = file->f_dentry->d_inode;
struct ceph_mds_client *mdsc =
&ceph_sb_to_client(inode->i_sb)->mdsc;
struct ceph_mds_request *req;
int err;
req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS);
if (IS_ERR(req))
return PTR_ERR(req);
req->r_inode = igrab(inode);
dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
"length: %llu, wait: %d, type`: %d", (int)lock_type,
(int)operation, pid, start, length, wait, cmd);
req->r_args.filelock_change.rule = lock_type;
req->r_args.filelock_change.type = cmd;
req->r_args.filelock_change.pid = cpu_to_le64(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)pid_ns);
req->r_args.filelock_change.start = cpu_to_le64(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);
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, pid, start, length, wait, cmd, err);
return err;
}
/**
* 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)
{
u64 length;
u8 lock_cmd;
int err;
u8 wait = 0;
u16 op = CEPH_MDS_OP_SETFILELOCK;
fl->fl_nspid = get_pid(task_tgid(current));
dout("ceph_lock, fl_pid:%d", fl->fl_pid);
/* set wait bit as appropriate, then make command as Ceph expects it*/
if (F_SETLKW == cmd)
wait = 1;
if (F_GETLK == cmd)
op = CEPH_MDS_OP_GETFILELOCK;
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;
if (LLONG_MAX == fl->fl_end)
length = 0;
else
length = fl->fl_end - fl->fl_start + 1;
err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
(u64)fl->fl_pid, (u64)fl->fl_nspid,
lock_cmd, fl->fl_start,
length, wait);
if (!err) {
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,
(u64)fl->fl_pid, (u64)fl->fl_nspid,
CEPH_LOCK_UNLOCK, fl->fl_start,
length, 0);
dout("got %d on posix_lock_file, undid lock", err);
}
} else {
dout("mds returned error code %d", err);
}
return err;
}
int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
{
u64 length;
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);
/* 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)
lock_cmd = CEPH_LOCK_SHARED;
else if (LOCK_EX == cmd)
lock_cmd = CEPH_LOCK_EXCL;
else
lock_cmd = CEPH_LOCK_UNLOCK;
/* 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;
err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
file, (u64)fl->fl_pid, (u64)fl->fl_nspid,
lock_cmd, fl->fl_start,
length, wait);
if (!err) {
err = flock_lock_file_wait(file, fl);
if (err) {
ceph_lock_message(CEPH_LOCK_FLOCK,
CEPH_MDS_OP_SETFILELOCK,
file, (u64)fl->fl_pid,
(u64)fl->fl_nspid,
CEPH_LOCK_UNLOCK, fl->fl_start,
length, 0);
dout("got %d on flock_lock_file_wait, undid lock", err);
}
} else {
dout("mds error code %d", err);
}
return err;
}
/**
* Must be called with BKL 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 pagelist.
* Format is: #fcntl locks, sequential fcntl locks, #flock locks,
* sequential flock locks.
* Must be called with BLK already held, and the lock numbers should have
* been gathered under the same lock holding window.
*/
int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
int num_fcntl_locks, int num_flock_locks)
{
struct file_lock *lock;
struct ceph_filelock cephlock;
int err = 0;
dout("encoding %d flock and %d fcntl locks", num_flock_locks,
num_fcntl_locks);
err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32));
if (err)
goto fail;
for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
if (lock->fl_flags & FL_POSIX) {
err = lock_to_ceph_filelock(lock, &cephlock);
if (err)
goto fail;
err = ceph_pagelist_append(pagelist, &cephlock,
sizeof(struct ceph_filelock));
}
if (err)
goto fail;
}
err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32));
if (err)
goto fail;
for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
if (lock->fl_flags & FL_FLOCK) {
err = lock_to_ceph_filelock(lock, &cephlock);
if (err)
goto fail;
err = ceph_pagelist_append(pagelist, &cephlock,
sizeof(struct ceph_filelock));
}
if (err)
goto fail;
}
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)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;
}
return err;
}

View File

@ -3,6 +3,7 @@
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include "mds_client.h"
#include "mon_client.h"
@ -2335,7 +2336,22 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
}
spin_unlock(&inode->i_lock);
err = ceph_pagelist_append(pagelist, &rec, reclen);
if (recon_state->flock) {
int num_fcntl_locks, num_flock_locks;
lock_kernel();
ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
rec.v2.flock_len = (2*sizeof(u32) +
(num_fcntl_locks+num_flock_locks) *
sizeof(struct ceph_filelock));
err = ceph_pagelist_append(pagelist, &rec, reclen);
if (!err)
err = ceph_encode_locks(inode, pagelist,
num_fcntl_locks,
num_flock_locks);
unlock_kernel();
}
out:
kfree(path);

View File

@ -892,6 +892,14 @@ extern void ceph_debugfs_cleanup(void);
extern int ceph_debugfs_client_init(struct ceph_client *client);
extern void ceph_debugfs_client_cleanup(struct ceph_client *client);
/* locks.c */
extern int ceph_lock(struct file *file, int cmd, struct file_lock *fl);
extern int ceph_flock(struct file *file, int cmd, struct file_lock *fl);
extern void ceph_count_locks(struct inode *inode, int *p_num, int *f_num);
extern int ceph_encode_locks(struct inode *i, struct ceph_pagelist *p,
int p_locks, int f_locks);
extern int lock_to_ceph_filelock(struct file_lock *fl, struct ceph_filelock *c);
static inline struct inode *get_dentry_parent_inode(struct dentry *dentry)
{
if (dentry && dentry->d_parent)