diff options
Diffstat (limited to 'fs/9p')
| -rw-r--r-- | fs/9p/v9fs_vfs.h | 2 | ||||
| -rw-r--r-- | fs/9p/vfs_file.c | 160 |
2 files changed, 160 insertions, 2 deletions
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h index 09861295eef..d26db1932f7 100644 --- a/fs/9p/v9fs_vfs.h +++ b/fs/9p/v9fs_vfs.h @@ -65,3 +65,5 @@ int v9fs_uflags2omode(int uflags, int extended); ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64); void v9fs_blank_wstat(struct p9_wstat *wstat); int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *); + +#define P9_LOCK_TIMEOUT (30*HZ) diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index fdf303207c7..6f77abd2318 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -33,6 +33,7 @@ #include <linux/inet.h> #include <linux/list.h> #include <linux/pagemap.h> +#include <linux/utsname.h> #include <asm/uaccess.h> #include <linux/idr.h> #include <net/9p/9p.h> @@ -133,6 +134,159 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) return res; } +static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl) +{ + struct p9_flock flock; + struct p9_fid *fid; + uint8_t status; + int res = 0; + unsigned char fl_type; + + fid = filp->private_data; + BUG_ON(fid == NULL); + + if ((fl->fl_flags & FL_POSIX) != FL_POSIX) + BUG(); + + res = posix_lock_file_wait(filp, fl); + if (res < 0) + goto out; + + /* convert posix lock to p9 tlock args */ + memset(&flock, 0, sizeof(flock)); + flock.type = fl->fl_type; + flock.start = fl->fl_start; + if (fl->fl_end == OFFSET_MAX) + flock.length = 0; + else + flock.length = fl->fl_end - fl->fl_start + 1; + flock.proc_id = fl->fl_pid; + flock.client_id = utsname()->nodename; + if (IS_SETLKW(cmd)) + flock.flags = P9_LOCK_FLAGS_BLOCK; + + /* + * if its a blocked request and we get P9_LOCK_BLOCKED as the status + * for lock request, keep on trying + */ + for (;;) { + res = p9_client_lock_dotl(fid, &flock, &status); + if (res < 0) + break; + + if (status != P9_LOCK_BLOCKED) + break; + if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd)) + break; + schedule_timeout_interruptible(P9_LOCK_TIMEOUT); + } + + /* map 9p status to VFS status */ + switch (status) { + case P9_LOCK_SUCCESS: + res = 0; + break; + case P9_LOCK_BLOCKED: + res = -EAGAIN; + break; + case P9_LOCK_ERROR: + case P9_LOCK_GRACE: + res = -ENOLCK; + break; + default: + BUG(); + } + + /* + * incase server returned error for lock request, revert + * it locally + */ + if (res < 0 && fl->fl_type != F_UNLCK) { + fl_type = fl->fl_type; + fl->fl_type = F_UNLCK; + res = posix_lock_file_wait(filp, fl); + fl->fl_type = fl_type; + } +out: + return res; +} + +/** + * v9fs_file_lock_dotl - lock a file (or directory) + * @filp: file to be locked + * @cmd: lock command + * @fl: file lock structure + * + */ + +static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + int ret = -ENOLCK; + + P9_DPRINTK(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n", filp, + cmd, fl, filp->f_path.dentry->d_name.name); + + /* No mandatory locks */ + if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) + goto out_err; + + if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { + filemap_write_and_wait(inode->i_mapping); + invalidate_mapping_pages(&inode->i_data, 0, -1); + } + + if (IS_SETLK(cmd) || IS_SETLKW(cmd)) + ret = v9fs_file_do_lock(filp, cmd, fl); + else + ret = -EINVAL; +out_err: + return ret; +} + +/** + * v9fs_file_flock_dotl - lock a file + * @filp: file to be locked + * @cmd: lock command + * @fl: file lock structure + * + */ + +static int v9fs_file_flock_dotl(struct file *filp, int cmd, + struct file_lock *fl) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + int ret = -ENOLCK; + + P9_DPRINTK(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n", filp, + cmd, fl, filp->f_path.dentry->d_name.name); + + /* No mandatory locks */ + if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) + goto out_err; + + if (!(fl->fl_flags & FL_FLOCK)) + goto out_err; + + if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { + filemap_write_and_wait(inode->i_mapping); + invalidate_mapping_pages(&inode->i_data, 0, -1); + } + /* Convert flock to posix lock */ + fl->fl_owner = (fl_owner_t)filp; + fl->fl_start = 0; + fl->fl_end = OFFSET_MAX; + fl->fl_flags |= FL_POSIX; + fl->fl_flags ^= FL_FLOCK; + + if (IS_SETLK(cmd) | IS_SETLKW(cmd)) + ret = v9fs_file_do_lock(filp, cmd, fl); + else + ret = -EINVAL; +out_err: + return ret; +} + /** * v9fs_file_readn - read from a file * @filp: file pointer to read @@ -323,7 +477,8 @@ static const struct file_operations v9fs_cached_file_operations_dotl = { .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, - .lock = v9fs_file_lock, + .lock = v9fs_file_lock_dotl, + .flock = v9fs_file_flock_dotl, .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync_dotl, }; @@ -345,7 +500,8 @@ const struct file_operations v9fs_file_operations_dotl = { .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, - .lock = v9fs_file_lock, + .lock = v9fs_file_lock_dotl, + .flock = v9fs_file_flock_dotl, .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync_dotl, }; |