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| author | M. Mohan Kumar <mohan@in.ibm.com> | 2010-09-27 10:52:13 +0400 |
|---|---|---|
| committer | Eric Van Hensbergen <ericvh@gmail.com> | 2010-10-28 18:08:47 +0400 |
| commit | 1d769cd192fc8c4097b1e2cd41fdee6ba3d1b2af (patch) | |
| tree | 16fd71ff9178bbfe144a28a2e168c85fb541a11b /fs/9p | |
| parent | a099027c779068b834f335cfdc3f2bf10f531dd9 (diff) | |
| download | linux-1d769cd192fc8c4097b1e2cd41fdee6ba3d1b2af.tar.xz | |
9p: Implement TGETLOCK
Synopsis
size[4] TGetlock tag[2] fid[4] getlock[n]
size[4] RGetlock tag[2] getlock[n]
Description
TGetlock is used to test for the existence of byte range posix locks on a file
identified by given fid. The reply contains getlock structure. If the lock could
be placed it returns F_UNLCK in type field of getlock structure. Otherwise it
returns the details of the conflicting locks in the getlock structure
getlock structure:
type[1] - Type of lock: F_RDLCK, F_WRLCK
start[8] - Starting offset for lock
length[8] - Number of bytes to check for the lock
If length is 0, check for lock in all bytes starting at the location
'start' through to the end of file
pid[4] - PID of the process that wants to take lock/owns the task
in case of reply
client[4] - Client id of the system that owns the process which
has the conflicting lock
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p')
| -rw-r--r-- | fs/9p/vfs_file.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 6f77abd23184..3a4352f23a98 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -211,6 +211,51 @@ out: return res; } +static int v9fs_file_getlock(struct file *filp, struct file_lock *fl) +{ + struct p9_getlock glock; + struct p9_fid *fid; + int res = 0; + + fid = filp->private_data; + BUG_ON(fid == NULL); + + posix_test_lock(filp, fl); + /* + * if we have a conflicting lock locally, no need to validate + * with server + */ + if (fl->fl_type != F_UNLCK) + return res; + + /* convert posix lock to p9 tgetlock args */ + memset(&glock, 0, sizeof(glock)); + glock.type = fl->fl_type; + glock.start = fl->fl_start; + if (fl->fl_end == OFFSET_MAX) + glock.length = 0; + else + glock.length = fl->fl_end - fl->fl_start + 1; + glock.proc_id = fl->fl_pid; + glock.client_id = utsname()->nodename; + + res = p9_client_getlock_dotl(fid, &glock); + if (res < 0) + return res; + if (glock.type != F_UNLCK) { + fl->fl_type = glock.type; + fl->fl_start = glock.start; + if (glock.length == 0) + fl->fl_end = OFFSET_MAX; + else + fl->fl_end = glock.start + glock.length - 1; + fl->fl_pid = glock.proc_id; + } else + fl->fl_type = F_UNLCK; + + return res; +} + /** * v9fs_file_lock_dotl - lock a file (or directory) * @filp: file to be locked @@ -238,6 +283,8 @@ static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl) if (IS_SETLK(cmd) || IS_SETLKW(cmd)) ret = v9fs_file_do_lock(filp, cmd, fl); + else if (IS_GETLK(cmd)) + ret = v9fs_file_getlock(filp, fl); else ret = -EINVAL; out_err: |