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authorM. Mohan Kumar <mohan@in.ibm.com>2010-09-27 12:22:13 +0530
committerEric Van Hensbergen <ericvh@gmail.com>2010-10-28 09:08:47 -0500
commit1d769cd192fc8c4097b1e2cd41fdee6ba3d1b2af (patch)
tree16fd71ff9178bbfe144a28a2e168c85fb541a11b /fs/9p/vfs_file.c
parenta099027c779068b834f335cfdc3f2bf10f531dd9 (diff)
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/vfs_file.c')
-rw-r--r--fs/9p/vfs_file.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 6f77abd2318..3a4352f23a9 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: