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authorDouglas Fuller <dfuller@redhat.com>2015-06-18 13:06:10 -0700
committerIlya Dryomov <idryomov@gmail.com>2016-08-24 23:49:15 +0200
commitf66241cb99dac861aa2cedb9f05ffa98d70cbc6e (patch)
treef3ef9ad38ebb057b0e0942b2a87d585a8f3fb41f /net/ceph/cls_lock_client.c
parent428a715811fe74e8a8f09b830c8d3b5245096f8d (diff)
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libceph: support for advisory locking on RADOS objects
This patch adds support for rados lock, unlock and break lock. Based heavily on code by Mike Christie <michaelc@cs.wisc.edu>. Signed-off-by: Douglas Fuller <dfuller@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Alex Elder <elder@linaro.org>
Diffstat (limited to 'net/ceph/cls_lock_client.c')
-rw-r--r--net/ceph/cls_lock_client.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/net/ceph/cls_lock_client.c b/net/ceph/cls_lock_client.c
new file mode 100644
index 000000000000..2a314537f958
--- /dev/null
+++ b/net/ceph/cls_lock_client.c
@@ -0,0 +1,180 @@
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#include <linux/ceph/cls_lock_client.h>
+#include <linux/ceph/decode.h>
+
+/**
+ * ceph_cls_lock - grab rados lock for object
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @type: lock type (CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED)
+ * @cookie: user-defined identifier for this instance of the lock
+ * @tag: user-defined tag
+ * @desc: user-defined lock description
+ * @flags: lock flags
+ *
+ * All operations on the same lock should use the same tag.
+ */
+int ceph_cls_lock(struct ceph_osd_client *osdc,
+ struct ceph_object_id *oid,
+ struct ceph_object_locator *oloc,
+ char *lock_name, u8 type, char *cookie,
+ char *tag, char *desc, u8 flags)
+{
+ int lock_op_buf_size;
+ int name_len = strlen(lock_name);
+ int cookie_len = strlen(cookie);
+ int tag_len = strlen(tag);
+ int desc_len = strlen(desc);
+ void *p, *end;
+ struct page *lock_op_page;
+ struct timespec mtime;
+ int ret;
+
+ lock_op_buf_size = name_len + sizeof(__le32) +
+ cookie_len + sizeof(__le32) +
+ tag_len + sizeof(__le32) +
+ desc_len + sizeof(__le32) +
+ sizeof(struct ceph_timespec) +
+ /* flag and type */
+ sizeof(u8) + sizeof(u8) +
+ CEPH_ENCODING_START_BLK_LEN;
+ if (lock_op_buf_size > PAGE_SIZE)
+ return -E2BIG;
+
+ lock_op_page = alloc_page(GFP_NOIO);
+ if (!lock_op_page)
+ return -ENOMEM;
+
+ p = page_address(lock_op_page);
+ end = p + lock_op_buf_size;
+
+ /* encode cls_lock_lock_op struct */
+ ceph_start_encoding(&p, 1, 1,
+ lock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+ ceph_encode_string(&p, end, lock_name, name_len);
+ ceph_encode_8(&p, type);
+ ceph_encode_string(&p, end, cookie, cookie_len);
+ ceph_encode_string(&p, end, tag, tag_len);
+ ceph_encode_string(&p, end, desc, desc_len);
+ /* only support infinite duration */
+ memset(&mtime, 0, sizeof(mtime));
+ ceph_encode_timespec(p, &mtime);
+ p += sizeof(struct ceph_timespec);
+ ceph_encode_8(&p, flags);
+
+ dout("%s lock_name %s type %d cookie %s tag %s desc %s flags 0x%x\n",
+ __func__, lock_name, type, cookie, tag, desc, flags);
+ ret = ceph_osdc_call(osdc, oid, oloc, "lock", "lock",
+ CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+ lock_op_page, lock_op_buf_size, NULL, NULL);
+
+ dout("%s: status %d\n", __func__, ret);
+ __free_page(lock_op_page);
+ return ret;
+}
+EXPORT_SYMBOL(ceph_cls_lock);
+
+/**
+ * ceph_cls_unlock - release rados lock for object
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @cookie: user-defined identifier for this instance of the lock
+ */
+int ceph_cls_unlock(struct ceph_osd_client *osdc,
+ struct ceph_object_id *oid,
+ struct ceph_object_locator *oloc,
+ char *lock_name, char *cookie)
+{
+ int unlock_op_buf_size;
+ int name_len = strlen(lock_name);
+ int cookie_len = strlen(cookie);
+ void *p, *end;
+ struct page *unlock_op_page;
+ int ret;
+
+ unlock_op_buf_size = name_len + sizeof(__le32) +
+ cookie_len + sizeof(__le32) +
+ CEPH_ENCODING_START_BLK_LEN;
+ if (unlock_op_buf_size > PAGE_SIZE)
+ return -E2BIG;
+
+ unlock_op_page = alloc_page(GFP_NOIO);
+ if (!unlock_op_page)
+ return -ENOMEM;
+
+ p = page_address(unlock_op_page);
+ end = p + unlock_op_buf_size;
+
+ /* encode cls_lock_unlock_op struct */
+ ceph_start_encoding(&p, 1, 1,
+ unlock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+ ceph_encode_string(&p, end, lock_name, name_len);
+ ceph_encode_string(&p, end, cookie, cookie_len);
+
+ dout("%s lock_name %s cookie %s\n", __func__, lock_name, cookie);
+ ret = ceph_osdc_call(osdc, oid, oloc, "lock", "unlock",
+ CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+ unlock_op_page, unlock_op_buf_size, NULL, NULL);
+
+ dout("%s: status %d\n", __func__, ret);
+ __free_page(unlock_op_page);
+ return ret;
+}
+EXPORT_SYMBOL(ceph_cls_unlock);
+
+/**
+ * ceph_cls_break_lock - release rados lock for object for specified client
+ * @oid, @oloc: object to lock
+ * @lock_name: the name of the lock
+ * @cookie: user-defined identifier for this instance of the lock
+ * @locker: current lock owner
+ */
+int ceph_cls_break_lock(struct ceph_osd_client *osdc,
+ struct ceph_object_id *oid,
+ struct ceph_object_locator *oloc,
+ char *lock_name, char *cookie,
+ struct ceph_entity_name *locker)
+{
+ int break_op_buf_size;
+ int name_len = strlen(lock_name);
+ int cookie_len = strlen(cookie);
+ struct page *break_op_page;
+ void *p, *end;
+ int ret;
+
+ break_op_buf_size = name_len + sizeof(__le32) +
+ cookie_len + sizeof(__le32) +
+ sizeof(u8) + sizeof(__le64) +
+ CEPH_ENCODING_START_BLK_LEN;
+ if (break_op_buf_size > PAGE_SIZE)
+ return -E2BIG;
+
+ break_op_page = alloc_page(GFP_NOIO);
+ if (!break_op_page)
+ return -ENOMEM;
+
+ p = page_address(break_op_page);
+ end = p + break_op_buf_size;
+
+ /* encode cls_lock_break_op struct */
+ ceph_start_encoding(&p, 1, 1,
+ break_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
+ ceph_encode_string(&p, end, lock_name, name_len);
+ ceph_encode_copy(&p, locker, sizeof(*locker));
+ ceph_encode_string(&p, end, cookie, cookie_len);
+
+ dout("%s lock_name %s cookie %s locker %s%llu\n", __func__, lock_name,
+ cookie, ENTITY_NAME(*locker));
+ ret = ceph_osdc_call(osdc, oid, oloc, "lock", "break_lock",
+ CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
+ break_op_page, break_op_buf_size, NULL, NULL);
+
+ dout("%s: status %d\n", __func__, ret);
+ __free_page(break_op_page);
+ return ret;
+}
+EXPORT_SYMBOL(ceph_cls_break_lock);