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authorJeff Layton <jlayton@kernel.org>2022-02-11 19:38:02 +0300
committerIlya Dryomov <idryomov@gmail.com>2023-08-22 10:01:47 +0300
commitf628d799972799023d32c2542bb2639eb8c4f84e (patch)
treef6ae659115e694ff6d5f7b5c4701c5df22e4fc6b /include/linux
parentd396f89db39a2f259e2125ca43b4c31bb65afcad (diff)
downloadlinux-f628d799972799023d32c2542bb2639eb8c4f84e.tar.xz
libceph: add sparse read support to OSD client
Have get_reply check for the presence of sparse read ops in the request and set the sparse_read boolean in the msg. That will queue the messenger layer to use the sparse read codepath instead of the normal data receive. Add a new sparse_read operation for the OSD client, driven by its own state machine. The messenger will repeatedly call the sparse_read operation, and it will pass back the necessary info to set up to read the next extent of data, while zero-filling the sparse regions. The state machine will stop at the end of the last extent, and will attach the extent map buffer to the ceph_osd_req_op so that the caller can use it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Xiubo Li <xiubli@redhat.com> Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de> Reviewed-by: Milind Changire <mchangir@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/ceph/osd_client.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 05da1e755b7b..bfa4813590da 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -40,6 +40,36 @@ struct ceph_sparse_extent {
u64 len;
} __packed;
+/* Sparse read state machine state values */
+enum ceph_sparse_read_state {
+ CEPH_SPARSE_READ_HDR = 0,
+ CEPH_SPARSE_READ_EXTENTS,
+ CEPH_SPARSE_READ_DATA_LEN,
+ CEPH_SPARSE_READ_DATA,
+};
+
+/*
+ * A SPARSE_READ reply is a 32-bit count of extents, followed by an array of
+ * 64-bit offset/length pairs, and then all of the actual file data
+ * concatenated after it (sans holes).
+ *
+ * Unfortunately, we don't know how long the extent array is until we've
+ * started reading the data section of the reply. The caller should send down
+ * a destination buffer for the array, but we'll alloc one if it's too small
+ * or if the caller doesn't.
+ */
+struct ceph_sparse_read {
+ enum ceph_sparse_read_state sr_state; /* state machine state */
+ u64 sr_req_off; /* orig request offset */
+ u64 sr_req_len; /* orig request length */
+ u64 sr_pos; /* current pos in buffer */
+ int sr_index; /* current extent index */
+ __le32 sr_datalen; /* length of actual data */
+ u32 sr_count; /* extent count in reply */
+ int sr_ext_len; /* length of extent array */
+ struct ceph_sparse_extent *sr_extent; /* extent array */
+};
+
/*
* A given osd we're communicating with.
*
@@ -48,6 +78,7 @@ struct ceph_sparse_extent {
*/
struct ceph_osd {
refcount_t o_ref;
+ int o_sparse_op_idx;
struct ceph_osd_client *o_osdc;
int o_osd;
int o_incarnation;
@@ -63,6 +94,7 @@ struct ceph_osd {
unsigned long lru_ttl;
struct list_head o_keepalive_item;
struct mutex lock;
+ struct ceph_sparse_read o_sparse_read;
};
#define CEPH_OSD_SLAB_OPS 2