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-rw-r--r--fs/ceph/mdsmap.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
new file mode 100644
index 0000000..15913cbe
--- /dev/null
+++ b/fs/ceph/mdsmap.c
@@ -0,0 +1,166 @@
+#include "ceph_debug.h"
+
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "mdsmap.h"
+#include "messenger.h"
+#include "decode.h"
+
+#include "super.h"
+
+
+/*
+ * choose a random mds that is "up" (i.e. has a state > 0), or -1.
+ */
+int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
+{
+ int n = 0;
+ int i;
+ char r;
+
+ /* count */
+ for (i = 0; i < m->m_max_mds; i++)
+ if (m->m_info[i].state > 0)
+ n++;
+ if (n == 0)
+ return -1;
+
+ /* pick */
+ get_random_bytes(&r, 1);
+ n = r % n;
+ i = 0;
+ for (i = 0; n > 0; i++, n--)
+ while (m->m_info[i].state <= 0)
+ i++;
+
+ return i;
+}
+
+/*
+ * Decode an MDS map
+ *
+ * Ignore any fields we don't care about (there are quite a few of
+ * them).
+ */
+struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
+{
+ struct ceph_mdsmap *m;
+ int i, j, n;
+ int err = -EINVAL;
+ u16 version;
+
+ m = kzalloc(sizeof(*m), GFP_NOFS);
+ if (m == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ ceph_decode_16_safe(p, end, version, bad);
+
+ ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
+ ceph_decode_32(p, m->m_epoch);
+ ceph_decode_32(p, m->m_client_epoch);
+ ceph_decode_32(p, m->m_last_failure);
+ ceph_decode_32(p, m->m_root);
+ ceph_decode_32(p, m->m_session_timeout);
+ ceph_decode_32(p, m->m_session_autoclose);
+ ceph_decode_64(p, m->m_max_file_size);
+ ceph_decode_32(p, m->m_max_mds);
+
+ m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
+ if (m->m_info == NULL)
+ goto badmem;
+
+ /* pick out active nodes from mds_info (state > 0) */
+ ceph_decode_32(p, n);
+ for (i = 0; i < n; i++) {
+ u32 namelen;
+ s32 mds, inc, state;
+ u64 state_seq;
+ u8 infoversion;
+ struct ceph_entity_addr addr;
+ u32 num_export_targets;
+ void *pexport_targets = NULL;
+
+ ceph_decode_need(p, end, sizeof(addr) + 1 + sizeof(u32), bad);
+ *p += sizeof(addr); /* skip addr key */
+ ceph_decode_8(p, infoversion);
+ ceph_decode_32(p, namelen); /* skip mds name */
+ *p += namelen;
+
+ ceph_decode_need(p, end,
+ 5*sizeof(u32) + sizeof(u64) +
+ sizeof(addr) + sizeof(struct ceph_timespec),
+ bad);
+ ceph_decode_32(p, mds);
+ ceph_decode_32(p, inc);
+ ceph_decode_32(p, state);
+ ceph_decode_64(p, state_seq);
+ ceph_decode_copy(p, &addr, sizeof(addr));
+ *p += sizeof(struct ceph_timespec);
+ *p += sizeof(u32);
+ ceph_decode_32_safe(p, end, namelen, bad);
+ *p += sizeof(namelen);
+ if (infoversion >= 2) {
+ ceph_decode_32_safe(p, end, num_export_targets, bad);
+ pexport_targets = *p;
+ *p += sizeof(num_export_targets * sizeof(u32));
+ } else {
+ num_export_targets = 0;
+ }
+
+ dout("mdsmap_decode %d/%d mds%d.%d %s %s\n",
+ i+1, n, mds, inc, pr_addr(&addr.in_addr),
+ ceph_mds_state_name(state));
+ if (mds >= 0 && mds < m->m_max_mds && state > 0) {
+ m->m_info[mds].state = state;
+ m->m_info[mds].addr = addr;
+ m->m_info[mds].num_export_targets = num_export_targets;
+ if (num_export_targets) {
+ m->m_info[mds].export_targets =
+ kcalloc(num_export_targets, sizeof(u32),
+ GFP_NOFS);
+ for (j = 0; j < num_export_targets; j++)
+ ceph_decode_32(&pexport_targets,
+ m->m_info[mds].export_targets[j]);
+ } else {
+ m->m_info[mds].export_targets = NULL;
+ }
+ }
+ }
+
+ /* pg_pools */
+ ceph_decode_32_safe(p, end, n, bad);
+ m->m_num_data_pg_pools = n;
+ m->m_data_pg_pools = kcalloc(n, sizeof(u32), GFP_NOFS);
+ if (!m->m_data_pg_pools)
+ goto badmem;
+ ceph_decode_need(p, end, sizeof(u32)*(n+1), bad);
+ for (i = 0; i < n; i++)
+ ceph_decode_32(p, m->m_data_pg_pools[i]);
+ ceph_decode_32(p, m->m_cas_pg_pool);
+
+ /* ok, we don't care about the rest. */
+ dout("mdsmap_decode success epoch %u\n", m->m_epoch);
+ return m;
+
+badmem:
+ err = -ENOMEM;
+bad:
+ pr_err("corrupt mdsmap\n");
+ ceph_mdsmap_destroy(m);
+ return ERR_PTR(-EINVAL);
+}
+
+void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
+{
+ int i;
+
+ for (i = 0; i < m->m_max_mds; i++)
+ kfree(m->m_info[i].export_targets);
+ kfree(m->m_info);
+ kfree(m->m_data_pg_pools);
+ kfree(m);
+}
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