#define lmv_adjust_dirpages(pages, ncfspgs, nlupgs) do {} while (0)
#endif /* PAGE_CACHE_SIZE > LU_PAGE_SIZE */
+/**
+ * This function will read entry from a striped directory, bascially, it will
+ * read entries from all of stripes, and choose one closest to the required
+ * offset(&op_data->op_hash_offset). A few notes
+ * 1. skip . and .. for non-zero stripes, because there can only have one .
+ * and .. in a directory.
+ * 2. op_data will be shared by all of stripes, instead of allocating new
+ * one, so need to restore before reusing.
+ * 3. release the entry page if that is not being chosen.
+ *
+ * param[in]exp obd export refer to LMV
+ * param[in]op_data hold those MD parameters of read_entry.
+ * param[in]cb_op ldlm callback being used in enqueue in mdc_read_entry
+ * param[out]ldp the entry being read.
+ * param[out]ppage the page holding the entry, note: because the entry
+ * will be accessed in upper layer, so we need hold the
+ * page until the usages of entry is finished, see
+ * ll_dir_entry_next.
+ *
+ * retval =0 if get entry successfully
+ * <0 can not get entry.
+ */
#define NORMAL_MAX_STRIPES 4
-int lmv_read_entry(struct obd_export *exp, struct md_op_data *op_data,
- struct md_callback *cb_op, struct lu_dirent **ldp,
- struct page **ppage)
+static int lmv_read_striped_entry(struct obd_export *exp,
+ struct md_op_data *op_data,
+ struct md_callback *cb_op,
+ struct lu_dirent **ldp,
+ struct page **ppage)
{
struct obd_device *obd = exp->exp_obd;
struct lmv_obd *lmv = &obd->u.lmv;
struct lmv_stripe_md *lsm = op_data->op_mea1;
+ struct lmv_tgt_desc *tgt;
struct lu_dirent *tmp_ents[NORMAL_MAX_STRIPES];
struct lu_dirent **ents = NULL;
+ struct lu_fid master_fid = op_data->op_fid1;
+ void *master_data = op_data->op_data;
+ __u64 last_idx = op_data->op_stripe_offset;
+ __u64 hash_offset = op_data->op_hash_offset;
+ __u32 same_hash_offset = op_data->op_same_hash_offset;
+ __u32 cli_flags = op_data->op_cli_flags;
int stripe_count;
__u64 min_hash;
+ int min_same_hash_offset = 0;
int min_idx = 0;
struct page *min_page = NULL;
int i;
int rc;
ENTRY;
+ LASSERT(lsm != NULL);
+
rc = lmv_check_connect(obd);
if (rc)
RETURN(rc);
- if (lsm == NULL)
- stripe_count = 1;
- else
- stripe_count = lsm->lsm_md_stripe_count;
-
+ /* . and .. will be stored on the master object, so we need iterate
+ * the master object as well */
+ stripe_count = lsm->lsm_md_stripe_count;
if (stripe_count > NORMAL_MAX_STRIPES) {
OBD_ALLOC(ents, sizeof(ents[0]) * stripe_count);
if (ents == NULL)
min_hash = MDS_DIR_END_OFF;
for (i = 0; i < stripe_count; i++) {
- struct lmv_tgt_desc *tgt;
struct page *page = NULL;
- if (likely(lsm == NULL)) {
- tgt = lmv_find_target(lmv, &op_data->op_fid1);
- if (IS_ERR(tgt))
- GOTO(out, rc = PTR_ERR(tgt));
- LASSERT(op_data->op_data != NULL);
- } else {
- tgt = lmv_get_target(lmv, lsm->lsm_md_oinfo[i].lmo_mds);
- if (IS_ERR(tgt))
- GOTO(out, rc = PTR_ERR(tgt));
- op_data->op_fid1 = lsm->lsm_md_oinfo[i].lmo_fid;
- op_data->op_fid2 = lsm->lsm_md_oinfo[i].lmo_fid;
- op_data->op_stripe_offset = i;
- }
+ tgt = lmv_get_target(lmv, lsm->lsm_md_oinfo[i].lmo_mds);
+ if (IS_ERR(tgt))
+ GOTO(out, rc = PTR_ERR(tgt));
+ if (last_idx != i)
+ op_data->op_same_hash_offset = 0;
+ else
+ op_data->op_same_hash_offset = same_hash_offset;
+
+ /* op_data will be shared by each stripe, so we need
+ * reset these value for each stripe */
+ op_data->op_stripe_offset = i;
+ op_data->op_hash_offset = hash_offset;
+ op_data->op_cli_flags = cli_flags;
+ op_data->op_fid1 = lsm->lsm_md_oinfo[i].lmo_fid;
+ op_data->op_fid2 = lsm->lsm_md_oinfo[i].lmo_fid;
+ op_data->op_data = lsm->lsm_md_oinfo[i].lmo_root;
+
+next:
rc = md_read_entry(tgt->ltd_exp, op_data, cb_op, &ents[i],
&page);
if (rc != 0)
GOTO(out, rc);
if (ents[i] != NULL &&
- le64_to_cpu(ents[i]->lde_hash) <= min_hash) {
- if (min_page != NULL)
- page_cache_release(min_page);
- min_page = page;
- min_hash = le64_to_cpu(ents[i]->lde_hash);
- min_idx = i;
+ (strncmp(ents[i]->lde_name, ".",
+ le16_to_cpu(ents[i]->lde_namelen)) == 0 ||
+ strncmp(ents[i]->lde_name, "..",
+ le16_to_cpu(ents[i]->lde_namelen)) == 0)) {
+ if (i == 0) {
+ /* replace . with master FID */
+ if (le16_to_cpu(ents[i]->lde_namelen) == 1)
+ fid_cpu_to_le(&ents[i]->lde_fid,
+ &master_fid);
+ else
+ fid_cpu_to_le(&ents[i]->lde_fid,
+ &op_data->op_fid3);
+ } else {
+ /* skip . and .. for other stripes */
+ op_data->op_cli_flags |= CLI_NEXT_ENTRY;
+ op_data->op_hash_offset =
+ le64_to_cpu(ents[i]->lde_hash);
+ kunmap(page);
+ page_cache_release(page);
+ goto next;
+ }
+ }
+
+ if (ents[i] != NULL) {
+ /* If the hash value of read_entry is equal to the
+ * current min_hash, which is very rare and only
+ * happens if two entries have the same hash value
+ * but on different stripes, in this case, we need
+ * make sure these entries are being reading forward,
+ * not backward, i.e. only reset the min_entry, if
+ * current stripe is ahead of last entry. Note: if
+ * there are hash conflict inside the entry, MDC
+ * (see mdc_read_entry) will resolve them. */
+ if (le64_to_cpu(ents[i]->lde_hash) < min_hash ||
+ (le64_to_cpu(ents[i]->lde_hash) == min_hash &&
+ i >= last_idx)) {
+ if (min_page != NULL) {
+ kunmap(min_page);
+ page_cache_release(min_page);
+ }
+ min_page = page;
+ min_hash = le64_to_cpu(ents[i]->lde_hash);
+ min_same_hash_offset =
+ op_data->op_same_hash_offset;
+ min_idx = i;
+ } else {
+ kunmap(page);
+ page_cache_release(page);
+ }
}
}
- if (min_hash != MDS_DIR_END_OFF)
+ if (min_hash != MDS_DIR_END_OFF) {
*ldp = ents[min_idx];
- else
+ op_data->op_stripe_offset = min_idx;
+ op_data->op_same_hash_offset = min_same_hash_offset;
+ *ppage = min_page;
+ } else {
*ldp = NULL;
+ *ppage = NULL;
+ }
out:
+ /* We do not want to allocate md_op_data during each
+ * dir entry reading, so op_data will be shared by every stripe,
+ * then we need to restore it back to original value before
+ * return to the upper layer */
+ op_data->op_hash_offset = hash_offset;
+ op_data->op_fid1 = master_fid;
+ op_data->op_fid2 = master_fid;
+ op_data->op_data = master_data;
+ op_data->op_cli_flags = cli_flags;
if (stripe_count > NORMAL_MAX_STRIPES && ents != NULL)
OBD_FREE(ents, sizeof(ents[0]) * stripe_count);
if (rc != 0 && min_page != NULL) {
kunmap(min_page);
page_cache_release(min_page);
- } else {
- *ppage = min_page;
}
RETURN(rc);
}
+int lmv_read_entry(struct obd_export *exp, struct md_op_data *op_data,
+ struct md_callback *cb_op, struct lu_dirent **ldp,
+ struct page **ppage)
+{
+ struct obd_device *obd = exp->exp_obd;
+ struct lmv_obd *lmv = &obd->u.lmv;
+ struct lmv_stripe_md *lsm = op_data->op_mea1;
+ struct lmv_tgt_desc *tgt;
+ int rc;
+ ENTRY;
+
+ rc = lmv_check_connect(obd);
+ if (rc != 0)
+ RETURN(rc);
+
+ if (unlikely(lsm != NULL)) {
+ rc = lmv_read_striped_entry(exp, op_data, cb_op,
+ ldp, ppage);
+ RETURN(rc);
+ }
+
+ tgt = lmv_find_target(lmv, &op_data->op_fid1);
+ if (IS_ERR(tgt))
+ RETURN(PTR_ERR(tgt));
+
+ rc = md_read_entry(tgt->ltd_exp, op_data, cb_op, ldp,
+ ppage);
+ RETURN(rc);
+}
+
static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
struct ptlrpc_request **request)
{
RETURN(0);
}
+ if (le32_to_cpu(lmm->lmv_magic) == LMV_MAGIC_STRIPE)
+ RETURN(-EPERM);
+
/* Unpack memmd */
if (le32_to_cpu(lmm->lmv_magic) != LMV_MAGIC_V1 &&
le32_to_cpu(lmm->lmv_magic) != LMV_USER_MAGIC) {