LU-4603 lmv: a few fixes about readdir of striped dir.

[fs/lustre-release.git] / lustre / lmv / lmv_obd.c

diff --git a/lustre/lmv/lmv_obd.c b/lustre/lmv/lmv_obd.c
index c18a68b..8a7395f 100644 (file)
--- a/lustre/lmv/lmv_obd.c
+++ b/lustre/lmv/lmv_obd.c
@@ -2331,33 +2331,65 @@ static void lmv_adjust_dirpages(struct page **pages, int ncfspgs, int nlupgs)
 #define lmv_adjust_dirpages(pages, ncfspgs, nlupgs) do {} while (0)
 #endif /* PAGE_CACHE_SIZE > LU_PAGE_SIZE */
 
 #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
 #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 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_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                     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;
 
        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);
 
        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)
        if (stripe_count > NORMAL_MAX_STRIPES) {
                OBD_ALLOC(ents, sizeof(ents[0]) * stripe_count);
                if (ents == NULL)


@@ -2369,56 +2401,145 @@ int lmv_read_entry(struct obd_export *exp, struct md_op_data *op_data,
 
        min_hash = MDS_DIR_END_OFF;
        for (i = 0; i < stripe_count; i++) {
 
        min_hash = MDS_DIR_END_OFF;
        for (i = 0; i < stripe_count; i++) {

-               struct lmv_tgt_desc *tgt;

                struct page *page = NULL;
 
                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 &&
                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];
                *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;
                *ldp = NULL;

+               *ppage = NULL;
+       }

 out:
 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);
        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);
 }
 
        }
 
        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)
 {
 static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
                       struct ptlrpc_request **request)
 {