LU-9008 pfl: Read should not trigger layout write intent

[fs/lustre-release.git] / lustre / lov / lov_io.c

diff --git a/lustre/lov/lov_io.c b/lustre/lov/lov_io.c
index aa32f58..1bf1bcb 100644 (file)
--- a/lustre/lov/lov_io.c
+++ b/lustre/lov/lov_io.c
@@ -384,6 +384,7 @@ static loff_t lov_offset_mod(loff_t val, int delta)
 static int lov_io_iter_init(const struct lu_env *env,
                            const struct cl_io_slice *ios)
 {
+       struct cl_io         *io = ios->cis_io;
        struct lov_io        *lio = cl2lov_io(env, ios);
        struct lov_stripe_md *lsm = lio->lis_object->lo_lsm;
        struct lov_io_sub    *sub;
@@ -404,15 +405,26 @@ static int lov_io_iter_init(const struct lu_env *env,
                u64 end;
                int stripe;
 
-               CDEBUG(D_VFSTRACE, "component[%d] flags %#x\n",
-                      index, lsm->lsm_entries[index]->lsme_flags);
-               if (!lsm_entry_inited(lsm, index))
-                       break;
-
                index++;
                if (!lu_extent_is_overlapped(&ext, &le->lle_extent))
                        continue;
 
+               CDEBUG(D_VFSTRACE, "component[%d] flags %#x\n",
+                      index - 1, lsm->lsm_entries[index - 1]->lsme_flags);
+               if (!lsm_entry_inited(lsm, index - 1)) {
+                       /* truncate IO will trigger write intent as well, and
+                        * it's handled in lov_io_setattr_iter_init() */
+                       if (io->ci_type == CIT_WRITE || cl_io_is_mkwrite(io)) {
+                               io->ci_need_write_intent = 1;
+                               rc = -ENODATA;
+                               break;
+                       }
+
+                       /* Read from uninitialized components should return
+                        * zero filled pages. */
+                       continue;
+               }
+
                for (stripe = 0; stripe < r0->lo_nr; stripe++) {
                        if (!lov_stripe_intersects(lsm, index - 1, stripe,
                                                   &ext, &start, &end))
@@ -507,12 +519,6 @@ static int lov_io_rw_iter_init(const struct lu_env *env,
               (__u64)start, lio->lis_pos, lio->lis_endpos,
               (__u64)lio->lis_io_endpos, io->u.ci_rw.crw_count);
 
-       index = lov_lsm_entry(lsm, lio->lis_endpos - 1);
-       if (index > 0 && !lsm_entry_inited(lsm, index)) {
-               io->ci_need_write_intent = 1;
-               RETURN(io->ci_result = -ENODATA);
-       }
-
        /*
         * XXX The following call should be optimized: we know, that
         * [lio->lis_pos, lio->lis_endpos) intersects with exactly one stripe.
@@ -529,7 +535,7 @@ static int lov_io_setattr_iter_init(const struct lu_env *env,
        int index;
        ENTRY;
 
-       if (cl_io_is_trunc(io) && lio->lis_pos) {
+       if (cl_io_is_trunc(io) && lio->lis_pos > 0) {
                index = lov_lsm_entry(lsm, lio->lis_pos - 1);
                if (index > 0 && !lsm_entry_inited(lsm, index)) {
                        io->ci_need_write_intent = 1;