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LU-13134 osc: re-declare ops_from/to to shrink osc_page
[fs/lustre-release.git] / lustre / osc / osc_cache.c
index 7721c13..795040d 100644 (file)
@@ -38,6 +38,7 @@
 #define DEBUG_SUBSYSTEM S_OSC
 
 #include <lustre_osc.h>
+#include <lustre_dlm.h>
 
 #include "osc_internal.h"
 
@@ -57,10 +58,10 @@ static int osc_io_unplug_async(const struct lu_env *env,
 static void osc_free_grant(struct client_obd *cli, unsigned int nr_pages,
                           unsigned int lost_grant, unsigned int dirty_grant);
 
-static void osc_extent_tree_dump0(int level, struct osc_object *obj,
+static void osc_extent_tree_dump0(int mask, struct osc_object *obj,
                                  const char *func, int line);
-#define osc_extent_tree_dump(lvl, obj) \
-       osc_extent_tree_dump0(lvl, obj, __func__, __LINE__)
+#define osc_extent_tree_dump(mask, obj) \
+       osc_extent_tree_dump0(mask, obj, __func__, __LINE__)
 
 static void osc_unreserve_grant(struct client_obd *cli, unsigned int reserved,
                                unsigned int unused);
@@ -74,7 +75,7 @@ static inline char *ext_flags(struct osc_extent *ext, char *flags)
 {
        char *buf = flags;
        *buf++ = ext->oe_rw ? 'r' : 'w';
-       if (ext->oe_intree)
+       if (!RB_EMPTY_NODE(&ext->oe_node))
                *buf++ = 'i';
        if (ext->oe_sync)
                *buf++ = 'S';
@@ -94,28 +95,24 @@ static inline char *ext_flags(struct osc_extent *ext, char *flags)
        return flags;
 }
 
-static inline char list_empty_marker(struct list_head *list)
-{
-       return list_empty(list) ? '-' : '+';
-}
-
 #define EXTSTR       "[%lu -> %lu/%lu]"
 #define EXTPARA(ext) (ext)->oe_start, (ext)->oe_end, (ext)->oe_max_end
 static const char *oes_strings[] = {
        "inv", "active", "cache", "locking", "lockdone", "rpc", "trunc", NULL };
 
-#define OSC_EXTENT_DUMP(lvl, extent, fmt, ...) do {                          \
+#define OSC_EXTENT_DUMP_WITH_LOC(file, func, line, mask, extent, fmt, ...) do {\
+       static struct cfs_debug_limit_state cdls;                             \
        struct osc_extent *__ext = (extent);                                  \
        char __buf[16];                                                       \
                                                                              \
-       CDEBUG(lvl,                                                           \
+       __CDEBUG_WITH_LOC(file, func, line, mask, &cdls,                      \
                "extent %p@{" EXTSTR ", "                                     \
                "[%d|%d|%c|%s|%s|%p], [%d|%d|%c|%c|%p|%u|%p]} " fmt,          \
                /* ----- extent part 0 ----- */                               \
                __ext, EXTPARA(__ext),                                        \
                /* ----- part 1 ----- */                                      \
-               atomic_read(&__ext->oe_refc),                         \
-               atomic_read(&__ext->oe_users),                        \
+               kref_read(&__ext->oe_refc),                                   \
+               atomic_read(&__ext->oe_users),                                \
                list_empty_marker(&__ext->oe_link),                           \
                oes_strings[__ext->oe_state], ext_flags(__ext, __buf),        \
                __ext->oe_obj,                                                \
@@ -126,12 +123,16 @@ static const char *oes_strings[] = {
                __ext->oe_dlmlock, __ext->oe_mppr, __ext->oe_owner,           \
                /* ----- part 4 ----- */                                      \
                ## __VA_ARGS__);                                              \
-       if (lvl == D_ERROR && __ext->oe_dlmlock != NULL)                      \
+       if (mask == D_ERROR && __ext->oe_dlmlock != NULL)                     \
                LDLM_ERROR(__ext->oe_dlmlock, "extent: %p", __ext);           \
        else                                                                  \
                LDLM_DEBUG(__ext->oe_dlmlock, "extent: %p", __ext);           \
 } while (0)
 
+#define OSC_EXTENT_DUMP(mask, ext, fmt, ...)                           \
+       OSC_EXTENT_DUMP_WITH_LOC(__FILE__, __func__, __LINE__,          \
+                                mask, ext, fmt, ## __VA_ARGS__)
+
 #undef EASSERTF
 #define EASSERTF(expr, ext, fmt, args...) do {                         \
        if (!(expr)) {                                                  \
@@ -146,10 +147,7 @@ static const char *oes_strings[] = {
 
 static inline struct osc_extent *rb_extent(struct rb_node *n)
 {
-       if (n == NULL)
-               return NULL;
-
-       return container_of(n, struct osc_extent, oe_node);
+       return rb_entry_safe(n, struct osc_extent, oe_node);
 }
 
 static inline struct osc_extent *next_extent(struct osc_extent *ext)
@@ -157,7 +155,7 @@ static inline struct osc_extent *next_extent(struct osc_extent *ext)
        if (ext == NULL)
                return NULL;
 
-       LASSERT(ext->oe_intree);
+       LASSERT(!RB_EMPTY_NODE(&ext->oe_node));
        return rb_extent(rb_next(&ext->oe_node));
 }
 
@@ -166,7 +164,7 @@ static inline struct osc_extent *prev_extent(struct osc_extent *ext)
        if (ext == NULL)
                return NULL;
 
-       LASSERT(ext->oe_intree);
+       LASSERT(!RB_EMPTY_NODE(&ext->oe_node));
        return rb_extent(rb_prev(&ext->oe_node));
 }
 
@@ -184,16 +182,15 @@ static int osc_extent_sanity_check0(struct osc_extent *ext,
        size_t page_count;
        int rc = 0;
 
-       if (!osc_object_is_locked(obj))
-               GOTO(out, rc = 9);
+       assert_osc_object_is_locked(obj);
 
        if (ext->oe_state >= OES_STATE_MAX)
                GOTO(out, rc = 10);
 
-       if (atomic_read(&ext->oe_refc) <= 0)
+       if (kref_read(&ext->oe_refc) <= 0)
                GOTO(out, rc = 20);
 
-       if (atomic_read(&ext->oe_refc) < atomic_read(&ext->oe_users))
+       if (kref_read(&ext->oe_refc) < atomic_read(&ext->oe_users))
                GOTO(out, rc = 30);
 
        switch (ext->oe_state) {
@@ -215,6 +212,7 @@ static int osc_extent_sanity_check0(struct osc_extent *ext,
                        GOTO(out, rc = 60);
                if (ext->oe_fsync_wait && !ext->oe_urgent && !ext->oe_hp)
                        GOTO(out, rc = 65);
+               /* fallthrough */
        default:
                if (atomic_read(&ext->oe_users) > 0)
                        GOTO(out, rc = 70);
@@ -263,9 +261,9 @@ static int osc_extent_sanity_check0(struct osc_extent *ext,
 
 out:
        if (rc != 0)
-               OSC_EXTENT_DUMP(D_ERROR, ext,
-                               "%s:%d sanity check %p failed with rc = %d\n",
-                               func, line, ext, rc);
+               OSC_EXTENT_DUMP_WITH_LOC(__FILE__, func, line, D_ERROR, ext,
+                                        "sanity check %p failed: rc = %d\n",
+                                        ext, rc);
        return rc;
 }
 
@@ -280,6 +278,11 @@ out:
        __res;                                                                 \
 })
 
+static inline bool
+overlapped(const struct osc_extent *ex1, const struct osc_extent *ex2)
+{
+       return !(ex1->oe_end < ex2->oe_start || ex2->oe_end < ex1->oe_start);
+}
 
 /**
  * sanity check - to make sure there is no overlapped extent in the tree.
@@ -289,7 +292,7 @@ static int osc_extent_is_overlapped(struct osc_object *obj,
 {
        struct osc_extent *tmp;
 
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
 
        if (!extent_debug)
                return 0;
@@ -297,8 +300,7 @@ static int osc_extent_is_overlapped(struct osc_object *obj,
        for (tmp = first_extent(obj); tmp != NULL; tmp = next_extent(tmp)) {
                if (tmp == ext)
                        continue;
-               if (tmp->oe_end >= ext->oe_start &&
-                   tmp->oe_start <= ext->oe_end)
+               if (overlapped(tmp, ext))
                        return 1;
        }
        return 0;
@@ -306,15 +308,15 @@ static int osc_extent_is_overlapped(struct osc_object *obj,
 
 static void osc_extent_state_set(struct osc_extent *ext, int state)
 {
-       LASSERT(osc_object_is_locked(ext->oe_obj));
+       assert_osc_object_is_locked(ext->oe_obj);
        LASSERT(state >= OES_INV && state < OES_STATE_MAX);
 
        /* Never try to sanity check a state changing extent :-) */
        /* LASSERT(sanity_check_nolock(ext) == 0); */
 
        /* TODO: validate the state machine */
-       ext->oe_state = state;
-       wake_up_all(&ext->oe_waitq);
+       smp_store_release(&ext->oe_state, state);
+       wake_up(&ext->oe_waitq);
 }
 
 static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
@@ -328,7 +330,7 @@ static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
        RB_CLEAR_NODE(&ext->oe_node);
        ext->oe_obj = obj;
        cl_object_get(osc2cl(obj));
-       atomic_set(&ext->oe_refc, 1);
+       kref_init(&ext->oe_refc);
        atomic_set(&ext->oe_users, 0);
        INIT_LIST_HEAD(&ext->oe_link);
        ext->oe_state = OES_INV;
@@ -339,35 +341,50 @@ static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
        return ext;
 }
 
-static void osc_extent_free(struct osc_extent *ext)
+static void osc_extent_free(struct kref *kref)
 {
+       struct osc_extent *ext = container_of(kref, struct osc_extent,
+                                             oe_refc);
+
+       LASSERT(list_empty(&ext->oe_link));
+       LASSERT(atomic_read(&ext->oe_users) == 0);
+       LASSERT(ext->oe_state == OES_INV);
+       LASSERT(RB_EMPTY_NODE(&ext->oe_node));
+
+       if (ext->oe_dlmlock) {
+               lu_ref_del(&ext->oe_dlmlock->l_reference,
+                          "osc_extent", ext);
+               LDLM_LOCK_PUT(ext->oe_dlmlock);
+               ext->oe_dlmlock = NULL;
+       }
+#if 0
+       /* If/When cl_object_put drops the need for 'env',
+        * this code can be enabled, and matching code in
+        * osc_extent_put removed.
+        */
+       cl_object_put(osc2cl(ext->oe_obj));
+
        OBD_SLAB_FREE_PTR(ext, osc_extent_kmem);
+#endif
 }
 
 static struct osc_extent *osc_extent_get(struct osc_extent *ext)
 {
-       LASSERT(atomic_read(&ext->oe_refc) >= 0);
-       atomic_inc(&ext->oe_refc);
+       LASSERT(kref_read(&ext->oe_refc) >= 0);
+       kref_get(&ext->oe_refc);
        return ext;
 }
 
 static void osc_extent_put(const struct lu_env *env, struct osc_extent *ext)
 {
-       LASSERT(atomic_read(&ext->oe_refc) > 0);
-       if (atomic_dec_and_test(&ext->oe_refc)) {
-               LASSERT(list_empty(&ext->oe_link));
-               LASSERT(atomic_read(&ext->oe_users) == 0);
-               LASSERT(ext->oe_state == OES_INV);
-               LASSERT(!ext->oe_intree);
-
-               if (ext->oe_dlmlock != NULL) {
-                       lu_ref_add(&ext->oe_dlmlock->l_reference,
-                                  "osc_extent", ext);
-                       LDLM_LOCK_PUT(ext->oe_dlmlock);
-                       ext->oe_dlmlock = NULL;
-               }
+       LASSERT(kref_read(&ext->oe_refc) > 0);
+       if (kref_put(&ext->oe_refc, osc_extent_free)) {
+               /* This should be in osc_extent_free(), but
+                * while we need to pass 'env' it cannot be.
+                */
                cl_object_put(env, osc2cl(ext->oe_obj));
-               osc_extent_free(ext);
+
+               OBD_SLAB_FREE_PTR(ext, osc_extent_kmem);
        }
 }
 
@@ -378,9 +395,9 @@ static void osc_extent_put(const struct lu_env *env, struct osc_extent *ext)
  */
 static void osc_extent_put_trust(struct osc_extent *ext)
 {
-       LASSERT(atomic_read(&ext->oe_refc) > 1);
-       LASSERT(osc_object_is_locked(ext->oe_obj));
-       atomic_dec(&ext->oe_refc);
+       LASSERT(kref_read(&ext->oe_refc) > 1);
+       assert_osc_object_is_locked(ext->oe_obj);
+       osc_extent_put(NULL, ext);
 }
 
 /**
@@ -393,7 +410,7 @@ static struct osc_extent *osc_extent_search(struct osc_object *obj,
        struct rb_node    *n = obj->oo_root.rb_node;
        struct osc_extent *tmp, *p = NULL;
 
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
        while (n != NULL) {
                tmp = rb_extent(n);
                if (index < tmp->oe_start) {
@@ -430,9 +447,9 @@ static void osc_extent_insert(struct osc_object *obj, struct osc_extent *ext)
        struct rb_node    *parent = NULL;
        struct osc_extent *tmp;
 
-       LASSERT(ext->oe_intree == 0);
+       LASSERT(RB_EMPTY_NODE(&ext->oe_node));
        LASSERT(ext->oe_obj == obj);
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
        while (*n != NULL) {
                tmp = rb_extent(*n);
                parent = *n;
@@ -447,17 +464,16 @@ static void osc_extent_insert(struct osc_object *obj, struct osc_extent *ext)
        rb_link_node(&ext->oe_node, parent, n);
        rb_insert_color(&ext->oe_node, &obj->oo_root);
        osc_extent_get(ext);
-       ext->oe_intree = 1;
 }
 
 /* caller must have held object lock. */
 static void osc_extent_erase(struct osc_extent *ext)
 {
        struct osc_object *obj = ext->oe_obj;
-       LASSERT(osc_object_is_locked(obj));
-       if (ext->oe_intree) {
+       assert_osc_object_is_locked(obj);
+       if (!RB_EMPTY_NODE(&ext->oe_node)) {
                rb_erase(&ext->oe_node, &obj->oo_root);
-               ext->oe_intree = 0;
+               RB_CLEAR_NODE(&ext->oe_node);
                /* rbtree held a refcount */
                osc_extent_put_trust(ext);
        }
@@ -467,7 +483,7 @@ static struct osc_extent *osc_extent_hold(struct osc_extent *ext)
 {
        struct osc_object *obj = ext->oe_obj;
 
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
        LASSERT(ext->oe_state == OES_ACTIVE || ext->oe_state == OES_CACHE);
        if (ext->oe_state == OES_CACHE) {
                osc_extent_state_set(ext, OES_ACTIVE);
@@ -480,7 +496,7 @@ static struct osc_extent *osc_extent_hold(struct osc_extent *ext)
 
 static void __osc_extent_remove(struct osc_extent *ext)
 {
-       LASSERT(osc_object_is_locked(ext->oe_obj));
+       assert_osc_object_is_locked(ext->oe_obj);
        LASSERT(list_empty(&ext->oe_pages));
        osc_extent_erase(ext);
        list_del_init(&ext->oe_link);
@@ -511,7 +527,7 @@ static int osc_extent_merge(const struct lu_env *env, struct osc_extent *cur,
        int                      ppc_bits;
 
        LASSERT(cur->oe_state == OES_CACHE);
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
        if (victim == NULL)
                return -EINVAL;
 
@@ -521,6 +537,14 @@ static int osc_extent_merge(const struct lu_env *env, struct osc_extent *cur,
        if (cur->oe_max_end != victim->oe_max_end)
                return -ERANGE;
 
+       /*
+        * In the rare case max_pages_per_rpc (mppr) is changed, don't
+        * merge extents until after old ones have been sent, or the
+        * "extents are aligned to RPCs" checks are unhappy.
+        */
+       if (cur->oe_mppr != victim->oe_mppr)
+               return -ERANGE;
+
        LASSERT(cur->oe_dlmlock == victim->oe_dlmlock);
        ppc_bits = osc_cli(obj)->cl_chunkbits - PAGE_SHIFT;
        chunk_start = cur->oe_start >> ppc_bits;
@@ -546,7 +570,6 @@ static int osc_extent_merge(const struct lu_env *env, struct osc_extent *cur,
        cur->oe_urgent   |= victim->oe_urgent;
        cur->oe_memalloc |= victim->oe_memalloc;
        list_splice_init(&victim->oe_pages, &cur->oe_pages);
-       list_del_init(&victim->oe_link);
        victim->oe_nr_pages = 0;
 
        osc_extent_get(victim);
@@ -579,6 +602,7 @@ int osc_extent_release(const struct lu_env *env, struct osc_extent *ext)
                         * osc_cache_truncate_start(). */
                        osc_extent_state_set(ext, OES_TRUNC);
                        ext->oe_trunc_pending = 0;
+                       osc_object_unlock(obj);
                } else {
                        int grant = 0;
 
@@ -591,18 +615,21 @@ int osc_extent_release(const struct lu_env *env, struct osc_extent *ext)
                                grant += cli->cl_grant_extent_tax;
                        if (osc_extent_merge(env, ext, next_extent(ext)) == 0)
                                grant += cli->cl_grant_extent_tax;
-                       if (grant > 0)
-                               osc_unreserve_grant(cli, 0, grant);
 
-                       if (ext->oe_urgent)
+                       if (ext->oe_hp)
+                               list_move_tail(&ext->oe_link,
+                                              &obj->oo_hp_exts);
+                       else if (ext->oe_urgent)
                                list_move_tail(&ext->oe_link,
                                               &obj->oo_urgent_exts);
                        else if (ext->oe_nr_pages == ext->oe_mppr) {
                                list_move_tail(&ext->oe_link,
                                               &obj->oo_full_exts);
                        }
+                       osc_object_unlock(obj);
+                       if (grant > 0)
+                               osc_unreserve_grant(cli, 0, grant);
                }
-               osc_object_unlock(obj);
 
                osc_io_unplug_async(env, cli, obj);
        }
@@ -610,11 +637,6 @@ int osc_extent_release(const struct lu_env *env, struct osc_extent *ext)
        RETURN(rc);
 }
 
-static inline int overlapped(struct osc_extent *ex1, struct osc_extent *ex2)
-{
-       return !(ex1->oe_end < ex2->oe_start || ex2->oe_end < ex1->oe_start);
-}
-
 /**
  * Find or create an extent which includes @index, core function to manage
  * extent tree.
@@ -675,7 +697,7 @@ static struct osc_extent *osc_extent_find(const struct lu_env *env,
                cur->oe_start = descr->cld_start;
        if (cur->oe_end > max_end)
                cur->oe_end = max_end;
-       cur->oe_grants  = 0;
+       cur->oe_grants  = chunksize + cli->cl_grant_extent_tax;
        cur->oe_mppr    = max_pages;
        if (olck->ols_dlmlock != NULL) {
                LASSERT(olck->ols_hold);
@@ -692,11 +714,11 @@ static struct osc_extent *osc_extent_find(const struct lu_env *env,
 restart:
        osc_object_lock(obj);
        ext = osc_extent_search(obj, cur->oe_start);
-       if (ext == NULL)
+       if (!ext)
                ext = first_extent(obj);
-       while (ext != NULL) {
+       for (; ext; ext = next_extent(ext)) {
                pgoff_t ext_chk_start = ext->oe_start >> ppc_bits;
-               pgoff_t ext_chk_end   = ext->oe_end   >> ppc_bits;
+               pgoff_t ext_chk_end = ext->oe_end >> ppc_bits;
 
                LASSERT(sanity_check_nolock(ext) == 0);
                if (chunk > ext_chk_end + 1 || chunk < ext_chk_start)
@@ -707,15 +729,12 @@ restart:
                        EASSERTF(!overlapped(ext, cur), ext,
                                 EXTSTR"\n", EXTPARA(cur));
 
-                       ext = next_extent(ext);
                        continue;
                }
 
                /* discontiguous chunks? */
-               if (chunk + 1 < ext_chk_start) {
-                       ext = next_extent(ext);
+               if (chunk + 1 < ext_chk_start)
                        continue;
-               }
 
                /* ok, from now on, ext and cur have these attrs:
                 * 1. covered by the same lock
@@ -740,68 +759,27 @@ restart:
                }
 
                /* non-overlapped extent */
-               if (ext->oe_state != OES_CACHE || ext->oe_fsync_wait) {
+               if (ext->oe_state != OES_CACHE || ext->oe_fsync_wait)
                        /* we can't do anything for a non OES_CACHE extent, or
                         * if there is someone waiting for this extent to be
                         * flushed, try next one. */
-                       ext = next_extent(ext);
-                       continue;
-               }
-
-               /* check if they belong to the same rpc slot before trying to
-                * merge. the extents are not overlapped and contiguous at
-                * chunk level to get here. */
-               if (ext->oe_max_end != max_end) {
-                       /* if they don't belong to the same RPC slot or
-                        * max_pages_per_rpc has ever changed, do not merge. */
-                       ext = next_extent(ext);
                        continue;
-               }
-
-               /* check whether maximum extent size will be hit */
-               if ((ext_chk_end - ext_chk_start + 1 + 1) << ppc_bits >
-                   cli->cl_max_extent_pages) {
-                       ext = next_extent(ext);
-                       continue;
-               }
-
-               /* it's required that an extent must be contiguous at chunk
-                * level so that we know the whole extent is covered by grant
-                * (the pages in the extent are NOT required to be contiguous).
-                * Otherwise, it will be too much difficult to know which
-                * chunks have grants allocated. */
 
-               /* try to do front merge - extend ext's start */
-               if (chunk + 1 == ext_chk_start) {
-                       /* ext must be chunk size aligned */
-                       EASSERT((ext->oe_start & ~chunk_mask) == 0, ext);
-
-                       /* pull ext's start back to cover cur */
-                       ext->oe_start   = cur->oe_start;
-                       ext->oe_grants += chunksize;
+               if (osc_extent_merge(env, ext, cur) == 0) {
                        LASSERT(*grants >= chunksize);
                        *grants -= chunksize;
-
                        found = osc_extent_hold(ext);
-               } else if (chunk == ext_chk_end + 1) {
-                       /* rear merge */
-                       ext->oe_end     = cur->oe_end;
-                       ext->oe_grants += chunksize;
-                       LASSERT(*grants >= chunksize);
-                       *grants -= chunksize;
 
-                       /* try to merge with the next one because we just fill
-                        * in a gap */
+                       /*
+                        * Try to merge with the next one too because we
+                        * might have just filled in a gap.
+                        */
                        if (osc_extent_merge(env, ext, next_extent(ext)) == 0)
                                /* we can save extent tax from next extent */
                                *grants += cli->cl_grant_extent_tax;
 
-                       found = osc_extent_hold(ext);
-               }
-               if (found != NULL)
                        break;
-
-               ext = next_extent(ext);
+               }
        }
 
        osc_extent_tree_dump(D_CACHE, obj);
@@ -815,7 +793,6 @@ restart:
        } else if (conflict == NULL) {
                /* create a new extent */
                EASSERT(osc_extent_is_overlapped(obj, cur) == 0, cur);
-               cur->oe_grants = chunksize + cli->cl_grant_extent_tax;
                LASSERT(*grants >= cur->oe_grants);
                *grants -= cur->oe_grants;
 
@@ -907,17 +884,6 @@ int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext,
        RETURN(0);
 }
 
-static int extent_wait_cb(struct osc_extent *ext, enum osc_extent_state state)
-{
-       int ret;
-
-       osc_object_lock(ext->oe_obj);
-       ret = ext->oe_state == state;
-       osc_object_unlock(ext->oe_obj);
-
-       return ret;
-}
-
 /**
  * Wait for the extent's state to become @state.
  */
@@ -925,8 +891,6 @@ static int osc_extent_wait(const struct lu_env *env, struct osc_extent *ext,
                           enum osc_extent_state state)
 {
        struct osc_object *obj = ext->oe_obj;
-       struct l_wait_info lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(600), NULL,
-                                                 LWI_ON_SIGNAL_NOOP, NULL);
        int rc = 0;
        ENTRY;
 
@@ -948,18 +912,21 @@ static int osc_extent_wait(const struct lu_env *env, struct osc_extent *ext,
                osc_extent_release(env, ext);
 
        /* wait for the extent until its state becomes @state */
-       rc = l_wait_event(ext->oe_waitq, extent_wait_cb(ext, state), &lwi);
-       if (rc == -ETIMEDOUT) {
+       rc = wait_event_idle_timeout(ext->oe_waitq,
+                                    smp_load_acquire(&ext->oe_state) == state,
+                                    cfs_time_seconds(600));
+       if (rc == 0) {
                OSC_EXTENT_DUMP(D_ERROR, ext,
                        "%s: wait ext to %u timedout, recovery in progress?\n",
                        cli_name(osc_cli(obj)), state);
 
-               lwi = LWI_INTR(NULL, NULL);
-               rc = l_wait_event(ext->oe_waitq, extent_wait_cb(ext, state),
-                                 &lwi);
+               wait_event_idle(ext->oe_waitq,
+                               smp_load_acquire(&ext->oe_state) == state);
        }
-       if (rc == 0 && ext->oe_rc < 0)
+       if (ext->oe_rc < 0)
                rc = ext->oe_rc;
+       else
+               rc = 0;
        RETURN(rc);
 }
 
@@ -1228,34 +1195,34 @@ out:
        RETURN(rc);
 }
 
-static void osc_extent_tree_dump0(int level, struct osc_object *obj,
+static void osc_extent_tree_dump0(int mask, struct osc_object *obj,
                                  const char *func, int line)
 {
        struct osc_extent *ext;
        int cnt;
 
-       if (!cfs_cdebug_show(level, DEBUG_SUBSYSTEM))
+       if (!cfs_cdebug_show(mask, DEBUG_SUBSYSTEM))
                return;
 
-       CDEBUG(level, "Dump object %p extents at %s:%d, mppr: %u.\n",
+       CDEBUG(mask, "Dump object %p extents at %s:%d, mppr: %u.\n",
               obj, func, line, osc_cli(obj)->cl_max_pages_per_rpc);
 
        /* osc_object_lock(obj); */
        cnt = 1;
        for (ext = first_extent(obj); ext != NULL; ext = next_extent(ext))
-               OSC_EXTENT_DUMP(level, ext, "in tree %d.\n", cnt++);
+               OSC_EXTENT_DUMP(mask, ext, "in tree %d.\n", cnt++);
 
        cnt = 1;
        list_for_each_entry(ext, &obj->oo_hp_exts, oe_link)
-               OSC_EXTENT_DUMP(level, ext, "hp %d.\n", cnt++);
+               OSC_EXTENT_DUMP(mask, ext, "hp %d.\n", cnt++);
 
        cnt = 1;
        list_for_each_entry(ext, &obj->oo_urgent_exts, oe_link)
-               OSC_EXTENT_DUMP(level, ext, "urgent %d.\n", cnt++);
+               OSC_EXTENT_DUMP(mask, ext, "urgent %d.\n", cnt++);
 
        cnt = 1;
        list_for_each_entry(ext, &obj->oo_reading_exts, oe_link)
-               OSC_EXTENT_DUMP(level, ext, "reading %d.\n", cnt++);
+               OSC_EXTENT_DUMP(mask, ext, "reading %d.\n", cnt++);
        /* osc_object_unlock(obj); */
 }
 
@@ -1321,7 +1288,7 @@ static int osc_refresh_count(const struct lu_env *env,
                return 0;
        else if (cl_offset(obj, index + 1) > kms)
                /* catch sub-page write at end of file */
-               return kms % PAGE_SIZE;
+               return kms & ~PAGE_MASK;
        else
                return PAGE_SIZE;
 }
@@ -1375,9 +1342,9 @@ static int osc_completion(const struct lu_env *env, struct osc_async_page *oap,
        RETURN(0);
 }
 
-#define OSC_DUMP_GRANT(lvl, cli, fmt, args...) do {                    \
+#define OSC_DUMP_GRANT(mask, cli, fmt, args...) do {                   \
        struct client_obd *__tmp = (cli);                               \
-       CDEBUG(lvl, "%s: grant { dirty: %ld/%ld dirty_pages: %ld/%lu "  \
+       CDEBUG(mask, "%s: grant { dirty: %ld/%ld dirty_pages: %ld/%lu " \
               "dropped: %ld avail: %ld, dirty_grant: %ld, "            \
               "reserved: %ld, flight: %d } lru {in list: %ld, "        \
               "left: %ld, waiters: %d }" fmt "\n",                     \
@@ -1398,7 +1365,6 @@ static void osc_consume_write_grant(struct client_obd *cli,
 {
        assert_spin_locked(&cli->cl_loi_list_lock);
        LASSERT(!(pga->flag & OBD_BRW_FROM_GRANT));
-       atomic_long_inc(&obd_dirty_pages);
        cli->cl_dirty_pages++;
        pga->flag |= OBD_BRW_FROM_GRANT;
        CDEBUG(D_CACHE, "using %lu grant credits for brw %p page %p\n",
@@ -1422,11 +1388,6 @@ static void osc_release_write_grant(struct client_obd *cli,
        pga->flag &= ~OBD_BRW_FROM_GRANT;
        atomic_long_dec(&obd_dirty_pages);
        cli->cl_dirty_pages--;
-       if (pga->flag & OBD_BRW_NOCACHE) {
-               pga->flag &= ~OBD_BRW_NOCACHE;
-               atomic_long_dec(&obd_dirty_transit_pages);
-               cli->cl_dirty_transit--;
-       }
        EXIT;
 }
 
@@ -1466,13 +1427,20 @@ static void __osc_unreserve_grant(struct client_obd *cli,
        }
 }
 
-static void osc_unreserve_grant(struct client_obd *cli,
-                               unsigned int reserved, unsigned int unused)
+static void osc_unreserve_grant_nolock(struct client_obd *cli,
+                                      unsigned int reserved,
+                                      unsigned int unused)
 {
-       spin_lock(&cli->cl_loi_list_lock);
        __osc_unreserve_grant(cli, reserved, unused);
        if (unused > 0)
                osc_wake_cache_waiters(cli);
+}
+
+static void osc_unreserve_grant(struct client_obd *cli,
+                               unsigned int reserved, unsigned int unused)
+{
+       spin_lock(&cli->cl_loi_list_lock);
+       osc_unreserve_grant_nolock(cli, reserved, unused);
        spin_unlock(&cli->cl_loi_list_lock);
 }
 
@@ -1532,7 +1500,7 @@ static void osc_exit_cache(struct client_obd *cli, struct osc_async_page *oap)
  */
 static int osc_enter_cache_try(struct client_obd *cli,
                               struct osc_async_page *oap,
-                              int bytes, int transient)
+                              int bytes)
 {
        int rc;
 
@@ -1542,31 +1510,41 @@ static int osc_enter_cache_try(struct client_obd *cli,
        if (rc < 0)
                return 0;
 
-       if (cli->cl_dirty_pages < cli->cl_dirty_max_pages &&
-           1 + atomic_long_read(&obd_dirty_pages) <= obd_max_dirty_pages) {
-               osc_consume_write_grant(cli, &oap->oap_brw_page);
-               if (transient) {
-                       cli->cl_dirty_transit++;
-                       atomic_long_inc(&obd_dirty_transit_pages);
-                       oap->oap_brw_flags |= OBD_BRW_NOCACHE;
-               }
-               rc = 1;
-       } else {
-               __osc_unreserve_grant(cli, bytes, bytes);
-               rc = 0;
+       if (cli->cl_dirty_pages < cli->cl_dirty_max_pages) {
+               if (atomic_long_add_return(1, &obd_dirty_pages) <=
+                   obd_max_dirty_pages) {
+                       osc_consume_write_grant(cli, &oap->oap_brw_page);
+                       rc = 1;
+                       goto out;
+               } else
+                       atomic_long_dec(&obd_dirty_pages);
        }
+       __osc_unreserve_grant(cli, bytes, bytes);
+
+out:
        return rc;
 }
 
-static int ocw_granted(struct client_obd *cli, struct osc_cache_waiter *ocw)
+/* Following two inlines exist to pass code fragments
+ * to wait_event_idle_exclusive_timeout_cmd().  Passing
+ * code fragments as macro args can look confusing, so
+ * we provide inlines to encapsulate them.
+ */
+static inline void cli_unlock_and_unplug(const struct lu_env *env,
+                                        struct client_obd *cli,
+                                        struct osc_async_page *oap)
 {
-       int rc;
-       spin_lock(&cli->cl_loi_list_lock);
-       rc = list_empty(&ocw->ocw_entry);
        spin_unlock(&cli->cl_loi_list_lock);
-       return rc;
+       osc_io_unplug_async(env, cli, NULL);
+       CDEBUG(D_CACHE,
+              "%s: sleeping for cache space for %p\n",
+              cli_name(cli), oap);
 }
 
+static inline void cli_lock_after_unplug(struct client_obd *cli)
+{
+       spin_lock(&cli->cl_loi_list_lock);
+}
 /**
  * The main entry to reserve dirty page accounting. Usually the grant reserved
  * in this function will be freed in bulk in osc_free_grant() unless it fails
@@ -1577,15 +1555,23 @@ static int ocw_granted(struct client_obd *cli, struct osc_cache_waiter *ocw)
 static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
                           struct osc_async_page *oap, int bytes)
 {
-       struct osc_object       *osc = oap->oap_obj;
-       struct lov_oinfo        *loi = osc->oo_oinfo;
-       struct osc_cache_waiter  ocw;
-       struct l_wait_info       lwi;
-       int                      rc = -EDQUOT;
-       ENTRY;
+       struct osc_object *osc = oap->oap_obj;
+       struct lov_oinfo *loi = osc->oo_oinfo;
+       int rc = -EDQUOT;
+       int remain;
+       bool entered = false;
+       /* We cannot wait for a long time here since we are holding ldlm lock
+        * across the actual IO. If no requests complete fast (e.g. due to
+        * overloaded OST that takes a long time to process everything, we'd
+        * get evicted if we wait for a normal obd_timeout or some such.
+        * So we try to wait half the time it would take the client to be
+        * evicted by server which is half obd_timeout when AT is off
+        * or at least ldlm_enqueue_min with AT on.
+        * See LU-13131 */
+       unsigned long timeout = cfs_time_seconds(AT_OFF ? obd_timeout / 2 :
+                                                         ldlm_enqueue_min / 2);
 
-       lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(AT_OFF ? obd_timeout : at_max),
-                              NULL, LWI_ON_SIGNAL_NOOP, NULL);
+       ENTRY;
 
        OSC_DUMP_GRANT(D_CACHE, cli, "need:%d\n", bytes);
 
@@ -1600,77 +1586,40 @@ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
                GOTO(out, rc = -EDQUOT);
        }
 
-       /* Hopefully normal case - cache space and write credits available */
-       if (list_empty(&cli->cl_cache_waiters) &&
-           osc_enter_cache_try(cli, oap, bytes, 0)) {
-               OSC_DUMP_GRANT(D_CACHE, cli, "granted from cache\n");
-               GOTO(out, rc = 0);
-       }
-
-       /* We can get here for two reasons: too many dirty pages in cache, or
+       /*
+        * We can wait here for two reasons: too many dirty pages in cache, or
         * run out of grants. In both cases we should write dirty pages out.
         * Adding a cache waiter will trigger urgent write-out no matter what
         * RPC size will be.
-        * The exiting condition is no avail grants and no dirty pages caching,
-        * that really means there is no space on the OST. */
-       init_waitqueue_head(&ocw.ocw_waitq);
-       ocw.ocw_oap   = oap;
-       ocw.ocw_grant = bytes;
-       while (cli->cl_dirty_pages > 0 || cli->cl_w_in_flight > 0) {
-               list_add_tail(&ocw.ocw_entry, &cli->cl_cache_waiters);
-               ocw.ocw_rc = 0;
-               spin_unlock(&cli->cl_loi_list_lock);
-
-               osc_io_unplug_async(env, cli, NULL);
-
-               CDEBUG(D_CACHE, "%s: sleeping for cache space @ %p for %p\n",
-                      cli_name(cli), &ocw, oap);
-
-               rc = l_wait_event(ocw.ocw_waitq, ocw_granted(cli, &ocw), &lwi);
-
-               spin_lock(&cli->cl_loi_list_lock);
-
-               if (rc < 0) {
-                       /* l_wait_event is interrupted by signal or timed out */
-                       list_del_init(&ocw.ocw_entry);
-                       break;
-               }
-               LASSERT(list_empty(&ocw.ocw_entry));
-               rc = ocw.ocw_rc;
-
-               if (rc != -EDQUOT)
-                       break;
-               if (osc_enter_cache_try(cli, oap, bytes, 0)) {
-                       rc = 0;
-                       break;
-               }
-       }
-
-       switch (rc) {
-       case 0:
-               OSC_DUMP_GRANT(D_CACHE, cli, "finally got grant space\n");
-               break;
-       case -ETIMEDOUT:
+        * The exiting condition (other than success) is no avail grants
+        * and no dirty pages caching, that really means there is no space
+        * on the OST.
+        */
+       remain = wait_event_idle_exclusive_timeout_cmd(
+               cli->cl_cache_waiters,
+               (entered = osc_enter_cache_try(cli, oap, bytes)) ||
+               (cli->cl_dirty_pages == 0 && cli->cl_w_in_flight == 0),
+               timeout,
+               cli_unlock_and_unplug(env, cli, oap),
+               cli_lock_after_unplug(cli));
+
+       if (entered) {
+               if (remain == timeout)
+                       OSC_DUMP_GRANT(D_CACHE, cli, "granted from cache\n");
+               else
+                       OSC_DUMP_GRANT(D_CACHE, cli,
+                                      "finally got grant space\n");
+               wake_up(&cli->cl_cache_waiters);
+               rc = 0;
+       } else if (remain == 0) {
                OSC_DUMP_GRANT(D_CACHE, cli,
                               "timeout, fall back to sync i/o\n");
                osc_extent_tree_dump(D_CACHE, osc);
                /* fall back to synchronous I/O */
-               rc = -EDQUOT;
-               break;
-       case -EINTR:
-               /* Ensures restartability - LU-3581 */
-               OSC_DUMP_GRANT(D_CACHE, cli, "interrupted\n");
-               rc = -ERESTARTSYS;
-               break;
-       case -EDQUOT:
+       } else {
                OSC_DUMP_GRANT(D_CACHE, cli,
                               "no grant space, fall back to sync i/o\n");
-               break;
-       default:
-               CDEBUG(D_CACHE, "%s: event for cache space @ %p never arrived "
-                      "due to %d, fall back to sync i/o\n",
-                      cli_name(cli), &ocw, rc);
-               break;
+               wake_up_all(&cli->cl_cache_waiters);
        }
        EXIT;
 out:
@@ -1678,36 +1627,6 @@ out:
        RETURN(rc);
 }
 
-/* caller must hold loi_list_lock */
-void osc_wake_cache_waiters(struct client_obd *cli)
-{
-       struct list_head *l, *tmp;
-       struct osc_cache_waiter *ocw;
-
-       ENTRY;
-       list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
-               ocw = list_entry(l, struct osc_cache_waiter, ocw_entry);
-
-               ocw->ocw_rc = -EDQUOT;
-
-               if (osc_enter_cache_try(cli, ocw->ocw_oap, ocw->ocw_grant, 0))
-                       ocw->ocw_rc = 0;
-
-               if (ocw->ocw_rc == 0 ||
-                   !(cli->cl_dirty_pages > 0 || cli->cl_w_in_flight > 0)) {
-                       list_del_init(&ocw->ocw_entry);
-                       CDEBUG(D_CACHE, "wake up %p for oap %p, avail grant "
-                              "%ld, %d\n", ocw, ocw->ocw_oap,
-                              cli->cl_avail_grant, ocw->ocw_rc);
-
-                       wake_up(&ocw->ocw_waitq);
-               }
-       }
-
-       EXIT;
-}
-EXPORT_SYMBOL(osc_wake_cache_waiters);
-
 static int osc_max_rpc_in_flight(struct client_obd *cli, struct osc_object *osc)
 {
        int hprpc = !!list_empty(&osc->oo_hp_exts);
@@ -1747,8 +1666,9 @@ static int osc_makes_rpc(struct client_obd *cli, struct osc_object *osc,
                }
                /* trigger a write rpc stream as long as there are dirtiers
                 * waiting for space.  as they're waiting, they're not going to
-                * create more pages to coalesce with what's waiting.. */
-               if (!list_empty(&cli->cl_cache_waiters)) {
+                * create more pages to coalesce with what's waiting..
+                */
+               if (waitqueue_active(&cli->cl_cache_waiters)) {
                        CDEBUG(D_CACHE, "cache waiters forcing RPC\n");
                        RETURN(1);
                }
@@ -1877,7 +1797,6 @@ static void osc_ap_completion(const struct lu_env *env, struct client_obd *cli,
        spin_lock(&oap->oap_lock);
        oap->oap_async_flags = 0;
        spin_unlock(&oap->oap_lock);
-       oap->oap_interrupted = 0;
 
        if (oap->oap_cmd & OBD_BRW_WRITE && xid > 0) {
                spin_lock(&cli->cl_loi_list_lock);
@@ -1910,6 +1829,34 @@ static inline unsigned osc_extent_chunks(const struct osc_extent *ext)
        return (ext->oe_end >> ppc_bits) - (ext->oe_start >> ppc_bits) + 1;
 }
 
+static inline bool
+can_merge(const struct osc_extent *ext, const struct osc_extent *in_rpc)
+{
+       if (ext->oe_no_merge || in_rpc->oe_no_merge)
+               return false;
+
+       if (ext->oe_srvlock != in_rpc->oe_srvlock)
+               return false;
+
+       if (ext->oe_ndelay != in_rpc->oe_ndelay)
+               return false;
+
+       if (!ext->oe_grants != !in_rpc->oe_grants)
+               return false;
+
+       if (ext->oe_dio != in_rpc->oe_dio)
+               return false;
+
+       /* It's possible to have overlap on DIO */
+       if (in_rpc->oe_dio && overlapped(ext, in_rpc))
+               return false;
+
+       if (ext->oe_is_rdma_only != in_rpc->oe_is_rdma_only)
+               return false;
+
+       return true;
+}
+
 /**
  * Try to add extent to one RPC. We need to think about the following things:
  * - # of pages must not be over max_pages_per_rpc
@@ -1921,9 +1868,6 @@ static int try_to_add_extent_for_io(struct client_obd *cli,
 {
        struct osc_extent *tmp;
        unsigned int chunk_count;
-       struct osc_async_page *oap = list_first_entry(&ext->oe_pages,
-                                                     struct osc_async_page,
-                                                     oap_pending_item);
        ENTRY;
 
        EASSERT((ext->oe_state == OES_CACHE || ext->oe_state == OES_LOCK_DONE),
@@ -1952,30 +1896,10 @@ static int try_to_add_extent_for_io(struct client_obd *cli,
                RETURN(0);
 
        list_for_each_entry(tmp, data->erd_rpc_list, oe_link) {
-               struct osc_async_page *oap2;
-               oap2 = list_first_entry(&tmp->oe_pages, struct osc_async_page,
-                                       oap_pending_item);
                EASSERT(tmp->oe_owner == current, tmp);
-#if 0
-               if (overlapped(tmp, ext)) {
-                       OSC_EXTENT_DUMP(D_ERROR, tmp, "overlapped %p.\n", ext);
-                       EASSERT(0, ext);
-               }
-#endif
-               if (oap2cl_page(oap)->cp_type != oap2cl_page(oap2)->cp_type) {
-                       CDEBUG(D_CACHE, "Do not permit different types of IO "
-                              "in one RPC\n");
-                       RETURN(0);
-               }
 
-               if (tmp->oe_srvlock != ext->oe_srvlock ||
-                   !tmp->oe_grants != !ext->oe_grants ||
-                   tmp->oe_ndelay != ext->oe_ndelay ||
-                   tmp->oe_no_merge || ext->oe_no_merge)
+               if (!can_merge(ext, tmp))
                        RETURN(0);
-
-               /* remove break for strict check */
-               break;
        }
 
        data->erd_max_extents--;
@@ -2012,11 +1936,10 @@ static unsigned int get_write_extents(struct osc_object *obj,
                .erd_max_extents = 256,
        };
 
-       LASSERT(osc_object_is_locked(obj));
+       assert_osc_object_is_locked(obj);
        while (!list_empty(&obj->oo_hp_exts)) {
                ext = list_entry(obj->oo_hp_exts.next, struct osc_extent,
                                 oe_link);
-               LASSERT(ext->oe_state == OES_CACHE);
                if (!try_to_add_extent_for_io(cli, ext, &data))
                        return data.erd_page_count;
                EASSERT(ext->oe_nr_pages <= data.erd_max_pages, ext);
@@ -2047,19 +1970,16 @@ static unsigned int get_write_extents(struct osc_object *obj,
        if (data.erd_page_count == data.erd_max_pages)
                return data.erd_page_count;
 
-       ext = first_extent(obj);
-       while (ext != NULL) {
+       for (ext = first_extent(obj);
+            ext;
+            ext = next_extent(ext)) {
                if ((ext->oe_state != OES_CACHE) ||
                    /* this extent may be already in current rpclist */
-                   (!list_empty(&ext->oe_link) && ext->oe_owner != NULL)) {
-                       ext = next_extent(ext);
+                   (!list_empty(&ext->oe_link) && ext->oe_owner))
                        continue;
-               }
 
                if (!try_to_add_extent_for_io(cli, ext, &data))
                        return data.erd_page_count;
-
-               ext = next_extent(ext);
        }
        return data.erd_page_count;
 }
@@ -2069,7 +1989,7 @@ osc_send_write_rpc(const struct lu_env *env, struct client_obd *cli,
                   struct osc_object *osc)
 __must_hold(osc)
 {
-       struct list_head   rpclist = LIST_HEAD_INIT(rpclist);
+       LIST_HEAD(rpclist);
        struct osc_extent *ext;
        struct osc_extent *tmp;
        struct osc_extent *first = NULL;
@@ -2078,7 +1998,7 @@ __must_hold(osc)
        int rc = 0;
        ENTRY;
 
-       LASSERT(osc_object_is_locked(osc));
+       assert_osc_object_is_locked(osc);
 
        page_count = get_write_extents(osc, &rpclist);
        LASSERT(equi(page_count == 0, list_empty(&rpclist)));
@@ -2145,7 +2065,7 @@ __must_hold(osc)
 {
        struct osc_extent *ext;
        struct osc_extent *next;
-       struct list_head rpclist = LIST_HEAD_INIT(rpclist);
+       LIST_HEAD(rpclist);
        struct extent_rpc_data data = {
                .erd_rpc_list   = &rpclist,
                .erd_page_count = 0,
@@ -2156,7 +2076,7 @@ __must_hold(osc)
        int rc = 0;
        ENTRY;
 
-       LASSERT(osc_object_is_locked(osc));
+       assert_osc_object_is_locked(osc);
        list_for_each_entry_safe(ext, next, &osc->oo_reading_exts, oe_link) {
                EASSERT(ext->oe_state == OES_LOCK_DONE, ext);
                if (!try_to_add_extent_for_io(cli, ext, &data))
@@ -2202,8 +2122,9 @@ static struct osc_object *osc_next_obj(struct client_obd *cli)
        /* then if we have cache waiters, return all objects with queued
         * writes.  This is especially important when many small files
         * have filled up the cache and not been fired into rpcs because
-        * they don't pass the nr_pending/object threshhold */
-       if (!list_empty(&cli->cl_cache_waiters) &&
+        * they don't pass the nr_pending/object threshhold
+        */
+       if (waitqueue_active(&cli->cl_cache_waiters) &&
            !list_empty(&cli->cl_loi_write_list))
                RETURN(list_to_obj(&cli->cl_loi_write_list, write_item));
 
@@ -2234,7 +2155,12 @@ __must_hold(&cli->cl_loi_list_lock)
 
                OSC_IO_DEBUG(osc, "%lu in flight\n", rpcs_in_flight(cli));
 
-               if (osc_max_rpc_in_flight(cli, osc)) {
+               /* even if we have reached our max in flight RPCs, we still
+                * allow all high-priority RPCs through to prevent their
+                * starvation and leading to server evicting us for not
+                * writing out pages in a timely manner LU-13131 */
+               if (osc_max_rpc_in_flight(cli, osc) &&
+                   list_empty(&osc->oo_hp_exts)) {
                        __osc_list_maint(cli, osc);
                        break;
                }
@@ -2328,9 +2254,6 @@ int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops,
        oap->oap_obj_off = offset;
        LASSERT(!(offset & ~PAGE_MASK));
 
-       if (cfs_capable(CFS_CAP_SYS_RESOURCE))
-               oap->oap_brw_flags = OBD_BRW_NOQUOTA;
-
        INIT_LIST_HEAD(&oap->oap_pending_item);
        INIT_LIST_HEAD(&oap->oap_rpc_item);
 
@@ -2342,13 +2265,14 @@ int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops,
 EXPORT_SYMBOL(osc_prep_async_page);
 
 int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
-                      struct osc_page *ops)
+                      struct osc_page *ops, cl_commit_cbt cb)
 {
        struct osc_io *oio = osc_env_io(env);
        struct osc_extent     *ext = NULL;
        struct osc_async_page *oap = &ops->ops_oap;
        struct client_obd     *cli = oap->oap_cli;
        struct osc_object     *osc = oap->oap_obj;
+       struct pagevec        *pvec = &osc_env_info(env)->oti_pagevec;
        pgoff_t index;
        unsigned int tmp;
        unsigned int grants = 0;
@@ -2370,7 +2294,7 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
 
        /* Set the OBD_BRW_SRVLOCK before the page is queued. */
        brw_flags |= ops->ops_srvlock ? OBD_BRW_SRVLOCK : 0;
-       if (cfs_capable(CFS_CAP_SYS_RESOURCE)) {
+       if (oio->oi_cap_sys_resource || io->ci_noquota) {
                brw_flags |= OBD_BRW_NOQUOTA;
                cmd |= OBD_BRW_NOQUOTA;
        }
@@ -2391,7 +2315,7 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
                qid[USRQUOTA] = attr->cat_uid;
                qid[GRPQUOTA] = attr->cat_gid;
                qid[PRJQUOTA] = attr->cat_projid;
-               if (rc == 0 && osc_quota_chkdq(cli, qid) == NO_QUOTA)
+               if (rc == 0 && osc_quota_chkdq(cli, qid) == -EDQUOT)
                        rc = -EDQUOT;
                if (rc)
                        RETURN(rc);
@@ -2399,7 +2323,7 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
 
        oap->oap_cmd = cmd;
        oap->oap_page_off = ops->ops_from;
-       oap->oap_count = ops->ops_to - ops->ops_from;
+       oap->oap_count = ops->ops_to - ops->ops_from + 1;
        /* No need to hold a lock here,
         * since this page is not in any list yet. */
        oap->oap_async_flags = 0;
@@ -2426,8 +2350,7 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
 
                /* it doesn't need any grant to dirty this page */
                spin_lock(&cli->cl_loi_list_lock);
-               rc = osc_enter_cache_try(cli, oap, grants, 0);
-               spin_unlock(&cli->cl_loi_list_lock);
+               rc = osc_enter_cache_try(cli, oap, grants);
                if (rc == 0) { /* try failed */
                        grants = 0;
                        need_release = 1;
@@ -2441,10 +2364,11 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
                        } else {
                                OSC_EXTENT_DUMP(D_CACHE, ext,
                                                "expanded for %lu.\n", index);
-                               osc_unreserve_grant(cli, grants, tmp);
+                               osc_unreserve_grant_nolock(cli, grants, tmp);
                                grants = 0;
                        }
                }
+               spin_unlock(&cli->cl_loi_list_lock);
                rc = 0;
        } else if (ext != NULL) {
                /* index is located outside of active extent */
@@ -2467,7 +2391,14 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
 
                rc = 0;
                if (grants == 0) {
-                       /* we haven't allocated grant for this page. */
+                       /* We haven't allocated grant for this page, and we
+                        * must not hold a page lock while we do enter_cache,
+                        * so we must mark dirty & unlock any pages in the
+                        * write commit pagevec. */
+                       if (pagevec_count(pvec)) {
+                               cb(env, io, pvec);
+                               pagevec_reinit(pvec);
+                       }
                        rc = osc_enter_cache(env, cli, oap, tmp);
                        if (rc == 0)
                                grants = tmp;
@@ -2606,7 +2537,7 @@ int osc_flush_async_page(const struct lu_env *env, struct cl_io *io,
        oap->oap_async_flags |= ASYNC_READY|ASYNC_URGENT;
        spin_unlock(&oap->oap_lock);
 
-       if (memory_pressure_get())
+       if (current->flags & PF_MEMALLOC)
                ext->oe_memalloc = 1;
 
        ext->oe_urgent = 1;
@@ -2628,71 +2559,6 @@ out:
        return rc;
 }
 
-/**
- * this is called when a sync waiter receives an interruption.  Its job is to
- * get the caller woken as soon as possible.  If its page hasn't been put in an
- * rpc yet it can dequeue immediately.  Otherwise it has to mark the rpc as
- * desiring interruption which will forcefully complete the rpc once the rpc
- * has timed out.
- */
-int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops)
-{
-       struct osc_async_page *oap = &ops->ops_oap;
-       struct osc_object     *obj = oap->oap_obj;
-       struct client_obd     *cli = osc_cli(obj);
-       struct osc_extent     *ext;
-       struct osc_extent     *found = NULL;
-       struct list_head            *plist;
-       pgoff_t index = osc_index(ops);
-       int     rc = -EBUSY;
-       int     cmd;
-       ENTRY;
-
-       LASSERT(!oap->oap_interrupted);
-       oap->oap_interrupted = 1;
-
-       /* Find out the caching extent */
-       osc_object_lock(obj);
-       if (oap->oap_cmd & OBD_BRW_WRITE) {
-               plist = &obj->oo_urgent_exts;
-               cmd   = OBD_BRW_WRITE;
-       } else {
-               plist = &obj->oo_reading_exts;
-               cmd   = OBD_BRW_READ;
-       }
-       list_for_each_entry(ext, plist, oe_link) {
-               if (ext->oe_start <= index && ext->oe_end >= index) {
-                       LASSERT(ext->oe_state == OES_LOCK_DONE);
-                       /* For OES_LOCK_DONE state extent, it has already held
-                        * a refcount for RPC. */
-                       found = osc_extent_get(ext);
-                       break;
-               }
-       }
-       if (found != NULL) {
-               list_del_init(&found->oe_link);
-               osc_update_pending(obj, cmd, -found->oe_nr_pages);
-               osc_object_unlock(obj);
-
-               osc_extent_finish(env, found, 0, -EINTR);
-               osc_extent_put(env, found);
-               rc = 0;
-       } else {
-               osc_object_unlock(obj);
-               /* ok, it's been put in an rpc. only one oap gets a request
-                * reference */
-               if (oap->oap_request != NULL) {
-                       ptlrpc_mark_interrupted(oap->oap_request);
-                       ptlrpcd_wake(oap->oap_request);
-                       ptlrpc_req_finished(oap->oap_request);
-                       oap->oap_request = NULL;
-               }
-       }
-
-       osc_list_maint(cli, obj);
-       RETURN(rc);
-}
-
 int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
                         struct osc_object *obj, struct list_head *list,
                         int brw_flags)
@@ -2718,7 +2584,8 @@ int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
                ++page_count;
                mppr <<= (page_count > mppr);
 
-               if (unlikely(opg->ops_from > 0 || opg->ops_to < PAGE_SIZE))
+               if (unlikely(opg->ops_from > 0 ||
+                            opg->ops_to < PAGE_SIZE - 1))
                        can_merge = false;
        }
 
@@ -2742,6 +2609,8 @@ int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
        ext->oe_obj = obj;
        ext->oe_srvlock = !!(brw_flags & OBD_BRW_SRVLOCK);
        ext->oe_ndelay = !!(brw_flags & OBD_BRW_NDELAY);
+       ext->oe_dio = !!(brw_flags & OBD_BRW_NOCACHE);
+       ext->oe_is_rdma_only = !!(brw_flags & OBD_BRW_RDMA_ONLY);
        ext->oe_nr_pages = page_count;
        ext->oe_mppr = mppr;
        list_splice_init(list, &ext->oe_pages);
@@ -2751,7 +2620,21 @@ int osc_queue_sync_pages(const struct lu_env *env, const struct cl_io *io,
        /* Reuse the initial refcount for RPC, don't drop it */
        osc_extent_state_set(ext, OES_LOCK_DONE);
        if (!ext->oe_rw) { /* write */
-               list_add_tail(&ext->oe_link, &obj->oo_urgent_exts);
+               if (!ext->oe_srvlock && !ext->oe_dio) {
+                       /* The most likely case here is from lack of grants
+                        * so we are either out of quota or out of space.
+                        * Since this means we are holding locks across
+                        * potentially multi-striped IO, we must send out
+                        * everything out instantly to avoid prolonged
+                        * waits resulting in lock eviction (likely since
+                        * the extended wait in osc_cache_enter() did not
+                        * yield any additional grant due to a timeout.
+                        * LU-13131 */
+                       ext->oe_hp = 1;
+                       list_add_tail(&ext->oe_link, &obj->oo_hp_exts);
+               } else {
+                       list_add_tail(&ext->oe_link, &obj->oo_urgent_exts);
+               }
                osc_update_pending(obj, OBD_BRW_WRITE, page_count);
        } else {
                list_add_tail(&ext->oe_link, &obj->oo_reading_exts);
@@ -2773,7 +2656,7 @@ int osc_cache_truncate_start(const struct lu_env *env, struct osc_object *obj,
        struct osc_extent *ext;
        struct osc_extent *waiting = NULL;
        pgoff_t index;
-       struct list_head list = LIST_HEAD_INIT(list);
+       LIST_HEAD(list);
        int result = 0;
        bool partial;
        ENTRY;
@@ -2991,7 +2874,7 @@ int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
                              pgoff_t start, pgoff_t end, int hp, int discard)
 {
        struct osc_extent *ext;
-       struct list_head discard_list = LIST_HEAD_INIT(discard_list);
+       LIST_HEAD(discard_list);
        bool unplug = false;
        int result = 0;
        ENTRY;
@@ -3016,7 +2899,7 @@ int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
                                        EASSERT(!ext->oe_hp, ext);
                                        ext->oe_hp = 1;
                                        list = &obj->oo_hp_exts;
-                               } else if (!ext->oe_urgent) {
+                               } else if (!ext->oe_urgent && !ext->oe_hp) {
                                        ext->oe_urgent = 1;
                                        list = &obj->oo_urgent_exts;
                                }
@@ -3024,10 +2907,25 @@ int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
                                        list_move_tail(&ext->oe_link, list);
                                unplug = true;
                        } else {
+                               struct client_obd *cli = osc_cli(obj);
+                               int pcc_bits = cli->cl_chunkbits - PAGE_SHIFT;
+                               pgoff_t align_by = (1 << pcc_bits);
+                               pgoff_t a_start = round_down(start, align_by);
+                               pgoff_t a_end = round_up(end, align_by);
+
+                               /* overflow case */
+                               if (end && !a_end)
+                                       a_end = CL_PAGE_EOF;
                                /* the only discarder is lock cancelling, so
-                                * [start, end] must contain this extent */
-                               EASSERT(ext->oe_start >= start &&
-                                       ext->oe_max_end <= end, ext);
+                                * [start, end], aligned by chunk size, must
+                                * contain this extent */
+                               LASSERTF(ext->oe_start >= a_start &&
+                                        ext->oe_end <= a_end,
+                                        "ext [%lu, %lu] reg [%lu, %lu] "
+                                        "orig [%lu %lu] align %lu bits "
+                                        "%d\n", ext->oe_start, ext->oe_end,
+                                        a_start, a_end, start, end,
+                                        align_by, pcc_bits);
                                osc_extent_state_set(ext, OES_LOCKING);
                                ext->oe_owner = current;
                                list_move_tail(&ext->oe_link,
@@ -3098,18 +2996,14 @@ EXPORT_SYMBOL(osc_cache_writeback_range);
 /**
  * Returns a list of pages by a given [start, end] of \a obj.
  *
- * \param resched If not NULL, then we give up before hogging CPU for too
- * long and set *resched = 1, in that case caller should implement a retry
- * logic.
- *
  * Gang tree lookup (radix_tree_gang_lookup()) optimization is absolutely
  * crucial in the face of [offset, EOF] locks.
  *
  * Return at least one page in @queue unless there is no covered page.
  */
-int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
-                       struct osc_object *osc, pgoff_t start, pgoff_t end,
-                       osc_page_gang_cbt cb, void *cbdata)
+bool osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
+                         struct osc_object *osc, pgoff_t start, pgoff_t end,
+                         osc_page_gang_cbt cb, void *cbdata)
 {
        struct osc_page *ops;
        struct pagevec  *pagevec;
@@ -3118,7 +3012,7 @@ int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
        unsigned int    nr;
        unsigned int    i;
        unsigned int    j;
-       int             res = CLP_GANG_OKAY;
+       bool            res = true;
        bool            tree_lock = true;
        ENTRY;
 
@@ -3167,7 +3061,7 @@ int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
 
                for (i = 0; i < j; ++i) {
                        ops = pvec[i];
-                       if (res == CLP_GANG_OKAY)
+                       if (res)
                                res = (*cb)(env, io, ops, cbdata);
 
                        page = ops->ops_cl.cpl_page;
@@ -3179,10 +3073,10 @@ int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
                if (nr < OTI_PVEC_SIZE || end_of_region)
                        break;
 
-               if (res == CLP_GANG_OKAY && need_resched())
-                       res = CLP_GANG_RESCHED;
-               if (res != CLP_GANG_OKAY)
+               if (!res)
                        break;
+               if (need_resched())
+                       cond_resched();
 
                spin_lock(&osc->oo_tree_lock);
                tree_lock = true;
@@ -3196,7 +3090,7 @@ EXPORT_SYMBOL(osc_page_gang_lookup);
 /**
  * Check if page @page is covered by an extra lock or discard it.
  */
-static int check_and_discard_cb(const struct lu_env *env, struct cl_io *io,
+static bool check_and_discard_cb(const struct lu_env *env, struct cl_io *io,
                                struct osc_page *ops, void *cbdata)
 {
        struct osc_thread_info *info = osc_env_info(env);
@@ -3231,10 +3125,10 @@ static int check_and_discard_cb(const struct lu_env *env, struct cl_io *io,
        }
 
        info->oti_next_index = index + 1;
-       return CLP_GANG_OKAY;
+       return true;
 }
 
-int osc_discard_cb(const struct lu_env *env, struct cl_io *io,
+bool osc_discard_cb(const struct lu_env *env, struct cl_io *io,
                   struct osc_page *ops, void *cbdata)
 {
        struct osc_thread_info *info = osc_env_info(env);
@@ -3255,7 +3149,7 @@ int osc_discard_cb(const struct lu_env *env, struct cl_io *io,
                LASSERT(page->cp_state == CPS_FREEING);
        }
 
-       return CLP_GANG_OKAY;
+       return true;
 }
 EXPORT_SYMBOL(osc_discard_cb);
 
@@ -3273,7 +3167,6 @@ int osc_lock_discard_pages(const struct lu_env *env, struct osc_object *osc,
        struct osc_thread_info *info = osc_env_info(env);
        struct cl_io *io = osc_env_thread_io(env);
        osc_page_gang_cbt cb;
-       int res;
        int result;
 
        ENTRY;
@@ -3286,15 +3179,9 @@ int osc_lock_discard_pages(const struct lu_env *env, struct osc_object *osc,
 
        cb = discard ? osc_discard_cb : check_and_discard_cb;
        info->oti_fn_index = info->oti_next_index = start;
-       do {
-               res = osc_page_gang_lookup(env, io, osc,
-                                          info->oti_next_index, end, cb, osc);
-               if (info->oti_next_index > end)
-                       break;
 
-               if (res == CLP_GANG_RESCHED)
-                       cond_resched();
-       } while (res != CLP_GANG_OKAY);
+       osc_page_gang_lookup(env, io, osc,
+                            info->oti_next_index, end, cb, osc);
 out:
        cl_io_fini(env, io);
        RETURN(result);