1 files changed, 171 insertions, 47 deletions

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index e6941e622d31..00e6589ee7d2 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -10,6 +10,7 @@
  * Ext4 extents status tree core functions.
  */
 #include <linux/rbtree.h>
+#include <linux/list_sort.h>
 #include "ext4.h"
 #include "extents_status.h"
 #include "ext4_extents.h"
@@ -147,6 +148,8 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 			      ext4_lblk_t end);
 static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
 				       int nr_to_scan);
+static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
+			    struct ext4_inode_info *locked_ei);
 
 int __init ext4_init_es(void)
 {
@@ -260,7 +263,7 @@ void ext4_es_find_delayed_extent_range(struct inode *inode,
 	if (tree->cache_es) {
 		es1 = tree->cache_es;
 		if (in_range(lblk, es1->es_lblk, es1->es_len)) {
-			es_debug("%u cached by [%u/%u) %llu %llx\n",
+			es_debug("%u cached by [%u/%u) %llu %x\n",
 				 lblk, es1->es_lblk, es1->es_len,
 				 ext4_es_pblock(es1), ext4_es_status(es1));
 			goto out;
@@ -291,7 +294,6 @@ out:
 
 	read_unlock(&EXT4_I(inode)->i_es_lock);
 
-	ext4_es_lru_add(inode);
 	trace_ext4_es_find_delayed_extent_range_exit(inode, es);
 }
 
@@ -417,7 +419,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
 	unsigned short ee_len;
 	int depth, ee_status, es_status;
 
-	path = ext4_ext_find_extent(inode, es->es_lblk, NULL);
+	path = ext4_ext_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
 	if (IS_ERR(path))
 		return;
 
@@ -439,7 +441,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
 		 */
 		if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
 			if (in_range(es->es_lblk, ee_block, ee_len)) {
-				pr_warn("ES insert assertation failed for "
+				pr_warn("ES insert assertion failed for "
 					"inode: %lu we can find an extent "
 					"at block [%d/%d/%llu/%c], but we "
 					"want to add an delayed/hole extent "
@@ -458,7 +460,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
 		 */
 		if (es->es_lblk < ee_block ||
 		    ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
-			pr_warn("ES insert assertation failed for inode: %lu "
+			pr_warn("ES insert assertion failed for inode: %lu "
 				"ex_status [%d/%d/%llu/%c] != "
 				"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
 				ee_block, ee_len, ee_start,
@@ -468,7 +470,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
 		}
 
 		if (ee_status ^ es_status) {
-			pr_warn("ES insert assertation failed for inode: %lu "
+			pr_warn("ES insert assertion failed for inode: %lu "
 				"ex_status [%d/%d/%llu/%c] != "
 				"es_status [%d/%d/%llu/%c]\n", inode->i_ino,
 				ee_block, ee_len, ee_start,
@@ -481,7 +483,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
 		 * that we don't want to add an written/unwritten extent.
 		 */
 		if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
-			pr_warn("ES insert assertation failed for inode: %lu "
+			pr_warn("ES insert assertion failed for inode: %lu "
 				"can't find an extent at block %d but we want "
 				"to add an written/unwritten extent "
 				"[%d/%d/%llu/%llx]\n", inode->i_ino,
@@ -519,7 +521,7 @@ static void ext4_es_insert_extent_ind_check(struct inode *inode,
 			 * We want to add a delayed/hole extent but this
 			 * block has been allocated.
 			 */
-			pr_warn("ES insert assertation failed for inode: %lu "
+			pr_warn("ES insert assertion failed for inode: %lu "
 				"We can find blocks but we want to add a "
 				"delayed/hole extent [%d/%d/%llu/%llx]\n",
 				inode->i_ino, es->es_lblk, es->es_len,
@@ -527,13 +529,13 @@ static void ext4_es_insert_extent_ind_check(struct inode *inode,
 			return;
 		} else if (ext4_es_is_written(es)) {
 			if (retval != es->es_len) {
-				pr_warn("ES insert assertation failed for "
+				pr_warn("ES insert assertion failed for "
 					"inode: %lu retval %d != es_len %d\n",
 					inode->i_ino, retval, es->es_len);
 				return;
 			}
 			if (map.m_pblk != ext4_es_pblock(es)) {
-				pr_warn("ES insert assertation failed for "
+				pr_warn("ES insert assertion failed for "
 					"inode: %lu m_pblk %llu != "
 					"es_pblk %llu\n",
 					inode->i_ino, map.m_pblk,
@@ -549,7 +551,7 @@ static void ext4_es_insert_extent_ind_check(struct inode *inode,
 		}
 	} else if (retval == 0) {
 		if (ext4_es_is_written(es)) {
-			pr_warn("ES insert assertation failed for inode: %lu "
+			pr_warn("ES insert assertion failed for inode: %lu "
 				"We can't find the block but we want to add "
 				"an written extent [%d/%d/%llu/%llx]\n",
 				inode->i_ino, es->es_lblk, es->es_len,
@@ -632,22 +634,20 @@ out:
 }
 
 /*
- * ext4_es_insert_extent() adds a space to a extent status tree.
- *
- * ext4_es_insert_extent is called by ext4_da_write_begin and
- * ext4_es_remove_extent.
+ * ext4_es_insert_extent() adds information to an inode's extent
+ * status tree.
  *
  * Return 0 on success, error code on failure.
  */
 int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 			  ext4_lblk_t len, ext4_fsblk_t pblk,
-			  unsigned long long status)
+			  unsigned int status)
 {
 	struct extent_status newes;
 	ext4_lblk_t end = lblk + len - 1;
 	int err = 0;
 
-	es_debug("add [%u/%u) %llu %llx to extent status tree of inode %lu\n",
+	es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
 		 lblk, len, pblk, status, inode->i_ino);
 
 	if (!len)
@@ -667,18 +667,55 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 	err = __es_remove_extent(inode, lblk, end);
 	if (err != 0)
 		goto error;
+retry:
 	err = __es_insert_extent(inode, &newes);
+	if (err == -ENOMEM && __ext4_es_shrink(EXT4_SB(inode->i_sb), 1,
+					       EXT4_I(inode)))
+		goto retry;
+	if (err == -ENOMEM && !ext4_es_is_delayed(&newes))
+		err = 0;
 
 error:
 	write_unlock(&EXT4_I(inode)->i_es_lock);
 
-	ext4_es_lru_add(inode);
 	ext4_es_print_tree(inode);
 
 	return err;
 }
 
 /*
+ * ext4_es_cache_extent() inserts information into the extent status
+ * tree if and only if there isn't information about the range in
+ * question already.
+ */
+void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
+			  ext4_lblk_t len, ext4_fsblk_t pblk,
+			  unsigned int status)
+{
+	struct extent_status *es;
+	struct extent_status newes;
+	ext4_lblk_t end = lblk + len - 1;
+
+	newes.es_lblk = lblk;
+	newes.es_len = len;
+	ext4_es_store_pblock(&newes, pblk);
+	ext4_es_store_status(&newes, status);
+	trace_ext4_es_cache_extent(inode, &newes);
+
+	if (!len)
+		return;
+
+	BUG_ON(end < lblk);
+
+	write_lock(&EXT4_I(inode)->i_es_lock);
+
+	es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
+	if (!es || es->es_lblk > end)
+		__es_insert_extent(inode, &newes);
+	write_unlock(&EXT4_I(inode)->i_es_lock);
+}
+
+/*
  * ext4_es_lookup_extent() looks up an extent in extent status tree.
  *
  * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
@@ -734,7 +771,6 @@ out:
 
 	read_unlock(&EXT4_I(inode)->i_es_lock);
 
-	ext4_es_lru_add(inode);
 	trace_ext4_es_lookup_extent_exit(inode, es, found);
 	return found;
 }
@@ -748,8 +784,10 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	struct extent_status orig_es;
 	ext4_lblk_t len1, len2;
 	ext4_fsblk_t block;
-	int err = 0;
+	int err;
 
+retry:
+	err = 0;
 	es = __es_tree_search(&tree->root, lblk);
 	if (!es)
 		goto out;
@@ -784,6 +822,10 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 			if (err) {
 				es->es_lblk = orig_es.es_lblk;
 				es->es_len = orig_es.es_len;
+				if ((err == -ENOMEM) &&
+				    __ext4_es_shrink(EXT4_SB(inode->i_sb), 1,
+						     EXT4_I(inode)))
+					goto retry;
 				goto out;
 			}
 		} else {
@@ -878,38 +920,69 @@ int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
 				     EXTENT_STATUS_WRITTEN);
 }
 
-static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static int ext4_inode_touch_time_cmp(void *priv, struct list_head *a,
+				     struct list_head *b)
 {
-	struct ext4_sb_info *sbi = container_of(shrink,
-					struct ext4_sb_info, s_es_shrinker);
-	struct ext4_inode_info *ei;
-	struct list_head *cur, *tmp, scanned;
-	int nr_to_scan = sc->nr_to_scan;
-	int ret, nr_shrunk = 0;
+	struct ext4_inode_info *eia, *eib;
+	eia = list_entry(a, struct ext4_inode_info, i_es_lru);
+	eib = list_entry(b, struct ext4_inode_info, i_es_lru);
 
-	ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
-	trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
-
-	if (!nr_to_scan)
-		return ret;
+	if (ext4_test_inode_state(&eia->vfs_inode, EXT4_STATE_EXT_PRECACHED) &&
+	    !ext4_test_inode_state(&eib->vfs_inode, EXT4_STATE_EXT_PRECACHED))
+		return 1;
+	if (!ext4_test_inode_state(&eia->vfs_inode, EXT4_STATE_EXT_PRECACHED) &&
+	    ext4_test_inode_state(&eib->vfs_inode, EXT4_STATE_EXT_PRECACHED))
+		return -1;
+	if (eia->i_touch_when == eib->i_touch_when)
+		return 0;
+	if (time_after(eia->i_touch_when, eib->i_touch_when))
+		return 1;
+	else
+		return -1;
+}
 
-	INIT_LIST_HEAD(&scanned);
+static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
+			    struct ext4_inode_info *locked_ei)
+{
+	struct ext4_inode_info *ei;
+	struct list_head *cur, *tmp;
+	LIST_HEAD(skiped);
+	int ret, nr_shrunk = 0;
+	int retried = 0, skip_precached = 1, nr_skipped = 0;
 
 	spin_lock(&sbi->s_es_lru_lock);
+
+retry:
 	list_for_each_safe(cur, tmp, &sbi->s_es_lru) {
-		list_move_tail(cur, &scanned);
+		/*
+		 * If we have already reclaimed all extents from extent
+		 * status tree, just stop the loop immediately.
+		 */
+		if (percpu_counter_read_positive(&sbi->s_extent_cache_cnt) == 0)
+			break;
 
 		ei = list_entry(cur, struct ext4_inode_info, i_es_lru);
 
-		read_lock(&ei->i_es_lock);
-		if (ei->i_es_lru_nr == 0) {
-			read_unlock(&ei->i_es_lock);
+		/*
+		 * Skip the inode that is newer than the last_sorted
+		 * time.  Normally we try hard to avoid shrinking
+		 * precached inodes, but we will as a last resort.
+		 */
+		if ((sbi->s_es_last_sorted < ei->i_touch_when) ||
+		    (skip_precached && ext4_test_inode_state(&ei->vfs_inode,
+						EXT4_STATE_EXT_PRECACHED))) {
+			nr_skipped++;
+			list_move_tail(cur, &skiped);
 			continue;
 		}
-		read_unlock(&ei->i_es_lock);
+
+		if (ei->i_es_lru_nr == 0 || ei == locked_ei)
+			continue;
 
 		write_lock(&ei->i_es_lock);
 		ret = __es_try_to_reclaim_extents(ei, nr_to_scan);
+		if (ei->i_es_lru_nr == 0)
+			list_del_init(&ei->i_es_lru);
 		write_unlock(&ei->i_es_lock);
 
 		nr_shrunk += ret;
@@ -917,29 +990,71 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
 		if (nr_to_scan == 0)
 			break;
 	}
-	list_splice_tail(&scanned, &sbi->s_es_lru);
+
+	/* Move the newer inodes into the tail of the LRU list. */
+	list_splice_tail(&skiped, &sbi->s_es_lru);
+
+	/*
+	 * If we skipped any inodes, and we weren't able to make any
+	 * forward progress, sort the list and try again.
+	 */
+	if ((nr_shrunk == 0) && nr_skipped && !retried) {
+		retried++;
+		list_sort(NULL, &sbi->s_es_lru, ext4_inode_touch_time_cmp);
+		sbi->s_es_last_sorted = jiffies;
+		ei = list_first_entry(&sbi->s_es_lru, struct ext4_inode_info,
+				      i_es_lru);
+		/*
+		 * If there are no non-precached inodes left on the
+		 * list, start releasing precached extents.
+		 */
+		if (ext4_test_inode_state(&ei->vfs_inode,
+					  EXT4_STATE_EXT_PRECACHED))
+			skip_precached = 0;
+		goto retry;
+	}
+
 	spin_unlock(&sbi->s_es_lru_lock);
 
+	if (locked_ei && nr_shrunk == 0)
+		nr_shrunk = __es_try_to_reclaim_extents(locked_ei, nr_to_scan);
+
+	return nr_shrunk;
+}
+
+static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct ext4_sb_info *sbi = container_of(shrink,
+					struct ext4_sb_info, s_es_shrinker);
+	int nr_to_scan = sc->nr_to_scan;
+	int ret, nr_shrunk;
+
+	ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
+	trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
+
+	if (!nr_to_scan)
+		return ret;
+
+	nr_shrunk = __ext4_es_shrink(sbi, nr_to_scan, NULL);
+
 	ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
 	trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
 	return ret;
 }
 
-void ext4_es_register_shrinker(struct super_block *sb)
+void ext4_es_register_shrinker(struct ext4_sb_info *sbi)
 {
-	struct ext4_sb_info *sbi;
-
-	sbi = EXT4_SB(sb);
 	INIT_LIST_HEAD(&sbi->s_es_lru);
 	spin_lock_init(&sbi->s_es_lru_lock);
+	sbi->s_es_last_sorted = 0;
 	sbi->s_es_shrinker.shrink = ext4_es_shrink;
 	sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
 	register_shrinker(&sbi->s_es_shrinker);
 }
 
-void ext4_es_unregister_shrinker(struct super_block *sb)
+void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
 {
-	unregister_shrinker(&EXT4_SB(sb)->s_es_shrinker);
+	unregister_shrinker(&sbi->s_es_shrinker);
 }
 
 void ext4_es_lru_add(struct inode *inode)
@@ -947,11 +1062,14 @@ void ext4_es_lru_add(struct inode *inode)
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 
+	ei->i_touch_when = jiffies;
+
+	if (!list_empty(&ei->i_es_lru))
+		return;
+
 	spin_lock(&sbi->s_es_lru_lock);
 	if (list_empty(&ei->i_es_lru))
 		list_add_tail(&ei->i_es_lru, &sbi->s_es_lru);
-	else
-		list_move_tail(&ei->i_es_lru, &sbi->s_es_lru);
 	spin_unlock(&sbi->s_es_lru_lock);
 }
 
@@ -974,10 +1092,16 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
 	struct rb_node *node;
 	struct extent_status *es;
 	int nr_shrunk = 0;
+	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+				      DEFAULT_RATELIMIT_BURST);
 
 	if (ei->i_es_lru_nr == 0)
 		return 0;
 
+	if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
+	    __ratelimit(&_rs))
+		ext4_warning(inode->i_sb, "forced shrink of precached extents");
+
 	node = rb_first(&tree->root);
 	while (node != NULL) {
 		es = rb_entry(node, struct extent_status, rb_node);