Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "New features for 3.12:

   - Added aggressive extent caching using the extent status tree.  This
     can actually decrease memory usage in read-mostly workloads since
     the information is much more compactly stored in the extent status
     tree than if we had to keep the extent tree metadata blocks in the
     buffer cache.  This also improves Asynchronous I/O since it is it
     makes much less likely that we need to do metadata I/O to lookup
     the extent tree information.

   - Improve the recovery after corrupted allocation bitmaps are found
     when running in errors=ignore mode.

  Also fixed some writeback vs truncate races when using a blocksize
  less than the page size"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: allow specifying external journal by pathname mount option
  ext4: mark group corrupt on group descriptor checksum
  ext4: mark block group as corrupt on inode bitmap error
  ext4: mark block group as corrupt on block bitmap error
  ext4: fix type declaration of ext4_validate_block_bitmap
  ext4: error out if verifying the block bitmap fails
  jbd2: Fix endian mixing problems in the checksumming code
  ext4: isolate ext4_extents.h file
  ext4: Fix misspellings using 'codespell' tool
  ext4: convert write_begin methods to stable_page_writes semantics
  ext4: fix use of potentially uninitialized variables in debugging code
  ext4: fix lost truncate due to race with writeback
  ext4: simplify truncation code in ext4_setattr()
  ext4: fix ext4_writepages() in presence of truncate
  ext4: move test whether extent to map can be extended to one place
  ext4: fix warning in ext4_da_update_reserve_space()
  quota: provide interface for readding allocated space into reserved space
  ext4: avoid reusing recently deleted inodes in no journal mode
  ext4: allocate delayed allocation blocks before rename
  ext4: start handle at least possible moment when renaming files
  ...

1 files changed, 87 insertions, 38 deletions

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 91cb110da1b4..2d1bdbe78c04 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -13,7 +13,6 @@
 #include <linux/list_sort.h>
 #include "ext4.h"
 #include "extents_status.h"
-#include "ext4_extents.h"
 
 #include <trace/events/ext4.h>
 
@@ -263,7 +262,7 @@ 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;
@@ -409,6 +408,8 @@ ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
 }
 
 #ifdef ES_AGGRESSIVE_TEST
+#include "ext4_extents.h"	/* Needed when ES_AGGRESSIVE_TEST is defined */
+
 static void ext4_es_insert_extent_ext_check(struct inode *inode,
 					    struct extent_status *es)
 {
@@ -419,7 +420,7 @@ 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;
 
@@ -641,13 +642,13 @@ out:
  */
 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)
@@ -684,6 +685,38 @@ error:
 }
 
 /*
+ * 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.
@@ -871,23 +904,6 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	return err;
 }
 
-int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
-{
-	ext4_lblk_t  ee_block;
-	ext4_fsblk_t ee_pblock;
-	unsigned int ee_len;
-
-	ee_block  = le32_to_cpu(ex->ee_block);
-	ee_len    = ext4_ext_get_actual_len(ex);
-	ee_pblock = ext4_ext_pblock(ex);
-
-	if (ee_len == 0)
-		return 0;
-
-	return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
-				     EXTENT_STATUS_WRITTEN);
-}
-
 static int ext4_inode_touch_time_cmp(void *priv, struct list_head *a,
 				     struct list_head *b)
 {
@@ -895,6 +911,12 @@ static int ext4_inode_touch_time_cmp(void *priv, struct list_head *a,
 	eia = list_entry(a, struct ext4_inode_info, i_es_lru);
 	eib = list_entry(b, struct ext4_inode_info, i_es_lru);
 
+	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))
@@ -908,21 +930,13 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
 {
 	struct ext4_inode_info *ei;
 	struct list_head *cur, *tmp;
-	LIST_HEAD(skiped);
+	LIST_HEAD(skipped);
 	int ret, nr_shrunk = 0;
+	int retried = 0, skip_precached = 1, nr_skipped = 0;
 
 	spin_lock(&sbi->s_es_lru_lock);
 
-	/*
-	 * If the inode that is at the head of LRU list is newer than
-	 * last_sorted time, that means that we need to sort this list.
-	 */
-	ei = list_first_entry(&sbi->s_es_lru, struct ext4_inode_info, i_es_lru);
-	if (sbi->s_es_last_sorted < ei->i_touch_when) {
-		list_sort(NULL, &sbi->s_es_lru, ext4_inode_touch_time_cmp);
-		sbi->s_es_last_sorted = jiffies;
-	}
-
+retry:
 	list_for_each_safe(cur, tmp, &sbi->s_es_lru) {
 		/*
 		 * If we have already reclaimed all extents from extent
@@ -933,9 +947,16 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
 
 		ei = list_entry(cur, struct ext4_inode_info, i_es_lru);
 
-		/* Skip the inode that is newer than the last_sorted time */
-		if (sbi->s_es_last_sorted < ei->i_touch_when) {
-			list_move_tail(cur, &skiped);
+		/*
+		 * 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, &skipped);
 			continue;
 		}
 
@@ -955,11 +976,33 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
 	}
 
 	/* Move the newer inodes into the tail of the LRU list. */
-	list_splice_tail(&skiped, &sbi->s_es_lru);
+	list_splice_tail(&skipped, &sbi->s_es_lru);
+	INIT_LIST_HEAD(&skipped);
+
+	/*
+	 * 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(ei, nr_to_scan);
+		nr_shrunk = __es_try_to_reclaim_extents(locked_ei, nr_to_scan);
 
 	return nr_shrunk;
 }
@@ -1034,10 +1077,16 @@ 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);