Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: extent macros cleanup
  Fix compilation with EXT_DEBUG, also fix leXX_to_cpu conversions.
  ext4: remove extra IS_RDONLY() check
  ext4: Use is_power_of_2()
  Use zero_user_page() in ext4 where possible
  ext4: Remove 65000 subdirectory limit
  ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields 
  ext4: Add nanosecond timestamps
  jbd2: Move jbd2-debug file to debugfs
  jbd2: Fix CONFIG_JBD_DEBUG ifdef to be CONFIG_JBD2_DEBUG
  ext4: Set the journal JBD2_FEATURE_INCOMPAT_64BIT on large devices
  ext4: Make extents code sanely handle on-disk corruption
  ext4: copy i_flags to inode flags on write
  ext4: Enable extents by default
  Change on-disk format to support 2^15 uninitialized extents
  write support for preallocated blocks
  fallocate support in ext4
  sys_fallocate() implementation on i386, x86_64 and powerpc

14 files changed, 1143 insertions, 248 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 613df554728..6a649902c5a 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -251,7 +251,7 @@ config JBD2
 
 config JBD2_DEBUG
 	bool "JBD2 (ext4dev/ext4) debugging support"
-	depends on JBD2
+	depends on JBD2 && DEBUG_FS
 	help
 	  If you are using the ext4dev/ext4 journaled file system (or
 	  potentially any other filesystem/device using JBD2), this option
@@ -260,10 +260,10 @@ config JBD2_DEBUG
 	  By default, the debugging output will be turned off.
 
 	  If you select Y here, then you will be able to turn on debugging
-	  with "echo N > /proc/sys/fs/jbd2-debug", where N is a number between
-	  1 and 5. The higher the number, the more debugging output is
-	  generated.  To turn debugging off again, do
-	  "echo 0 > /proc/sys/fs/jbd2-debug".
+	  with "echo N > /sys/kernel/debug/jbd2/jbd2-debug", where N is a
+	  number between 1 and 5. The higher the number, the more debugging
+	  output is generated.  To turn debugging off again, do
+	  "echo 0 > /sys/kernel/debug/jbd2/jbd2-debug".
 
 config FS_MBCACHE
 # Meta block cache for Extended Attributes (ext2/ext3/ext4)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 9de54ae48de..e53b4af52f1 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -517,7 +517,7 @@ do_more:
 		/*
 		 * An HJ special.  This is expensive...
 		 */
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 		jbd_unlock_bh_state(bitmap_bh);
 		{
 			struct buffer_head *debug_bh;
@@ -1597,7 +1597,7 @@ allocated:
 
 	performed_allocation = 1;
 
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	{
 		struct buffer_head *debug_bh;
 
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index b9ce2412907..750c46f7d89 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -39,6 +39,7 @@
 #include <linux/quotaops.h>
 #include <linux/string.h>
 #include <linux/slab.h>
+#include <linux/falloc.h>
 #include <linux/ext4_fs_extents.h>
 #include <asm/uaccess.h>
 
@@ -91,36 +92,6 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
 	ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
-static int ext4_ext_check_header(const char *function, struct inode *inode,
-				struct ext4_extent_header *eh)
-{
-	const char *error_msg = NULL;
-
-	if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
-		error_msg = "invalid magic";
-		goto corrupted;
-	}
-	if (unlikely(eh->eh_max == 0)) {
-		error_msg = "invalid eh_max";
-		goto corrupted;
-	}
-	if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
-		error_msg = "invalid eh_entries";
-		goto corrupted;
-	}
-	return 0;
-
-corrupted:
-	ext4_error(inode->i_sb, function,
-			"bad header in inode #%lu: %s - magic %x, "
-			"entries %u, max %u, depth %u",
-			inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
-			le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
-			le16_to_cpu(eh->eh_depth));
-
-	return -EIO;
-}
-
 static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
 {
 	int err;
@@ -269,6 +240,70 @@ static int ext4_ext_space_root_idx(struct inode *inode)
 	return size;
 }
 
+static int
+ext4_ext_max_entries(struct inode *inode, int depth)
+{
+	int max;
+
+	if (depth == ext_depth(inode)) {
+		if (depth == 0)
+			max = ext4_ext_space_root(inode);
+		else
+			max = ext4_ext_space_root_idx(inode);
+	} else {
+		if (depth == 0)
+			max = ext4_ext_space_block(inode);
+		else
+			max = ext4_ext_space_block_idx(inode);
+	}
+
+	return max;
+}
+
+static int __ext4_ext_check_header(const char *function, struct inode *inode,
+					struct ext4_extent_header *eh,
+					int depth)
+{
+	const char *error_msg;
+	int max = 0;
+
+	if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
+		error_msg = "invalid magic";
+		goto corrupted;
+	}
+	if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
+		error_msg = "unexpected eh_depth";
+		goto corrupted;
+	}
+	if (unlikely(eh->eh_max == 0)) {
+		error_msg = "invalid eh_max";
+		goto corrupted;
+	}
+	max = ext4_ext_max_entries(inode, depth);
+	if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
+		error_msg = "too large eh_max";
+		goto corrupted;
+	}
+	if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
+		error_msg = "invalid eh_entries";
+		goto corrupted;
+	}
+	return 0;
+
+corrupted:
+	ext4_error(inode->i_sb, function,
+			"bad header in inode #%lu: %s - magic %x, "
+			"entries %u, max %u(%u), depth %u(%u)",
+			inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
+			le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
+			max, le16_to_cpu(eh->eh_depth), depth);
+
+	return -EIO;
+}
+
+#define ext4_ext_check_header(inode, eh, depth)	\
+	__ext4_ext_check_header(__FUNCTION__, inode, eh, depth)
+
 #ifdef EXT_DEBUG
 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 {
@@ -282,7 +317,7 @@ static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 		} else if (path->p_ext) {
 			ext_debug("  %d:%d:%llu ",
 				  le32_to_cpu(path->p_ext->ee_block),
-				  le16_to_cpu(path->p_ext->ee_len),
+				  ext4_ext_get_actual_len(path->p_ext),
 				  ext_pblock(path->p_ext));
 		} else
 			ext_debug("  []");
@@ -305,7 +340,7 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 
 	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
 		ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
-			  le16_to_cpu(ex->ee_len), ext_pblock(ex));
+			  ext4_ext_get_actual_len(ex), ext_pblock(ex));
 	}
 	ext_debug("\n");
 }
@@ -329,6 +364,7 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path)
 /*
  * ext4_ext_binsearch_idx:
  * binary search for the closest index of the given block
+ * the header must be checked before calling this
  */
 static void
 ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block)
@@ -336,27 +372,25 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
 	struct ext4_extent_header *eh = path->p_hdr;
 	struct ext4_extent_idx *r, *l, *m;
 
-	BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
-	BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-	BUG_ON(le16_to_cpu(eh->eh_entries) <= 0);
 
 	ext_debug("binsearch for %d(idx):  ", block);
 
 	l = EXT_FIRST_INDEX(eh) + 1;
-	r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1;
+	r = EXT_LAST_INDEX(eh);
 	while (l <= r) {
 		m = l + (r - l) / 2;
 		if (block < le32_to_cpu(m->ei_block))
 			r = m - 1;
 		else
 			l = m + 1;
-		ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block,
-				m, m->ei_block, r, r->ei_block);
+		ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
+				m, le32_to_cpu(m->ei_block),
+				r, le32_to_cpu(r->ei_block));
 	}
 
 	path->p_idx = l - 1;
 	ext_debug("  -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
-		  idx_block(path->p_idx));
+		  idx_pblock(path->p_idx));
 
 #ifdef CHECK_BINSEARCH
 	{
@@ -388,6 +422,7 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
 /*
  * ext4_ext_binsearch:
  * binary search for closest extent of the given block
+ * the header must be checked before calling this
  */
 static void
 ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
@@ -395,9 +430,6 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
 	struct ext4_extent_header *eh = path->p_hdr;
 	struct ext4_extent *r, *l, *m;
 
-	BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
-	BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-
 	if (eh->eh_entries == 0) {
 		/*
 		 * this leaf is empty:
@@ -409,7 +441,7 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
 	ext_debug("binsearch for %d:  ", block);
 
 	l = EXT_FIRST_EXTENT(eh) + 1;
-	r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1;
+	r = EXT_LAST_EXTENT(eh);
 
 	while (l <= r) {
 		m = l + (r - l) / 2;
@@ -417,15 +449,16 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
 			r = m - 1;
 		else
 			l = m + 1;
-		ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block,
-				m, m->ee_block, r, r->ee_block);
+		ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
+				m, le32_to_cpu(m->ee_block),
+				r, le32_to_cpu(r->ee_block));
 	}
 
 	path->p_ext = l - 1;
 	ext_debug("  -> %d:%llu:%d ",
 			le32_to_cpu(path->p_ext->ee_block),
 			ext_pblock(path->p_ext),
-			le16_to_cpu(path->p_ext->ee_len));
+			ext4_ext_get_actual_len(path->p_ext));
 
 #ifdef CHECK_BINSEARCH
 	{
@@ -468,11 +501,10 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
 	short int depth, i, ppos = 0, alloc = 0;
 
 	eh = ext_inode_hdr(inode);
-	BUG_ON(eh == NULL);
-	if (ext4_ext_check_header(__FUNCTION__, inode, eh))
+	depth = ext_depth(inode);
+	if (ext4_ext_check_header(inode, eh, depth))
 		return ERR_PTR(-EIO);
 
-	i = depth = ext_depth(inode);
 
 	/* account possible depth increase */
 	if (!path) {
@@ -484,10 +516,12 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
 	}
 	path[0].p_hdr = eh;
 
+	i = depth;
 	/* walk through the tree */
 	while (i) {
 		ext_debug("depth %d: num %d, max %d\n",
 			  ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+
 		ext4_ext_binsearch_idx(inode, path + ppos, block);
 		path[ppos].p_block = idx_pblock(path[ppos].p_idx);
 		path[ppos].p_depth = i;
@@ -504,7 +538,7 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
 		path[ppos].p_hdr = eh;
 		i--;
 
-		if (ext4_ext_check_header(__FUNCTION__, inode, eh))
+		if (ext4_ext_check_header(inode, eh, i))
 			goto err;
 	}
 
@@ -513,9 +547,6 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
 	path[ppos].p_ext = NULL;
 	path[ppos].p_idx = NULL;
 
-	if (ext4_ext_check_header(__FUNCTION__, inode, eh))
-		goto err;
-
 	/* find extent */
 	ext4_ext_binsearch(inode, path + ppos, block);
 
@@ -553,7 +584,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
 			len = (len - 1) * sizeof(struct ext4_extent_idx);
 			len = len < 0 ? 0 : len;
-			ext_debug("insert new index %d after: %d. "
+			ext_debug("insert new index %d after: %llu. "
 					"move %d from 0x%p to 0x%p\n",
 					logical, ptr, len,
 					(curp->p_idx + 1), (curp->p_idx + 2));
@@ -564,7 +595,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		/* insert before */
 		len = len * sizeof(struct ext4_extent_idx);
 		len = len < 0 ? 0 : len;
-		ext_debug("insert new index %d before: %d. "
+		ext_debug("insert new index %d before: %llu. "
 				"move %d from 0x%p to 0x%p\n",
 				logical, ptr, len,
 				curp->p_idx, (curp->p_idx + 1));
@@ -686,7 +717,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		ext_debug("move %d:%llu:%d in new leaf %llu\n",
 				le32_to_cpu(path[depth].p_ext->ee_block),
 				ext_pblock(path[depth].p_ext),
-				le16_to_cpu(path[depth].p_ext->ee_len),
+				ext4_ext_get_actual_len(path[depth].p_ext),
 				newblock);
 		/*memmove(ex++, path[depth].p_ext++,
 				sizeof(struct ext4_extent));
@@ -764,7 +795,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
 				EXT_LAST_INDEX(path[i].p_hdr));
 		while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
-			ext_debug("%d: move %d:%d in new index %llu\n", i,
+			ext_debug("%d: move %d:%llu in new index %llu\n", i,
 					le32_to_cpu(path[i].p_idx->ei_block),
 					idx_pblock(path[i].p_idx),
 					newblock);
@@ -893,8 +924,13 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
 	curp->p_hdr->eh_entries = cpu_to_le16(1);
 	curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
-	/* FIXME: it works, but actually path[0] can be index */
-	curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
+
+	if (path[0].p_hdr->eh_depth)
+		curp->p_idx->ei_block =
+			EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
+	else
+		curp->p_idx->ei_block =
+			EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
 	ext4_idx_store_pblock(curp->p_idx, newblock);
 
 	neh = ext_inode_hdr(inode);
@@ -1106,7 +1142,24 @@ static int
 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
 				struct ext4_extent *ex2)
 {
-	if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len) !=
+	unsigned short ext1_ee_len, ext2_ee_len, max_len;
+
+	/*
+	 * Make sure that either both extents are uninitialized, or
+	 * both are _not_.
+	 */
+	if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
+		return 0;
+
+	if (ext4_ext_is_uninitialized(ex1))
+		max_len = EXT_UNINIT_MAX_LEN;
+	else
+		max_len = EXT_INIT_MAX_LEN;
+
+	ext1_ee_len = ext4_ext_get_actual_len(ex1);
+	ext2_ee_len = ext4_ext_get_actual_len(ex2);
+
+	if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
 			le32_to_cpu(ex2->ee_block))
 		return 0;
 
@@ -1115,19 +1168,66 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
 	 * as an RO_COMPAT feature, refuse to merge to extents if
 	 * this can result in the top bit of ee_len being set.
 	 */
-	if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN)
+	if (ext1_ee_len + ext2_ee_len > max_len)
 		return 0;
 #ifdef AGGRESSIVE_TEST
 	if (le16_to_cpu(ex1->ee_len) >= 4)
 		return 0;
 #endif
 
-	if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2))
+	if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
 		return 1;
 	return 0;
 }
 
 /*
+ * This function tries to merge the "ex" extent to the next extent in the tree.
+ * It always tries to merge towards right. If you want to merge towards
+ * left, pass "ex - 1" as argument instead of "ex".
+ * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
+ * 1 if they got merged.
+ */
+int ext4_ext_try_to_merge(struct inode *inode,
+			  struct ext4_ext_path *path,
+			  struct ext4_extent *ex)
+{
+	struct ext4_extent_header *eh;
+	unsigned int depth, len;
+	int merge_done = 0;
+	int uninitialized = 0;
+
+	depth = ext_depth(inode);
+	BUG_ON(path[depth].p_hdr == NULL);
+	eh = path[depth].p_hdr;
+
+	while (ex < EXT_LAST_EXTENT(eh)) {
+		if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
+			break;
+		/* merge with next extent! */
+		if (ext4_ext_is_uninitialized(ex))
+			uninitialized = 1;
+		ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+				+ ext4_ext_get_actual_len(ex + 1));
+		if (uninitialized)
+			ext4_ext_mark_uninitialized(ex);
+
+		if (ex + 1 < EXT_LAST_EXTENT(eh)) {
+			len = (EXT_LAST_EXTENT(eh) - ex - 1)
+				* sizeof(struct ext4_extent);
+			memmove(ex + 1, ex + 2, len);
+		}
+		eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries) - 1);
+		merge_done = 1;
+		WARN_ON(eh->eh_entries == 0);
+		if (!eh->eh_entries)
+			ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
+			   "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
+	}
+
+	return merge_done;
+}
+
+/*
  * check if a portion of the "newext" extent overlaps with an
  * existing extent.
  *
@@ -1144,7 +1244,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
 	unsigned int ret = 0;
 
 	b1 = le32_to_cpu(newext->ee_block);
-	len1 = le16_to_cpu(newext->ee_len);
+	len1 = ext4_ext_get_actual_len(newext);
 	depth = ext_depth(inode);
 	if (!path[depth].p_ext)
 		goto out;
@@ -1191,8 +1291,9 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	struct ext4_extent *nearex; /* nearest extent */
 	struct ext4_ext_path *npath = NULL;
 	int depth, len, err, next;
+	unsigned uninitialized = 0;
 
-	BUG_ON(newext->ee_len == 0);
+	BUG_ON(ext4_ext_get_actual_len(newext) == 0);
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
 	BUG_ON(path[depth].p_hdr == NULL);
@@ -1200,14 +1301,24 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	/* try to insert block into found extent and return */
 	if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
 		ext_debug("append %d block to %d:%d (from %llu)\n",
-				le16_to_cpu(newext->ee_len),
+				ext4_ext_get_actual_len(newext),
 				le32_to_cpu(ex->ee_block),
-				le16_to_cpu(ex->ee_len), ext_pblock(ex));
+				ext4_ext_get_actual_len(ex), ext_pblock(ex));
 		err = ext4_ext_get_access(handle, inode, path + depth);
 		if (err)
 			return err;
-		ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len)
-					 + le16_to_cpu(newext->ee_len));
+
+		/*
+		 * ext4_can_extents_be_merged should have checked that either
+		 * both extents are uninitialized, or both aren't. Thus we
+		 * need to check only one of them here.
+		 */
+		if (ext4_ext_is_uninitialized(ex))
+			uninitialized = 1;
+		ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+					+ ext4_ext_get_actual_len(newext));
+		if (uninitialized)
+			ext4_ext_mark_uninitialized(ex);
 		eh = path[depth].p_hdr;
 		nearex = ex;
 		goto merge;
@@ -1263,7 +1374,7 @@ has_space:
 		ext_debug("first extent in the leaf: %d:%llu:%d\n",
 				le32_to_cpu(newext->ee_block),
 				ext_pblock(newext),
-				le16_to_cpu(newext->ee_len));
+				ext4_ext_get_actual_len(newext));
 		path[depth].p_ext = EXT_FIRST_EXTENT(eh);
 	} else if (le32_to_cpu(newext->ee_block)
 			   > le32_to_cpu(nearex->ee_block)) {
@@ -1276,7 +1387,7 @@ has_space:
 					"move %d from 0x%p to 0x%p\n",
 					le32_to_cpu(newext->ee_block),
 					ext_pblock(newext),
-					le16_to_cpu(newext->ee_len),
+					ext4_ext_get_actual_len(newext),
 					nearex, len, nearex + 1, nearex + 2);
 			memmove(nearex + 2, nearex + 1, len);
 		}
@@ -1289,7 +1400,7 @@ has_space:
 				"move %d from 0x%p to 0x%p\n",
 				le32_to_cpu(newext->ee_block),
 				ext_pblock(newext),
-				le16_to_cpu(newext->ee_len),
+				ext4_ext_get_actual_len(newext),
 				nearex, len, nearex + 1, nearex + 2);
 		memmove(nearex + 1, nearex, len);
 		path[depth].p_ext = nearex;
@@ -1304,20 +1415,7 @@ has_space:
 
 merge:
 	/* try to merge extents to the right */
-	while (nearex < EXT_LAST_EXTENT(eh)) {
-		if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1))
-			break;
-		/* merge with next extent! */
-		nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len)
-					     + le16_to_cpu(nearex[1].ee_len));
-		if (nearex + 1 < EXT_LAST_EXTENT(eh)) {
-			len = (EXT_LAST_EXTENT(eh) - nearex - 1)
-					* sizeof(struct ext4_extent);
-			memmove(nearex + 1, nearex + 2, len);
-		}
-		eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
-		BUG_ON(eh->eh_entries == 0);
-	}
+	ext4_ext_try_to_merge(inode, path, nearex);
 
 	/* try to merge extents to the left */
 
@@ -1379,8 +1477,8 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
 			end = le32_to_cpu(ex->ee_block);
 			if (block + num < end)
 				end = block + num;
-		} else if (block >=
-			     le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) {
+		} else if (block >= le32_to_cpu(ex->ee_block)
+					+ ext4_ext_get_actual_len(ex)) {
 			/* need to allocate space after found extent */
 			start = block;
 			end = block + num;
@@ -1392,7 +1490,8 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
 			 * by found extent
 			 */
 			start = block;
-			end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len);
+			end = le32_to_cpu(ex->ee_block)
+				+ ext4_ext_get_actual_len(ex);
 			if (block + num < end)
 				end = block + num;
 			exists = 1;
@@ -1408,7 +1507,7 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
 			cbex.ec_type = EXT4_EXT_CACHE_GAP;
 		} else {
 			cbex.ec_block = le32_to_cpu(ex->ee_block);
-			cbex.ec_len = le16_to_cpu(ex->ee_len);
+			cbex.ec_len = ext4_ext_get_actual_len(ex);
 			cbex.ec_start = ext_pblock(ex);
 			cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
 		}
@@ -1481,15 +1580,15 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
 		ext_debug("cache gap(before): %lu [%lu:%lu]",
 				(unsigned long) block,
 				(unsigned long) le32_to_cpu(ex->ee_block),
-				(unsigned long) le16_to_cpu(ex->ee_len));
+				(unsigned long) ext4_ext_get_actual_len(ex));
 	} else if (block >= le32_to_cpu(ex->ee_block)
-			    + le16_to_cpu(ex->ee_len)) {
+			+ ext4_ext_get_actual_len(ex)) {
 		lblock = le32_to_cpu(ex->ee_block)
-			 + le16_to_cpu(ex->ee_len);
+			+ ext4_ext_get_actual_len(ex);
 		len = ext4_ext_next_allocated_block(path);
 		ext_debug("cache gap(after): [%lu:%lu] %lu",
 				(unsigned long) le32_to_cpu(ex->ee_block),
-				(unsigned long) le16_to_cpu(ex->ee_len),
+				(unsigned long) ext4_ext_get_actual_len(ex),
 				(unsigned long) block);
 		BUG_ON(len == lblock);
 		len = len - lblock;
@@ -1619,12 +1718,12 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 				unsigned long from, unsigned long to)
 {
 	struct buffer_head *bh;
+	unsigned short ee_len =  ext4_ext_get_actual_len(ex);
 	int i;
 
 #ifdef EXTENTS_STATS
 	{
 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-		unsigned short ee_len =  le16_to_cpu(ex->ee_len);
 		spin_lock(&sbi->s_ext_stats_lock);
 		sbi->s_ext_blocks += ee_len;
 		sbi->s_ext_extents++;
@@ -1638,12 +1737,12 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 	}
 #endif
 	if (from >= le32_to_cpu(ex->ee_block)
-	    && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
+	    && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
 		/* tail removal */
 		unsigned long num;
 		ext4_fsblk_t start;
-		num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from;
-		start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num;
+		num = le32_to_cpu(ex->ee_block) + ee_len - from;
+		start = ext_pblock(ex) + ee_len - num;
 		ext_debug("free last %lu blocks starting %llu\n", num, start);
 		for (i = 0; i < num; i++) {
 			bh = sb_find_get_block(inode->i_sb, start + i);
@@ -1651,12 +1750,12 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 		}
 		ext4_free_blocks(handle, inode, start, num);
 	} else if (from == le32_to_cpu(ex->ee_block)
-		   && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
+		   && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
 		printk("strange request: removal %lu-%lu from %u:%u\n",
-		       from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
+			from, to, le32_to_cpu(ex->ee_block), ee_len);
 	} else {
 		printk("strange request: removal(2) %lu-%lu from %u:%u\n",
-		       from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
+			from, to, le32_to_cpu(ex->ee_block), ee_len);
 	}
 	return 0;
 }
@@ -1671,21 +1770,23 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 	unsigned a, b, block, num;
 	unsigned long ex_ee_block;
 	unsigned short ex_ee_len;
+	unsigned uninitialized = 0;
 	struct ext4_extent *ex;
 
+	/* the header must be checked already in ext4_ext_remove_space() */
 	ext_debug("truncate since %lu in leaf\n", start);
 	if (!path[depth].p_hdr)
 		path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
 	eh = path[depth].p_hdr;
 	BUG_ON(eh == NULL);
-	BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-	BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
 
 	/* find where to start removing */
 	ex = EXT_LAST_EXTENT(eh);
 
 	ex_ee_block = le32_to_cpu(ex->ee_block);
-	ex_ee_len = le16_to_cpu(ex->ee_len);
+	if (ext4_ext_is_uninitialized(ex))
+		uninitialized = 1;
+	ex_ee_len = ext4_ext_get_actual_len(ex);
 
 	while (ex >= EXT_FIRST_EXTENT(eh) &&
 			ex_ee_block + ex_ee_len > start) {
@@ -1753,6 +1854,12 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 
 		ex->ee_block = cpu_to_le32(block);
 		ex->ee_len = cpu_to_le16(num);
+		/*
+		 * Do not mark uninitialized if all the blocks in the
+		 * extent have been removed.
+		 */
+		if (uninitialized && num)
+			ext4_ext_mark_uninitialized(ex);
 
 		err = ext4_ext_dirty(handle, inode, path + depth);
 		if (err)
@@ -1762,7 +1869,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 				ext_pblock(ex));
 		ex--;
 		ex_ee_block = le32_to_cpu(ex->ee_block);
-		ex_ee_len = le16_to_cpu(ex->ee_len);
+		ex_ee_len = ext4_ext_get_actual_len(ex);
 	}
 
 	if (correct_index && eh->eh_entries)
@@ -1825,7 +1932,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
 		return -ENOMEM;
 	}
 	path[0].p_hdr = ext_inode_hdr(inode);
-	if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) {
+	if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) {
 		err = -EIO;
 		goto out;
 	}
@@ -1846,17 +1953,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
 		if (!path[i].p_hdr) {
 			ext_debug("initialize header\n");
 			path[i].p_hdr = ext_block_hdr(path[i].p_bh);
-			if (ext4_ext_check_header(__FUNCTION__, inode,
-							path[i].p_hdr)) {
-				err = -EIO;
-				goto out;
-			}
 		}
 
-		BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries)
-			   > le16_to_cpu(path[i].p_hdr->eh_max));
-		BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC);
-
 		if (!path[i].p_idx) {
 			/* this level hasn't been touched yet */
 			path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
@@ -1873,17 +1971,27 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
 				i, EXT_FIRST_INDEX(path[i].p_hdr),
 				path[i].p_idx);
 		if (ext4_ext_more_to_rm(path + i)) {
+			struct buffer_head *bh;
 			/* go to the next level */
 			ext_debug("move to level %d (block %llu)\n",
 				  i + 1, idx_pblock(path[i].p_idx));
 			memset(path + i + 1, 0, sizeof(*path));
-			path[i+1].p_bh =
-				sb_bread(sb, idx_pblock(path[i].p_idx));
-			if (!path[i+1].p_bh) {
+			bh = sb_bread(sb, idx_pblock(path[i].p_idx));
+			if (!bh) {
 				/* should we reset i_size? */
 				err = -EIO;
 				break;
 			}
+			if (WARN_ON(i + 1 > depth)) {
+				err = -EIO;
+				break;
+			}
+			if (ext4_ext_check_header(inode, ext_block_hdr(bh),
+							depth - i - 1)) {
+				err = -EIO;
+				break;
+			}
+			path[i + 1].p_bh = bh;
 
 			/* save actual number of indexes since this
 			 * number is changed at the next iteration */
@@ -1977,15 +2085,158 @@ void ext4_ext_release(struct super_block *sb)
 #endif
 }
 
+/*
+ * This function is called by ext4_ext_get_blocks() if someone tries to write
+ * to an uninitialized extent. It may result in splitting the uninitialized
+ * extent into multiple extents (upto three - one initialized and two
+ * uninitialized).
+ * There are three possibilities:
+ *   a> There is no split required: Entire extent should be initialized
+ *   b> Splits in two extents: Write is happening at either end of the extent
+ *   c> Splits in three extents: Somone is writing in middle of the extent
+ */
+int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
+					struct ext4_ext_path *path,
+					ext4_fsblk_t iblock,
+					unsigned long max_blocks)
+{
+	struct ext4_extent *ex, newex;
+	struct ext4_extent *ex1 = NULL;
+	struct ext4_extent *ex2 = NULL;
+	struct ext4_extent *ex3 = NULL;
+	struct ext4_extent_header *eh;
+	unsigned int allocated, ee_block, ee_len, depth;
+	ext4_fsblk_t newblock;
+	int err = 0;
+	int ret = 0;
+
+	depth = ext_depth(inode);
+	eh = path[depth].p_hdr;
+	ex = path[depth].p_ext;
+	ee_block = le32_to_cpu(ex->ee_block);
+	ee_len = ext4_ext_get_actual_len(ex);
+	allocated = ee_len - (iblock - ee_block);
+	newblock = iblock - ee_block + ext_pblock(ex);
+	ex2 = ex;
+
+	/* ex1: ee_block to iblock - 1 : uninitialized */
+	if (iblock > ee_block) {
+		ex1 = ex;
+		ex1->ee_len = cpu_to_le16(iblock - ee_block);
+		ext4_ext_mark_uninitialized(ex1);
+		ex2 = &newex;
+	}
+	/*
+	 * for sanity, update the length of the ex2 extent before
+	 * we insert ex3, if ex1 is NULL. This is to avoid temporary
+	 * overlap of blocks.
+	 */
+	if (!ex1 && allocated > max_blocks)
+		ex2->ee_len = cpu_to_le16(max_blocks);
+	/* ex3: to ee_block + ee_len : uninitialised */
+	if (allocated > max_blocks) {
+		unsigned int newdepth;
+		ex3 = &newex;
+		ex3->ee_block = cpu_to_le32(iblock + max_blocks);
+		ext4_ext_store_pblock(ex3, newblock + max_blocks);
+		ex3->ee_len = cpu_to_le16(allocated - max_blocks);
+		ext4_ext_mark_uninitialized(ex3);
+		err = ext4_ext_insert_extent(handle, inode, path, ex3);
+		if (err)
+			goto out;
+		/*
+		 * The depth, and hence eh & ex might change
+		 * as part of the insert above.
+		 */
+		newdepth = ext_depth(inode);
+		if (newdepth != depth) {
+			depth = newdepth;
+			path = ext4_ext_find_extent(inode, iblock, NULL);
+			if (IS_ERR(path)) {
+				err = PTR_ERR(path);
+				path = NULL;
+				goto out;
+			}
+			eh = path[depth].p_hdr;
+			ex = path[depth].p_ext;
+			if (ex2 != &newex)
+				ex2 = ex;
+		}
+		allocated = max_blocks;
+	}
+	/*
+	 * If there was a change of depth as part of the
+	 * insertion of ex3 above, we need to update the length
+	 * of the ex1 extent again here
+	 */
+	if (ex1 && ex1 != ex) {
+		ex1 = ex;
+		ex1->ee_len = cpu_to_le16(iblock - ee_block);
+		ext4_ext_mark_uninitialized(ex1);
+		ex2 = &newex;
+	}
+	/* ex2: iblock to iblock + maxblocks-1 : initialised */
+	ex2->ee_block = cpu_to_le32(iblock);
+	ex2->ee_start = cpu_to_le32(newblock);
+	ext4_ext_store_pblock(ex2, newblock);
+	ex2->ee_len = cpu_to_le16(allocated);
+	if (ex2 != ex)
+		goto insert;
+	err = ext4_ext_get_access(handle, inode, path + depth);
+	if (err)
+		goto out;
+	/*
+	 * New (initialized) extent starts from the first block
+	 * in the current extent. i.e., ex2 == ex
+	 * We have to see if it can be merged with the extent
+	 * on the left.
+	 */
+	if (ex2 > EXT_FIRST_EXTENT(eh)) {
+		/*
+		 * To merge left, pass "ex2 - 1" to try_to_merge(),
+		 * since it merges towards right _only_.
+		 */
+		ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
+		if (ret) {
+			err = ext4_ext_correct_indexes(handle, inode, path);
+			if (err)
+				goto out;
+			depth = ext_depth(inode);
+			ex2--;
+		}
+	}
+	/*
+	 * Try to Merge towards right. This might be required
+	 * only when the whole extent is being written to.
+	 * i.e. ex2 == ex and ex3 == NULL.
+	 */
+	if (!ex3) {
+		ret = ext4_ext_try_to_merge(inode, path, ex2);
+		if (ret) {
+			err = ext4_ext_correct_indexes(handle, inode, path);
+			if (err)
+				goto out;
+		}
+	}
+	/* Mark modified extent as dirty */
+	err = ext4_ext_dirty(handle, inode, path + depth);
+	goto out;
+insert:
+	err = ext4_ext_insert_extent(handle, inode, path, &newex);
+out:
+	return err ? err : allocated;
+}
+
 int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 			ext4_fsblk_t iblock,
 			unsigned long max_blocks, struct buffer_head *bh_result,
 			int create, int extend_disksize)
 {
 	struct ext4_ext_path *path = NULL;
+	struct ext4_extent_header *eh;
 	struct ext4_extent newex, *ex;
 	ext4_fsblk_t goal, newblock;
-	int err = 0, depth;
+	int err = 0, depth, ret;
 	unsigned long allocated = 0;
 
 	__clear_bit(BH_New, &bh_result->b_state);
@@ -1998,8 +2249,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	if (goal) {
 		if (goal == EXT4_EXT_CACHE_GAP) {
 			if (!create) {
-				/* block isn't allocated yet and
-				 * user doesn't want to allocate it */
+				/*
+				 * block isn't allocated yet and
+				 * user doesn't want to allocate it
+				 */
 				goto out2;
 			}
 			/* we should allocate requested block */
@@ -2033,21 +2286,19 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	 * this is why assert can't be put in ext4_ext_find_extent()
 	 */
 	BUG_ON(path[depth].p_ext == NULL && depth != 0);
+	eh = path[depth].p_hdr;
 
 	ex = path[depth].p_ext;
 	if (ex) {
 		unsigned long ee_block = le32_to_cpu(ex->ee_block);
 		ext4_fsblk_t ee_start = ext_pblock(ex);
-		unsigned short ee_len  = le16_to_cpu(ex->ee_len);
+		unsigned short ee_len;
 
 		/*
-		 * Allow future support for preallocated extents to be added
-		 * as an RO_COMPAT feature:
 		 * Uninitialized extents are treated as holes, except that
-		 * we avoid (fail) allocating new blocks during a write.
+		 * we split out initialized portions during a write.
 		 */
-		if (ee_len > EXT_MAX_LEN)
-			goto out2;
+		ee_len = ext4_ext_get_actual_len(ex);
 		/* if found extent covers block, simply return it */
 		if (iblock >= ee_block && iblock < ee_block + ee_len) {
 			newblock = iblock - ee_block + ee_start;
@@ -2055,9 +2306,27 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 			allocated = ee_len - (iblock - ee_block);
 			ext_debug("%d fit into %lu:%d -> %llu\n", (int) iblock,
 					ee_block, ee_len, newblock);
-			ext4_ext_put_in_cache(inode, ee_block, ee_len,
-						ee_start, EXT4_EXT_CACHE_EXTENT);
-			goto out;
+
+			/* Do not put uninitialized extent in the cache */
+			if (!ext4_ext_is_uninitialized(ex)) {
+				ext4_ext_put_in_cache(inode, ee_block,
+							ee_len, ee_start,
+							EXT4_EXT_CACHE_EXTENT);
+				goto out;
+			}
+			if (create == EXT4_CREATE_UNINITIALIZED_EXT)
+				goto out;
+			if (!create)
+				goto out2;
+
+			ret = ext4_ext_convert_to_initialized(handle, inode,
+								path, iblock,
+								max_blocks);
+			if (ret <= 0)
+				goto out2;
+			else
+				allocated = ret;
+			goto outnew;
 		}
 	}
 
@@ -2066,8 +2335,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	 * we couldn't try to create block if create flag is zero
 	 */
 	if (!create) {
-		/* put just found gap into cache to speed up
-		 * subsequent requests */
+		/*
+		 * put just found gap into cache to speed up
+		 * subsequent requests
+		 */
 		ext4_ext_put_gap_in_cache(inode, path, iblock);
 		goto out2;
 	}
@@ -2081,6 +2352,19 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	/* allocate new block */
 	goal = ext4_ext_find_goal(inode, path, iblock);
 
+	/*
+	 * See if request is beyond maximum number of blocks we can have in
+	 * a single extent. For an initialized extent this limit is
+	 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
+	 * EXT_UNINIT_MAX_LEN.
+	 */
+	if (max_blocks > EXT_INIT_MAX_LEN &&
+	    create != EXT4_CREATE_UNINITIALIZED_EXT)
+		max_blocks = EXT_INIT_MAX_LEN;
+	else if (max_blocks > EXT_UNINIT_MAX_LEN &&
+		 create == EXT4_CREATE_UNINITIALIZED_EXT)
+		max_blocks = EXT_UNINIT_MAX_LEN;
+
 	/* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
 	newex.ee_block = cpu_to_le32(iblock);
 	newex.ee_len = cpu_to_le16(max_blocks);
@@ -2098,6 +2382,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	/* try to insert new extent into found leaf and return */
 	ext4_ext_store_pblock(&newex, newblock);
 	newex.ee_len = cpu_to_le16(allocated);
+	if (create == EXT4_CREATE_UNINITIALIZED_EXT)  /* Mark uninitialized */
+		ext4_ext_mark_uninitialized(&newex);
 	err = ext4_ext_insert_extent(handle, inode, path, &newex);
 	if (err) {
 		/* free data blocks we just allocated */
@@ -2111,10 +2397,13 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
 	/* previous routine could use block we allocated */
 	newblock = ext_pblock(&newex);
+outnew:
 	__set_bit(BH_New, &bh_result->b_state);
 
-	ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
-				EXT4_EXT_CACHE_EXTENT);
+	/* Cache only when it is _not_ an uninitialized extent */
+	if (create != EXT4_CREATE_UNINITIALIZED_EXT)
+		ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
+						EXT4_EXT_CACHE_EXTENT);
 out:
 	if (allocated > max_blocks)
 		allocated = max_blocks;
@@ -2178,7 +2467,8 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
 	err = ext4_ext_remove_space(inode, last_block);
 
 	/* In a multi-transaction truncate, we only make the final
-	 * transaction synchronous. */
+	 * transaction synchronous.
+	 */
 	if (IS_SYNC(inode))
 		handle->h_sync = 1;
 
@@ -2217,3 +2507,127 @@ int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
 
 	return needed;
 }
+
+/*
+ * preallocate space for a file. This implements ext4's fallocate inode
+ * operation, which gets called from sys_fallocate system call.
+ * For block-mapped files, posix_fallocate should fall back to the method
+ * of writing zeroes to the required new blocks (the same behavior which is
+ * expected for file systems which do not support fallocate() system call).
+ */
+long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
+{
+	handle_t *handle;
+	ext4_fsblk_t block, max_blocks;
+	ext4_fsblk_t nblocks = 0;
+	int ret = 0;
+	int ret2 = 0;
+	int retries = 0;
+	struct buffer_head map_bh;
+	unsigned int credits, blkbits = inode->i_blkbits;
+
+	/*
+	 * currently supporting (pre)allocate mode for extent-based
+	 * files _only_
+	 */
+	if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+		return -EOPNOTSUPP;
+
+	/* preallocation to directories is currently not supported */
+	if (S_ISDIR(inode->i_mode))
+		return -ENODEV;
+
+	block = offset >> blkbits;
+	max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
+			- block;
+
+	/*
+	 * credits to insert 1 extent into extent tree + buffers to be able to
+	 * modify 1 super block, 1 block bitmap and 1 group descriptor.
+	 */
+	credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+retry:
+	while (ret >= 0 && ret < max_blocks) {
+		block = block + ret;
+		max_blocks = max_blocks - ret;
+		handle = ext4_journal_start(inode, credits);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			break;
+		}
+
+		ret = ext4_ext_get_blocks(handle, inode, block,
+					  max_blocks, &map_bh,
+					  EXT4_CREATE_UNINITIALIZED_EXT, 0);
+		WARN_ON(!ret);
+		if (!ret) {
+			ext4_error(inode->i_sb, "ext4_fallocate",
+				   "ext4_ext_get_blocks returned 0! inode#%lu"
+				   ", block=%llu, max_blocks=%llu",
+				   inode->i_ino, block, max_blocks);
+			ret = -EIO;
+			ext4_mark_inode_dirty(handle, inode);
+			ret2 = ext4_journal_stop(handle);
+			break;
+		}
+		if (ret > 0) {
+			/* check wrap through sign-bit/zero here */
+			if ((block + ret) < 0 || (block + ret) < block) {
+				ret = -EIO;
+				ext4_mark_inode_dirty(handle, inode);
+				ret2 = ext4_journal_stop(handle);
+				break;
+			}
+			if (buffer_new(&map_bh) && ((block + ret) >
+			    (EXT4_BLOCK_ALIGN(i_size_read(inode), blkbits)
+			    >> blkbits)))
+					nblocks = nblocks + ret;
+		}
+
+		/* Update ctime if new blocks get allocated */
+		if (nblocks) {
+			struct timespec now;
+
+			now = current_fs_time(inode->i_sb);
+			if (!timespec_equal(&inode->i_ctime, &now))
+				inode->i_ctime = now;
+		}
+
+		ext4_mark_inode_dirty(handle, inode);
+		ret2 = ext4_journal_stop(handle);
+		if (ret2)
+			break;
+	}
+
+	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+		goto retry;
+
+	/*
+	 * Time to update the file size.
+	 * Update only when preallocation was requested beyond the file size.
+	 */
+	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+	    (offset + len) > i_size_read(inode)) {
+		if (ret > 0) {
+			/*
+			 * if no error, we assume preallocation succeeded
+			 * completely
+			 */
+			mutex_lock(&inode->i_mutex);
+			i_size_write(inode, offset + len);
+			EXT4_I(inode)->i_disksize = i_size_read(inode);
+			mutex_unlock(&inode->i_mutex);
+		} else if (ret < 0 && nblocks) {
+			/* Handle partial allocation scenario */
+			loff_t newsize;
+
+			mutex_lock(&inode->i_mutex);
+			newsize  = (nblocks << blkbits) + i_size_read(inode);
+			i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits));
+			EXT4_I(inode)->i_disksize = i_size_read(inode);
+			mutex_unlock(&inode->i_mutex);
+		}
+	}
+
+	return ret > 0 ? ret2 : ret;
+}
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index d4c8186aed6..1a81cd66d63 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -134,5 +134,6 @@ const struct inode_operations ext4_file_inode_operations = {
 	.removexattr	= generic_removexattr,
 #endif
 	.permission	= ext4_permission,
+	.fallocate	= ext4_fallocate,
 };
 
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index c88b439ba5c..427f83066a0 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -563,7 +563,8 @@ got:
 	inode->i_ino = ino;
 	/* This is the optimal IO size (for stat), not the fs block size */
 	inode->i_blocks = 0;
-	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
+						       ext4_current_time(inode);
 
 	memset(ei->i_data, 0, sizeof(ei->i_data));
 	ei->i_dir_start_lookup = 0;
@@ -595,9 +596,8 @@ got:
 	spin_unlock(&sbi->s_next_gen_lock);
 
 	ei->i_state = EXT4_STATE_NEW;
-	ei->i_extra_isize =
-		(EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) ?
-		sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE : 0;
+
+	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
 
 	ret = inode;
 	if(DQUOT_ALLOC_INODE(inode)) {
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8416fa28c42..de26c25d6a1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -726,7 +726,7 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 
 	/* We are done with atomic stuff, now do the rest of housekeeping */
 
-	inode->i_ctime = CURRENT_TIME_SEC;
+	inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 
 	/* had we spliced it onto indirect block? */
@@ -1766,7 +1766,6 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
 	struct inode *inode = mapping->host;
 	struct buffer_head *bh;
 	int err = 0;
-	void *kaddr;
 
 	blocksize = inode->i_sb->s_blocksize;
 	length = blocksize - (offset & (blocksize - 1));
@@ -1778,10 +1777,7 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
 	 */
 	if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
 	     ext4_should_writeback_data(inode) && PageUptodate(page)) {
-		kaddr = kmap_atomic(page, KM_USER0);
-		memset(kaddr + offset, 0, length);
-		flush_dcache_page(page);
-		kunmap_atomic(kaddr, KM_USER0);
+		zero_user_page(page, offset, length, KM_USER0);
 		set_page_dirty(page);
 		goto unlock;
 	}
@@ -1834,10 +1830,7 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
 			goto unlock;
 	}
 
-	kaddr = kmap_atomic(page, KM_USER0);
-	memset(kaddr + offset, 0, length);
-	flush_dcache_page(page);
-	kunmap_atomic(kaddr, KM_USER0);
+	zero_user_page(page, offset, length, KM_USER0);
 
 	BUFFER_TRACE(bh, "zeroed end of block");
 
@@ -2375,7 +2368,7 @@ do_indirects:
 	ext4_discard_reservation(inode);
 
 	mutex_unlock(&ei->truncate_mutex);
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 
 	/*
@@ -2583,6 +2576,25 @@ void ext4_set_inode_flags(struct inode *inode)
 		inode->i_flags |= S_DIRSYNC;
 }
 
+/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
+void ext4_get_inode_flags(struct ext4_inode_info *ei)
+{
+	unsigned int flags = ei->vfs_inode.i_flags;
+
+	ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
+			EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL);
+	if (flags & S_SYNC)
+		ei->i_flags |= EXT4_SYNC_FL;
+	if (flags & S_APPEND)
+		ei->i_flags |= EXT4_APPEND_FL;
+	if (flags & S_IMMUTABLE)
+		ei->i_flags |= EXT4_IMMUTABLE_FL;
+	if (flags & S_NOATIME)
+		ei->i_flags |= EXT4_NOATIME_FL;
+	if (flags & S_DIRSYNC)
+		ei->i_flags |= EXT4_DIRSYNC_FL;
+}
+
 void ext4_read_inode(struct inode * inode)
 {
 	struct ext4_iloc iloc;
@@ -2610,10 +2622,6 @@ void ext4_read_inode(struct inode * inode)
 	}
 	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
 	inode->i_size = le32_to_cpu(raw_inode->i_size);
-	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
-	inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
-	inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
-	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
 
 	ei->i_state = 0;
 	ei->i_dir_start_lookup = 0;
@@ -2691,6 +2699,11 @@ void ext4_read_inode(struct inode * inode)
 	} else
 		ei->i_extra_isize = 0;
 
+	EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
+	EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
+	EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
+	EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
+
 	if (S_ISREG(inode->i_mode)) {
 		inode->i_op = &ext4_file_inode_operations;
 		inode->i_fop = &ext4_file_operations;
@@ -2744,6 +2757,7 @@ static int ext4_do_update_inode(handle_t *handle,
 	if (ei->i_state & EXT4_STATE_NEW)
 		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
 
+	ext4_get_inode_flags(ei);
 	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 	if(!(test_opt(inode->i_sb, NO_UID32))) {
 		raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
@@ -2771,9 +2785,12 @@ static int ext4_do_update_inode(handle_t *handle,
 	}
 	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 	raw_inode->i_size = cpu_to_le32(ei->i_disksize);
-	raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
-	raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
-	raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+
+	EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
+	EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
+	EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
+	EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
+
 	raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
 	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
 	raw_inode->i_flags = cpu_to_le32(ei->i_flags);
@@ -3082,6 +3099,39 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 }
 
 /*
+ * Expand an inode by new_extra_isize bytes.
+ * Returns 0 on success or negative error number on failure.
+ */
+int ext4_expand_extra_isize(struct inode *inode, unsigned int new_extra_isize,
+			struct ext4_iloc iloc, handle_t *handle)
+{
+	struct ext4_inode *raw_inode;
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_xattr_entry *entry;
+
+	if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
+		return 0;
+
+	raw_inode = ext4_raw_inode(&iloc);
+
+	header = IHDR(inode, raw_inode);
+	entry = IFIRST(header);
+
+	/* No extended attributes present */
+	if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||
+		header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
+		memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
+			new_extra_isize);
+		EXT4_I(inode)->i_extra_isize = new_extra_isize;
+		return 0;
+	}
+
+	/* try to expand with EAs present */
+	return ext4_expand_extra_isize_ea(inode, new_extra_isize,
+					  raw_inode, handle);
+}
+
+/*
  * What we do here is to mark the in-core inode as clean with respect to inode
  * dirtiness (it may still be data-dirty).
  * This means that the in-core inode may be reaped by prune_icache
@@ -3105,10 +3155,38 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 {
 	struct ext4_iloc iloc;
-	int err;
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	static unsigned int mnt_count;
+	int err, ret;
 
 	might_sleep();
 	err = ext4_reserve_inode_write(handle, inode, &iloc);
+	if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
+	    !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
+		/*
+		 * We need extra buffer credits since we may write into EA block
+		 * with this same handle. If journal_extend fails, then it will
+		 * only result in a minor loss of functionality for that inode.
+		 * If this is felt to be critical, then e2fsck should be run to
+		 * force a large enough s_min_extra_isize.
+		 */
+		if ((jbd2_journal_extend(handle,
+			     EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
+			ret = ext4_expand_extra_isize(inode,
+						      sbi->s_want_extra_isize,
+						      iloc, handle);
+			if (ret) {
+				EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+				if (mnt_count != sbi->s_es->s_mnt_count) {
+					ext4_warning(inode->i_sb, __FUNCTION__,
+					"Unable to expand inode %lu. Delete"
+					" some EAs or run e2fsck.",
+					inode->i_ino);
+					mnt_count = sbi->s_es->s_mnt_count;
+				}
+			}
+		}
+	}
 	if (!err)
 		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 	return err;
@@ -3197,7 +3275,7 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 	 */
 
 	journal = EXT4_JOURNAL(inode);
-	if (is_journal_aborted(journal) || IS_RDONLY(inode))
+	if (is_journal_aborted(journal))
 		return -EROFS;
 
 	jbd2_journal_lock_updates(journal);
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 7b4aa4543c8..c04c7ccba9e 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -28,6 +28,7 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
 
 	switch (cmd) {
 	case EXT4_IOC_GETFLAGS:
+		ext4_get_inode_flags(ei);
 		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
 		return put_user(flags, (int __user *) arg);
 	case EXT4_IOC_SETFLAGS: {
@@ -96,7 +97,7 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
 		ei->i_flags = flags;
 
 		ext4_set_inode_flags(inode);
-		inode->i_ctime = CURRENT_TIME_SEC;
+		inode->i_ctime = ext4_current_time(inode);
 
 		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 flags_err:
@@ -133,14 +134,14 @@ flags_err:
 			return PTR_ERR(handle);
 		err = ext4_reserve_inode_write(handle, inode, &iloc);
 		if (err == 0) {
-			inode->i_ctime = CURRENT_TIME_SEC;
+			inode->i_ctime = ext4_current_time(inode);
 			inode->i_generation = generation;
 			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 		}
 		ext4_journal_stop(handle);
 		return err;
 	}
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	case EXT4_IOC_WAIT_FOR_READONLY:
 		/*
 		 * This is racy - by the time we're woken up and running,
@@ -282,7 +283,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case EXT4_IOC32_SETVERSION_OLD:
 		cmd = EXT4_IOC_SETVERSION_OLD;
 		break;
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	case EXT4_IOC32_WAIT_FOR_READONLY:
 		cmd = EXT4_IOC_WAIT_FOR_READONLY;
 		break;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 2de339dd755..da224974af7 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1295,7 +1295,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	 * happen is that the times are slightly out of date
 	 * and/or different from the directory change time.
 	 */
-	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
 	ext4_update_dx_flag(dir);
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
@@ -1629,6 +1629,35 @@ static int ext4_delete_entry (handle_t *handle,
 	return -ENOENT;
 }
 
+/*
+ * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
+ * since this indicates that nlinks count was previously 1.
+ */
+static void ext4_inc_count(handle_t *handle, struct inode *inode)
+{
+	inc_nlink(inode);
+	if (is_dx(inode) && inode->i_nlink > 1) {
+		/* limit is 16-bit i_links_count */
+		if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
+			inode->i_nlink = 1;
+			EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
+					      EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
+		}
+	}
+}
+
+/*
+ * If a directory had nlink == 1, then we should let it be 1. This indicates
+ * directory has >EXT4_LINK_MAX subdirs.
+ */
+static void ext4_dec_count(handle_t *handle, struct inode *inode)
+{
+	drop_nlink(inode);
+	if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
+		inc_nlink(inode);
+}
+
+
 static int ext4_add_nondir(handle_t *handle,
 		struct dentry *dentry, struct inode *inode)
 {
@@ -1725,7 +1754,7 @@ static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 	struct ext4_dir_entry_2 * de;
 	int err, retries = 0;
 
-	if (dir->i_nlink >= EXT4_LINK_MAX)
+	if (EXT4_DIR_LINK_MAX(dir))
 		return -EMLINK;
 
 retry:
@@ -1748,7 +1777,7 @@ retry:
 	inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
 	dir_block = ext4_bread (handle, inode, 0, 1, &err);
 	if (!dir_block) {
-		drop_nlink(inode); /* is this nlink == 0? */
+		ext4_dec_count(handle, inode); /* is this nlink == 0? */
 		ext4_mark_inode_dirty(handle, inode);
 		iput (inode);
 		goto out_stop;
@@ -1780,7 +1809,7 @@ retry:
 		iput (inode);
 		goto out_stop;
 	}
-	inc_nlink(dir);
+	ext4_inc_count(handle, dir);
 	ext4_update_dx_flag(dir);
 	ext4_mark_inode_dirty(handle, dir);
 	d_instantiate(dentry, inode);
@@ -2045,9 +2074,9 @@ static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
 	retval = ext4_delete_entry(handle, dir, de, bh);
 	if (retval)
 		goto end_rmdir;
-	if (inode->i_nlink != 2)
+	if (!EXT4_DIR_LINK_EMPTY(inode))
 		ext4_warning (inode->i_sb, "ext4_rmdir",
-			      "empty directory has nlink!=2 (%d)",
+			      "empty directory has too many links (%d)",
 			      inode->i_nlink);
 	inode->i_version++;
 	clear_nlink(inode);
@@ -2056,9 +2085,9 @@ static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
 	 * recovery. */
 	inode->i_size = 0;
 	ext4_orphan_add(handle, inode);
-	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+	inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
-	drop_nlink(dir);
+	ext4_dec_count(handle, dir);
 	ext4_update_dx_flag(dir);
 	ext4_mark_inode_dirty(handle, dir);
 
@@ -2106,13 +2135,13 @@ static int ext4_unlink(struct inode * dir, struct dentry *dentry)
 	retval = ext4_delete_entry(handle, dir, de, bh);
 	if (retval)
 		goto end_unlink;
-	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+	dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
 	ext4_update_dx_flag(dir);
 	ext4_mark_inode_dirty(handle, dir);
-	drop_nlink(inode);
+	ext4_dec_count(handle, inode);
 	if (!inode->i_nlink)
 		ext4_orphan_add(handle, inode);
-	inode->i_ctime = dir->i_ctime;
+	inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	retval = 0;
 
@@ -2159,7 +2188,7 @@ retry:
 		err = __page_symlink(inode, symname, l,
 				mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 		if (err) {
-			drop_nlink(inode);
+			ext4_dec_count(handle, inode);
 			ext4_mark_inode_dirty(handle, inode);
 			iput (inode);
 			goto out_stop;
@@ -2185,8 +2214,9 @@ static int ext4_link (struct dentry * old_dentry,
 	struct inode *inode = old_dentry->d_inode;
 	int err, retries = 0;
 
-	if (inode->i_nlink >= EXT4_LINK_MAX)
+	if (EXT4_DIR_LINK_MAX(inode))
 		return -EMLINK;
+
 	/*
 	 * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
 	 * otherwise has the potential to corrupt the orphan inode list.
@@ -2203,8 +2233,8 @@ retry:
 	if (IS_DIRSYNC(dir))
 		handle->h_sync = 1;
 
-	inode->i_ctime = CURRENT_TIME_SEC;
-	inc_nlink(inode);
+	inode->i_ctime = ext4_current_time(inode);
+	ext4_inc_count(handle, inode);
 	atomic_inc(&inode->i_count);
 
 	err = ext4_add_nondir(handle, dentry, inode);
@@ -2305,7 +2335,7 @@ static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
 	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
 	 */
-	old_inode->i_ctime = CURRENT_TIME_SEC;
+	old_inode->i_ctime = ext4_current_time(old_inode);
 	ext4_mark_inode_dirty(handle, old_inode);
 
 	/*
@@ -2337,10 +2367,10 @@ static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
 	}
 
 	if (new_inode) {
-		drop_nlink(new_inode);
-		new_inode->i_ctime = CURRENT_TIME_SEC;
+		ext4_dec_count(handle, new_inode);
+		new_inode->i_ctime = ext4_current_time(new_inode);
 	}
-	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
+	old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
 	ext4_update_dx_flag(old_dir);
 	if (dir_bh) {
 		BUFFER_TRACE(dir_bh, "get_write_access");
@@ -2348,11 +2378,13 @@ static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
 		PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
 		BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata");
 		ext4_journal_dirty_metadata(handle, dir_bh);
-		drop_nlink(old_dir);
+		ext4_dec_count(handle, old_dir);
 		if (new_inode) {
-			drop_nlink(new_inode);
+			/* checked empty_dir above, can't have another parent,
+			 * ext3_dec_count() won't work for many-linked dirs */
+			new_inode->i_nlink = 0;
 		} else {
-			inc_nlink(new_dir);
+			ext4_inc_count(handle, new_dir);
 			ext4_update_dx_flag(new_dir);
 			ext4_mark_inode_dirty(handle, new_dir);
 		}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b806e689c4a..6dcbb28dc06 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -36,6 +36,7 @@
 #include <linux/namei.h>
 #include <linux/quotaops.h>
 #include <linux/seq_file.h>
+#include <linux/log2.h>
 
 #include <asm/uaccess.h>
 
@@ -734,7 +735,7 @@ enum {
 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
-	Opt_grpquota, Opt_extents,
+	Opt_grpquota, Opt_extents, Opt_noextents,
 };
 
 static match_table_t tokens = {
@@ -785,6 +786,7 @@ static match_table_t tokens = {
 	{Opt_usrquota, "usrquota"},
 	{Opt_barrier, "barrier=%u"},
 	{Opt_extents, "extents"},
+	{Opt_noextents, "noextents"},
 	{Opt_err, NULL},
 	{Opt_resize, "resize"},
 };
@@ -1120,6 +1122,9 @@ clear_qf_name:
 		case Opt_extents:
 			set_opt (sbi->s_mount_opt, EXTENTS);
 			break;
+		case Opt_noextents:
+			clear_opt (sbi->s_mount_opt, EXTENTS);
+			break;
 		default:
 			printk (KERN_ERR
 				"EXT4-fs: Unrecognized mount option \"%s\" "
@@ -1551,6 +1556,12 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
 	set_opt(sbi->s_mount_opt, RESERVATION);
 
+	/*
+	 * turn on extents feature by default in ext4 filesystem
+	 * User -o noextents to turn it off
+	 */
+	set_opt(sbi->s_mount_opt, EXTENTS);
+
 	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
 			    NULL, 0))
 		goto failed_mount;
@@ -1634,13 +1645,15 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
-		    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+		    (!is_power_of_2(sbi->s_inode_size)) ||
 		    (sbi->s_inode_size > blocksize)) {
 			printk (KERN_ERR
 				"EXT4-fs: unsupported inode size: %d\n",
 				sbi->s_inode_size);
 			goto failed_mount;
 		}
+		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
+			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
 	}
 	sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
 				   le32_to_cpu(es->s_log_frag_size);
@@ -1803,6 +1816,13 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount3;
 	}
 
+	if (ext4_blocks_count(es) > 0xffffffffULL &&
+	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
+				       JBD2_FEATURE_INCOMPAT_64BIT)) {
+		printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
+		goto failed_mount4;
+	}
+
 	/* We have now updated the journal if required, so we can
 	 * validate the data journaling mode. */
 	switch (test_opt(sb, DATA_FLAGS)) {
@@ -1857,6 +1877,32 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	}
 
 	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+
+	/* determine the minimum size of new large inodes, if present */
+	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
+		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
+						     EXT4_GOOD_OLD_INODE_SIZE;
+		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
+			if (sbi->s_want_extra_isize <
+			    le16_to_cpu(es->s_want_extra_isize))
+				sbi->s_want_extra_isize =
+					le16_to_cpu(es->s_want_extra_isize);
+			if (sbi->s_want_extra_isize <
+			    le16_to_cpu(es->s_min_extra_isize))
+				sbi->s_want_extra_isize =
+					le16_to_cpu(es->s_min_extra_isize);
+		}
+	}
+	/* Check if enough inode space is available */
+	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
+							sbi->s_inode_size) {
+		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
+						       EXT4_GOOD_OLD_INODE_SIZE;
+		printk(KERN_INFO "EXT4-fs: required extra inode space not"
+			"available.\n");
+	}
+
 	/*
 	 * akpm: core read_super() calls in here with the superblock locked.
 	 * That deadlocks, because orphan cleanup needs to lock the superblock
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index e832e96095b..b10d68fffb5 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -66,13 +66,6 @@
 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
 
-#define IHDR(inode, raw_inode) \
-	((struct ext4_xattr_ibody_header *) \
-		((void *)raw_inode + \
-		 EXT4_GOOD_OLD_INODE_SIZE + \
-		 EXT4_I(inode)->i_extra_isize))
-#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
-
 #ifdef EXT4_XATTR_DEBUG
 # define ea_idebug(inode, f...) do { \
 		printk(KERN_DEBUG "inode %s:%lu: ", \
@@ -508,6 +501,24 @@ out:
 	return;
 }
 
+/*
+ * Find the available free space for EAs. This also returns the total number of
+ * bytes used by EA entries.
+ */
+static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
+				    size_t *min_offs, void *base, int *total)
+{
+	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+		*total += EXT4_XATTR_LEN(last->e_name_len);
+		if (!last->e_value_block && last->e_value_size) {
+			size_t offs = le16_to_cpu(last->e_value_offs);
+			if (offs < *min_offs)
+				*min_offs = offs;
+		}
+	}
+	return (*min_offs - ((void *)last - base) - sizeof(__u32));
+}
+
 struct ext4_xattr_info {
 	int name_index;
 	const char *name;
@@ -1013,7 +1024,9 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 	}
 	if (!error) {
 		ext4_xattr_update_super_block(handle, inode->i_sb);
-		inode->i_ctime = CURRENT_TIME_SEC;
+		inode->i_ctime = ext4_current_time(inode);
+		if (!value)
+			EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
 		error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
 		/*
 		 * The bh is consumed by ext4_mark_iloc_dirty, even with
@@ -1067,6 +1080,253 @@ retry:
 }
 
 /*
+ * Shift the EA entries in the inode to create space for the increased
+ * i_extra_isize.
+ */
+static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
+				     int value_offs_shift, void *to,
+				     void *from, size_t n, int blocksize)
+{
+	struct ext4_xattr_entry *last = entry;
+	int new_offs;
+
+	/* Adjust the value offsets of the entries */
+	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+		if (!last->e_value_block && last->e_value_size) {
+			new_offs = le16_to_cpu(last->e_value_offs) +
+							value_offs_shift;
+			BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
+				 > blocksize);
+			last->e_value_offs = cpu_to_le16(new_offs);
+		}
+	}
+	/* Shift the entries by n bytes */
+	memmove(to, from, n);
+}
+
+/*
+ * Expand an inode by new_extra_isize bytes when EAs are present.
+ * Returns 0 on success or negative error number on failure.
+ */
+int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+			       struct ext4_inode *raw_inode, handle_t *handle)
+{
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_xattr_entry *entry, *last, *first;
+	struct buffer_head *bh = NULL;
+	struct ext4_xattr_ibody_find *is = NULL;
+	struct ext4_xattr_block_find *bs = NULL;
+	char *buffer = NULL, *b_entry_name = NULL;
+	size_t min_offs, free;
+	int total_ino, total_blk;
+	void *base, *start, *end;
+	int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
+	int s_min_extra_isize = EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize;
+
+	down_write(&EXT4_I(inode)->xattr_sem);
+retry:
+	if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
+		up_write(&EXT4_I(inode)->xattr_sem);
+		return 0;
+	}
+
+	header = IHDR(inode, raw_inode);
+	entry = IFIRST(header);
+
+	/*
+	 * Check if enough free space is available in the inode to shift the
+	 * entries ahead by new_extra_isize.
+	 */
+
+	base = start = entry;
+	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+	min_offs = end - base;
+	last = entry;
+	total_ino = sizeof(struct ext4_xattr_ibody_header);
+
+	free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
+	if (free >= new_extra_isize) {
+		entry = IFIRST(header);
+		ext4_xattr_shift_entries(entry,	EXT4_I(inode)->i_extra_isize
+				- new_extra_isize, (void *)raw_inode +
+				EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
+				(void *)header, total_ino,
+				inode->i_sb->s_blocksize);
+		EXT4_I(inode)->i_extra_isize = new_extra_isize;
+		error = 0;
+		goto cleanup;
+	}
+
+	/*
+	 * Enough free space isn't available in the inode, check if
+	 * EA block can hold new_extra_isize bytes.
+	 */
+	if (EXT4_I(inode)->i_file_acl) {
+		bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
+		error = -EIO;
+		if (!bh)
+			goto cleanup;
+		if (ext4_xattr_check_block(bh)) {
+			ext4_error(inode->i_sb, __FUNCTION__,
+				"inode %lu: bad block %llu", inode->i_ino,
+				EXT4_I(inode)->i_file_acl);
+			error = -EIO;
+			goto cleanup;
+		}
+		base = BHDR(bh);
+		first = BFIRST(bh);
+		end = bh->b_data + bh->b_size;
+		min_offs = end - base;
+		free = ext4_xattr_free_space(first, &min_offs, base,
+					     &total_blk);
+		if (free < new_extra_isize) {
+			if (!tried_min_extra_isize && s_min_extra_isize) {
+				tried_min_extra_isize++;
+				new_extra_isize = s_min_extra_isize;
+				brelse(bh);
+				goto retry;
+			}
+			error = -1;
+			goto cleanup;
+		}
+	} else {
+		free = inode->i_sb->s_blocksize;
+	}
+
+	while (new_extra_isize > 0) {
+		size_t offs, size, entry_size;
+		struct ext4_xattr_entry *small_entry = NULL;
+		struct ext4_xattr_info i = {
+			.value = NULL,
+			.value_len = 0,
+		};
+		unsigned int total_size;  /* EA entry size + value size */
+		unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
+		unsigned int min_total_size = ~0U;
+
+		is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
+		bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
+		if (!is || !bs) {
+			error = -ENOMEM;
+			goto cleanup;
+		}
+
+		is->s.not_found = -ENODATA;
+		bs->s.not_found = -ENODATA;
+		is->iloc.bh = NULL;
+		bs->bh = NULL;
+
+		last = IFIRST(header);
+		/* Find the entry best suited to be pushed into EA block */
+		entry = NULL;
+		for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+			total_size =
+			EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
+					EXT4_XATTR_LEN(last->e_name_len);
+			if (total_size <= free && total_size < min_total_size) {
+				if (total_size < new_extra_isize) {
+					small_entry = last;
+				} else {
+					entry = last;
+					min_total_size = total_size;
+				}
+			}
+		}
+
+		if (entry == NULL) {
+			if (small_entry) {
+				entry = small_entry;
+			} else {
+				if (!tried_min_extra_isize &&
+				    s_min_extra_isize) {
+					tried_min_extra_isize++;
+					new_extra_isize = s_min_extra_isize;
+					goto retry;
+				}
+				error = -1;
+				goto cleanup;
+			}
+		}
+		offs = le16_to_cpu(entry->e_value_offs);
+		size = le32_to_cpu(entry->e_value_size);
+		entry_size = EXT4_XATTR_LEN(entry->e_name_len);
+		i.name_index = entry->e_name_index,
+		buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
+		b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
+		if (!buffer || !b_entry_name) {
+			error = -ENOMEM;
+			goto cleanup;
+		}
+		/* Save the entry name and the entry value */
+		memcpy(buffer, (void *)IFIRST(header) + offs,
+		       EXT4_XATTR_SIZE(size));
+		memcpy(b_entry_name, entry->e_name, entry->e_name_len);
+		b_entry_name[entry->e_name_len] = '\0';
+		i.name = b_entry_name;
+
+		error = ext4_get_inode_loc(inode, &is->iloc);
+		if (error)
+			goto cleanup;
+
+		error = ext4_xattr_ibody_find(inode, &i, is);
+		if (error)
+			goto cleanup;
+
+		/* Remove the chosen entry from the inode */
+		error = ext4_xattr_ibody_set(handle, inode, &i, is);
+
+		entry = IFIRST(header);
+		if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
+			shift_bytes = new_extra_isize;
+		else
+			shift_bytes = entry_size + size;
+		/* Adjust the offsets and shift the remaining entries ahead */
+		ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
+			shift_bytes, (void *)raw_inode +
+			EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
+			(void *)header, total_ino - entry_size,
+			inode->i_sb->s_blocksize);
+
+		extra_isize += shift_bytes;
+		new_extra_isize -= shift_bytes;
+		EXT4_I(inode)->i_extra_isize = extra_isize;
+
+		i.name = b_entry_name;
+		i.value = buffer;
+		i.value_len = cpu_to_le32(size);
+		error = ext4_xattr_block_find(inode, &i, bs);
+		if (error)
+			goto cleanup;
+
+		/* Add entry which was removed from the inode into the block */
+		error = ext4_xattr_block_set(handle, inode, &i, bs);
+		if (error)
+			goto cleanup;
+		kfree(b_entry_name);
+		kfree(buffer);
+		brelse(is->iloc.bh);
+		kfree(is);
+		kfree(bs);
+	}
+	brelse(bh);
+	up_write(&EXT4_I(inode)->xattr_sem);
+	return 0;
+
+cleanup:
+	kfree(b_entry_name);
+	kfree(buffer);
+	if (is)
+		brelse(is->iloc.bh);
+	kfree(is);
+	kfree(bs);
+	brelse(bh);
+	up_write(&EXT4_I(inode)->xattr_sem);
+	return error;
+}
+
+
+
+/*
  * ext4_xattr_delete_inode()
  *
  * Free extended attribute resources associated with this inode. This
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 79432b35398..d7f5d6a1265 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -56,6 +56,13 @@ struct ext4_xattr_entry {
 #define EXT4_XATTR_SIZE(size) \
 	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
 
+#define IHDR(inode, raw_inode) \
+	((struct ext4_xattr_ibody_header *) \
+		((void *)raw_inode + \
+		EXT4_GOOD_OLD_INODE_SIZE + \
+		EXT4_I(inode)->i_extra_isize))
+#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+
 # ifdef CONFIG_EXT4DEV_FS_XATTR
 
 extern struct xattr_handler ext4_xattr_user_handler;
@@ -74,6 +81,9 @@ extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *,
 extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
 extern void ext4_xattr_put_super(struct super_block *);
 
+extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+			    struct ext4_inode *raw_inode, handle_t *handle);
+
 extern int init_ext4_xattr(void);
 extern void exit_ext4_xattr(void);
 
@@ -129,6 +139,13 @@ exit_ext4_xattr(void)
 {
 }
 
+static inline int
+ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+			    struct ext4_inode *raw_inode, handle_t *handle)
+{
+	return -EOPNOTSUPP;
+}
+
 #define ext4_xattr_handlers	NULL
 
 # endif  /* CONFIG_EXT4DEV_FS_XATTR */
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 78d63b818f0..f290cb7cb83 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -35,6 +35,7 @@
 #include <linux/kthread.h>
 #include <linux/poison.h>
 #include <linux/proc_fs.h>
+#include <linux/debugfs.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -528,7 +529,7 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
 {
 	int err = 0;
 
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	spin_lock(&journal->j_state_lock);
 	if (!tid_geq(journal->j_commit_request, tid)) {
 		printk(KERN_EMERG
@@ -1709,7 +1710,7 @@ void jbd2_slab_free(void *ptr,  size_t size)
  * Journal_head storage management
  */
 static struct kmem_cache *jbd2_journal_head_cache;
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
 #endif
 
@@ -1747,7 +1748,7 @@ static struct journal_head *journal_alloc_journal_head(void)
 	struct journal_head *ret;
 	static unsigned long last_warning;
 
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	atomic_inc(&nr_journal_heads);
 #endif
 	ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
@@ -1768,7 +1769,7 @@ static struct journal_head *journal_alloc_journal_head(void)
 
 static void journal_free_journal_head(struct journal_head *jh)
 {
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	atomic_dec(&nr_journal_heads);
 	memset(jh, JBD_POISON_FREE, sizeof(*jh));
 #endif
@@ -1951,64 +1952,50 @@ void jbd2_journal_put_journal_head(struct journal_head *jh)
 }
 
 /*
- * /proc tunables
+ * debugfs tunables
  */
-#if defined(CONFIG_JBD_DEBUG)
-int jbd2_journal_enable_debug;
+#if defined(CONFIG_JBD2_DEBUG)
+u8 jbd2_journal_enable_debug;
 EXPORT_SYMBOL(jbd2_journal_enable_debug);
 #endif
 
-#if defined(CONFIG_JBD_DEBUG) && defined(CONFIG_PROC_FS)
+#if defined(CONFIG_JBD2_DEBUG) && defined(CONFIG_DEBUG_FS)
 
-static struct proc_dir_entry *proc_jbd_debug;
+#define JBD2_DEBUG_NAME "jbd2-debug"
 
-static int read_jbd_debug(char *page, char **start, off_t off,
-			  int count, int *eof, void *data)
-{
-	int ret;
+struct dentry *jbd2_debugfs_dir, *jbd2_debug;
 
-	ret = sprintf(page + off, "%d\n", jbd2_journal_enable_debug);
-	*eof = 1;
-	return ret;
+static void __init jbd2_create_debugfs_entry(void)
+{
+	jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
+	if (jbd2_debugfs_dir)
+		jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO,
+					       jbd2_debugfs_dir,
+					       &jbd2_journal_enable_debug);
 }
 
-static int write_jbd_debug(struct file *file, const char __user *buffer,
-			   unsigned long count, void *data)
+static void __exit jbd2_remove_debugfs_entry(void)
 {
-	char buf[32];
-
-	if (count > ARRAY_SIZE(buf) - 1)
-		count = ARRAY_SIZE(buf) - 1;
-	if (copy_from_user(buf, buffer, count))
-		return -EFAULT;
-	buf[ARRAY_SIZE(buf) - 1] = '\0';
-	jbd2_journal_enable_debug = simple_strtoul(buf, NULL, 10);
-	return count;
+	if (jbd2_debug)
+		debugfs_remove(jbd2_debug);
+	if (jbd2_debugfs_dir)
+		debugfs_remove(jbd2_debugfs_dir);
 }
 
-#define JBD_PROC_NAME "sys/fs/jbd2-debug"
+#else
 
-static void __init create_jbd_proc_entry(void)
+static void __init jbd2_create_debugfs_entry(void)
 {
-	proc_jbd_debug = create_proc_entry(JBD_PROC_NAME, 0644, NULL);
-	if (proc_jbd_debug) {
-		/* Why is this so hard? */
-		proc_jbd_debug->read_proc = read_jbd_debug;
-		proc_jbd_debug->write_proc = write_jbd_debug;
-	}
+	do {
+	} while (0);
 }
 
-static void __exit jbd2_remove_jbd_proc_entry(void)
+static void __exit jbd2_remove_debugfs_entry(void)
 {
-	if (proc_jbd_debug)
-		remove_proc_entry(JBD_PROC_NAME, NULL);
+	do {
+	} while (0);
 }
 
-#else
-
-#define create_jbd_proc_entry() do {} while (0)
-#define jbd2_remove_jbd_proc_entry() do {} while (0)
-
 #endif
 
 struct kmem_cache *jbd2_handle_cache;
@@ -2067,18 +2054,18 @@ static int __init journal_init(void)
 	ret = journal_init_caches();
 	if (ret != 0)
 		jbd2_journal_destroy_caches();
-	create_jbd_proc_entry();
+	jbd2_create_debugfs_entry();
 	return ret;
 }
 
 static void __exit journal_exit(void)
 {
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 	int n = atomic_read(&nr_journal_heads);
 	if (n)
 		printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
 #endif
-	jbd2_remove_jbd_proc_entry();
+	jbd2_remove_debugfs_entry();
 	jbd2_journal_destroy_caches();
 }
 
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 395c92a04ac..e7730a045b9 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -295,7 +295,7 @@ int jbd2_journal_skip_recovery(journal_t *journal)
 		printk(KERN_ERR "JBD: error %d scanning journal\n", err);
 		++journal->j_transaction_sequence;
 	} else {
-#ifdef CONFIG_JBD_DEBUG
+#ifdef CONFIG_JBD2_DEBUG
 		int dropped = info.end_transaction - be32_to_cpu(sb->s_sequence);
 #endif
 		jbd_debug(0,
diff --git a/fs/open.c b/fs/open.c
index be6a457f422..a6b054edacb 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -26,6 +26,7 @@
 #include <linux/syscalls.h>
 #include <linux/rcupdate.h>
 #include <linux/audit.h>
+#include <linux/falloc.h>
 
 int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
@@ -352,6 +353,64 @@ asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
 }
 #endif
 
+asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
+{
+	struct file *file;
+	struct inode *inode;
+	long ret = -EINVAL;
+
+	if (offset < 0 || len <= 0)
+		goto out;
+
+	/* Return error if mode is not supported */
+	ret = -EOPNOTSUPP;
+	if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
+		goto out;
+
+	ret = -EBADF;
+	file = fget(fd);
+	if (!file)
+		goto out;
+	if (!(file->f_mode & FMODE_WRITE))
+		goto out_fput;
+	/*
+	 * Revalidate the write permissions, in case security policy has
+	 * changed since the files were opened.
+	 */
+	ret = security_file_permission(file, MAY_WRITE);
+	if (ret)
+		goto out_fput;
+
+	inode = file->f_path.dentry->d_inode;
+
+	ret = -ESPIPE;
+	if (S_ISFIFO(inode->i_mode))
+		goto out_fput;
+
+	ret = -ENODEV;
+	/*
+	 * Let individual file system decide if it supports preallocation
+	 * for directories or not.
+	 */
+	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+		goto out_fput;
+
+	ret = -EFBIG;
+	/* Check for wrap through zero too */
+	if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
+		goto out_fput;
+
+	if (inode->i_op && inode->i_op->fallocate)
+		ret = inode->i_op->fallocate(inode, mode, offset, len);
+	else
+		ret = -ENOSYS;
+
+out_fput:
+	fput(file);
+out:
+	return ret;
+}
+
 /*
  * access() needs to use the real uid/gid, not the effective uid/gid.
  * We do this by temporarily clearing all FS-related capabilities and