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

30 files changed, 1328 insertions, 259 deletions

diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index bf6adce5226..8344c70adf6 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -323,3 +323,4 @@ ENTRY(sys_call_table)
 	.long sys_signalfd
 	.long sys_timerfd
 	.long sys_eventfd
+	.long sys_fallocate
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index b42cbf1e2d7..bd85b5fd08c 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -773,6 +773,13 @@ asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
 	return sys_truncate(path, (high << 32) | low);
 }
 
+asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
+				     u32 lenhi, u32 lenlo)
+{
+	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+			     ((loff_t)lenhi << 32) | lenlo);
+}
+
 asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
 				 unsigned long low)
 {
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 782dea81943..3f66e970d86 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -719,4 +719,5 @@ ia32_sys_call_table:
 	.quad compat_sys_signalfd
 	.quad compat_sys_timerfd
 	.quad sys_eventfd
+	.quad sys32_fallocate
 ia32_syscall_end:
diff --git a/arch/x86_64/ia32/sys_ia32.c b/arch/x86_64/ia32/sys_ia32.c
index 99a78a3cce7..bee96d61443 100644
--- a/arch/x86_64/ia32/sys_ia32.c
+++ b/arch/x86_64/ia32/sys_ia32.c
@@ -879,3 +879,11 @@ asmlinkage long sys32_fadvise64(int fd, unsigned offset_lo, unsigned offset_hi,
 	return sys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
 				len, advice);
 }
+
+asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_lo,
+				unsigned offset_hi, unsigned len_lo,
+				unsigned len_hi)
+{
+	return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
+			     ((u64)len_hi << 32) | len_lo);
+}
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