linux-ext4 - [PATCH 2/3] libext2fs: allow ext2fs_extent

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Date:	Tue, 20 May 2008 10:15:27 -0500
From:	Eric Sandeen <sandeen@...hat.com>
To:	ext4 development <linux-ext4@...r.kernel.org>
Subject: [PATCH 2/3] libext2fs: allow ext2fs_extent_insert to split if needed

If ext2fs_extent_insert finds that the requested node
for insertion is full, it will currently fail.

With this patch it will split as necessary to make room, unless
an EXT2_EXTENT_INSERT_NOSPLIT flag is sent in.

Signed-off-by: Eric Sandeen <sandeen@...hat.com>
---
 lib/ext2fs/ext2fs.h |    4 ++--
 lib/ext2fs/extent.c |   15 ++++++++++++---
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 7a1d966..30ca906 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -332,8 +332,8 @@ typedef struct ext2_extent_path *ext2_extent_path_t;
 /*
  * Flags used by ext2fs_extent_insert()
  */
-
-#define EXT2_EXTENT_INSERT_AFTER  0x0001
+#define EXT2_EXTENT_INSERT_AFTER	0x0001 /* insert after handle loc'n */
+#define EXT2_EXTENT_INSERT_NOSPLIT	0x0002 /* insert may not cause split */
 
 /*
  * Data structure returned by ext2fs_extent_get_info()
diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index 5ec5c3e..34719d5 100644
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -894,8 +894,17 @@ errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
 
 	path = handle->path + handle->level;
 
-	if (path->entries >= path->max_entries)
-		return EXT2_ET_CANT_INSERT_EXTENT;
+	if (path->entries >= path->max_entries) {
+		if (flags & EXT2_EXTENT_INSERT_NOSPLIT) {
+			return EXT2_ET_CANT_INSERT_EXTENT;
+		} else {
+			dbg_printf("node full - splitting\n");
+			retval = ext2fs_node_split(handle, 0);
+			if (retval)
+				goto errout;
+			path = handle->path + handle->level;
+		}
+	}
 
 	eh = (struct ext3_extent_header *) path->buf;
 	if (path->curr) {
@@ -1245,7 +1254,7 @@ void do_insert_node(int argc, char *argv[])
 	}
 
 	if (argc != 4) {
-		fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
+		fprintf(stderr, "usage: %s [--after] <lblk> <len> <pblk>\n", cmd);
 		return;
 	}
 
-- 1.5.4.1

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