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From: Yongqiang Yang <xiaoqiangnk@gmail.com>
To: tytso@mit.edu
Cc: adilger@dilger.ca, linux-ext4@vger.kernel.org,
	Yongqiang Yang <xiaoqiangnk@gmail.com>
Subject: [PATCH v4 02/15] ext4: add a function which adds a new desc to a fs
Date: Sat, 19 Nov 2011 17:57:08 +0800	[thread overview]
Message-ID: <1321696641-14437-3-git-send-email-xiaoqiangnk@gmail.com> (raw)
In-Reply-To: <1321696641-14437-1-git-send-email-xiaoqiangnk@gmail.com>

From: Yongqiang Yang <xiaoqiangnk@gmail.com>

This patch adds a function named ext4_add_new_desc() which adds
a new desc to a fs and whose code is copied from ext4_group_add().

The function will be used by new resize implementation.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
 fs/ext4/resize.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index ac5565c..9a5486e 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -735,6 +735,48 @@ exit_err:
 	}
 }
 
+/*
+ * ext4_add_new_desc() adds group descriptor of group @group
+ *
+ * @handle: journal handle
+ * @sb; super block
+ * @group: the group no. of the first group desc to be added
+ * @resize_inode: the resize inode
+ */
+static int ext4_add_new_desc(handle_t *handle, struct super_block *sb,
+			     ext4_group_t group, struct inode *resize_inode)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	struct buffer_head *gdb_bh;
+	int gdb_off, gdb_num, err = 0;
+	int reserved_gdb = ext4_bg_has_super(sb, group) ?
+		le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
+
+	gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
+	gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+
+	/*
+	 * We will only either add reserved group blocks to a backup group
+	 * or remove reserved blocks for the first group in a new group block.
+	 * Doing both would be mean more complex code, and sane people don't
+	 * use non-sparse filesystems anymore.  This is already checked above.
+	 */
+	if (gdb_off) {
+		gdb_bh = sbi->s_group_desc[gdb_num];
+		err = ext4_journal_get_write_access(handle, gdb_bh);
+		if (err)
+			goto out;
+
+		if (reserved_gdb && ext4_bg_num_gdb(sb, group))
+			err = reserve_backup_gdb(handle, resize_inode, group);
+	} else
+		err = add_new_gdb(handle, resize_inode, group);
+
+out:
+	return err;
+}
+
 /* Add group descriptor data to an existing or new group descriptor block.
  * Ensure we handle all possible error conditions _before_ we start modifying
  * the filesystem, because we cannot abort the transaction and not have it
-- 
1.7.5.1


  parent reply	other threads:[~2011-11-19 12:31 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-19  9:57 [PATCH v4 0/15] ext4: add new online resize interface Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 01/15] ext4: add a function which extends a group without checking parameters Yongqiang Yang
2011-11-19  9:57 ` Yongqiang Yang [this message]
2011-11-19  9:57 ` [PATCH v4 03/15] ext4: add a function which sets up a new group desc Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 04/15] ext4: add a function which updates super block Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 05/15] ext4: add a structure which will be used by 64bit-resize interface Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 06/15] ext4: add a function which sets up group blocks of a flex groups Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 07/15] ext4: add a function which adds several group descriptors Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 08/15] ext4: add a function which sets up a flex groups each time Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 09/15] ext4: enable ext4_update_super() to handle a flex groups Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 10/15] ext4: pass verify_reserved_gdb() the number of group decriptors Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 11/15] ext4: add a new function which allocates bitmaps and inode tables Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 12/15] ext4: add a new function which adds a flex group to a fs Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 13/15] ext4: add new online resize interface Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 14/15] ext4: let ext4_group_extend() use common code Yongqiang Yang
2011-11-19  9:57 ` [PATCH v4 15/15] ext4: let ext4_group_add() " Yongqiang Yang
2011-11-19 18:13 ` [PATCH v4 0/15] ext4: add new online resize interface Andreas Dilger
2011-11-20  3:14   ` Yongqiang Yang
2011-11-20 17:15     ` Andreas Dilger

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