linux-ext4 - [PATCH]mke2fs: don't check mount flags for regular files

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Date:	Tue, 24 Mar 2009 16:31:33 +0800
From:	Peng Tao <bergwolf@...il.com>
To:	linux-ext4@...r.kernel.org
Cc:	tytso@....edu, Peng Tao <bergwolf@...il.com>
Subject: [PATCH]mke2fs: don't check mount flags for regular files

mke2fs scans /proc/mounts for mount flags of a device. But for regular files,
this is unnecessary and may cause troubles.

This can be triggered by:
$dd if=/dev/null of=rootfs bs=1024 seek=100000 count=0
$mke2fs -t ext3 -F rootfs
mke2fs 1.41.4 (27-Jan-2009)
rootfs is mounted; will not make a filesystem here!

Signed-off-by: Peng Tao <bergwolf@...il.com>
---
 lib/ext2fs/mkjournal.c |    5 +++++
 misc/util.c            |    3 +++
 2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index f5a9dba..ba7c6a8 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -466,6 +466,11 @@ errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
 					       jfile, sizeof(jfile)-10)))
 		return retval;
 
+	/*
+	 * Discard mounted flag if it is a regular file.
+	 */
+	if (stat(fs->device_name, &st) < 0 || S_ISREG(st.st_mode))
+		mount_flags &= ~EXT2_MF_MOUNTED;
 	if (mount_flags & EXT2_MF_MOUNTED) {
 		strcat(jfile, "/.journal");
 
diff --git a/misc/util.c b/misc/util.c
index 837d60f..d5b8033 100644
--- a/misc/util.c
+++ b/misc/util.c
@@ -144,7 +144,10 @@ void check_mount(const char *device, int force, const char *type)
 {
 	errcode_t	retval;
 	int		mount_flags;
+	struct stat	st_buf;
 
+	if ((stat(device, &st_buf) != 0) || S_ISREG(st_buf.st_mode))
+		return;
 	retval = ext2fs_check_if_mounted(device, &mount_flags);
 	if (retval) {
 		com_err("ext2fs_check_if_mount", retval,
-- 
1.6.2-rc2.GIT

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