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authorDave Hansen <haveblue@us.ibm.com>2008-02-15 14:37:32 -0800
committerAl Viro <viro@zeniv.linux.org.uk>2008-04-19 00:25:33 -0400
commit49e0d02cf018d4edf24bfc8531a816a26367e4ce (patch)
treef1695d9ec2298b726ff39f42aaf8d4fd3ade8487 /fs/super.c
parentaceaf78da92a53f5e1b105649a1b8c0afdb2135c (diff)
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[PATCH] r/o bind mounts: drop write during emergency remount
The emergency remount code forcibly removes FMODE_WRITE from filps. The r/o bind mount code notices that this was done without a proper mnt_drop_write() and properly gives a warning. This patch does a mnt_drop_write() to keep everything balanced. Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/super.c')
-rw-r--r--fs/super.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/super.c b/fs/super.c
index 09008dbd264e..01d5c40e9119 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -37,6 +37,7 @@
#include <linux/idr.h>
#include <linux/kobject.h>
#include <linux/mutex.h>
+#include <linux/file.h>
#include <asm/uaccess.h>
@@ -567,10 +568,26 @@ static void mark_files_ro(struct super_block *sb)
{
struct file *f;
+retry:
file_list_lock();
list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
- if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f))
- f->f_mode &= ~FMODE_WRITE;
+ struct vfsmount *mnt;
+ if (!S_ISREG(f->f_path.dentry->d_inode->i_mode))
+ continue;
+ if (!file_count(f))
+ continue;
+ if (!(f->f_mode & FMODE_WRITE))
+ continue;
+ f->f_mode &= ~FMODE_WRITE;
+ mnt = mntget(f->f_path.mnt);
+ file_list_unlock();
+ /*
+ * This can sleep, so we can't hold
+ * the file_list_lock() spinlock.
+ */
+ mnt_drop_write(mnt);
+ mntput(mnt);
+ goto retry;
}
file_list_unlock();
}