Commit 49e0d02c authored by Dave Hansen's avatar Dave Hansen Committed by Al Viro

[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: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent aceaf78d
......@@ -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();
}
......
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