diff options
| author | Dave Hansen <haveblue@us.ibm.com> | 2008-02-15 23:37:32 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-19 06:25:33 +0200 |
| commit | 49e0d02cf018d4edf24bfc8531a816a26367e4ce (patch) | |
| tree | f1695d9ec2298b726ff39f42aaf8d4fd3ade8487 | |
| parent | [PATCH] r/o bind mounts: create helper to drop file write access (diff) | |
| download | linux-49e0d02cf018d4edf24bfc8531a816a26367e4ce.tar.xz linux-49e0d02cf018d4edf24bfc8531a816a26367e4ce.zip | |
[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>
| -rw-r--r-- | fs/super.c | 21 |
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(); } |