diff options
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index 54018fe48840..334ce39881f8 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -214,7 +214,7 @@ int init_file(struct file *file, struct vfsmount *mnt, struct dentry *dentry, */ if ((mode & FMODE_WRITE) && !special_file(dentry->d_inode->i_mode)) { file_take_write(file); - error = mnt_want_write(mnt); + error = mnt_clone_write(mnt); WARN_ON(error); } return error; @@ -399,6 +399,44 @@ too_bad: return 0; } +/** + * mark_files_ro - mark all files read-only + * @sb: superblock in question + * + * All files are marked read-only. We don't care about pending + * delete files so this should be used in 'force' mode only. + */ +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) { + 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; + if (file_check_writeable(f) != 0) + continue; + file_release_write(f); + 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(); +} + void __init files_init(unsigned long mempages) { int n; |