mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 06:56:46 +07:00
4ed5e82fe7
Currently remouting superblock read-only is racy in a major way. With the per mount read-only infrastructure it is now possible to prevent most races, which this patch attempts. Before starting the remount read-only, iterate through all mounts belonging to the superblock and if none of them have any pending writes, set sb->s_readonly_remount. This indicates that remount is in progress and no further write requests are allowed. If the remount succeeds set MS_RDONLY and reset s_readonly_remount. If the remounting is unsuccessful just reset s_readonly_remount. This can result in transient EROFS errors, despite the fact the remount failed. Unfortunately hodling off writes is difficult as remount itself may touch the filesystem (e.g. through load_nls()) which would deadlock. A later patch deals with delayed writes due to nlink going to zero. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
122 lines
2.9 KiB
C
122 lines
2.9 KiB
C
/* fs/ internal definitions
|
|
*
|
|
* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/lglock.h>
|
|
|
|
struct super_block;
|
|
struct file_system_type;
|
|
struct linux_binprm;
|
|
struct path;
|
|
struct mount;
|
|
|
|
/*
|
|
* block_dev.c
|
|
*/
|
|
#ifdef CONFIG_BLOCK
|
|
extern void __init bdev_cache_init(void);
|
|
|
|
extern int __sync_blockdev(struct block_device *bdev, int wait);
|
|
|
|
#else
|
|
static inline void bdev_cache_init(void)
|
|
{
|
|
}
|
|
|
|
static inline int __sync_blockdev(struct block_device *bdev, int wait)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* char_dev.c
|
|
*/
|
|
extern void __init chrdev_init(void);
|
|
|
|
/*
|
|
* namespace.c
|
|
*/
|
|
extern int copy_mount_options(const void __user *, unsigned long *);
|
|
extern int copy_mount_string(const void __user *, char **);
|
|
|
|
extern struct vfsmount *lookup_mnt(struct path *);
|
|
extern int finish_automount(struct vfsmount *, struct path *);
|
|
|
|
extern void mnt_make_longterm(struct vfsmount *);
|
|
extern void mnt_make_shortterm(struct vfsmount *);
|
|
extern int sb_prepare_remount_readonly(struct super_block *);
|
|
|
|
extern void __init mnt_init(void);
|
|
|
|
DECLARE_BRLOCK(vfsmount_lock);
|
|
|
|
|
|
/*
|
|
* fs_struct.c
|
|
*/
|
|
extern void chroot_fs_refs(struct path *, struct path *);
|
|
|
|
/*
|
|
* file_table.c
|
|
*/
|
|
extern void file_sb_list_add(struct file *f, struct super_block *sb);
|
|
extern void file_sb_list_del(struct file *f);
|
|
extern void mark_files_ro(struct super_block *);
|
|
extern struct file *get_empty_filp(void);
|
|
|
|
/*
|
|
* super.c
|
|
*/
|
|
extern int do_remount_sb(struct super_block *, int, void *, int);
|
|
extern bool grab_super_passive(struct super_block *sb);
|
|
extern struct dentry *mount_fs(struct file_system_type *,
|
|
int, const char *, void *);
|
|
extern struct super_block *user_get_super(dev_t);
|
|
|
|
/*
|
|
* open.c
|
|
*/
|
|
struct nameidata;
|
|
extern struct file *nameidata_to_filp(struct nameidata *);
|
|
extern void release_open_intent(struct nameidata *);
|
|
struct open_flags {
|
|
int open_flag;
|
|
umode_t mode;
|
|
int acc_mode;
|
|
int intent;
|
|
};
|
|
extern struct file *do_filp_open(int dfd, const char *pathname,
|
|
const struct open_flags *op, int lookup_flags);
|
|
extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
|
|
const char *, const struct open_flags *, int lookup_flags);
|
|
|
|
extern long do_handle_open(int mountdirfd,
|
|
struct file_handle __user *ufh, int open_flag);
|
|
|
|
/*
|
|
* inode.c
|
|
*/
|
|
extern spinlock_t inode_sb_list_lock;
|
|
|
|
/*
|
|
* fs-writeback.c
|
|
*/
|
|
extern void inode_wb_list_del(struct inode *inode);
|
|
|
|
extern int get_nr_dirty_inodes(void);
|
|
extern void evict_inodes(struct super_block *);
|
|
extern int invalidate_inodes(struct super_block *, bool);
|
|
|
|
/*
|
|
* dcache.c
|
|
*/
|
|
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
|