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linux/fs/exfat/exfat_fs.h
Linus Torvalds 7d6beb71da idmapped-mounts-v5.12 
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull idmapped mounts from Christian Brauner:
 "This introduces idmapped mounts which has been in the making for some
  time. Simply put, different mounts can expose the same file or
  directory with different ownership. This initial implementation comes
  with ports for fat, ext4 and with Christoph's port for xfs with more
  filesystems being actively worked on by independent people and
  maintainers.

  Idmapping mounts handle a wide range of long standing use-cases. Here
  are just a few:

   - Idmapped mounts make it possible to easily share files between
     multiple users or multiple machines especially in complex
     scenarios. For example, idmapped mounts will be used in the
     implementation of portable home directories in
     systemd-homed.service(8) where they allow users to move their home
     directory to an external storage device and use it on multiple
     computers where they are assigned different uids and gids. This
     effectively makes it possible to assign random uids and gids at
     login time.

   - It is possible to share files from the host with unprivileged
     containers without having to change ownership permanently through
     chown(2).

   - It is possible to idmap a container's rootfs and without having to
     mangle every file. For example, Chromebooks use it to share the
     user's Download folder with their unprivileged containers in their
     Linux subsystem.

   - It is possible to share files between containers with
     non-overlapping idmappings.

   - Filesystem that lack a proper concept of ownership such as fat can
     use idmapped mounts to implement discretionary access (DAC)
     permission checking.

   - They allow users to efficiently changing ownership on a per-mount
     basis without having to (recursively) chown(2) all files. In
     contrast to chown (2) changing ownership of large sets of files is
     instantenous with idmapped mounts. This is especially useful when
     ownership of a whole root filesystem of a virtual machine or
     container is changed. With idmapped mounts a single syscall
     mount_setattr syscall will be sufficient to change the ownership of
     all files.

   - Idmapped mounts always take the current ownership into account as
     idmappings specify what a given uid or gid is supposed to be mapped
     to. This contrasts with the chown(2) syscall which cannot by itself
     take the current ownership of the files it changes into account. It
     simply changes the ownership to the specified uid and gid. This is
     especially problematic when recursively chown(2)ing a large set of
     files which is commong with the aforementioned portable home
     directory and container and vm scenario.

   - Idmapped mounts allow to change ownership locally, restricting it
     to specific mounts, and temporarily as the ownership changes only
     apply as long as the mount exists.

  Several userspace projects have either already put up patches and
  pull-requests for this feature or will do so should you decide to pull
  this:

   - systemd: In a wide variety of scenarios but especially right away
     in their implementation of portable home directories.

         https://systemd.io/HOME_DIRECTORY/

   - container runtimes: containerd, runC, LXD:To share data between
     host and unprivileged containers, unprivileged and privileged
     containers, etc. The pull request for idmapped mounts support in
     containerd, the default Kubernetes runtime is already up for quite
     a while now: https://github.com/containerd/containerd/pull/4734

   - The virtio-fs developers and several users have expressed interest
     in using this feature with virtual machines once virtio-fs is
     ported.

   - ChromeOS: Sharing host-directories with unprivileged containers.

  I've tightly synced with all those projects and all of those listed
  here have also expressed their need/desire for this feature on the
  mailing list. For more info on how people use this there's a bunch of
  talks about this too. Here's just two recent ones:

      https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
      https://fosdem.org/2021/schedule/event/containers_idmap/

  This comes with an extensive xfstests suite covering both ext4 and
  xfs:

      https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts

  It covers truncation, creation, opening, xattrs, vfscaps, setid
  execution, setgid inheritance and more both with idmapped and
  non-idmapped mounts. It already helped to discover an unrelated xfs
  setgid inheritance bug which has since been fixed in mainline. It will
  be sent for inclusion with the xfstests project should you decide to
  merge this.

  In order to support per-mount idmappings vfsmounts are marked with
  user namespaces. The idmapping of the user namespace will be used to
  map the ids of vfs objects when they are accessed through that mount.
  By default all vfsmounts are marked with the initial user namespace.
  The initial user namespace is used to indicate that a mount is not
  idmapped. All operations behave as before and this is verified in the
  testsuite.

  Based on prior discussions we want to attach the whole user namespace
  and not just a dedicated idmapping struct. This allows us to reuse all
  the helpers that already exist for dealing with idmappings instead of
  introducing a whole new range of helpers. In addition, if we decide in
  the future that we are confident enough to enable unprivileged users
  to setup idmapped mounts the permission checking can take into account
  whether the caller is privileged in the user namespace the mount is
  currently marked with.

  The user namespace the mount will be marked with can be specified by
  passing a file descriptor refering to the user namespace as an
  argument to the new mount_setattr() syscall together with the new
  MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
  of extensibility.

  The following conditions must be met in order to create an idmapped
  mount:

   - The caller must currently have the CAP_SYS_ADMIN capability in the
     user namespace the underlying filesystem has been mounted in.

   - The underlying filesystem must support idmapped mounts.

   - The mount must not already be idmapped. This also implies that the
     idmapping of a mount cannot be altered once it has been idmapped.

   - The mount must be a detached/anonymous mount, i.e. it must have
     been created by calling open_tree() with the OPEN_TREE_CLONE flag
     and it must not already have been visible in the filesystem.

  The last two points guarantee easier semantics for userspace and the
  kernel and make the implementation significantly simpler.

  By default vfsmounts are marked with the initial user namespace and no
  behavioral or performance changes are observed.

  The manpage with a detailed description can be found here:

      1d7b902e28

  In order to support idmapped mounts, filesystems need to be changed
  and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
  patches to convert individual filesystem are not very large or
  complicated overall as can be seen from the included fat, ext4, and
  xfs ports. Patches for other filesystems are actively worked on and
  will be sent out separately. The xfstestsuite can be used to verify
  that port has been done correctly.

  The mount_setattr() syscall is motivated independent of the idmapped
  mounts patches and it's been around since July 2019. One of the most
  valuable features of the new mount api is the ability to perform
  mounts based on file descriptors only.

  Together with the lookup restrictions available in the openat2()
  RESOLVE_* flag namespace which we added in v5.6 this is the first time
  we are close to hardened and race-free (e.g. symlinks) mounting and
  path resolution.

  While userspace has started porting to the new mount api to mount
  proper filesystems and create new bind-mounts it is currently not
  possible to change mount options of an already existing bind mount in
  the new mount api since the mount_setattr() syscall is missing.

  With the addition of the mount_setattr() syscall we remove this last
  restriction and userspace can now fully port to the new mount api,
  covering every use-case the old mount api could. We also add the
  crucial ability to recursively change mount options for a whole mount
  tree, both removing and adding mount options at the same time. This
  syscall has been requested multiple times by various people and
  projects.

  There is a simple tool available at

      https://github.com/brauner/mount-idmapped

  that allows to create idmapped mounts so people can play with this
  patch series. I'll add support for the regular mount binary should you
  decide to pull this in the following weeks:

  Here's an example to a simple idmapped mount of another user's home
  directory:

	u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt

	u1001@f2-vm:/$ ls -al /home/ubuntu/
	total 28
	drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
	drwxr-xr-x 4 root   root   4096 Oct 28 04:00 ..
	-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
	-rw-r--r-- 1 ubuntu ubuntu  220 Feb 25  2020 .bash_logout
	-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25  2020 .bashrc
	-rw-r--r-- 1 ubuntu ubuntu  807 Feb 25  2020 .profile
	-rw-r--r-- 1 ubuntu ubuntu    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ ls -al /mnt/
	total 28
	drwxr-xr-x  2 u1001 u1001 4096 Oct 28 22:07 .
	drwxr-xr-x 29 root  root  4096 Oct 28 22:01 ..
	-rw-------  1 u1001 u1001 3154 Oct 28 22:12 .bash_history
	-rw-r--r--  1 u1001 u1001  220 Feb 25  2020 .bash_logout
	-rw-r--r--  1 u1001 u1001 3771 Feb 25  2020 .bashrc
	-rw-r--r--  1 u1001 u1001  807 Feb 25  2020 .profile
	-rw-r--r--  1 u1001 u1001    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw-------  1 u1001 u1001 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ touch /mnt/my-file

	u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file

	u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file

	u1001@f2-vm:/$ ls -al /mnt/my-file
	-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file

	u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
	-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file

	u1001@f2-vm:/$ getfacl /mnt/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: mnt/my-file
	# owner: u1001
	# group: u1001
	user::rw-
	user:u1001:rwx
	group::rw-
	mask::rwx
	other::r--

	u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: home/ubuntu/my-file
	# owner: ubuntu
	# group: ubuntu
	user::rw-
	user:ubuntu:rwx
	group::rw-
	mask::rwx
	other::r--"

* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
  xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
  xfs: support idmapped mounts
  ext4: support idmapped mounts
  fat: handle idmapped mounts
  tests: add mount_setattr() selftests
  fs: introduce MOUNT_ATTR_IDMAP
  fs: add mount_setattr()
  fs: add attr_flags_to_mnt_flags helper
  fs: split out functions to hold writers
  namespace: only take read lock in do_reconfigure_mnt()
  mount: make {lock,unlock}_mount_hash() static
  namespace: take lock_mount_hash() directly when changing flags
  nfs: do not export idmapped mounts
  overlayfs: do not mount on top of idmapped mounts
  ecryptfs: do not mount on top of idmapped mounts
  ima: handle idmapped mounts
  apparmor: handle idmapped mounts
  fs: make helpers idmap mount aware
  exec: handle idmapped mounts
  would_dump: handle idmapped mounts
  ...
2021-02-23 13:39:45 -08:00

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#ifndef _EXFAT_FS_H
#define _EXFAT_FS_H
#include <linux/fs.h>
#include <linux/ratelimit.h>
#include <linux/nls.h>
#define EXFAT_SUPER_MAGIC 0x2011BAB0UL
#define EXFAT_ROOT_INO 1
#define EXFAT_CLUSTERS_UNTRACKED (~0u)
/*
* exfat error flags
*/
enum exfat_error_mode {
EXFAT_ERRORS_CONT, /* ignore error and continue */
EXFAT_ERRORS_PANIC, /* panic on error */
EXFAT_ERRORS_RO, /* remount r/o on error */
};
/*
* exfat nls lossy flag
*/
enum {
NLS_NAME_NO_LOSSY, /* no lossy */
NLS_NAME_LOSSY, /* just detected incorrect filename(s) */
NLS_NAME_OVERLEN, /* the length is over than its limit */
};
#define EXFAT_HASH_BITS 8
#define EXFAT_HASH_SIZE (1UL << EXFAT_HASH_BITS)
/*
* Type Definitions
*/
#define ES_2_ENTRIES 2
#define ES_ALL_ENTRIES 0
#define DIR_DELETED 0xFFFF0321
/* type values */
#define TYPE_UNUSED 0x0000
#define TYPE_DELETED 0x0001
#define TYPE_INVALID 0x0002
#define TYPE_CRITICAL_PRI 0x0100
#define TYPE_BITMAP 0x0101
#define TYPE_UPCASE 0x0102
#define TYPE_VOLUME 0x0103
#define TYPE_DIR 0x0104
#define TYPE_FILE 0x011F
#define TYPE_CRITICAL_SEC 0x0200
#define TYPE_STREAM 0x0201
#define TYPE_EXTEND 0x0202
#define TYPE_ACL 0x0203
#define TYPE_BENIGN_PRI 0x0400
#define TYPE_GUID 0x0401
#define TYPE_PADDING 0x0402
#define TYPE_ACLTAB 0x0403
#define TYPE_BENIGN_SEC 0x0800
#define TYPE_ALL 0x0FFF
#define MAX_CHARSET_SIZE 6 /* max size of multi-byte character */
#define MAX_NAME_LENGTH 255 /* max len of file name excluding NULL */
#define MAX_VFSNAME_BUF_SIZE ((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)
/* Enough size to hold 256 dentry (even 512 Byte sector) */
#define DIR_CACHE_SIZE (256*sizeof(struct exfat_dentry)/512+1)
#define EXFAT_HINT_NONE -1
#define EXFAT_MIN_SUBDIR 2
/*
* helpers for cluster size to byte conversion.
*/
#define EXFAT_CLU_TO_B(b, sbi) ((b) << (sbi)->cluster_size_bits)
#define EXFAT_B_TO_CLU(b, sbi) ((b) >> (sbi)->cluster_size_bits)
#define EXFAT_B_TO_CLU_ROUND_UP(b, sbi) \
(((b - 1) >> (sbi)->cluster_size_bits) + 1)
#define EXFAT_CLU_OFFSET(off, sbi) ((off) & ((sbi)->cluster_size - 1))
/*
* helpers for block size to byte conversion.
*/
#define EXFAT_BLK_TO_B(b, sb) ((b) << (sb)->s_blocksize_bits)
#define EXFAT_B_TO_BLK(b, sb) ((b) >> (sb)->s_blocksize_bits)
#define EXFAT_B_TO_BLK_ROUND_UP(b, sb) \
(((b - 1) >> (sb)->s_blocksize_bits) + 1)
#define EXFAT_BLK_OFFSET(off, sb) ((off) & ((sb)->s_blocksize - 1))
/*
* helpers for block size to dentry size conversion.
*/
#define EXFAT_B_TO_DEN_IDX(b, sbi) \
((b) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
#define EXFAT_B_TO_DEN(b) ((b) >> DENTRY_SIZE_BITS)
#define EXFAT_DEN_TO_B(b) ((b) << DENTRY_SIZE_BITS)
/*
* helpers for fat entry.
*/
#define FAT_ENT_SIZE (4)
#define FAT_ENT_SIZE_BITS (2)
#define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \
(((u64)loc << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits))
#define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc) \
((loc << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1))
/*
* helpers for bitmap.
*/
#define CLUSTER_TO_BITMAP_ENT(clu) ((clu) - EXFAT_RESERVED_CLUSTERS)
#define BITMAP_ENT_TO_CLUSTER(ent) ((ent) + EXFAT_RESERVED_CLUSTERS)
#define BITS_PER_SECTOR(sb) ((sb)->s_blocksize * BITS_PER_BYTE)
#define BITS_PER_SECTOR_MASK(sb) (BITS_PER_SECTOR(sb) - 1)
#define BITMAP_OFFSET_SECTOR_INDEX(sb, ent) \
((ent / BITS_PER_BYTE) >> (sb)->s_blocksize_bits)
#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
#define BITS_PER_BYTE_MASK 0x7
#define IGNORED_BITS_REMAINED(clu, clu_base) ((1 << ((clu) - (clu_base))) - 1)
struct exfat_dentry_namebuf {
char *lfn;
int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */
};
/* unicode name structure */
struct exfat_uni_name {
/* +3 for null and for converting */
unsigned short name[MAX_NAME_LENGTH + 3];
u16 name_hash;
unsigned char name_len;
};
/* directory structure */
struct exfat_chain {
unsigned int dir;
unsigned int size;
unsigned char flags;
};
/* first empty entry hint information */
struct exfat_hint_femp {
/* entry index of a directory */
int eidx;
/* count of continuous empty entry */
int count;
/* the cluster that first empty slot exists in */
struct exfat_chain cur;
};
/* hint structure */
struct exfat_hint {
unsigned int clu;
union {
unsigned int off; /* cluster offset */
int eidx; /* entry index */
};
};
struct exfat_entry_set_cache {
struct super_block *sb;
bool modified;
unsigned int start_off;
int num_bh;
struct buffer_head *bh[DIR_CACHE_SIZE];
unsigned int num_entries;
};
struct exfat_dir_entry {
struct exfat_chain dir;
int entry;
unsigned int type;
unsigned int start_clu;
unsigned char flags;
unsigned short attr;
loff_t size;
unsigned int num_subdirs;
struct timespec64 atime;
struct timespec64 mtime;
struct timespec64 crtime;
struct exfat_dentry_namebuf namebuf;
};
/*
* exfat mount in-memory data
*/
struct exfat_mount_options {
kuid_t fs_uid;
kgid_t fs_gid;
unsigned short fs_fmask;
unsigned short fs_dmask;
/* permission for setting the [am]time */
unsigned short allow_utime;
/* charset for filename input/display */
char *iocharset;
/* on error: continue, panic, remount-ro */
enum exfat_error_mode errors;
unsigned utf8:1, /* Use of UTF-8 character set */
discard:1; /* Issue discard requests on deletions */
int time_offset; /* Offset of timestamps from UTC (in minutes) */
};
/*
* EXFAT file system superblock in-memory data
*/
struct exfat_sb_info {
unsigned long long num_sectors; /* num of sectors in volume */
unsigned int num_clusters; /* num of clusters in volume */
unsigned int cluster_size; /* cluster size in bytes */
unsigned int cluster_size_bits;
unsigned int sect_per_clus; /* cluster size in sectors */
unsigned int sect_per_clus_bits;
unsigned long long FAT1_start_sector; /* FAT1 start sector */
unsigned long long FAT2_start_sector; /* FAT2 start sector */
unsigned long long data_start_sector; /* data area start sector */
unsigned int num_FAT_sectors; /* num of FAT sectors */
unsigned int root_dir; /* root dir cluster */
unsigned int dentries_per_clu; /* num of dentries per cluster */
unsigned int vol_flags; /* volume flags */
unsigned int vol_flags_persistent; /* volume flags to retain */
struct buffer_head *boot_bh; /* buffer_head of BOOT sector */
unsigned int map_clu; /* allocation bitmap start cluster */
unsigned int map_sectors; /* num of allocation bitmap sectors */
struct buffer_head **vol_amap; /* allocation bitmap */
unsigned short *vol_utbl; /* upcase table */
unsigned int clu_srch_ptr; /* cluster search pointer */
unsigned int used_clusters; /* number of used clusters */
struct mutex s_lock; /* superblock lock */
struct exfat_mount_options options;
struct nls_table *nls_io; /* Charset used for input and display */
struct ratelimit_state ratelimit;
spinlock_t inode_hash_lock;
struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
struct rcu_head rcu;
};
#define EXFAT_CACHE_VALID 0
/*
* EXFAT file system inode in-memory data
*/
struct exfat_inode_info {
struct exfat_chain dir;
int entry;
unsigned int type;
unsigned short attr;
unsigned int start_clu;
unsigned char flags;
/*
* the copy of low 32bit of i_version to check
* the validation of hint_stat.
*/
unsigned int version;
/* hint for cluster last accessed */
struct exfat_hint hint_bmap;
/* hint for entry index we try to lookup next time */
struct exfat_hint hint_stat;
/* hint for first empty entry */
struct exfat_hint_femp hint_femp;
spinlock_t cache_lru_lock;
struct list_head cache_lru;
int nr_caches;
/* for avoiding the race between alloc and free */
unsigned int cache_valid_id;
/*
* NOTE: i_size_ondisk is 64bits, so must hold ->inode_lock to access.
* physically allocated size.
*/
loff_t i_size_ondisk;
/* block-aligned i_size (used in cont_write_begin) */
loff_t i_size_aligned;
/* on-disk position of directory entry or 0 */
loff_t i_pos;
/* hash by i_location */
struct hlist_node i_hash_fat;
/* protect bmap against truncate */
struct rw_semaphore truncate_lock;
struct inode vfs_inode;
/* File creation time */
struct timespec64 i_crtime;
};
static inline struct exfat_sb_info *EXFAT_SB(struct super_block *sb)
{
return sb->s_fs_info;
}
static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
{
return container_of(inode, struct exfat_inode_info, vfs_inode);
}
/*
* If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
* save ATTR_RO instead of ->i_mode.
*
* If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
* bit, it's just used as flag for app.
*/
static inline int exfat_mode_can_hold_ro(struct inode *inode)
{
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
if (S_ISDIR(inode->i_mode))
return 0;
if ((~sbi->options.fs_fmask) & 0222)
return 1;
return 0;
}
/* Convert attribute bits and a mask to the UNIX mode. */
static inline mode_t exfat_make_mode(struct exfat_sb_info *sbi,
unsigned short attr, mode_t mode)
{
if ((attr & ATTR_READONLY) && !(attr & ATTR_SUBDIR))
mode &= ~0222;
if (attr & ATTR_SUBDIR)
return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
return (mode & ~sbi->options.fs_fmask) | S_IFREG;
}
/* Return the FAT attribute byte for this inode */
static inline unsigned short exfat_make_attr(struct inode *inode)
{
unsigned short attr = EXFAT_I(inode)->attr;
if (S_ISDIR(inode->i_mode))
attr |= ATTR_SUBDIR;
if (exfat_mode_can_hold_ro(inode) && !(inode->i_mode & 0222))
attr |= ATTR_READONLY;
return attr;
}
static inline void exfat_save_attr(struct inode *inode, unsigned short attr)
{
if (exfat_mode_can_hold_ro(inode))
EXFAT_I(inode)->attr = attr & (ATTR_RWMASK | ATTR_READONLY);
else
EXFAT_I(inode)->attr = attr & ATTR_RWMASK;
}
static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
sector_t sec)
{
return ((sec - sbi->data_start_sector + 1) &
((1 << sbi->sect_per_clus_bits) - 1)) == 0;
}
static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
unsigned int clus)
{
return ((sector_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
sbi->data_start_sector;
}
static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
sector_t sec)
{
return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
EXFAT_RESERVED_CLUSTERS;
}
/* super.c */
int exfat_set_volume_dirty(struct super_block *sb);
int exfat_clear_volume_dirty(struct super_block *sb);
/* fatent.c */
#define exfat_get_next_cluster(sb, pclu) exfat_ent_get(sb, *(pclu), pclu)
int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
struct exfat_chain *p_chain);
int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
int exfat_ent_get(struct super_block *sb, unsigned int loc,
unsigned int *content);
int exfat_ent_set(struct super_block *sb, unsigned int loc,
unsigned int content);
int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
int entry, struct exfat_dentry *p_entry);
int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
unsigned int len);
int exfat_zeroed_cluster(struct inode *dir, unsigned int clu);
int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
unsigned int *ret_clu);
int exfat_count_num_clusters(struct super_block *sb,
struct exfat_chain *p_chain, unsigned int *ret_count);
/* balloc.c */
int exfat_load_bitmap(struct super_block *sb);
void exfat_free_bitmap(struct exfat_sb_info *sbi);
int exfat_set_bitmap(struct inode *inode, unsigned int clu);
void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync);
unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
/* file.c */
extern const struct file_operations exfat_file_operations;
int __exfat_truncate(struct inode *inode, loff_t new_size);
void exfat_truncate(struct inode *inode, loff_t size);
int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct iattr *attr);
int exfat_getattr(struct user_namespace *mnt_userns, const struct path *path,
struct kstat *stat, unsigned int request_mask,
unsigned int query_flags);
int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
/* namei.c */
extern const struct dentry_operations exfat_dentry_ops;
extern const struct dentry_operations exfat_utf8_dentry_ops;
/* cache.c */
int exfat_cache_init(void);
void exfat_cache_shutdown(void);
void exfat_cache_inval_inode(struct inode *inode);
int exfat_get_cluster(struct inode *inode, unsigned int cluster,
unsigned int *fclus, unsigned int *dclus,
unsigned int *last_dclus, int allow_eof);
/* dir.c */
extern const struct inode_operations exfat_dir_inode_operations;
extern const struct file_operations exfat_dir_operations;
unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
int entry, unsigned int type, unsigned int start_clu,
unsigned long long size);
int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
int entry, int num_entries, struct exfat_uni_name *p_uniname);
int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
int entry, int order, int num_entries);
int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
int entry);
void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es);
int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
int num_entries, unsigned int type);
int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
int entry, sector_t *sector, int *offset);
struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
sector_t *sector);
struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
int num);
struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
struct exfat_chain *p_dir, int entry, unsigned int type);
int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
/* inode.c */
extern const struct inode_operations exfat_file_inode_operations;
void exfat_sync_inode(struct inode *inode);
struct inode *exfat_build_inode(struct super_block *sb,
struct exfat_dir_entry *info, loff_t i_pos);
void exfat_hash_inode(struct inode *inode, loff_t i_pos);
void exfat_unhash_inode(struct inode *inode);
struct inode *exfat_iget(struct super_block *sb, loff_t i_pos);
int exfat_write_inode(struct inode *inode, struct writeback_control *wbc);
void exfat_evict_inode(struct inode *inode);
int exfat_block_truncate_page(struct inode *inode, loff_t from);
/* exfat/nls.c */
unsigned short exfat_toupper(struct super_block *sb, unsigned short a);
int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
unsigned short *b, unsigned int len);
int exfat_utf16_to_nls(struct super_block *sb,
struct exfat_uni_name *uniname, unsigned char *p_cstring,
int len);
int exfat_nls_to_utf16(struct super_block *sb,
const unsigned char *p_cstring, const int len,
struct exfat_uni_name *uniname, int *p_lossy);
int exfat_create_upcase_table(struct super_block *sb);
void exfat_free_upcase_table(struct exfat_sb_info *sbi);
/* exfat/misc.c */
void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
__printf(3, 4) __cold;
#define exfat_fs_error(sb, fmt, args...) \
__exfat_fs_error(sb, 1, fmt, ## args)
#define exfat_fs_error_ratelimit(sb, fmt, args...) \
__exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
fmt, ## args)
void exfat_msg(struct super_block *sb, const char *lv, const char *fmt, ...)
__printf(3, 4) __cold;
#define exfat_err(sb, fmt, ...) \
exfat_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__)
#define exfat_warn(sb, fmt, ...) \
exfat_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__)
#define exfat_info(sb, fmt, ...) \
exfat_msg(sb, KERN_INFO, fmt, ##__VA_ARGS__)
void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 tz, __le16 time, __le16 date, u8 time_cs);
void exfat_truncate_atime(struct timespec64 *ts);
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
void exfat_update_bh(struct buffer_head *bh, int sync);
int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
unsigned int size, unsigned char flags);
void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
#endif /* !_EXFAT_FS_H */
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