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Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kern…
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…el/git/viro/vfs

Pull misc mount API conversions from Al Viro:
 "Conversions to new API for shmem and friends and for mount_mtd()-using
  filesystems.

  As for the rest of the mount API conversions in -next, some of them
  belong in the individual trees (e.g. binderfs one should definitely go
  through android folks, after getting redone on top of their changes).
  I'm going to drop those and send the rest (trivial ones + stuff ACKed
  by maintainers) in a separate series - by that point they are
  independent from each other.

  Some stuff has already migrated into individual trees (NFS conversion,
  for example, or FUSE stuff, etc.); those presumably will go through
  the regular merges from corresponding trees."

* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Make fs_parse() handle fs_param_is_fd-type params better
  vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
  shmem_parse_one(): switch to use of fs_parse()
  shmem_parse_options(): take handling a single option into a helper
  shmem_parse_options(): don't bother with mpol in separate variable
  shmem_parse_options(): use a separate structure to keep the results
  make shmem_fill_super() static
  make ramfs_fill_super() static
  devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
  vfs: Convert squashfs to use the new mount API
  mtd: Kill mount_mtd()
  vfs: Convert jffs2 to use the new mount API
  vfs: Convert cramfs to use the new mount API
  vfs: Convert romfs to use the new mount API
  vfs: Add a single-or-reconfig keying to vfs_get_super()
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@torvalds
torvalds committed Sep 19, 2019
2 parents cfb82e1 + 74983ac commit bc7d9ae
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Showing 17 changed files with 609 additions and 594 deletions.
38 changes: 29 additions & 9 deletions drivers/base/devtmpfs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,20 +56,32 @@ static int __init mount_param(char *str)
}
__setup("devtmpfs.mount=", mount_param);

static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
static struct vfsmount *mnt;

static struct dentry *public_dev_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data)
{
struct super_block *s = mnt->mnt_sb;
atomic_inc(&s->s_active);
down_write(&s->s_umount);
return dget(s->s_root);
}

static struct file_system_type internal_fs_type = {
.name = "devtmpfs",
#ifdef CONFIG_TMPFS
return mount_single(fs_type, flags, data, shmem_fill_super);
.init_fs_context = shmem_init_fs_context,
.parameters = &shmem_fs_parameters,
#else
return mount_single(fs_type, flags, data, ramfs_fill_super);
.init_fs_context = ramfs_init_fs_context,
.parameters = &ramfs_fs_parameters,
#endif
}
.kill_sb = kill_litter_super,
};

static struct file_system_type dev_fs_type = {
.name = "devtmpfs",
.mount = dev_mount,
.kill_sb = kill_litter_super,
.mount = public_dev_mount,
};

#ifdef CONFIG_BLOCK
Expand Down Expand Up @@ -378,12 +390,11 @@ static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid,

static int devtmpfsd(void *p)
{
char options[] = "mode=0755";
int *err = p;
*err = ksys_unshare(CLONE_NEWNS);
if (*err)
goto out;
*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
if (*err)
goto out;
ksys_chdir("/.."); /* will traverse into overmounted root */
Expand Down Expand Up @@ -420,7 +431,16 @@ static int devtmpfsd(void *p)
*/
int __init devtmpfs_init(void)
{
int err = register_filesystem(&dev_fs_type);
char opts[] = "mode=0755";
int err;

mnt = vfs_kern_mount(&internal_fs_type, 0, "devtmpfs", opts);
if (IS_ERR(mnt)) {
printk(KERN_ERR "devtmpfs: unable to create devtmpfs %ld\n",
PTR_ERR(mnt));
return PTR_ERR(mnt);
}
err = register_filesystem(&dev_fs_type);
if (err) {
printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
"type %i\n", err);
Expand Down
189 changes: 0 additions & 189 deletions drivers/mtd/mtdsuper.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -193,195 +193,6 @@ int get_tree_mtd(struct fs_context *fc,
}
EXPORT_SYMBOL_GPL(get_tree_mtd);

/*
* compare superblocks to see if they're equivalent
* - they are if the underlying MTD device is the same
*/
static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
{
struct mtd_info *mtd = _mtd;

if (sb->s_mtd == mtd) {
pr_debug("MTDSB: Match on device %d (\"%s\")\n",
mtd->index, mtd->name);
return 1;
}

pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
return 0;
}

/*
* mark the superblock by the MTD device it is using
* - set the device number to be the correct MTD block device for pesuperstence
* of NFS exports
*/
static int get_sb_mtd_set(struct super_block *sb, void *_mtd)
{
struct mtd_info *mtd = _mtd;

sb->s_mtd = mtd;
sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
sb->s_bdi = bdi_get(mtd_bdi);

return 0;
}

/*
* get a superblock on an MTD-backed filesystem
*/
static struct dentry *mount_mtd_aux(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
struct mtd_info *mtd,
int (*fill_super)(struct super_block *, void *, int))
{
struct super_block *sb;
int ret;

sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, flags, mtd);
if (IS_ERR(sb))
goto out_error;

if (sb->s_root)
goto already_mounted;

/* fresh new superblock */
pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
mtd->index, mtd->name);

ret = fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
if (ret < 0) {
deactivate_locked_super(sb);
return ERR_PTR(ret);
}

/* go */
sb->s_flags |= SB_ACTIVE;
return dget(sb->s_root);

/* new mountpoint for an already mounted superblock */
already_mounted:
pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
mtd->index, mtd->name);
put_mtd_device(mtd);
return dget(sb->s_root);

out_error:
put_mtd_device(mtd);
return ERR_CAST(sb);
}

/*
* get a superblock on an MTD-backed filesystem by MTD device number
*/
static struct dentry *mount_mtd_nr(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data, int mtdnr,
int (*fill_super)(struct super_block *, void *, int))
{
struct mtd_info *mtd;

mtd = get_mtd_device(NULL, mtdnr);
if (IS_ERR(mtd)) {
pr_debug("MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
return ERR_CAST(mtd);
}

return mount_mtd_aux(fs_type, flags, dev_name, data, mtd, fill_super);
}

/*
* set up an MTD-based superblock
*/
struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int))
{
#ifdef CONFIG_BLOCK
struct block_device *bdev;
int ret, major;
#endif
int mtdnr;

if (!dev_name)
return ERR_PTR(-EINVAL);

pr_debug("MTDSB: dev_name \"%s\"\n", dev_name);

/* the preferred way of mounting in future; especially when
* CONFIG_BLOCK=n - we specify the underlying MTD device by number or
* by name, so that we don't require block device support to be present
* in the kernel. */
if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
if (dev_name[3] == ':') {
struct mtd_info *mtd;

/* mount by MTD device name */
pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
dev_name + 4);

mtd = get_mtd_device_nm(dev_name + 4);
if (!IS_ERR(mtd))
return mount_mtd_aux(
fs_type, flags,
dev_name, data, mtd,
fill_super);

printk(KERN_NOTICE "MTD:"
" MTD device with name \"%s\" not found.\n",
dev_name + 4);

} else if (isdigit(dev_name[3])) {
/* mount by MTD device number name */
char *endptr;

mtdnr = simple_strtoul(dev_name + 3, &endptr, 0);
if (!*endptr) {
/* It was a valid number */
pr_debug("MTDSB: mtd%%d, mtdnr %d\n",
mtdnr);
return mount_mtd_nr(fs_type, flags,
dev_name, data,
mtdnr, fill_super);
}
}
}

#ifdef CONFIG_BLOCK
/* try the old way - the hack where we allowed users to mount
* /dev/mtdblock$(n) but didn't actually _use_ the blockdev
*/
bdev = lookup_bdev(dev_name);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
pr_debug("MTDSB: lookup_bdev() returned %d\n", ret);
return ERR_PTR(ret);
}
pr_debug("MTDSB: lookup_bdev() returned 0\n");

ret = -EINVAL;

major = MAJOR(bdev->bd_dev);
mtdnr = MINOR(bdev->bd_dev);
bdput(bdev);

if (major != MTD_BLOCK_MAJOR)
goto not_an_MTD_device;

return mount_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super);

not_an_MTD_device:
#endif /* CONFIG_BLOCK */

if (!(flags & SB_SILENT))
printk(KERN_NOTICE
"MTD: Attempt to mount non-MTD device \"%s\"\n",
dev_name);
return ERR_PTR(-EINVAL);
}

EXPORT_SYMBOL_GPL(mount_mtd);

/*
* destroy an MTD-based superblock
*/
Expand Down
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