mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-15 08:44:14 +08:00
btrfs: sanity mount option parsing and early mount code
Also adds lots of comments to describe what's going on here. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
parent
306929f364
commit
edf24abe51
@ -1616,7 +1616,6 @@ int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root, struct inode *inode);
|
||||
/* super.c */
|
||||
u64 btrfs_parse_size(char *str);
|
||||
int btrfs_parse_options(char *options, struct btrfs_root *root,
|
||||
char **subvol_name);
|
||||
int btrfs_parse_options(struct btrfs_root *root, char *options);
|
||||
int btrfs_sync_fs(struct super_block *sb, int wait);
|
||||
#endif
|
||||
|
@ -1266,8 +1266,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
|
||||
if (!btrfs_super_root(disk_super))
|
||||
goto fail_sb_buffer;
|
||||
|
||||
btrfs_parse_options(options, tree_root, NULL);
|
||||
err = btrfs_parse_options(tree_root, options);
|
||||
if (err)
|
||||
goto fail_sb_buffer;
|
||||
|
||||
err = -EINVAL;
|
||||
if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
|
||||
printk("Btrfs: wanted %llu devices, but found %llu\n",
|
||||
(unsigned long long)btrfs_super_num_devices(disk_super),
|
||||
|
237
fs/btrfs/super.c
237
fs/btrfs/super.c
@ -108,15 +108,18 @@ u64 btrfs_parse_size(char *str)
|
||||
return res;
|
||||
}
|
||||
|
||||
int btrfs_parse_options(char *options, struct btrfs_root *root,
|
||||
char **subvol_name)
|
||||
/*
|
||||
* Regular mount options parser. Everything that is needed only when
|
||||
* reading in a new superblock is parsed here.
|
||||
*/
|
||||
int btrfs_parse_options(struct btrfs_root *root, char *options)
|
||||
{
|
||||
char * p;
|
||||
struct btrfs_fs_info *info = NULL;
|
||||
struct btrfs_fs_info *info = root->fs_info;
|
||||
substring_t args[MAX_OPT_ARGS];
|
||||
char *p, *num;
|
||||
|
||||
if (!options)
|
||||
return 1;
|
||||
return 0;
|
||||
|
||||
/*
|
||||
* strsep changes the string, duplicate it because parse_options
|
||||
@ -126,10 +129,8 @@ int btrfs_parse_options(char *options, struct btrfs_root *root,
|
||||
if (!options)
|
||||
return -ENOMEM;
|
||||
|
||||
if (root)
|
||||
info = root->fs_info;
|
||||
|
||||
while ((p = strsep (&options, ",")) != NULL) {
|
||||
while ((p = strsep(&options, ",")) != NULL) {
|
||||
int token;
|
||||
if (!*p)
|
||||
continue;
|
||||
@ -137,83 +138,64 @@ int btrfs_parse_options(char *options, struct btrfs_root *root,
|
||||
token = match_token(p, tokens, args);
|
||||
switch (token) {
|
||||
case Opt_degraded:
|
||||
if (info) {
|
||||
printk("btrfs: allowing degraded mounts\n");
|
||||
btrfs_set_opt(info->mount_opt, DEGRADED);
|
||||
}
|
||||
printk(KERN_INFO "btrfs: allowing degraded mounts\n");
|
||||
btrfs_set_opt(info->mount_opt, DEGRADED);
|
||||
break;
|
||||
case Opt_subvol:
|
||||
if (subvol_name) {
|
||||
*subvol_name = match_strdup(&args[0]);
|
||||
}
|
||||
/*
|
||||
* This one is parsed by btrfs_parse_early_options
|
||||
* and can be happily ignored here.
|
||||
*/
|
||||
break;
|
||||
case Opt_nodatasum:
|
||||
if (info) {
|
||||
printk("btrfs: setting nodatacsum\n");
|
||||
btrfs_set_opt(info->mount_opt, NODATASUM);
|
||||
}
|
||||
printk(KERN_INFO "btrfs: setting nodatacsum\n");
|
||||
btrfs_set_opt(info->mount_opt, NODATASUM);
|
||||
break;
|
||||
case Opt_nodatacow:
|
||||
if (info) {
|
||||
printk("btrfs: setting nodatacow\n");
|
||||
btrfs_set_opt(info->mount_opt, NODATACOW);
|
||||
btrfs_set_opt(info->mount_opt, NODATASUM);
|
||||
}
|
||||
printk(KERN_INFO "btrfs: setting nodatacow\n");
|
||||
btrfs_set_opt(info->mount_opt, NODATACOW);
|
||||
btrfs_set_opt(info->mount_opt, NODATASUM);
|
||||
break;
|
||||
case Opt_ssd:
|
||||
if (info) {
|
||||
printk("btrfs: use ssd allocation scheme\n");
|
||||
btrfs_set_opt(info->mount_opt, SSD);
|
||||
}
|
||||
printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
|
||||
btrfs_set_opt(info->mount_opt, SSD);
|
||||
break;
|
||||
case Opt_nobarrier:
|
||||
if (info) {
|
||||
printk("btrfs: turning off barriers\n");
|
||||
btrfs_set_opt(info->mount_opt, NOBARRIER);
|
||||
}
|
||||
printk(KERN_INFO "btrfs: turning off barriers\n");
|
||||
btrfs_set_opt(info->mount_opt, NOBARRIER);
|
||||
break;
|
||||
case Opt_max_extent:
|
||||
if (info) {
|
||||
char *num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->max_extent =
|
||||
btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->max_extent = btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
|
||||
info->max_extent = max_t(u64,
|
||||
info->max_extent,
|
||||
root->sectorsize);
|
||||
printk("btrfs: max_extent at %Lu\n",
|
||||
info->max_extent);
|
||||
}
|
||||
info->max_extent = max_t(u64,
|
||||
info->max_extent, root->sectorsize);
|
||||
printk(KERN_INFO "btrfs: max_extent at %llu\n",
|
||||
info->max_extent);
|
||||
}
|
||||
break;
|
||||
case Opt_max_inline:
|
||||
if (info) {
|
||||
char *num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->max_inline =
|
||||
btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->max_inline = btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
|
||||
info->max_inline = max_t(u64,
|
||||
info->max_inline,
|
||||
root->sectorsize);
|
||||
printk("btrfs: max_inline at %Lu\n",
|
||||
info->max_inline);
|
||||
}
|
||||
info->max_inline = max_t(u64,
|
||||
info->max_inline, root->sectorsize);
|
||||
printk(KERN_INFO "btrfs: max_inline at %llu\n",
|
||||
info->max_inline);
|
||||
}
|
||||
break;
|
||||
case Opt_alloc_start:
|
||||
if (info) {
|
||||
char *num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->alloc_start =
|
||||
btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
printk("btrfs: allocations start at "
|
||||
"%Lu\n", info->alloc_start);
|
||||
}
|
||||
num = match_strdup(&args[0]);
|
||||
if (num) {
|
||||
info->alloc_start = btrfs_parse_size(num);
|
||||
kfree(num);
|
||||
printk(KERN_INFO
|
||||
"btrfs: allocations start at %llu\n",
|
||||
info->alloc_start);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
@ -221,7 +203,61 @@ int btrfs_parse_options(char *options, struct btrfs_root *root,
|
||||
}
|
||||
}
|
||||
kfree(options);
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Parse mount options that are required early in the mount process.
|
||||
*
|
||||
* All other options will be parsed on much later in the mount process and
|
||||
* only when we need to allocate a new super block.
|
||||
*/
|
||||
static int btrfs_parse_early_options(const char *options,
|
||||
char **subvol_name)
|
||||
{
|
||||
substring_t args[MAX_OPT_ARGS];
|
||||
char *opts, *p;
|
||||
int error = 0;
|
||||
|
||||
if (!options)
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* strsep changes the string, duplicate it because parse_options
|
||||
* gets called twice
|
||||
*/
|
||||
opts = kstrdup(options, GFP_KERNEL);
|
||||
if (!opts)
|
||||
return -ENOMEM;
|
||||
|
||||
while ((p = strsep(&opts, ",")) != NULL) {
|
||||
int token;
|
||||
if (!*p)
|
||||
continue;
|
||||
|
||||
token = match_token(p, tokens, args);
|
||||
switch (token) {
|
||||
case Opt_subvol:
|
||||
*subvol_name = match_strdup(&args[0]);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
kfree(opts);
|
||||
out:
|
||||
/*
|
||||
* If no subvolume name is specified we use the default one. Allocate
|
||||
* a copy of the string "default" here so that code later in the
|
||||
* mount path doesn't care if it's the default volume or another one.
|
||||
*/
|
||||
if (!*subvol_name) {
|
||||
*subvol_name = kstrdup("default", GFP_KERNEL);
|
||||
if (!*subvol_name)
|
||||
return -ENOMEM;
|
||||
}
|
||||
return error;
|
||||
}
|
||||
|
||||
static int btrfs_fill_super(struct super_block * sb,
|
||||
@ -328,23 +364,33 @@ static int btrfs_test_super(struct super_block *s, void *data)
|
||||
return root->fs_info->fs_devices == test_fs_devices;
|
||||
}
|
||||
|
||||
int btrfs_get_sb_bdev(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name, void *data,
|
||||
struct vfsmount *mnt, const char *subvol)
|
||||
/*
|
||||
* Find a superblock for the given device / mount point.
|
||||
*
|
||||
* Note: This is based on get_sb_bdev from fs/super.c with a few additions
|
||||
* for multiple device setup. Make sure to keep it in sync.
|
||||
*/
|
||||
static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data, struct vfsmount *mnt)
|
||||
{
|
||||
char *subvol_name = NULL;
|
||||
struct block_device *bdev = NULL;
|
||||
struct super_block *s;
|
||||
struct dentry *root;
|
||||
struct btrfs_fs_devices *fs_devices = NULL;
|
||||
int error = 0;
|
||||
|
||||
error = btrfs_parse_early_options(data, &subvol_name);
|
||||
if (error)
|
||||
goto error;
|
||||
|
||||
error = btrfs_scan_one_device(dev_name, flags, fs_type, &fs_devices);
|
||||
if (error)
|
||||
return error;
|
||||
goto error_free_subvol_name;
|
||||
|
||||
error = btrfs_open_devices(fs_devices, flags, fs_type);
|
||||
if (error)
|
||||
return error;
|
||||
goto error_free_subvol_name;
|
||||
|
||||
bdev = fs_devices->latest_bdev;
|
||||
btrfs_lock_volumes();
|
||||
@ -378,51 +424,36 @@ int btrfs_get_sb_bdev(struct file_system_type *fs_type,
|
||||
s->s_flags |= MS_ACTIVE;
|
||||
}
|
||||
|
||||
if (subvol) {
|
||||
root = lookup_one_len(subvol, s->s_root, strlen(subvol));
|
||||
if (IS_ERR(root)) {
|
||||
up_write(&s->s_umount);
|
||||
deactivate_super(s);
|
||||
error = PTR_ERR(root);
|
||||
goto error;
|
||||
}
|
||||
if (!root->d_inode) {
|
||||
dput(root);
|
||||
up_write(&s->s_umount);
|
||||
deactivate_super(s);
|
||||
error = -ENXIO;
|
||||
goto error;
|
||||
}
|
||||
} else {
|
||||
root = dget(s->s_root);
|
||||
root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
|
||||
if (IS_ERR(root)) {
|
||||
up_write(&s->s_umount);
|
||||
deactivate_super(s);
|
||||
error = PTR_ERR(root);
|
||||
goto error;
|
||||
}
|
||||
if (!root->d_inode) {
|
||||
dput(root);
|
||||
up_write(&s->s_umount);
|
||||
deactivate_super(s);
|
||||
error = -ENXIO;
|
||||
goto error;
|
||||
}
|
||||
|
||||
mnt->mnt_sb = s;
|
||||
mnt->mnt_root = root;
|
||||
|
||||
kfree(subvol_name);
|
||||
return 0;
|
||||
|
||||
error_s:
|
||||
error = PTR_ERR(s);
|
||||
error_bdev:
|
||||
btrfs_close_devices(fs_devices);
|
||||
error_free_subvol_name:
|
||||
kfree(subvol_name);
|
||||
error:
|
||||
return error;
|
||||
}
|
||||
/* end copy & paste */
|
||||
|
||||
static int btrfs_get_sb(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
||||
{
|
||||
int ret;
|
||||
char *subvol_name = NULL;
|
||||
|
||||
btrfs_parse_options((char *)data, NULL, &subvol_name);
|
||||
ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data, mnt,
|
||||
subvol_name ? subvol_name : "default");
|
||||
if (subvol_name)
|
||||
kfree(subvol_name);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
||||
{
|
||||
|
Loading…
Reference in New Issue
Block a user