Until then erofs is exactly blockdev based filesystem. In other using
scenarios (e.g. container image), erofs needs to run upon files.
This patch introduces a new mount option "bootstrap_path", which is used
to specify the bootstrap blob file containing the complete erofs image.
Then erofs could be mounted from the bootstrap blob file.
Signed-off-by: Jeffle Xu <jeffl...@linux.alibaba.com>
---
fs/erofs/data.c | 13 ++++++++++---
fs/erofs/internal.h | 1 +
fs/erofs/super.c | 40 +++++++++++++++++++++++++++++++++++-----
3 files changed, 46 insertions(+), 8 deletions(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 477aaff0c832..cf71082bd52f 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -11,11 +11,18 @@
struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)
{
- struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
+ struct address_space * mapping;
struct page *page;
- page = read_cache_page_gfp(mapping, blkaddr,
- mapping_gfp_constraint(mapping, ~__GFP_FS));
+ if (sb->s_bdev) {
+ mapping = sb->s_bdev->bd_inode->i_mapping;
+ page = read_cache_page_gfp(mapping, blkaddr,
+ mapping_gfp_constraint(mapping, ~__GFP_FS));
+ } else {
+ /* TODO: fscache based data path */
+ page = ERR_PTR(-EINVAL);
+ }
+
/* should already be PageUptodate */
if (!IS_ERR(page))
lock_page(page);
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 45fb6f5d11b5..cf69d9c9cbed 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -67,6 +67,7 @@ struct erofs_mount_opts {
unsigned int max_sync_decompress_pages;
#endif
unsigned int mount_opt;
+ char *bootstrap_path;
};
struct erofs_dev_context {
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 6a969b1e0ee6..51695f6d4449 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -440,6 +440,7 @@ enum {
Opt_dax,
Opt_dax_enum,
Opt_device,
+ Opt_bootstrap_path,
Opt_err
};
@@ -464,6 +465,7 @@ static const struct fs_parameter_spec erofs_fs_parameters[]
= {
fsparam_flag("dax", Opt_dax),
fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums),
fsparam_string("device", Opt_device),
+ fsparam_string("bootstrap_path",Opt_bootstrap_path),
{}
};
@@ -559,6 +561,14 @@ static int erofs_fc_parse_param(struct fs_context *fc,
}
++ctx->devs->extra_devices;
break;
+ case Opt_bootstrap_path:
+ kfree(ctx->opt.bootstrap_path);
+ ctx->opt.bootstrap_path = kstrdup(param->string, GFP_KERNEL);
+ if (!ctx->opt.bootstrap_path)
+ return -ENOMEM;
+ infofc(fc, "RAFS bootstrap_path %s", ctx->opt.bootstrap_path);
+ break;
+
default:
return -ENOPARAM;
}
@@ -633,9 +643,12 @@ static int erofs_fc_fill_super(struct super_block *sb,
struct fs_context *fc)
sb->s_magic = EROFS_SUPER_MAGIC;
- if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) {
+ if (sb->s_bdev && !sb_set_blocksize(sb, EROFS_BLKSIZ)) {
erofs_err(sb, "failed to set erofs blksize");
return -EINVAL;
+ } else {
+ sb->s_blocksize = EROFS_BLKSIZ;
+ sb->s_blocksize_bits = LOG_BLOCK_SIZE;
}
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
@@ -644,16 +657,21 @@ static int erofs_fc_fill_super(struct super_block *sb,
struct fs_context *fc)
sb->s_fs_info = sbi;
sbi->opt = ctx->opt;
- sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
sbi->devs = ctx->devs;
ctx->devs = NULL;
+ if (sb->s_bdev)
+ sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
+ else
+ sbi->dax_dev = NULL;
+
err = erofs_read_superblock(sb);
if (err)
return err;
if (test_opt(&sbi->opt, DAX_ALWAYS) &&
- !dax_supported(sbi->dax_dev, sb->s_bdev, EROFS_BLKSIZ, 0,
bdev_nr_sectors(sb->s_bdev))) {
+ (!sbi->dax_dev ||
+ !dax_supported(sbi->dax_dev, sb->s_bdev, EROFS_BLKSIZ, 0,
bdev_nr_sectors(sb->s_bdev)))) {
errorfc(fc, "DAX unsupported by block device. Turning off
DAX.");
clear_opt(&sbi->opt, DAX_ALWAYS);
}
@@ -701,6 +719,10 @@ static int erofs_fc_fill_super(struct super_block *sb,
struct fs_context *fc)
static int erofs_fc_get_tree(struct fs_context *fc)
{
+ struct erofs_fs_context *ctx = fc->fs_private;
+
+ if (ctx->opt.bootstrap_path)
+ return get_tree_nodev(fc, erofs_fc_fill_super);
return get_tree_bdev(fc, erofs_fc_fill_super);
}
@@ -749,6 +771,7 @@ static void erofs_fc_free(struct fs_context *fc)
struct erofs_fs_context *ctx = fc->fs_private;
erofs_free_dev_context(ctx->devs);
+ kfree(ctx->opt.bootstrap_path);
kfree(ctx);
}
@@ -789,7 +812,10 @@ static void erofs_kill_sb(struct super_block *sb)
WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
- kill_block_super(sb);
+ if (sb->s_bdev)
+ kill_block_super(sb);
+ else
+ generic_shutdown_super(sb);
sbi = EROFS_SB(sb);
if (!sbi)
@@ -889,7 +915,11 @@ static int erofs_statfs(struct dentry *dentry, struct
kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
- u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+ u64 id = 0;
+
+ /* TODO: fsid in nodev mode */
+ if (sb->s_bdev)
+ id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = sb->s_magic;
buf->f_bsize = EROFS_BLKSIZ;
--
2.27.0
--
Linux-cachefs mailing list
Linux-cachefs@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-cachefs
