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| author | Jeffle Xu <jefflexu@linux.alibaba.com> | 2022-04-25 20:21:32 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2022-05-18 00:11:19 +0800 |
| commit | 93b856bb5f66ae149ed91876b17c8c3fca576615 (patch) | |
| tree | 2167a51c26f000c812514a0e7044c23b4062296c /fs/erofs | |
| parent | 94d78946704f7facd010b9dee5e158921ab37398 (diff) | |
| download | linux-93b856bb5f66ae149ed91876b17c8c3fca576615.tar.gz | |
erofs: add fscache mode check helper
Until then erofs is exactly blockdev based filesystem. A new fscache-based mode is going to be introduced for erofs to support scenarios where on-demand read semantics is needed, e.g. container image distribution. In this case, erofs could be mounted from data blobs through fscache. Add a helper checking which mode erofs works in, and twist the code in preparation for the upcoming fscache mode. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20220425122143.56815-11-jefflexu@linux.alibaba.com Acked-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs')
| -rw-r--r-- | fs/erofs/internal.h | 5 | ||||
| -rw-r--r-- | fs/erofs/super.c | 44 |
2 files changed, 34 insertions, 15 deletions
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index c83bd3965cb5..52911eaf36f6 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -161,6 +161,11 @@ struct erofs_sb_info { #define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option) #define test_opt(opt, option) ((opt)->mount_opt & EROFS_MOUNT_##option) +static inline bool erofs_is_fscache_mode(struct super_block *sb) +{ + return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !sb->s_bdev; +} + enum { EROFS_ZIP_CACHE_DISABLED, EROFS_ZIP_CACHE_READAHEAD, diff --git a/fs/erofs/super.c b/fs/erofs/super.c index a326445af7d0..46ca7917cb2a 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -260,15 +260,19 @@ static int erofs_init_devices(struct super_block *sb, } dis = ptr + erofs_blkoff(pos); - bdev = blkdev_get_by_path(dif->path, - FMODE_READ | FMODE_EXCL, - sb->s_type); - if (IS_ERR(bdev)) { - err = PTR_ERR(bdev); - break; + if (!erofs_is_fscache_mode(sb)) { + bdev = blkdev_get_by_path(dif->path, + FMODE_READ | FMODE_EXCL, + sb->s_type); + if (IS_ERR(bdev)) { + err = PTR_ERR(bdev); + break; + } + dif->bdev = bdev; + dif->dax_dev = fs_dax_get_by_bdev(bdev, + &dif->dax_part_off); } - dif->bdev = bdev; - dif->dax_dev = fs_dax_get_by_bdev(bdev, &dif->dax_part_off); + dif->blocks = le32_to_cpu(dis->blocks); dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); sbi->total_blocks += dif->blocks; @@ -625,21 +629,28 @@ 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)) { - erofs_err(sb, "failed to set erofs blksize"); - return -EINVAL; - } - sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; sbi->opt = ctx->opt; - sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->dax_part_off); sbi->devs = ctx->devs; ctx->devs = NULL; + if (erofs_is_fscache_mode(sb)) { + sb->s_blocksize = EROFS_BLKSIZ; + sb->s_blocksize_bits = LOG_BLOCK_SIZE; + } else { + if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) { + erofs_err(sb, "failed to set erofs blksize"); + return -EINVAL; + } + + sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev, + &sbi->dax_part_off); + } + err = erofs_read_superblock(sb); if (err) return err; @@ -897,7 +908,10 @@ 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; + + if (!erofs_is_fscache_mode(sb)) + id = huge_encode_dev(sb->s_bdev->bd_dev); buf->f_type = sb->s_magic; buf->f_bsize = EROFS_BLKSIZ; |