Messages in this thread | | | Date | Thu, 2 Mar 2023 21:23:46 +0800 | Subject | Re: [PATCH v3 2/2] erofs: set block size to the on-disk block size | From | Gao Xiang <> |
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Hi Jingbo,
On 2023/2/20 10:50, Jingbo Xu wrote: > Set the block size to that specified in on-disk superblock. > > Also remove the hard constraint of PAGE_SIZE block size for the > uncompressed device backend. This constraint is temporarily remained > for compressed device and fscache backend, as there is more work needed > to handle the condition where the block size is not equal to PAGE_SIZE. > > It is worth noting that the on-disk block size is read prior to > erofs_superblock_csum_verify(), as the read block size is needed in the > latter. > > Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> > --- > fs/erofs/erofs_fs.h | 2 +- > fs/erofs/inode.c | 3 ++- > fs/erofs/internal.h | 8 -------- > fs/erofs/super.c | 42 +++++++++++++++++++++++++++--------------- > 4 files changed, 30 insertions(+), 25 deletions(-) > > diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h > index dbcd24371002..5c7647d68c07 100644 > --- a/fs/erofs/erofs_fs.h > +++ b/fs/erofs/erofs_fs.h > @@ -53,7 +53,7 @@ struct erofs_super_block { > __le32 magic; /* file system magic number */ > __le32 checksum; /* crc32c(super_block) */ > __le32 feature_compat; > - __u8 blkszbits; /* support block_size == PAGE_SIZE only */ > + __u8 blkszbits; /* filesystem block size */ > __u8 sb_extslots; /* superblock size = 128 + sb_extslots * 16 */ > > __le16 root_nid; /* nid of root directory */
Due to we already support < page_size blocks, laterly, we'd consider refer to tar data blobs (which is 512-byte aligned) for OCI containers.
So we will have another use case is to use 512-byte block size, but in that case, dir block size is too small.
So I'd like to add a reserved bit __u8 dirblkbits;
for this.
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c > index de26dac4e07e..0e6ff8a98c68 100644 > --- a/fs/erofs/inode.c > +++ b/fs/erofs/inode.c > @@ -291,7 +291,8 @@ static int erofs_fill_inode(struct inode *inode) > } > > if (erofs_inode_is_data_compressed(vi->datalayout)) { > - if (!erofs_is_fscache_mode(inode->i_sb)) > + if (!erofs_is_fscache_mode(inode->i_sb) && > + inode->i_sb->s_blocksize_bits == PAGE_SHIFT) > err = z_erofs_fill_inode(inode); > else > err = -EOPNOTSUPP; > diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h > index d8019d835405..612543915e9e 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -240,14 +240,6 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) > VAL != EROFS_LOCKED_MAGIC); > } > > -/* we strictly follow PAGE_SIZE and no buffer head yet */ > -#define LOG_BLOCK_SIZE PAGE_SHIFT > -#define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE) > - > -#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ) > -#error erofs cannot be used in this platform > -#endif > - > enum erofs_kmap_type { > EROFS_NO_KMAP, /* don't map the buffer */ > EROFS_KMAP, /* use kmap_local_page() to map the buffer */ > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index c97615c96ef8..89011a4ed274 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -349,6 +349,14 @@ static int erofs_read_superblock(struct super_block *sb) > goto out; > } > > + blkszbits = dsb->blkszbits; > + sbi->blkszbits = dsb->blkszbits; > + if (blkszbits < 9 || blkszbits > PAGE_SHIFT) { > + erofs_err(sb, "blkszbits %u isn't supported on this platform", > + blkszbits); > + goto out; > + }
Also, if (blkszbits != PAGE_SHIFT && dsb->dirblkbits) { erofs_err("dirblkbits %u isn't supported", dsb->dirblkbits); goto out; }
Thanks, Gao Xiang
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