Messages in this thread | | | Date | Mon, 13 Mar 2023 20:04:28 +0800 | Subject | Re: [PATCH v5 2/2] erofs: set block size to the on-disk block size | From | Gao Xiang <> |
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On 2023/3/6 18:02, 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. > > Besides, later we are going to make erofs refer to tar data blobs (which > is 512-byte aligned) for OCI containers, where the block size is 512 > bytes. In this case, the 512-byte block size may not be adequate for a > directory to contain enough dirents. To fix this, we are also going to > introduce directory block size independent on the block size. > > Due to we have already supported block size smaller than PAGE_SIZE now, > disable all these images with such separated directory block size until > we supported this feature later. > > Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> > Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> > --- > fs/erofs/erofs_fs.h | 5 +++-- > fs/erofs/inode.c | 3 ++- > fs/erofs/internal.h | 11 ++--------- > fs/erofs/super.c | 46 +++++++++++++++++++++++++++++---------------- > 4 files changed, 37 insertions(+), 28 deletions(-) > > diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h > index dbcd24371002..44876a97cabd 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 in bit shift */ > __u8 sb_extslots; /* superblock size = 128 + sb_extslots * 16 */ > > __le16 root_nid; /* nid of root directory */ > @@ -75,7 +75,8 @@ struct erofs_super_block { > } __packed u1; > __le16 extra_devices; /* # of devices besides the primary device */ > __le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */ > - __u8 reserved[6]; > + __u8 dirblkbits; /* directory block size in bit shift */ > + __u8 reserved[5]; > __le64 packed_nid; /* nid of the special packed inode */ > __u8 reserved2[24]; > }; > 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..561df4ce9a62 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -148,7 +148,8 @@ struct erofs_sb_info { > u16 device_id_mask; /* valid bits of device id to be used */ > > unsigned char islotbits; /* inode slot unit size in bit shift */ > - unsigned char blkszbits; > + unsigned char blkszbits; /* filesystem block size in bit shift */ > + unsigned char dirblkbits; /* directory block size in bit shift */ > > u32 sb_size; /* total superblock size */ > u32 build_time_nsec; > @@ -240,14 +241,6 @@ 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..d5fa0f582cbe 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -330,7 +330,6 @@ static int erofs_read_superblock(struct super_block *sb) > struct erofs_sb_info *sbi; > struct erofs_buf buf = __EROFS_BUF_INITIALIZER; > struct erofs_super_block *dsb; > - unsigned int blkszbits; > void *data; > int ret; > > @@ -349,6 +348,17 @@ static int erofs_read_superblock(struct super_block *sb) > goto out; > } > > + sbi->blkszbits = dsb->blkszbits; > + sbi->dirblkbits = dsb->dirblkbits; > + if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) { > + erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits); > + goto out; > + } > + if (sbi->dirblkbits) {
I think we could just
if (dsb->dirblkbits) {
so we could avoid "sbi->dirblkbits" in this patch for now and add in the later patches.
Thanks, Gao Xiang
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