On Thu, 2 Mar 2023 22:39:15 +0800 Jingbo Xu <[email protected]> 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 <[email protected]> > --- > 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..ac9c2ff3aa66 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 */ /* 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 */ Ditto. > + __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..f99ba4061a3b 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 */ Ditto. > + unsigned char dirblkbits; /* directory block size */ Ditto. > > 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) { > + erofs_err(sb, "dirblkbits %u isn't supported", sbi->dirblkbits); > + goto out; > + } > + > sbi->feature_compat = le32_to_cpu(dsb->feature_compat); > if (erofs_sb_has_sb_chksum(sbi)) { > ret = erofs_superblock_csum_verify(sb, data); > @@ -357,19 +367,11 @@ static int erofs_read_superblock(struct super_block *sb) > } > > ret = -EINVAL; > - blkszbits = dsb->blkszbits; > - /* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */ > - if (blkszbits != LOG_BLOCK_SIZE) { > - erofs_err(sb, "blkszbits %u isn't supported on this platform", > - blkszbits); > - goto out; > - } > - > if (!check_layout_compatibility(sb, dsb)) > goto out; > > sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE; > - if (sbi->sb_size > EROFS_BLKSIZ) { > + if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) { > erofs_err(sb, "invalid sb_extslots %u (more than a fs block)", > sbi->sb_size); > goto out; > @@ -736,8 +738,8 @@ static int erofs_fc_fill_super(struct super_block *sb, > struct fs_context *fc) > > sbi->blkszbits = PAGE_SHIFT; > if (erofs_is_fscache_mode(sb)) { > - sb->s_blocksize = EROFS_BLKSIZ; > - sb->s_blocksize_bits = LOG_BLOCK_SIZE; > + sb->s_blocksize = PAGE_SIZE; > + sb->s_blocksize_bits = PAGE_SHIFT; > > err = erofs_fscache_register_fs(sb); > if (err) > @@ -747,8 +749,8 @@ static int erofs_fc_fill_super(struct super_block *sb, > struct fs_context *fc) > if (err) > return err; > } else { > - if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) { > - erofs_err(sb, "failed to set erofs blksize"); > + if (!sb_set_blocksize(sb, PAGE_SIZE)) { > + errorfc(fc, "failed to set initial blksize"); > return -EINVAL; > } > > @@ -761,12 +763,24 @@ static int erofs_fc_fill_super(struct super_block *sb, > struct fs_context *fc) > if (err) > return err; > > - if (test_opt(&sbi->opt, DAX_ALWAYS)) { > - BUILD_BUG_ON(EROFS_BLKSIZ != PAGE_SIZE); > + if (sb->s_blocksize_bits != sbi->blkszbits) { > + if (erofs_is_fscache_mode(sb)) { > + errorfc(fc, "unsupported blksize for fscache mode"); > + return -EINVAL; > + } > + if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) { > + errorfc(fc, "failed to set erofs blksize"); > + return -EINVAL; > + } > + } > > + if (test_opt(&sbi->opt, DAX_ALWAYS)) { > if (!sbi->dax_dev) { > errorfc(fc, "DAX unsupported by block device. Turning > off DAX."); > clear_opt(&sbi->opt, DAX_ALWAYS); > + } else if (sbi->blkszbits != PAGE_SHIFT) { > + errorfc(fc, "unsupported blocksize for DAX"); > + clear_opt(&sbi->opt, DAX_ALWAYS); > } > } >
