Okay. Apologies. I think we already have erofs_blknr() to do this job. I can use that.:) --Pratik. On Mon, Dec 30, 2019 at 12:34 PM Pratik Shinde wrote: > Thanks got it. > > Then we can use LOG_BLOCK_SIZE , to get block no. for corresponding file > offset. > > --Pratik. > > On Mon, Dec 30, 2019 at 12:19 PM Gao Xiang wrote: > >> On Mon, Dec 30, 2019 at 11:49:55AM +0530, Pratik Shinde wrote: >> > Gao, >> > >> > Okay, I will rename the 'size' variables accordingly. >> > The 'S_SHIFT' gives the logical block number inside file. I am using it >> to >> > assign logical block no. >> > to extents. >> >> S_SHIFT is used to transfer between i_mode and filetype, see: >> https://elixir.bootlin.com/linux/latest/source/fs/ext4/ext4.h#L3196 >> >> IMO, which is not the above meaning, how about using EROFS_BLKSIZ >> instead? >> >> Thanks, >> Gao Xiang >> >> > Also, I will modify the code to record only data extents. >> > >> > --Pratik. >> > >> > On Sun, Dec 29, 2019 at 8:26 AM Gao Xiang wrote: >> > >> > > Hi Pratik, >> > > >> > > On Fri, Dec 27, 2019 at 09:13:48PM +0530, Pratik Shinde wrote: >> > > > since this patch is quite different from previous patches I am >> treating >> > > > this as new patch. >> > > > >> > > > 1) On disk extent format for erofs data blocks. >> > > > 2) Detect holes inside files & skip allocation for hole blocks. >> > > > >> > > > Signed-off-by: Pratik Shinde >> > > > --- >> > > > include/erofs/internal.h | 21 ++++++- >> > > > lib/inode.c | 155 >> > > +++++++++++++++++++++++++++++++++++++++++------ >> > > > 2 files changed, 156 insertions(+), 20 deletions(-) >> > > > >> > > > diff --git a/include/erofs/internal.h b/include/erofs/internal.h >> > > > index e13adda..128aa63 100644 >> > > > --- a/include/erofs/internal.h >> > > > +++ b/include/erofs/internal.h >> > > > @@ -63,7 +63,7 @@ struct erofs_sb_info { >> > > > extern struct erofs_sb_info sbi; >> > > > >> > > > struct erofs_inode { >> > > > - struct list_head i_hash, i_subdirs, i_xattrs; >> > > > + struct list_head i_hash, i_subdirs, i_xattrs, i_extents; >> > > > >> > > > unsigned int i_count; >> > > > struct erofs_inode *i_parent; >> > > > @@ -93,6 +93,7 @@ struct erofs_inode { >> > > > >> > > > unsigned int xattr_isize; >> > > > unsigned int extent_isize; >> > > > + unsigned int extent_meta_isize; >> > > >> > > maybe sparse_extent_isize is better... >> > > >> > > p.s. maybe we could send another patch rename extent_isize to >> > > compress_extent_isize or some better name... >> > > >> > > > >> > > > erofs_nid_t nid; >> > > > struct erofs_buffer_head *bh; >> > > > @@ -139,5 +140,23 @@ static inline const char *erofs_strerror(int >> err) >> > > > return msg; >> > > > } >> > > > >> > > > +#define HOLE_BLK -1 >> > > > +/* on disk extent format */ >> > > > +struct erofs_extent { >> > > > + __le32 ee_lblk; >> > > > + __le32 ee_pblk; >> > > > + __le32 ee_len; >> > > > +}; >> > > > + >> > > > +struct erofs_extent_node { >> > > > + struct list_head next; >> > > > + erofs_blk_t lblk; >> > > > + erofs_blk_t pblk; >> > > > + u32 len; >> > > > +}; >> > > > + >> > > > +struct erofs_inline_extent_header { >> > > > + u32 count; >> > > > +}; >> > > > #endif >> > > > >> > > > diff --git a/lib/inode.c b/lib/inode.c >> > > > index 0e19b11..a6af509 100644 >> > > > --- a/lib/inode.c >> > > > +++ b/lib/inode.c >> > > > @@ -38,6 +38,99 @@ static unsigned char erofs_type_by_mode[S_IFMT >> >> > > S_SHIFT] = { >> > > > >> > > > struct list_head inode_hashtable[NR_INODE_HASHTABLE]; >> > > > >> > > > + >> > > > +#define IS_HOLE(start, end) (roundup(start, EROFS_BLKSIZ) == start >> && >> > > \ >> > > > + roundup(end, EROFS_BLKSIZ) == end && >> \ >> > > > + (end - start) % EROFS_BLKSIZ == 0) >> > > >> > > See below.. >> > > >> > > > + >> > > > +/* returns the number of holes present in the file */ >> > > > +unsigned int erofs_read_extents(struct erofs_inode *inode, >> > > > + struct list_head *extents) >> > > > +{ >> > > > + int fd, st, en, dt; >> > > > + unsigned int nholes = 0; >> > > > + erofs_off_t data, hole, len, last_data; >> > > > + struct erofs_extent_node *e_hole, *e_data; >> > > > + >> > > > + fd = open(inode->i_srcpath, O_RDONLY); >> > > > + if (fd < 0) { >> > > > + return -errno; >> > > > + } >> > > > + len = lseek(fd, 0, SEEK_END); >> > > > + if (lseek(fd, 0, SEEK_SET) == -1) >> > > > + return -errno; >> > > > + data = 0; >> > > > + last_data = 0; >> > > > + while (data < len) { >> > > > + hole = lseek(fd, data, SEEK_HOLE); >> > > > + if (hole == len) >> > > > + break; >> > > > + data = lseek(fd, hole, SEEK_DATA); >> > > > + if (data < 0 || hole > data) { >> > > > + return -EINVAL; >> > > > + } >> > > > + if (IS_HOLE(hole, data)) { >> > > > + st = hole >> S_SHIFT; >> > > > + en = data >> S_SHIFT; >> > > > + dt = last_data >> S_SHIFT; >> > > >> > > Why using S_SHIFT here, some special meaning? >> > > >> > > > + last_data = data; >> > > > + e_data = malloc(sizeof(struct >> erofs_extent_node)); >> > > > + if (e_data == NULL) >> > > > + return -ENOMEM; >> > > > + e_data->lblk = dt; >> > > > + e_data->len = (st - dt); >> > > > + list_add_tail(&e_data->next, extents); >> > > > + e_hole = malloc(sizeof(struct >> erofs_extent_node)); >> > > > + if (e_hole == NULL) >> > > > + return -ENOMEM; >> > > > + e_hole->lblk = st; >> > > > + e_hole->pblk = HOLE_BLK; >> > > > + e_hole->len = (en - st); >> > > > + list_add_tail(&e_hole->next, extents); >> > > > + nholes += e_hole->len; >> > > >> > > Maybe we don't need to emit all HOLK extents since all data extents >> > > are with _length_... It is easy to detect all holes between extents... >> > > >> > > If some block doesn't belong to any extent, it's a hole. >> > > >> > > Thanks, >> > > Gao Xiang >> > > >> > > > + } >> > > > + } >> > > > + /* rounddown to exclude tail-end data */ >> > > > + if (last_data < len && (len - last_data) >= EROFS_BLKSIZ) { >> > > > + e_data = malloc(sizeof(struct erofs_extent_node)); >> > > > + if (e_data == NULL) >> > > > + return -ENOMEM; >> > > > + st = last_data >> S_SHIFT; >> > > > + e_data->lblk = st; >> > > > + e_data->len = rounddown((len - last_data), >> EROFS_BLKSIZ) >> > > >> S_SHIFT; >> > > > + list_add_tail(&e_data->next, extents); >> > > > + } >> > > > + return nholes; >> > > > +} >> > > > + >> > > > +char *erofs_create_extent_buffer(struct list_head *extents, >> unsigned >> > > int size) >> > > > +{ >> > > > + struct erofs_extent_node *e_node; >> > > > + struct erofs_inline_extent_header *header; >> > > > + char *buf; >> > > > + unsigned int p = 0; >> > > > + >> > > > + buf = malloc(size); >> > > > + if (buf == NULL) >> > > > + return ERR_PTR(-ENOMEM); >> > > > + header = (struct erofs_inline_extent_header *) buf; >> > > > + header->count = 0; >> > > > + p += sizeof(struct erofs_inline_extent_header); >> > > > + list_for_each_entry(e_node, extents, next) { >> > > > + const struct erofs_extent ee = { >> > > > + .ee_lblk = cpu_to_le32(e_node->lblk), >> > > > + .ee_pblk = cpu_to_le32(e_node->pblk), >> > > > + .ee_len = cpu_to_le32(e_node->len) >> > > > + }; >> > > > + memcpy(buf + p, &ee, sizeof(struct erofs_extent)); >> > > > + p += sizeof(struct erofs_extent); >> > > > + header->count++; >> > > > + list_del(&e_node->next); >> > > > + free(e_node); >> > > > + } >> > > > + return buf; >> > > > +} >> > > > + >> > > > void erofs_inode_manager_init(void) >> > > > { >> > > > unsigned int i; >> > > > @@ -304,8 +397,9 @@ static bool erofs_file_is_compressible(struct >> > > erofs_inode *inode) >> > > > >> > > > int erofs_write_file(struct erofs_inode *inode) >> > > > { >> > > > - unsigned int nblocks, i; >> > > > + unsigned int nblocks, i, j, nholes; >> > > > int ret, fd; >> > > > + struct erofs_extent_node *e_node; >> > > > >> > > > if (!inode->i_size) { >> > > > inode->datalayout = EROFS_INODE_FLAT_PLAIN; >> > > > @@ -322,31 +416,43 @@ int erofs_write_file(struct erofs_inode >> *inode) >> > > > /* fallback to all data uncompressed */ >> > > > inode->datalayout = EROFS_INODE_FLAT_INLINE; >> > > > nblocks = inode->i_size / EROFS_BLKSIZ; >> > > > - >> > > > - ret = __allocate_inode_bh_data(inode, nblocks); >> > > > + nholes = erofs_read_extents(inode, &inode->i_extents); >> > > > + if (nholes < 0) >> > > > + return nholes; >> > > > + if (nblocks < 0) >> > > > + return nblocks; >> > > > + ret = __allocate_inode_bh_data(inode, nblocks - nholes); >> > > > if (ret) >> > > > return ret; >> > > > >> > > > fd = open(inode->i_srcpath, O_RDONLY | O_BINARY); >> > > > if (fd < 0) >> > > > return -errno; >> > > > - >> > > > - for (i = 0; i < nblocks; ++i) { >> > > > - char buf[EROFS_BLKSIZ]; >> > > > - >> > > > - ret = read(fd, buf, EROFS_BLKSIZ); >> > > > - if (ret != EROFS_BLKSIZ) { >> > > > - if (ret < 0) >> > > > - goto fail; >> > > > - close(fd); >> > > > - return -EAGAIN; >> > > > + i = inode->u.i_blkaddr; >> > > > + inode->extent_meta_isize = sizeof(struct >> > > erofs_inline_extent_header); >> > > > + list_for_each_entry(e_node, &inode->i_extents, next) { >> > > > + inode->extent_meta_isize += sizeof(struct >> erofs_extent); >> > > > + if (e_node->pblk == HOLE_BLK) { >> > > > + lseek(fd, e_node->len * EROFS_BLKSIZ, >> SEEK_CUR); >> > > > + continue; >> > > > } >> > > > + e_node->pblk = i; >> > > > + i += e_node->len; >> > > > + for (j = 0; j < e_node->len; j++) { >> > > > + char buf[EROFS_BLKSIZ]; >> > > > + ret = read(fd, buf, EROFS_BLKSIZ); >> > > > + if (ret != EROFS_BLKSIZ) { >> > > > + if (ret < 0) >> > > > + goto fail; >> > > > + close(fd); >> > > > + return -EAGAIN; >> > > > + } >> > > > + ret = blk_write(buf, e_node->pblk + j, 1); >> > > > + if (ret) >> > > > + goto fail; >> > > > >> > > > - ret = blk_write(buf, inode->u.i_blkaddr + i, 1); >> > > > - if (ret) >> > > > - goto fail; >> > > > + } >> > > > } >> > > > - >> > > > /* read the tail-end data */ >> > > > inode->idata_size = inode->i_size % EROFS_BLKSIZ; >> > > > if (inode->idata_size) { >> > > > @@ -479,8 +585,19 @@ static bool erofs_bh_flush_write_inode(struct >> > > erofs_buffer_head *bh) >> > > > if (ret) >> > > > return false; >> > > > free(inode->compressmeta); >> > > > + off += inode->extent_isize; >> > > > } >> > > > >> > > > + if (inode->extent_meta_isize) { >> > > > + char *extents = >> > > erofs_create_extent_buffer(&inode->i_extents, >> > > > + >> > > inode->extent_meta_isize); >> > > > + if (IS_ERR(extents)) >> > > > + return false; >> > > > + ret = dev_write(extents, off, >> inode->extent_meta_isize); >> > > > + free(extents); >> > > > + if (ret) >> > > > + return false; >> > > > + } >> > > > inode->bh = NULL; >> > > > erofs_iput(inode); >> > > > return erofs_bh_flush_generic_end(bh); >> > > > @@ -737,10 +854,11 @@ struct erofs_inode *erofs_new_inode(void) >> > > > >> > > > init_list_head(&inode->i_subdirs); >> > > > init_list_head(&inode->i_xattrs); >> > > > + init_list_head(&inode->i_extents); >> > > > >> > > > inode->idata_size = 0; >> > > > inode->xattr_isize = 0; >> > > > - inode->extent_isize = 0; >> > > > + inode->extent_meta_isize = 0; >> > > > >> > > > inode->bh = inode->bh_inline = inode->bh_data = NULL; >> > > > inode->idata = NULL; >> > > > @@ -961,4 +1079,3 @@ struct erofs_inode >> > > *erofs_mkfs_build_tree_from_path(struct erofs_inode *parent, >> > > > >> > > > return erofs_mkfs_build_tree(inode); >> > > > } >> > > > - >> > > > -- >> > > > 2.9.3 >> > > > >> > > >> >