<div dir="ltr"><div>Okay. Apologies. I think we already have erofs_blknr() to do this job. I can use that.:)</div><div><br></div><div>--Pratik.<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Dec 30, 2019 at 12:34 PM Pratik Shinde <<a href="mailto:pratikshinde320@gmail.com">pratikshinde320@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Thanks got it.</div><div><br></div><div>Then we can use LOG_BLOCK_SIZE , to get block no. for corresponding file offset.</div><div><br></div><div>--Pratik.<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Dec 30, 2019 at 12:19 PM Gao Xiang <<a href="mailto:gaoxiang25@huawei.com" target="_blank">gaoxiang25@huawei.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Mon, Dec 30, 2019 at 11:49:55AM +0530, Pratik Shinde wrote:<br>
> Gao,<br>
> <br>
> Okay, I will rename the 'size' variables accordingly.<br>
> The 'S_SHIFT' gives the logical block number inside file. I am using it to<br>
> assign logical block no.<br>
> to extents.<br>
<br>
S_SHIFT is used to transfer between i_mode and filetype, see:<br>
<a href="https://elixir.bootlin.com/linux/latest/source/fs/ext4/ext4.h#L3196" rel="noreferrer" target="_blank">https://elixir.bootlin.com/linux/latest/source/fs/ext4/ext4.h#L3196</a><br>
<br>
IMO, which is not the above meaning, how about using EROFS_BLKSIZ<br>
instead?<br>
<br>
Thanks,<br>
Gao Xiang<br>
<br>
> Also, I will modify the code to record only data extents.<br>
> <br>
> --Pratik.<br>
> <br>
> On Sun, Dec 29, 2019 at 8:26 AM Gao Xiang <<a href="mailto:hsiangkao@aol.com" target="_blank">hsiangkao@aol.com</a>> wrote:<br>
> <br>
> > Hi Pratik,<br>
> ><br>
> > On Fri, Dec 27, 2019 at 09:13:48PM +0530, Pratik Shinde wrote:<br>
> > > since this patch is quite different from previous patches I am treating<br>
> > > this as new patch.<br>
> > ><br>
> > > 1) On disk extent format for erofs data blocks.<br>
> > > 2) Detect holes inside files & skip allocation for hole blocks.<br>
> > ><br>
> > > Signed-off-by: Pratik Shinde <<a href="mailto:pratikshinde320@gmail.com" target="_blank">pratikshinde320@gmail.com</a>><br>
> > > ---<br>
> > > include/erofs/internal.h | 21 ++++++-<br>
> > > lib/inode.c | 155<br>
> > +++++++++++++++++++++++++++++++++++++++++------<br>
> > > 2 files changed, 156 insertions(+), 20 deletions(-)<br>
> > ><br>
> > > diff --git a/include/erofs/internal.h b/include/erofs/internal.h<br>
> > > index e13adda..128aa63 100644<br>
> > > --- a/include/erofs/internal.h<br>
> > > +++ b/include/erofs/internal.h<br>
> > > @@ -63,7 +63,7 @@ struct erofs_sb_info {<br>
> > > extern struct erofs_sb_info sbi;<br>
> > ><br>
> > > struct erofs_inode {<br>
> > > - struct list_head i_hash, i_subdirs, i_xattrs;<br>
> > > + struct list_head i_hash, i_subdirs, i_xattrs, i_extents;<br>
> > ><br>
> > > unsigned int i_count;<br>
> > > struct erofs_inode *i_parent;<br>
> > > @@ -93,6 +93,7 @@ struct erofs_inode {<br>
> > ><br>
> > > unsigned int xattr_isize;<br>
> > > unsigned int extent_isize;<br>
> > > + unsigned int extent_meta_isize;<br>
> ><br>
> > maybe sparse_extent_isize is better...<br>
> ><br>
> > p.s. maybe we could send another patch rename extent_isize to<br>
> > compress_extent_isize or some better name...<br>
> ><br>
> > ><br>
> > > erofs_nid_t nid;<br>
> > > struct erofs_buffer_head *bh;<br>
> > > @@ -139,5 +140,23 @@ static inline const char *erofs_strerror(int err)<br>
> > > return msg;<br>
> > > }<br>
> > ><br>
> > > +#define HOLE_BLK -1<br>
> > > +/* on disk extent format */<br>
> > > +struct erofs_extent {<br>
> > > + __le32 ee_lblk;<br>
> > > + __le32 ee_pblk;<br>
> > > + __le32 ee_len;<br>
> > > +};<br>
> > > +<br>
> > > +struct erofs_extent_node {<br>
> > > + struct list_head next;<br>
> > > + erofs_blk_t lblk;<br>
> > > + erofs_blk_t pblk;<br>
> > > + u32 len;<br>
> > > +};<br>
> > > +<br>
> > > +struct erofs_inline_extent_header {<br>
> > > + u32 count;<br>
> > > +};<br>
> > > #endif<br>
> > ><br>
> > > diff --git a/lib/inode.c b/lib/inode.c<br>
> > > index 0e19b11..a6af509 100644<br>
> > > --- a/lib/inode.c<br>
> > > +++ b/lib/inode.c<br>
> > > @@ -38,6 +38,99 @@ static unsigned char erofs_type_by_mode[S_IFMT >><br>
> > S_SHIFT] = {<br>
> > ><br>
> > > struct list_head inode_hashtable[NR_INODE_HASHTABLE];<br>
> > ><br>
> > > +<br>
> > > +#define IS_HOLE(start, end) (roundup(start, EROFS_BLKSIZ) == start &&<br>
> > \<br>
> > > + roundup(end, EROFS_BLKSIZ) == end && \<br>
> > > + (end - start) % EROFS_BLKSIZ == 0)<br>
> ><br>
> > See below..<br>
> ><br>
> > > +<br>
> > > +/* returns the number of holes present in the file */<br>
> > > +unsigned int erofs_read_extents(struct erofs_inode *inode,<br>
> > > + struct list_head *extents)<br>
> > > +{<br>
> > > + int fd, st, en, dt;<br>
> > > + unsigned int nholes = 0;<br>
> > > + erofs_off_t data, hole, len, last_data;<br>
> > > + struct erofs_extent_node *e_hole, *e_data;<br>
> > > +<br>
> > > + fd = open(inode->i_srcpath, O_RDONLY);<br>
> > > + if (fd < 0) {<br>
> > > + return -errno;<br>
> > > + }<br>
> > > + len = lseek(fd, 0, SEEK_END);<br>
> > > + if (lseek(fd, 0, SEEK_SET) == -1)<br>
> > > + return -errno;<br>
> > > + data = 0;<br>
> > > + last_data = 0;<br>
> > > + while (data < len) {<br>
> > > + hole = lseek(fd, data, SEEK_HOLE);<br>
> > > + if (hole == len)<br>
> > > + break;<br>
> > > + data = lseek(fd, hole, SEEK_DATA);<br>
> > > + if (data < 0 || hole > data) {<br>
> > > + return -EINVAL;<br>
> > > + }<br>
> > > + if (IS_HOLE(hole, data)) {<br>
> > > + st = hole >> S_SHIFT;<br>
> > > + en = data >> S_SHIFT;<br>
> > > + dt = last_data >> S_SHIFT;<br>
> ><br>
> > Why using S_SHIFT here, some special meaning?<br>
> ><br>
> > > + last_data = data;<br>
> > > + e_data = malloc(sizeof(struct erofs_extent_node));<br>
> > > + if (e_data == NULL)<br>
> > > + return -ENOMEM;<br>
> > > + e_data->lblk = dt;<br>
> > > + e_data->len = (st - dt);<br>
> > > + list_add_tail(&e_data->next, extents);<br>
> > > + e_hole = malloc(sizeof(struct erofs_extent_node));<br>
> > > + if (e_hole == NULL)<br>
> > > + return -ENOMEM;<br>
> > > + e_hole->lblk = st;<br>
> > > + e_hole->pblk = HOLE_BLK;<br>
> > > + e_hole->len = (en - st);<br>
> > > + list_add_tail(&e_hole->next, extents);<br>
> > > + nholes += e_hole->len;<br>
> ><br>
> > Maybe we don't need to emit all HOLK extents since all data extents<br>
> > are with _length_... It is easy to detect all holes between extents...<br>
> ><br>
> > If some block doesn't belong to any extent, it's a hole.<br>
> ><br>
> > Thanks,<br>
> > Gao Xiang<br>
> ><br>
> > > + }<br>
> > > + }<br>
> > > + /* rounddown to exclude tail-end data */<br>
> > > + if (last_data < len && (len - last_data) >= EROFS_BLKSIZ) {<br>
> > > + e_data = malloc(sizeof(struct erofs_extent_node));<br>
> > > + if (e_data == NULL)<br>
> > > + return -ENOMEM;<br>
> > > + st = last_data >> S_SHIFT;<br>
> > > + e_data->lblk = st;<br>
> > > + e_data->len = rounddown((len - last_data), EROFS_BLKSIZ)<br>
> > >> S_SHIFT;<br>
> > > + list_add_tail(&e_data->next, extents);<br>
> > > + }<br>
> > > + return nholes;<br>
> > > +}<br>
> > > +<br>
> > > +char *erofs_create_extent_buffer(struct list_head *extents, unsigned<br>
> > int size)<br>
> > > +{<br>
> > > + struct erofs_extent_node *e_node;<br>
> > > + struct erofs_inline_extent_header *header;<br>
> > > + char *buf;<br>
> > > + unsigned int p = 0;<br>
> > > +<br>
> > > + buf = malloc(size);<br>
> > > + if (buf == NULL)<br>
> > > + return ERR_PTR(-ENOMEM);<br>
> > > + header = (struct erofs_inline_extent_header *) buf;<br>
> > > + header->count = 0;<br>
> > > + p += sizeof(struct erofs_inline_extent_header);<br>
> > > + list_for_each_entry(e_node, extents, next) {<br>
> > > + const struct erofs_extent ee = {<br>
> > > + .ee_lblk = cpu_to_le32(e_node->lblk),<br>
> > > + .ee_pblk = cpu_to_le32(e_node->pblk),<br>
> > > + .ee_len = cpu_to_le32(e_node->len)<br>
> > > + };<br>
> > > + memcpy(buf + p, &ee, sizeof(struct erofs_extent));<br>
> > > + p += sizeof(struct erofs_extent);<br>
> > > + header->count++;<br>
> > > + list_del(&e_node->next);<br>
> > > + free(e_node);<br>
> > > + }<br>
> > > + return buf;<br>
> > > +}<br>
> > > +<br>
> > > void erofs_inode_manager_init(void)<br>
> > > {<br>
> > > unsigned int i;<br>
> > > @@ -304,8 +397,9 @@ static bool erofs_file_is_compressible(struct<br>
> > erofs_inode *inode)<br>
> > ><br>
> > > int erofs_write_file(struct erofs_inode *inode)<br>
> > > {<br>
> > > - unsigned int nblocks, i;<br>
> > > + unsigned int nblocks, i, j, nholes;<br>
> > > int ret, fd;<br>
> > > + struct erofs_extent_node *e_node;<br>
> > ><br>
> > > if (!inode->i_size) {<br>
> > > inode->datalayout = EROFS_INODE_FLAT_PLAIN;<br>
> > > @@ -322,31 +416,43 @@ int erofs_write_file(struct erofs_inode *inode)<br>
> > > /* fallback to all data uncompressed */<br>
> > > inode->datalayout = EROFS_INODE_FLAT_INLINE;<br>
> > > nblocks = inode->i_size / EROFS_BLKSIZ;<br>
> > > -<br>
> > > - ret = __allocate_inode_bh_data(inode, nblocks);<br>
> > > + nholes = erofs_read_extents(inode, &inode->i_extents);<br>
> > > + if (nholes < 0)<br>
> > > + return nholes;<br>
> > > + if (nblocks < 0)<br>
> > > + return nblocks;<br>
> > > + ret = __allocate_inode_bh_data(inode, nblocks - nholes);<br>
> > > if (ret)<br>
> > > return ret;<br>
> > ><br>
> > > fd = open(inode->i_srcpath, O_RDONLY | O_BINARY);<br>
> > > if (fd < 0)<br>
> > > return -errno;<br>
> > > -<br>
> > > - for (i = 0; i < nblocks; ++i) {<br>
> > > - char buf[EROFS_BLKSIZ];<br>
> > > -<br>
> > > - ret = read(fd, buf, EROFS_BLKSIZ);<br>
> > > - if (ret != EROFS_BLKSIZ) {<br>
> > > - if (ret < 0)<br>
> > > - goto fail;<br>
> > > - close(fd);<br>
> > > - return -EAGAIN;<br>
> > > + i = inode->u.i_blkaddr;<br>
> > > + inode->extent_meta_isize = sizeof(struct<br>
> > erofs_inline_extent_header);<br>
> > > + list_for_each_entry(e_node, &inode->i_extents, next) {<br>
> > > + inode->extent_meta_isize += sizeof(struct erofs_extent);<br>
> > > + if (e_node->pblk == HOLE_BLK) {<br>
> > > + lseek(fd, e_node->len * EROFS_BLKSIZ, SEEK_CUR);<br>
> > > + continue;<br>
> > > }<br>
> > > + e_node->pblk = i;<br>
> > > + i += e_node->len;<br>
> > > + for (j = 0; j < e_node->len; j++) {<br>
> > > + char buf[EROFS_BLKSIZ];<br>
> > > + ret = read(fd, buf, EROFS_BLKSIZ);<br>
> > > + if (ret != EROFS_BLKSIZ) {<br>
> > > + if (ret < 0)<br>
> > > + goto fail;<br>
> > > + close(fd);<br>
> > > + return -EAGAIN;<br>
> > > + }<br>
> > > + ret = blk_write(buf, e_node->pblk + j, 1);<br>
> > > + if (ret)<br>
> > > + goto fail;<br>
> > ><br>
> > > - ret = blk_write(buf, inode->u.i_blkaddr + i, 1);<br>
> > > - if (ret)<br>
> > > - goto fail;<br>
> > > + }<br>
> > > }<br>
> > > -<br>
> > > /* read the tail-end data */<br>
> > > inode->idata_size = inode->i_size % EROFS_BLKSIZ;<br>
> > > if (inode->idata_size) {<br>
> > > @@ -479,8 +585,19 @@ static bool erofs_bh_flush_write_inode(struct<br>
> > erofs_buffer_head *bh)<br>
> > > if (ret)<br>
> > > return false;<br>
> > > free(inode->compressmeta);<br>
> > > + off += inode->extent_isize;<br>
> > > }<br>
> > ><br>
> > > + if (inode->extent_meta_isize) {<br>
> > > + char *extents =<br>
> > erofs_create_extent_buffer(&inode->i_extents,<br>
> > > +<br>
> > inode->extent_meta_isize);<br>
> > > + if (IS_ERR(extents))<br>
> > > + return false;<br>
> > > + ret = dev_write(extents, off, inode->extent_meta_isize);<br>
> > > + free(extents);<br>
> > > + if (ret)<br>
> > > + return false;<br>
> > > + }<br>
> > > inode->bh = NULL;<br>
> > > erofs_iput(inode);<br>
> > > return erofs_bh_flush_generic_end(bh);<br>
> > > @@ -737,10 +854,11 @@ struct erofs_inode *erofs_new_inode(void)<br>
> > ><br>
> > > init_list_head(&inode->i_subdirs);<br>
> > > init_list_head(&inode->i_xattrs);<br>
> > > + init_list_head(&inode->i_extents);<br>
> > ><br>
> > > inode->idata_size = 0;<br>
> > > inode->xattr_isize = 0;<br>
> > > - inode->extent_isize = 0;<br>
> > > + inode->extent_meta_isize = 0;<br>
> > ><br>
> > > inode->bh = inode->bh_inline = inode->bh_data = NULL;<br>
> > > inode->idata = NULL;<br>
> > > @@ -961,4 +1079,3 @@ struct erofs_inode<br>
> > *erofs_mkfs_build_tree_from_path(struct erofs_inode *parent,<br>
> > ><br>
> > > return erofs_mkfs_build_tree(inode);<br>
> > > }<br>
> > > -<br>
> > > --<br>
> > > 2.9.3<br>
> > ><br>
> ><br>
</blockquote></div>
</blockquote></div>