Add erofs_rebuild_load_tree() helper loading inode tree from given erofs image, and making it merged into a given inode tree in an overlayfs like model.
Signed-off-by: Jingbo Xu <[email protected]> --- include/erofs/rebuild.h | 2 + lib/rebuild.c | 269 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 271 insertions(+) diff --git a/include/erofs/rebuild.h b/include/erofs/rebuild.h index df7613a..57c0e42 100644 --- a/include/erofs/rebuild.h +++ b/include/erofs/rebuild.h @@ -21,6 +21,8 @@ struct erofs_img *erofs_get_img(const char *path); int erofs_add_img(const char *path); void erofs_cleanup_imgs(void); +int erofs_rebuild_load_tree(struct erofs_inode *root, struct erofs_img *img); + struct erofs_dentry *erofs_rebuild_get_dentry(struct erofs_inode *pwd, char *path, bool aufs, bool *whout, bool *opq); diff --git a/lib/rebuild.c b/lib/rebuild.c index e2f6c1d..33b539f 100644 --- a/lib/rebuild.c +++ b/lib/rebuild.c @@ -3,9 +3,14 @@ #include <unistd.h> #include <stdlib.h> #include <string.h> +#include <sys/stat.h> #include "erofs/print.h" #include "erofs/inode.h" #include "erofs/rebuild.h" +#include "erofs/io.h" +#include "erofs/dir.h" +#include "erofs/xattr.h" +#include "erofs/blobchunk.h" #include "erofs/internal.h" #ifdef HAVE_LINUX_AUFS_TYPE_H @@ -119,6 +124,270 @@ struct erofs_dentry *erofs_rebuild_get_dentry(struct erofs_inode *pwd, return d; } +static int erofs_rebuild_fill_inode_map(struct erofs_inode *inode, + struct erofs_inode *vi, dev_t dev) +{ + int ret; + unsigned int count, unit, chunkbits, deviceid, i; + erofs_off_t chunksize; + erofs_blk_t blkaddr; + struct erofs_inode_chunk_index *idx; + + /* TODO: fill data map in other layouts */ + if (vi->datalayout != EROFS_INODE_CHUNK_BASED) { + inode->u.i_blkaddr = NULL_ADDR; + return 0; + } + + inode->u.chunkformat = vi->u.chunkformat; + chunkbits = vi->u.chunkbits; + chunksize = 1ULL << chunkbits; + count = DIV_ROUND_UP(inode->i_size, chunksize); + + if (vi->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES) + unit = sizeof(struct erofs_inode_chunk_index); + else + unit = EROFS_BLOCK_MAP_ENTRY_SIZE; + + inode->extent_isize = count * unit; + idx = malloc(max(sizeof(*idx), sizeof(void *))); + if (!idx) + return -ENOMEM; + inode->chunkindexes = idx; + + if (vi->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES) + deviceid = dev; + else + deviceid = 0; + + for (i = 0; i < count; i++) { + struct erofs_blobchunk *chunk; + struct erofs_map_blocks map = { + .index = UINT_MAX, + }; + + map.m_la = i << chunkbits; + ret = erofs_map_blocks(vi, &map, 0); + if (ret) + goto err; + + blkaddr = erofs_blknr(vi->sbi, map.m_pa); + chunk = erofs_get_unhashed_chunk(deviceid, blkaddr, 0); + if (IS_ERR(chunk)) { + ret = PTR_ERR(chunk); + goto err; + } + *(void **)idx++ = chunk; + erofs_dbg("\t%s: chunk %d (deviceid %u, blkaddr %u)", + inode->i_srcpath, i, deviceid, blkaddr); + + } + inode->datalayout = EROFS_INODE_CHUNK_BASED; + return 0; +err: + free(idx); + inode->chunkindexes = NULL; + return ret; +} + +static int erofs_rebuild_fill_inode(struct erofs_inode *inode, + struct erofs_inode *vi, dev_t dev) +{ + int ret = 0; + + inode->i_srcpath = strdup(vi->i_srcpath); + inode->i_mode = vi->i_mode; + inode->i_uid = vi->i_uid; + inode->i_gid = vi->i_gid; + inode->i_mtime = vi->i_mtime; + inode->i_ino[1] = vi->i_ino[0]; + inode->i_nlink = 1; + + switch (inode->i_mode & S_IFMT) { + case S_IFCHR: + case S_IFBLK: + case S_IFIFO: + case S_IFSOCK: + inode->u.i_rdev = erofs_new_encode_dev(vi->u.i_rdev); + inode->i_size = 0; + erofs_dbg("\tdev: %d %d", major(vi->u.i_rdev), + minor(vi->u.i_rdev)); + break; + case S_IFDIR: + inode->i_size = 0; + ret = erofs_init_empty_dir(inode); + break; + case S_IFLNK: + inode->i_size = vi->i_size; + inode->i_link = malloc(inode->i_size + 1); + ret = erofs_pread(vi, inode->i_link, inode->i_size, 0); + erofs_dbg("\tsymlink: %s -> %s", inode->i_srcpath, inode->i_link); + break; + case S_IFREG: + inode->i_size = vi->i_size; + if (inode->i_size) + ret = erofs_rebuild_fill_inode_map(inode, vi, dev); + else + inode->u.i_blkaddr = NULL_ADDR; + break; + default: + ret = -EINVAL; + break; + } + return ret; +} + +struct erofs_rebuild_dir_context { + struct erofs_dir_context ctx; + struct erofs_inode *root; + dev_t dev; +}; + +static int erofs_rebuild_dirent_iter(struct erofs_dir_context *ctx) +{ + struct erofs_rebuild_dir_context *rctx = (void *)ctx; + struct erofs_inode *dir = ctx->dir; + struct erofs_sb_info *sbi = dir->sbi; + struct erofs_inode *inode, vi = {}; + struct erofs_dentry *d; + char *path; + int ret; + + if (ctx->dot_dotdot) + return 0; + + vi.nid = ctx->de_nid; + vi.sbi = sbi; + ret = erofs_read_inode_from_disk(&vi); + if (ret) { + erofs_err("file %s/%.*s: read failed", + dir->i_srcpath, ctx->de_namelen, ctx->dname); + return ret; + } + + ret = asprintf(&path, "%s/%.*s", dir->i_srcpath, ctx->de_namelen, + ctx->dname); + if (ret < 0) { + erofs_err("file %s/%.*s: failed to alloc path", + dir->i_srcpath, ctx->de_namelen, ctx->dname); + return ret; + } + vi.i_srcpath = path; + + d = erofs_rebuild_get_dentry(rctx->root, path, false, NULL, NULL); + if (IS_ERR(d)) { + ret = PTR_ERR(d); + goto exit; + } + + if (d->type != EROFS_FT_UNKNOWN) { + inode = d->inode; + DBG_BUGON((inode->i_mode & S_IFMT) != (vi.i_mode & S_IFMT)); + if (!S_ISDIR(inode->i_mode) || inode->opaque) { + erofs_dbg("file %s: %s (%d) exists", + path, inode->i_srcpath, + erofs_mode_to_ftype(inode->i_mode)); + free(path); + return 0; + } + erofs_dbg("dir %s: %s merging", path, inode->i_srcpath); + } else { + erofs_dbg("loading file: %s (%d) (nid %llu)", + path, erofs_mode_to_ftype(vi.i_mode), ctx->de_nid); + if (S_ISREG(vi.i_mode) && vi.i_nlink > 1 && + (inode = erofs_iget(rctx->dev, vi.i_ino[0]))) { + /* hardlink file */ + if (S_ISDIR(inode->i_mode)) { + erofs_dbg("hardlink directory not supported"); + erofs_iput(inode); + return -EISDIR; + } + inode->i_nlink++; + erofs_dbg("\thardlink: %s -> %s", vi.i_srcpath, inode->i_srcpath); + } else { + inode = erofs_new_inode(); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + goto exit; + } + + inode->i_parent = d->inode; + inode->dev = rctx->dev; + ret = erofs_rebuild_fill_inode(inode, &vi, rctx->dev); + if (ret) + goto exit_inode; + + ret = erofs_read_xattrs_from_disk(&vi); + if (ret) + goto exit_inode; + list_splice_tail(&vi.i_xattrs, &inode->i_xattrs); + erofs_inode_tag_opaque(inode); + + erofs_insert_ihash(inode, rctx->dev, inode->i_ino[1]); + } + + d->inode = inode; + d->type = erofs_mode_to_ftype(inode->i_mode); + } + + ret = 0; + if (S_ISDIR(vi.i_mode)) { + struct erofs_rebuild_dir_context nctx = *rctx; + + nctx.ctx.dir = &vi; + ret = erofs_iterate_dir(&nctx.ctx, false); + } +exit: + free(path); + return ret; +exit_inode: + erofs_iput(inode); + goto exit; +} + +int erofs_rebuild_load_tree(struct erofs_inode *root, struct erofs_img *img) +{ + struct erofs_inode inode = {}; + struct erofs_sb_info *sbi = &img->sbi; + struct erofs_rebuild_dir_context ctx; + int ret; + + erofs_dbg("Loading image %s...", img->path); + + ret = dev_open_ro(sbi, img->path); + if (ret) { + erofs_err("failed to open image %s", img->path); + return ret; + } + + ret = erofs_read_superblock(sbi); + if (ret) { + erofs_err("failed to read superblock of image %s", img->path); + goto exit; + } + + inode.nid = sbi->root_nid; + inode.sbi = sbi; + ret = erofs_read_inode_from_disk(&inode); + if (ret) { + erofs_err("failed to read root inode of image %s", img->path); + goto exit; + } + inode.i_srcpath = strdup("/"); + + ctx = (struct erofs_rebuild_dir_context) { + .ctx.dir = &inode, + .ctx.cb = erofs_rebuild_dirent_iter, + .root = root, + .dev = img->dev, + }; + ret = erofs_iterate_dir(&ctx.ctx, false); + free(inode.i_srcpath); +exit: + dev_close(sbi); + return ret; +} + struct erofs_img *erofs_get_img(const char *path) { struct erofs_img *img = malloc(sizeof(*img)); -- 2.19.1.6.gb485710b
