[PATCH v2 11/12] erofs-utils: lib: add erofs_rebuild_load_tree() helper
Jingbo Xu
jefflexu at linux.alibaba.com
Wed Aug 16 12:13:46 AEST 2023
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.
Since we need to read the content of the symlink file from disk when
loading tree, add dependency on zlib_LIBS for mkfs.erofs.
Signed-off-by: Jingbo Xu <jefflexu at linux.alibaba.com>
---
include/erofs/internal.h | 1 +
include/erofs/rebuild.h | 2 +
lib/rebuild.c | 270 +++++++++++++++++++++++++++++++++++++++
mkfs/Makefile.am | 3 +-
4 files changed, 275 insertions(+), 1 deletion(-)
diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 6e54c1f..d643d79 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -102,6 +102,7 @@ struct erofs_sb_info {
int devfd;
u64 devsz;
+ dev_t dev;
unsigned int nblobs;
unsigned int blobfd[256];
};
diff --git a/include/erofs/rebuild.h b/include/erofs/rebuild.h
index 92873c9..3ac074c 100644
--- a/include/erofs/rebuild.h
+++ b/include/erofs/rebuild.h
@@ -12,6 +12,8 @@ extern "C"
struct erofs_dentry *erofs_rebuild_get_dentry(struct erofs_inode *pwd,
char *path, bool aufs, bool *whout, bool *opq);
+int erofs_rebuild_load_tree(struct erofs_inode *root, struct erofs_sb_info *sbi);
+
#ifdef __cplusplus
}
#endif
diff --git a/lib/rebuild.c b/lib/rebuild.c
index 7aaa071..446ab23 100644
--- a/lib/rebuild.c
+++ b/lib/rebuild.c
@@ -3,9 +3,18 @@
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
+#include <config.h>
+#if defined(HAVE_SYS_SYSMACROS_H)
+#include <sys/sysmacros.h>
+#endif
#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
@@ -115,3 +124,264 @@ 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)
+{
+ int ret;
+ struct erofs_sb_info *sbi = vi->sbi;
+ unsigned int count, unit, chunkbits, i;
+ unsigned int deviceid = inode->dev;
+ 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 &&
+ vi->datalayout != EROFS_INODE_FLAT_PLAIN) {
+ erofs_err("unsupported datalayout %d", vi->datalayout);
+ return -EOPNOTSUPP;
+ }
+
+ if (sbi->extra_devices) {
+ chunkbits = vi->u.chunkbits;
+ inode->u.chunkformat = vi->u.chunkformat;
+ } else {
+ chunkbits = ilog2(inode->i_size - 1) + 1;
+ if (chunkbits < sbi->blkszbits)
+ chunkbits = sbi->blkszbits;
+ if (chunkbits - sbi->blkszbits > EROFS_CHUNK_FORMAT_BLKBITS_MASK)
+ chunkbits = EROFS_CHUNK_FORMAT_BLKBITS_MASK + sbi->blkszbits;
+ inode->u.chunkformat = EROFS_CHUNK_FORMAT_INDEXES;
+ inode->u.chunkformat |= chunkbits - sbi->blkszbits;
+ }
+ chunksize = 1ULL << chunkbits;
+ count = DIV_ROUND_UP(inode->i_size, chunksize);
+
+ unit = sizeof(struct erofs_inode_chunk_index);
+ inode->extent_isize = count * unit;
+ idx = malloc(max(sizeof(*idx), sizeof(void *)));
+ if (!idx)
+ return -ENOMEM;
+ inode->chunkindexes = idx;
+
+ 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(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)
+{
+ 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->nid;
+ 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);
+ 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), vi.nid);
+ if (S_ISREG(vi.i_mode) && vi.i_nlink > 1 &&
+ (inode = erofs_iget(rctx->dev, vi.nid))) {
+ /* 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);
+ 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);
+ inode->opaque = vi.opaque;
+
+ erofs_insert_ihash(inode, rctx->dev, vi.nid);
+ }
+
+ 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_sb_info *sbi)
+{
+ struct erofs_inode inode = {};
+ struct erofs_rebuild_dir_context ctx;
+ int ret;
+
+ if (!sbi->devname) {
+ erofs_err("please open the device first");
+ return -EINVAL;
+ }
+
+ ret = erofs_read_superblock(sbi);
+ if (ret) {
+ erofs_err("failed to read superblock of img %s", sbi->devname);
+ return ret;
+ }
+
+ 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 img %s", sbi->devname);
+ return ret;
+ }
+ inode.i_srcpath = strdup("/");
+
+ ctx = (struct erofs_rebuild_dir_context) {
+ .ctx.dir = &inode,
+ .ctx.cb = erofs_rebuild_dirent_iter,
+ .root = root,
+ .dev = sbi->dev,
+ };
+ ret = erofs_iterate_dir(&ctx.ctx, false);
+ free(inode.i_srcpath);
+ return ret;
+}
diff --git a/mkfs/Makefile.am b/mkfs/Makefile.am
index 603c2f3..dd75485 100644
--- a/mkfs/Makefile.am
+++ b/mkfs/Makefile.am
@@ -6,4 +6,5 @@ AM_CPPFLAGS = ${libselinux_CFLAGS}
mkfs_erofs_SOURCES = main.c
mkfs_erofs_CFLAGS = -Wall -I$(top_srcdir)/include
mkfs_erofs_LDADD = $(top_builddir)/lib/liberofs.la ${libselinux_LIBS} \
- ${libuuid_LIBS} ${liblz4_LIBS} ${liblzma_LIBS} ${libdeflate_LIBS}
+ ${libuuid_LIBS} ${liblz4_LIBS} ${liblzma_LIBS} ${zlib_LIBS} \
+ ${libdeflate_LIBS}
--
2.19.1.6.gb485710b
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