[PATCH v5 6/8] erofs-utils: lib: add erofs_rebuild_load_tree() helper
Jingbo Xu
jefflexu at linux.alibaba.com
Fri Sep 1 19:47:04 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.
Also rename tarerofs_dump_tree() to erofs_rebuild_dump_tree(), so that
it could also be called from rebuild mode.
Signed-off-by: Jingbo Xu <jefflexu at linux.alibaba.com>
---
include/erofs/inode.h | 2 +-
include/erofs/internal.h | 1 +
include/erofs/rebuild.h | 2 +
lib/inode.c | 4 +-
lib/rebuild.c | 283 +++++++++++++++++++++++++++++++++++++++
mkfs/main.c | 2 +-
6 files changed, 290 insertions(+), 4 deletions(-)
diff --git a/include/erofs/inode.h b/include/erofs/inode.h
index 1c602a8..fe9dda2 100644
--- a/include/erofs/inode.h
+++ b/include/erofs/inode.h
@@ -32,7 +32,7 @@ unsigned int erofs_iput(struct erofs_inode *inode);
erofs_nid_t erofs_lookupnid(struct erofs_inode *inode);
struct erofs_dentry *erofs_d_alloc(struct erofs_inode *parent,
const char *name);
-int tarerofs_dump_tree(struct erofs_inode *dir);
+int erofs_rebuild_dump_tree(struct erofs_inode *dir);
int erofs_init_empty_dir(struct erofs_inode *dir);
struct erofs_inode *erofs_new_inode(void);
struct erofs_inode *erofs_mkfs_build_tree_from_path(const char *path);
diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 6020553..3d5c337 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -108,6 +108,7 @@ 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/inode.c b/lib/inode.c
index cd51fd2..f71a6ab 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -1323,7 +1323,7 @@ struct erofs_inode *erofs_mkfs_build_special_from_fd(int fd, const char *name)
return inode;
}
-int tarerofs_dump_tree(struct erofs_inode *dir)
+int erofs_rebuild_dump_tree(struct erofs_inode *dir)
{
struct erofs_dentry *d;
unsigned int nr_subdirs;
@@ -1391,7 +1391,7 @@ int tarerofs_dump_tree(struct erofs_inode *dir)
continue;
inode = erofs_igrab(d->inode);
- ret = tarerofs_dump_tree(inode);
+ ret = erofs_rebuild_dump_tree(inode);
dir->i_nlink += (erofs_mode_to_ftype(inode->i_mode) == EROFS_FT_DIR);
erofs_iput(inode);
if (ret)
diff --git a/lib/rebuild.c b/lib/rebuild.c
index 7aaa071..6e5ae29 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 +124,277 @@ struct erofs_dentry *erofs_rebuild_get_dentry(struct erofs_inode *pwd,
}
return d;
}
+
+static int erofs_rebuild_fixup_inode_index(struct erofs_inode *inode)
+{
+ int ret;
+ unsigned int count, unit, chunkbits, i;
+ unsigned int deviceid = inode->dev;
+ struct erofs_inode_chunk_index *idx;
+ erofs_off_t chunksize;
+ erofs_blk_t blkaddr;
+
+ /* TODO: fill data map in other layouts */
+ if (inode->datalayout != EROFS_INODE_CHUNK_BASED &&
+ inode->datalayout != EROFS_INODE_FLAT_PLAIN) {
+ erofs_err("unsupported datalayout %d", inode->datalayout);
+ return -EOPNOTSUPP;
+ }
+
+ if (inode->sbi->extra_devices) {
+ chunkbits = inode->u.chunkbits;
+ if (chunkbits < sbi.blkszbits) {
+ erofs_err("blkszbits no greater than source blkszbits");
+ return -EINVAL;
+ }
+ } 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;
+ }
+ 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(inode, &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;
+
+ }
+ inode->datalayout = EROFS_INODE_CHUNK_BASED;
+ inode->u.chunkformat = EROFS_CHUNK_FORMAT_INDEXES;
+ inode->u.chunkformat |= chunkbits - sbi.blkszbits;
+ return 0;
+err:
+ free(idx);
+ inode->chunkindexes = NULL;
+ return ret;
+}
+
+static int erofs_rebuild_fill_inode(struct erofs_inode *inode)
+{
+ int ret = 0;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFCHR:
+ case S_IFBLK:
+ case S_IFIFO:
+ case S_IFSOCK:
+ inode->i_size = 0;
+ erofs_dbg("\tdev: %d %d", major(inode->u.i_rdev),
+ minor(inode->u.i_rdev));
+ inode->u.i_rdev = erofs_new_encode_dev(inode->u.i_rdev);
+ break;
+ case S_IFDIR:
+ ret = erofs_init_empty_dir(inode);
+ break;
+ case S_IFLNK:
+ inode->i_link = malloc(inode->i_size + 1);
+ if (!inode->i_link)
+ return -ENOMEM;
+ ret = erofs_pread(inode, inode->i_link, inode->i_size, 0);
+ erofs_dbg("\tsymlink: %s -> %s", inode->i_srcpath, inode->i_link);
+ break;
+ case S_IFREG:
+ if (inode->i_size)
+ ret = erofs_rebuild_fixup_inode_index(inode);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}
+
+/*
+ * @parent: parent directory in inode tree
+ * @ctx.dir: parent directory when itering erofs_iterate_dir()
+ */
+struct erofs_rebuild_dir_context {
+ struct erofs_dir_context ctx;
+ struct erofs_inode *parent;
+ 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 *parent = rctx->parent;
+ struct erofs_inode *dir = ctx->dir;
+ struct erofs_inode *inode, *candidate;
+ struct erofs_inode src;
+ struct erofs_dentry *d;
+ char *path, *dname;
+ int ret;
+
+ if (ctx->dot_dotdot)
+ return 0;
+
+ ret = asprintf(&path, "%s/%.*s", rctx->parent->i_srcpath,
+ ctx->de_namelen, ctx->dname);
+ if (ret < 0)
+ return ret;
+
+ erofs_dbg("parsing path %s", path);
+ dname = path + strlen(parent->i_srcpath) + 1;
+
+ d = erofs_rebuild_get_dentry(parent, dname, false, NULL, NULL);
+ if (IS_ERR(d)) {
+ ret = PTR_ERR(d);
+ goto out;
+ }
+ DBG_BUGON(parent != d->inode);
+
+ ret = 0;
+ if (d->type != EROFS_FT_UNKNOWN) {
+ /* file exists in upper layer */
+ if (!S_ISDIR(d->inode->i_mode) || d->inode->opaque)
+ goto out;
+
+ /* merging directories */
+ src = (struct erofs_inode) {
+ .sbi = dir->sbi,
+ .nid = ctx->de_nid
+ };
+ ret = erofs_read_inode_from_disk(&src);
+ if (ret || !S_ISDIR(src.i_mode))
+ goto out;
+ parent = d->inode;
+ inode = dir = &src;
+ } else {
+ u64 nid;
+
+ inode = erofs_new_inode();
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ goto out;
+ }
+
+ /* reuse i_ino[0] to read nid in source fs */
+ nid = inode->i_ino[0];
+ inode->sbi = dir->sbi;
+ inode->nid = ctx->de_nid;
+ ret = erofs_read_inode_from_disk(inode);
+ if (ret)
+ goto out;
+
+ /* restore nid in new generated fs */
+ inode->i_ino[1] = inode->i_ino[0];
+ inode->i_ino[0] = nid;
+
+ if (S_ISREG(inode->i_mode) && inode->i_nlink > 1 &&
+ (candidate = erofs_iget(rctx->dev, ctx->de_nid))) {
+ /* hardlink file */
+ erofs_iput(inode);
+ inode = candidate;
+ if (S_ISDIR(inode->i_mode)) {
+ erofs_err("hardlink directory not supported");
+ ret = -EISDIR;
+ goto out;
+ }
+ inode->i_nlink++;
+ erofs_dbg("\thardlink: %s -> %s", path, inode->i_srcpath);
+ } else {
+ ret = erofs_read_xattrs_from_disk(inode);
+ if (ret) {
+ erofs_iput(inode);
+ goto out;
+ }
+
+ inode->i_parent = d->inode;
+ inode->dev = rctx->dev;
+ inode->i_srcpath = path;
+ path = NULL;
+ inode->i_ino[1] = inode->nid;
+ inode->i_nlink = 1;
+
+ ret = erofs_rebuild_fill_inode(inode);
+ if (ret) {
+ erofs_iput(inode);
+ goto out;
+ }
+
+ erofs_insert_ihash(inode, rctx->dev, inode->i_ino[1]);
+ parent = dir = inode;
+ }
+
+ d->inode = inode;
+ d->type = erofs_mode_to_ftype(inode->i_mode);
+ }
+
+ ret = 0;
+ if (S_ISDIR(inode->i_mode)) {
+ struct erofs_rebuild_dir_context nctx = *rctx;
+ nctx.parent = parent;
+ nctx.ctx.dir = dir;
+ ret = erofs_iterate_dir(&nctx.ctx, false);
+ }
+
+ /* don't restore inode->sbi until all the read work has finished */
+ inode->sbi = &sbi;
+ inode->nid = 0;
+out:
+ if (path)
+ free(path);
+ return ret;
+}
+
+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("failed to find a device for rebuilding");
+ return -EINVAL;
+ }
+
+ ret = erofs_read_superblock(sbi);
+ if (ret) {
+ erofs_err("failed to read superblock of %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 %s", sbi->devname);
+ return ret;
+ }
+ inode.i_srcpath = strdup("/");
+
+ ctx = (struct erofs_rebuild_dir_context) {
+ .ctx.dir = &inode,
+ .ctx.cb = erofs_rebuild_dirent_iter,
+ .parent = root,
+ .dev = sbi->dev,
+ };
+ ret = erofs_iterate_dir(&ctx.ctx, false);
+ free(inode.i_srcpath);
+ return ret;
+}
diff --git a/mkfs/main.c b/mkfs/main.c
index 4352e62..0333cde 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -965,7 +965,7 @@ int main(int argc, char **argv)
if (err < 0)
goto exit;
- err = tarerofs_dump_tree(root_inode);
+ err = erofs_rebuild_dump_tree(root_inode);
if (err < 0)
goto exit;
}
--
2.19.1.6.gb485710b
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