[PATCH RFC 10/17] ubifs: repair: Create new root dir if there are no scanned files
Zhihao Cheng
chengzhihao1 at huawei.com
Wed Dec 27 17:41:05 PST 2023
This is a preparation for building TNC, there must at least one file
in filesystem, if not, just create new root dir.
Signed-off-by: Zhihao Cheng <chengzhihao1 at huawei.com>
---
fs/ubifs/repair.c | 187 +++++++++++++++++++++++++++++++++++++++++++++-
fs/ubifs/repair.h | 6 ++
fs/ubifs/sb.c | 24 +-----
fs/ubifs/ubifs.h | 28 +++++++
4 files changed, 220 insertions(+), 25 deletions(-)
diff --git a/fs/ubifs/repair.c b/fs/ubifs/repair.c
index 59b79481974a..c43150fff19d 100644
--- a/fs/ubifs/repair.c
+++ b/fs/ubifs/repair.c
@@ -50,9 +50,17 @@ static int init_repair_info(struct ubifs_info *c)
err = -ENOMEM;
goto free_used_lebs;
}
+ c->repair->write_buf = vmalloc(c->leb_size);
+ if (!c->repair->write_buf) {
+ err = -ENOMEM;
+ goto free_lpts;
+ }
+ c->repair->head_lnum = -1;
return 0;
+free_lpts:
+ kfree(c->repair->lpts);
free_used_lebs:
bitmap_free(c->repair->used_lebs);
free_repair:
@@ -62,6 +70,7 @@ static int init_repair_info(struct ubifs_info *c)
static void destroy_repair_info(struct ubifs_info *c)
{
+ vfree(c->repair->write_buf);
kfree(c->repair->lpts);
bitmap_free(c->repair->used_lebs);
kfree(c->repair);
@@ -1745,6 +1754,171 @@ static int check_and_correct_files(struct ubifs_info *c)
return 0;
}
+/**
+ * get_free_leb - get a free LEB according to @c->repair->used_lebs.
+ * @c: UBIFS file-system description object
+ *
+ * This function tries to find a free LEB, %0 is returned if found, otherwise
+ * %ENOSPC is returned.
+ */
+static int get_free_leb(struct ubifs_info *c)
+{
+ int lnum, err;
+
+ lnum = find_next_zero_bit(c->repair->used_lebs, c->main_lebs, 0);
+ if (lnum >= c->main_lebs) {
+ ubifs_err(c, "No space left.");
+ return -ENOSPC;
+ }
+ set_bit(lnum, c->repair->used_lebs);
+ lnum += c->main_first;
+
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+
+ c->repair->head_lnum = lnum;
+ c->repair->head_offs = 0;
+
+ return 0;
+}
+
+/**
+ * flush_write_buf - flush write buffer.
+ * @c: UBIFS file-system description object
+ *
+ * This function flush write buffer to LEB @c->repair->head_lnum, then set
+ * @c->repair->head_lnum to '-1'.
+ */
+static int flush_write_buf(struct ubifs_info *c)
+{
+ int len, pad, err;
+
+ if (!c->repair->head_offs)
+ return 0;
+
+ len = ALIGN(c->repair->head_offs, c->min_io_size);
+ pad = len - c->repair->head_offs;
+ if (pad)
+ ubifs_pad(c, c->repair->write_buf + c->repair->head_offs, pad);
+
+ err = ubifs_leb_write(c, c->repair->head_lnum, c->repair->write_buf, 0,
+ len);
+ if (err)
+ return err;
+
+ c->repair->head_lnum = -1;
+
+ return 0;
+}
+
+/**
+ * reserve_space - reserve enough space to write data.
+ * @c: UBIFS file-system description object
+ * @len: the length of written data
+ * @lnum: the write LEB number is returned here
+ * @offs: the write pos in LEB is returned here
+ *
+ * This function finds target position <@lnum, @offs> to write data with
+ * length of @len.
+ */
+static int reserve_space(struct ubifs_info *c, int len, int *lnum, int *offs)
+{
+ int err;
+
+ if (c->repair->head_lnum == -1) {
+get_new:
+ err = get_free_leb(c);
+ if (err)
+ return err;
+ }
+
+ if (len > c->leb_size - c->repair->head_offs) {
+ err = flush_write_buf(c);
+ if (err)
+ return err;
+
+ goto get_new;
+ }
+
+ *lnum = c->repair->head_lnum;
+ *offs = c->repair->head_offs;
+ c->repair->head_offs += ALIGN(len, 8);
+
+ return 0;
+}
+
+static void copy_node_data(struct ubifs_info *c, void *node, int offs, int len)
+{
+ memcpy(c->repair->write_buf + offs, node, len);
+ memset(c->repair->write_buf + offs + len, 0xff, ALIGN(len, 8) - len);
+}
+
+/**
+ * create_root - create root dir.
+ * @c: UBIFS file-system description object
+ *
+ * This function creates root dir.
+ */
+static int create_root(struct ubifs_info *c)
+{
+ int err, lnum, offs;
+ struct ubifs_ino_node *ino;
+ struct scanned_file *file;
+
+ ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL);
+ if (!ino)
+ return -ENOMEM;
+
+ c->max_sqnum = 0;
+ ubifs_init_root_ino(c, ino);
+ err = ubifs_prepare_node_hmac(c, ino, UBIFS_INO_NODE_SZ, -1, 1);
+ if (err)
+ goto out;
+
+ err = reserve_space(c, UBIFS_INO_NODE_SZ, &lnum, &offs);
+ if (err)
+ goto out;
+
+ copy_node_data(c, ino, offs, UBIFS_INO_NODE_SZ);
+
+ err = flush_write_buf(c);
+ if (err)
+ goto out;
+
+ file = kzalloc(sizeof(struct scanned_file), GFP_KERNEL);
+ if (!file) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ file->inum = UBIFS_ROOT_INO;
+ file->dent_nodes = RB_ROOT;
+ file->data_nodes = RB_ROOT;
+ INIT_LIST_HEAD(&file->list);
+
+ file->ino.header.exist = true;
+ file->ino.header.lnum = lnum;
+ file->ino.header.offs = offs;
+ file->ino.header.len = UBIFS_INO_NODE_SZ;
+ file->ino.header.sqnum = le64_to_cpu(ino->ch.sqnum);
+ ino_key_init(c, &file->ino.key, UBIFS_ROOT_INO);
+ file->ino.is_xattr = le32_to_cpu(ino->flags) & UBIFS_XATTR_FL;
+ file->ino.mode = le32_to_cpu(ino->mode);
+ file->calc_nlink = file->ino.nlink = le32_to_cpu(ino->nlink);
+ file->calc_xcnt = file->ino.xcnt = le32_to_cpu(ino->xattr_cnt);
+ file->calc_xsz = file->ino.xsz = le32_to_cpu(ino->xattr_size);
+ file->calc_xnms = file->ino.xnms = le32_to_cpu(ino->xattr_names);
+ file->calc_size = file->ino.size = le64_to_cpu(ino->size);
+
+ rb_link_node(&file->rb, NULL, &c->repair->scanned_files.rb_node);
+ rb_insert_color(&file->rb, &c->repair->scanned_files);
+
+out:
+ kfree(ino);
+ return err;
+}
+
static char *get_file_name(struct ubifs_info *c, struct scanned_file *file)
{
static char name[UBIFS_MAX_NLEN + 1];
@@ -1786,9 +1960,10 @@ static void parse_node_location(struct ubifs_info *c, struct scanned_node *sn)
*
* This function traverses all nodes from valid files and does following
* things:
- * 1. Record all used LEBs which may hold useful nodes, then left unused
+ * 1. If there are no scanned files, create default empty filesystem.
+ * 2. Record all used LEBs which may hold useful nodes, then left unused
* LEBs could be taken for storing new index tree.
- * 2. Re-write data to prevent failed gc scanning in the subsequent mounting
+ * 3. Re-write data to prevent failed gc scanning in the subsequent mounting
* process caused by corrupted data.
*/
static int traverse_files_and_nodes(struct ubifs_info *c)
@@ -1799,6 +1974,14 @@ static int traverse_files_and_nodes(struct ubifs_info *c)
struct scanned_dent_node *dent_node;
struct scanned_data_node *data_node;
+ if (rb_first(&c->repair->scanned_files) == NULL) {
+ /* No scanned files. Create root dir. */
+ ubifs_msg(c, "No scanned files, create empty filesystem");
+ err = create_root(c);
+ if (err)
+ return err;
+ }
+
ubifs_msg(c, "Step 8: Record used LEBs");
for (node = rb_first(&c->repair->scanned_files); node;
node = rb_next(node)) {
diff --git a/fs/ubifs/repair.h b/fs/ubifs/repair.h
index 2ab885fefee0..e3b879b3f999 100644
--- a/fs/ubifs/repair.h
+++ b/fs/ubifs/repair.h
@@ -165,11 +165,17 @@ struct lprops {
* @usen_lebs: a bitmap used for recording used lebs
* @lpts: lprops table
* @scanned_files: tree of all scanned files
+ * @write_buf: write buffer for LEB @head_lnum
+ * @head_lnum: current writing LEB number
+ * @head_offs: current writing position in LEB @head_lnum
*/
struct ubifs_repair_info {
unsigned long *used_lebs;
struct lprops *lpts;
struct rb_root scanned_files;
+ void *write_buf;
+ int head_lnum;
+ int head_offs;
};
#endif /* !__UBIFS_REPAIR_H__ */
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index e7693b94e5b5..d46798fd548b 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -86,8 +86,6 @@ static int create_default_filesystem(struct ubifs_info *c)
int min_leb_cnt = UBIFS_MIN_LEB_CNT;
int idx_node_size;
long long tmp64, main_bytes;
- __le64 tmp_le64;
- struct timespec64 ts;
u8 hash[UBIFS_HASH_ARR_SZ];
u8 hash_lpt[UBIFS_HASH_ARR_SZ];
@@ -287,27 +285,7 @@ static int create_default_filesystem(struct ubifs_info *c)
dbg_gen("default root indexing node created LEB %d:0",
main_first + DEFAULT_IDX_LEB);
- /* Create default root inode */
-
- ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
- ino->ch.node_type = UBIFS_INO_NODE;
- ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
- ino->nlink = cpu_to_le32(2);
-
- ktime_get_coarse_real_ts64(&ts);
- tmp_le64 = cpu_to_le64(ts.tv_sec);
- ino->atime_sec = tmp_le64;
- ino->ctime_sec = tmp_le64;
- ino->mtime_sec = tmp_le64;
- ino->atime_nsec = 0;
- ino->ctime_nsec = 0;
- ino->mtime_nsec = 0;
- ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
- ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
-
- /* Set compression enabled by default */
- ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
-
+ ubifs_init_root_ino(c, ino);
dbg_gen("root inode created at LEB %d:0",
main_first + DEFAULT_DATA_LEB);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 726161f46f3c..7d66440623cb 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -2207,6 +2207,34 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
extern const struct fscrypt_operations ubifs_crypt_operations;
+static inline void ubifs_init_root_ino(struct ubifs_info *c,
+ struct ubifs_ino_node *ino)
+{
+ __le64 tmp_le64;
+ struct timespec64 ts;
+
+ /* Create default root inode */
+
+ ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
+ ino->ch.node_type = UBIFS_INO_NODE;
+ ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
+ ino->nlink = cpu_to_le32(2);
+
+ ktime_get_coarse_real_ts64(&ts);
+ tmp_le64 = cpu_to_le64(ts.tv_sec);
+ ino->atime_sec = tmp_le64;
+ ino->ctime_sec = tmp_le64;
+ ino->mtime_sec = tmp_le64;
+ ino->atime_nsec = 0;
+ ino->ctime_nsec = 0;
+ ino->mtime_nsec = 0;
+ ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
+ ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
+
+ /* Set compression enabled by default */
+ ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
+}
+
/* Normal UBIFS messages */
__printf(2, 3)
void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...);
--
2.31.1
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