diff options
Diffstat (limited to 'fs/ubifs/recovery.c')
-rw-r--r-- | fs/ubifs/recovery.c | 88 |
1 files changed, 37 insertions, 51 deletions
diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c index 10662975d2ef..e5f6cf8a1155 100644 --- a/fs/ubifs/recovery.c +++ b/fs/ubifs/recovery.c @@ -53,6 +53,25 @@ static int is_empty(void *buf, int len) } /** + * first_non_ff - find offset of the first non-0xff byte. + * @buf: buffer to search in + * @len: length of buffer + * + * This function returns offset of the first non-0xff byte in @buf or %-1 if + * the buffer contains only 0xff bytes. + */ +static int first_non_ff(void *buf, int len) +{ + uint8_t *p = buf; + int i; + + for (i = 0; i < len; i++) + if (*p++ != 0xff) + return i; + return -1; +} + +/** * get_master_node - get the last valid master node allowing for corruption. * @c: UBIFS file-system description object * @lnum: LEB number @@ -343,43 +362,21 @@ int ubifs_write_rcvrd_mst_node(struct ubifs_info *c) * * This function returns %1 if @offs was in the last write to the LEB whose data * is in @buf, otherwise %0 is returned. The determination is made by checking - * for subsequent empty space starting from the next min_io_size boundary (or a - * bit less than the common header size if min_io_size is one). + * for subsequent empty space starting from the next @c->min_io_size boundary. */ static int is_last_write(const struct ubifs_info *c, void *buf, int offs) { - int empty_offs; - int check_len; + int empty_offs, check_len; uint8_t *p; - if (c->min_io_size == 1) { - check_len = c->leb_size - offs; - p = buf + check_len; - for (; check_len > 0; check_len--) - if (*--p != 0xff) - break; - /* - * 'check_len' is the size of the corruption which cannot be - * more than the size of 1 node if it was caused by an unclean - * unmount. - */ - if (check_len > UBIFS_MAX_NODE_SZ) - return 0; - return 1; - } - /* - * Round up to the next c->min_io_size boundary i.e. 'offs' is in the + * Round up to the next @c->min_io_size boundary i.e. @offs is in the * last wbuf written. After that should be empty space. */ empty_offs = ALIGN(offs + 1, c->min_io_size); check_len = c->leb_size - empty_offs; p = buf + empty_offs - offs; - - for (; check_len > 0; check_len--) - if (*p++ != 0xff) - return 0; - return 1; + return is_empty(p, check_len); } /** @@ -392,7 +389,7 @@ static int is_last_write(const struct ubifs_info *c, void *buf, int offs) * * This function pads up to the next min_io_size boundary (if there is one) and * sets empty space to all 0xff. @buf, @offs and @len are updated to the next - * min_io_size boundary (if there is one). + * @c->min_io_size boundary. */ static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, int *offs, int *len) @@ -402,11 +399,6 @@ static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, lnum = lnum; dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs); - if (c->min_io_size == 1) { - memset(*buf, 0xff, c->leb_size - *offs); - return; - } - ubifs_assert(!(*offs & 7)); empty_offs = ALIGN(*offs, c->min_io_size); pad_len = empty_offs - *offs; @@ -566,8 +558,8 @@ static int drop_incomplete_group(struct ubifs_scan_leb *sleb, int *offs) * * This function does a scan of a LEB, but caters for errors that might have * been caused by the unclean unmount from which we are attempting to recover. - * - * This function returns %0 on success and a negative error code on failure. + * Returns %0 in case of success, %-EUCLEAN if an unrecoverable corruption is + * found, and a negative error code in case of failure. */ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf, int grouped) @@ -666,7 +658,8 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, goto corrupted; default: dbg_err("unknown"); - goto corrupted; + err = -EINVAL; + goto error; } } @@ -675,8 +668,13 @@ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, clean_buf(c, &buf, lnum, &offs, &len); need_clean = 1; } else { - ubifs_err("corrupt empty space at LEB %d:%d", - lnum, offs); + int corruption = first_non_ff(buf, len); + + ubifs_err("corrupt empty space LEB %d:%d, corruption " + "starts at %d", lnum, offs, corruption); + /* Make sure we dump interesting non-0xFF data */ + offs = corruption; + buf += corruption; goto corrupted; } } @@ -836,7 +834,7 @@ struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum, static int recover_head(const struct ubifs_info *c, int lnum, int offs, void *sbuf) { - int len, err, need_clean = 0; + int len, err; if (c->min_io_size > 1) len = c->min_io_size; @@ -850,19 +848,7 @@ static int recover_head(const struct ubifs_info *c, int lnum, int offs, /* Read at the head location and check it is empty flash */ err = ubi_read(c->ubi, lnum, sbuf, offs, len); - if (err) - need_clean = 1; - else { - uint8_t *p = sbuf; - - while (len--) - if (*p++ != 0xff) { - need_clean = 1; - break; - } - } - - if (need_clean) { + if (err || !is_empty(sbuf, len)) { dbg_rcvry("cleaning head at %d:%d", lnum, offs); if (offs == 0) return ubifs_leb_unmap(c, lnum); |