From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from exprod5og115.obsmtp.com ([64.18.0.246]) by merlin.infradead.org with smtps (Exim 4.76 #1 (Red Hat Linux)) id 1TfaSN-000526-Gy for barebox@lists.infradead.org; Mon, 03 Dec 2012 18:09:31 +0000 From: Renaud Barbier Date: Mon, 3 Dec 2012 18:08:30 +0000 Message-Id: <1354558114-28799-15-git-send-email-renaud.barbier@ge.com> In-Reply-To: <1354558114-28799-1-git-send-email-renaud.barbier@ge.com> References: <1354558114-28799-1-git-send-email-renaud.barbier@ge.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5875151883672286455==" Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 14/18] UBIFS: scan To: barebox@lists.infradead.org --===============5875151883672286455== Content-Type: text/plain The scan function determines what nodes are in an eraseblock. Signed-off-by: Renaud Barbier --- fs/ubifs/scan.c | 362 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 362 insertions(+), 0 deletions(-) create mode 100644 fs/ubifs/scan.c diff --git a/fs/ubifs/scan.c b/fs/ubifs/scan.c new file mode 100644 index 0000000..0ed8247 --- /dev/null +++ b/fs/ubifs/scan.c @@ -0,0 +1,362 @@ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Authors: Adrian Hunter + * Artem Bityutskiy (���������������� ����������) + */ + +/* + * This file implements the scan which is a general-purpose function for + * determining what nodes are in an eraseblock. The scan is used to replay the + * journal, to do garbage collection. for the TNC in-the-gaps method, and by + * debugging functions. + */ + +#include "ubifs.h" + +/** + * scan_padding_bytes - scan for padding bytes. + * @buf: buffer to scan + * @len: length of buffer + * + * This function returns the number of padding bytes on success and + * %SCANNED_GARBAGE on failure. + */ +static int scan_padding_bytes(void *buf, int len) +{ + int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len); + uint8_t *p = buf; + + dbg_scan("not a node"); + + while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE) + pad_len += 1; + + if (!pad_len || (pad_len & 7)) + return SCANNED_GARBAGE; + + dbg_scan("%d padding bytes", pad_len); + + return pad_len; +} + +/** + * ubifs_scan_a_node - scan for a node or padding. + * @c: UBIFS file-system description object + * @buf: buffer to scan + * @len: length of buffer + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * @quiet: print no messages + * + * This function returns a scanning code to indicate what was scanned. + */ +int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum, + int offs, int quiet) +{ + struct ubifs_ch *ch = buf; + uint32_t magic; + + magic = le32_to_cpu(ch->magic); + + if (magic == 0xFFFFFFFF) { + dbg_scan("hit empty space"); + return SCANNED_EMPTY_SPACE; + } + + if (magic != UBIFS_NODE_MAGIC) + return scan_padding_bytes(buf, len); + + if (len < UBIFS_CH_SZ) + return SCANNED_GARBAGE; + + dbg_scan("scanning %s", dbg_ntype(ch->node_type)); + + if (ubifs_check_node(c, buf, lnum, offs, quiet, 1)) + return SCANNED_A_CORRUPT_NODE; + + if (ch->node_type == UBIFS_PAD_NODE) { + struct ubifs_pad_node *pad = buf; + int pad_len = le32_to_cpu(pad->pad_len); + int node_len = le32_to_cpu(ch->len); + + /* Validate the padding node */ + if (pad_len < 0 || + offs + node_len + pad_len > c->leb_size) { + if (!quiet) { + ubifs_err("bad pad node at LEB %d:%d", + lnum, offs); + dbg_dump_node(c, pad); + } + return SCANNED_A_BAD_PAD_NODE; + } + + /* Make the node pads to 8-byte boundary */ + if ((node_len + pad_len) & 7) { + if (!quiet) { + dbg_err("bad padding length %d - %d", + offs, offs + node_len + pad_len); + } + return SCANNED_A_BAD_PAD_NODE; + } + + dbg_scan("%d bytes padded, offset now %d", + pad_len, ALIGN(offs + node_len + pad_len, 8)); + + return node_len + pad_len; + } + + return SCANNED_A_NODE; +} + +/** + * ubifs_start_scan - create LEB scanning information at start of scan. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + * @sbuf: scan buffer (must be c->leb_size) + * + * This function returns %0 on success and a negative error code on failure. + */ +struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf) +{ + struct ubifs_scan_leb *sleb; + int err; + + dbg_scan("scan LEB %d:%d", lnum, offs); + + sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS); + if (!sleb) + return ERR_PTR(-ENOMEM); + + sleb->lnum = lnum; + INIT_LIST_HEAD(&sleb->nodes); + sleb->buf = sbuf; + + err = ubi_read(c->ubi, lnum, sbuf + offs, offs, c->leb_size - offs); + if (err && err != -EBADMSG) { + ubifs_err("cannot read %d bytes from LEB %d:%d," + " error %d", c->leb_size - offs, lnum, offs, err); + kfree(sleb); + return ERR_PTR(err); + } + + if (err == -EBADMSG) + sleb->ecc = 1; + + return sleb; +} + +/** + * ubifs_end_scan - update LEB scanning information at end of scan. + * @c: UBIFS file-system description object + * @sleb: scanning information + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + * + * This function returns %0 on success and a negative error code on failure. + */ +void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + int lnum, int offs) +{ + lnum = lnum; + dbg_scan("stop scanning LEB %d at offset %d", lnum, offs); + ubifs_assert(offs % c->min_io_size == 0); + + sleb->endpt = ALIGN(offs, c->min_io_size); +} + +/** + * ubifs_add_snod - add a scanned node to LEB scanning information. + * @c: UBIFS file-system description object + * @sleb: scanning information + * @buf: buffer containing node + * @offs: offset of node on flash + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + void *buf, int offs) +{ + struct ubifs_ch *ch = buf; + struct ubifs_ino_node *ino = buf; + struct ubifs_scan_node *snod; + + snod = kzalloc(sizeof(struct ubifs_scan_node), GFP_NOFS); + if (!snod) + return -ENOMEM; + + snod->sqnum = le64_to_cpu(ch->sqnum); + snod->type = ch->node_type; + snod->offs = offs; + snod->len = le32_to_cpu(ch->len); + snod->node = buf; + + switch (ch->node_type) { + case UBIFS_INO_NODE: + case UBIFS_DENT_NODE: + case UBIFS_XENT_NODE: + case UBIFS_DATA_NODE: + case UBIFS_TRUN_NODE: + /* + * The key is in the same place in all keyed + * nodes. + */ + key_read(c, &ino->key, &snod->key); + break; + } + list_add_tail(&snod->list, &sleb->nodes); + sleb->nodes_cnt += 1; + return 0; +} + +/** + * ubifs_scanned_corruption - print information after UBIFS scanned corruption. + * @c: UBIFS file-system description object + * @lnum: LEB number of corruption + * @offs: offset of corruption + * @buf: buffer containing corruption + */ +void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs, + void *buf) +{ + int len; + + ubifs_err("corrupted data at LEB %d:%d", lnum, offs); + if (dbg_failure_mode) + return; + len = c->leb_size - offs; + if (len > 4096) + len = 4096; + dbg_err("first %d bytes from LEB %d:%d", len, lnum, offs); + print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1); +} + +/** + * ubifs_scan - scan a logical eraseblock. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + * @sbuf: scan buffer (must be c->leb_size) + * + * This function scans LEB number @lnum and returns complete information about + * its contents. Returns an error code in case of failure. + */ +struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf) +{ + void *buf = sbuf + offs; + int err, len = c->leb_size - offs; + struct ubifs_scan_leb *sleb; + + sleb = ubifs_start_scan(c, lnum, offs, sbuf); + if (IS_ERR(sleb)) + return sleb; + + while (len >= 8) { + struct ubifs_ch *ch = buf; + int node_len, ret; + + dbg_scan("look at LEB %d:%d (%d bytes left)", + lnum, offs, len); + + cond_resched(); + + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 0); + + if (ret > 0) { + /* Padding bytes or a valid padding node */ + offs += ret; + buf += ret; + len -= ret; + continue; + } + + if (ret == SCANNED_EMPTY_SPACE) + /* Empty space is checked later */ + break; + + switch (ret) { + case SCANNED_GARBAGE: + dbg_err("garbage"); + goto corrupted; + case SCANNED_A_NODE: + break; + case SCANNED_A_CORRUPT_NODE: + case SCANNED_A_BAD_PAD_NODE: + dbg_err("bad node"); + goto corrupted; + default: + dbg_err("unknown"); + goto corrupted; + } + + err = ubifs_add_snod(c, sleb, buf, offs); + if (err) + goto error; + + node_len = ALIGN(le32_to_cpu(ch->len), 8); + offs += node_len; + buf += node_len; + len -= node_len; + } + + if (offs % c->min_io_size) + goto corrupted; + + ubifs_end_scan(c, sleb, lnum, offs); + + for (; len > 4; offs += 4, buf = buf + 4, len -= 4) + if (*(uint32_t *)buf != 0xffffffff) + break; + for (; len; offs++, buf++, len--) + if (*(uint8_t *)buf != 0xff) { + ubifs_err("corrupt empty space at LEB %d:%d", + lnum, offs); + goto corrupted; + } + + return sleb; + +corrupted: + ubifs_scanned_corruption(c, lnum, offs, buf); + err = -EUCLEAN; +error: + ubifs_err("LEB %d scanning failed", lnum); + ubifs_scan_destroy(sleb); + return ERR_PTR(err); +} + +/** + * ubifs_scan_destroy - destroy LEB scanning information. + * @sleb: scanning information to free + */ +void ubifs_scan_destroy(struct ubifs_scan_leb *sleb) +{ + struct ubifs_scan_node *node; + struct list_head *head; + + head = &sleb->nodes; + while (!list_empty(head)) { + node = list_entry(head->next, struct ubifs_scan_node, list); + list_del(&node->list); + kfree(node); + } + kfree(sleb); +} -- 1.7.1 --===============5875151883672286455== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox --===============5875151883672286455==--