cregit-Linux how code gets into the kernel

Release 4.11 fs/ubifs/scan.c

Directory: fs/ubifs
/*
 * 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 (Битюцкий Артём)
 */

/*
 * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy80100.00%1100.00%
Total80100.00%1100.00%

/** * 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 at LEB %d:%d", lnum, offs); 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 at LEB %d:%d", dbg_ntype(ch->node_type), lnum, offs); 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(c, "bad pad node at LEB %d:%d", lnum, offs); ubifs_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) ubifs_err(c, "bad padding length %d - %d", offs, offs + node_len + pad_len); return SCANNED_A_BAD_PAD_NODE; } dbg_scan("%d bytes padded at LEB %d:%d, offset now %d", pad_len, lnum, offs, ALIGN(offs + node_len + pad_len, 8)); return node_len + pad_len; } return SCANNED_A_NODE; }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy26997.82%466.67%
Sheng Yong41.45%116.67%
Adrian Hunter20.73%116.67%
Total275100.00%6100.00%

/** * 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 the scanned information 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 = ubifs_leb_read(c, lnum, sbuf + offs, offs, c->leb_size - offs, 0); if (err && err != -EBADMSG) { ubifs_err(c, "cannot read %d bytes from LEB %d:%d, error %d", c->leb_size - offs, lnum, offs, err); kfree(sleb); return ERR_PTR(err); } /* * Note, we ignore integrity errors (EBASMSG) because all the nodes are * protected by CRC checksums. */ return sleb; }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy15098.04%360.00%
Sheng Yong21.31%120.00%
hujianyang10.65%120.00%
Total153100.00%5100.00%

/** * 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) */
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); }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy59100.00%1100.00%
Total59100.00%1100.00%

/** * 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 = kmalloc(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: /* * The key is in the same place in all keyed * nodes. */ key_read(c, &ino->key, &snod->key); break; default: invalid_key_init(c, &snod->key); break; } list_add_tail(&snod->list, &sleb->nodes); sleb->nodes_cnt += 1; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy177100.00%2100.00%
Total177100.00%2100.00%

/** * 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(c, "corruption at LEB %d:%d", lnum, offs); len = c->leb_size - offs; if (len > 8192) len = 8192; ubifs_err(c, "first %d bytes from LEB %d:%d", len, lnum, offs); print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1); }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy8195.29%375.00%
Sheng Yong44.71%125.00%
Total85100.00%4100.00%

/** * 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 of @c->leb_size bytes in size) * @quiet: print no messages * * This function scans LEB number @lnum and returns complete information about * its contents. Returns the scanned information in case of success and, * %-EUCLEAN if the LEB neads recovery, and other negative error codes in case * of failure. * * If @quiet is non-zero, this function does not print large and scary * error messages and flash dumps in case of errors. */
struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum, int offs, void *sbuf, int quiet) { 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, quiet); 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: ubifs_err(c, "garbage"); goto corrupted; case SCANNED_A_NODE: break; case SCANNED_A_CORRUPT_NODE: case SCANNED_A_BAD_PAD_NODE: ubifs_err(c, "bad node"); goto corrupted; default: ubifs_err(c, "unknown"); err = -EINVAL; goto error; } 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) { if (!quiet) ubifs_err(c, "empty space starts at non-aligned offset %d", offs); 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) { if (!quiet) ubifs_err(c, "corrupt empty space at LEB %d:%d", lnum, offs); goto corrupted; } return sleb; corrupted: if (!quiet) { ubifs_scanned_corruption(c, lnum, offs, buf); ubifs_err(c, "LEB %d scanning failed", lnum); } err = -EUCLEAN; ubifs_scan_destroy(sleb); return ERR_PTR(err); error: ubifs_err(c, "LEB %d scanning failed, error %d", lnum, err); ubifs_scan_destroy(sleb); return ERR_PTR(err); }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy43096.85%480.00%
Sheng Yong143.15%120.00%
Total444100.00%5100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy69100.00%1100.00%
Total69100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Artem B. Bityutskiy132797.93%1173.33%
Sheng Yong241.77%16.67%
Adrian Hunter20.15%16.67%
hujianyang10.07%16.67%
SeungHun Lee10.07%16.67%
Total1355100.00%15100.00%
Directory: fs/ubifs
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