diff options
Diffstat (limited to 'fs/jffs2/scan.c')
| -rw-r--r-- | fs/jffs2/scan.c | 1182 |
1 files changed, 1182 insertions, 0 deletions
diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c new file mode 100644 index 0000000000..29671e33a1 --- /dev/null +++ b/fs/jffs2/scan.c @@ -0,0 +1,1182 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * + * Created by David Woodhouse <dwmw2@infradead.org> + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/mtd/mtd.h> +#include <linux/pagemap.h> +#include <linux/crc32.h> +#include <linux/compiler.h> +#include "nodelist.h" +#include "summary.h" +#include "debug.h" + +#define DEFAULT_EMPTY_SCAN_SIZE 256 + +#define noisy_printk(noise, fmt, ...) \ +do { \ + if (*(noise)) { \ + pr_notice(fmt, ##__VA_ARGS__); \ + (*(noise))--; \ + if (!(*(noise))) \ + pr_notice("Further such events for this erase block will not be printed\n"); \ + } \ +} while (0) + +static uint32_t pseudo_random; + +static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s); + +/* These helper functions _must_ increase ofs and also do the dirty/used space accounting. + * Returning an error will abort the mount - bad checksums etc. should just mark the space + * as dirty. + */ +static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s); +static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s); + +static inline int min_free(struct jffs2_sb_info *c) +{ + uint32_t min = 2 * sizeof(struct jffs2_raw_inode); +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize) + return c->wbuf_pagesize; +#endif + return min; + +} + +static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) { + if (sector_size < DEFAULT_EMPTY_SCAN_SIZE) + return sector_size; + else + return DEFAULT_EMPTY_SCAN_SIZE; +} + +static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) +{ + int ret; + + if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1))) + return ret; + if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size))) + return ret; + /* Turned wasted size into dirty, since we apparently + think it's recoverable now. */ + jeb->dirty_size += jeb->wasted_size; + c->dirty_size += jeb->wasted_size; + c->wasted_size -= jeb->wasted_size; + jeb->wasted_size = 0; + if (VERYDIRTY(c, jeb->dirty_size)) { + list_add(&jeb->list, &c->very_dirty_list); + } else { + list_add(&jeb->list, &c->dirty_list); + } + return 0; +} + +int jffs2_scan_medium(struct jffs2_sb_info *c) +{ + int i, ret; + uint32_t empty_blocks = 0, bad_blocks = 0; + unsigned char *flashbuf = NULL; + uint32_t buf_size = 0; + struct jffs2_summary *s = NULL; /* summary info collected by the scan process */ +#ifndef __ECOS + size_t pointlen, try_size; + + ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen, + (void **)&flashbuf, NULL); + if (!ret && pointlen < c->mtd->size) { + /* Don't muck about if it won't let us point to the whole flash */ + jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n", + pointlen); + mtd_unpoint(c->mtd, 0, pointlen); + flashbuf = NULL; + } + if (ret && ret != -EOPNOTSUPP) + jffs2_dbg(1, "MTD point failed %d\n", ret); +#endif + if (!flashbuf) { + /* For NAND it's quicker to read a whole eraseblock at a time, + apparently */ + if (jffs2_cleanmarker_oob(c)) + try_size = c->sector_size; + else + try_size = PAGE_SIZE; + + jffs2_dbg(1, "Trying to allocate readbuf of %zu " + "bytes\n", try_size); + + flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size); + if (!flashbuf) + return -ENOMEM; + + jffs2_dbg(1, "Allocated readbuf of %zu bytes\n", + try_size); + + buf_size = (uint32_t)try_size; + } + + if (jffs2_sum_active()) { + s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL); + if (!s) { + JFFS2_WARNING("Can't allocate memory for summary\n"); + ret = -ENOMEM; + goto out_buf; + } + } + + for (i=0; i<c->nr_blocks; i++) { + struct jffs2_eraseblock *jeb = &c->blocks[i]; + + cond_resched(); + + /* reset summary info for next eraseblock scan */ + jffs2_sum_reset_collected(s); + + ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), + buf_size, s); + + if (ret < 0) + goto out; + + jffs2_dbg_acct_paranoia_check_nolock(c, jeb); + + /* Now decide which list to put it on */ + switch(ret) { + case BLK_STATE_ALLFF: + /* + * Empty block. Since we can't be sure it + * was entirely erased, we just queue it for erase + * again. It will be marked as such when the erase + * is complete. Meanwhile we still count it as empty + * for later checks. + */ + empty_blocks++; + list_add(&jeb->list, &c->erase_pending_list); + c->nr_erasing_blocks++; + break; + + case BLK_STATE_CLEANMARKER: + /* Only a CLEANMARKER node is valid */ + if (!jeb->dirty_size) { + /* It's actually free */ + list_add(&jeb->list, &c->free_list); + c->nr_free_blocks++; + } else { + /* Dirt */ + jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n", + jeb->offset); + list_add(&jeb->list, &c->erase_pending_list); + c->nr_erasing_blocks++; + } + break; + + case BLK_STATE_CLEAN: + /* Full (or almost full) of clean data. Clean list */ + list_add(&jeb->list, &c->clean_list); + break; + + case BLK_STATE_PARTDIRTY: + /* Some data, but not full. Dirty list. */ + /* We want to remember the block with most free space + and stick it in the 'nextblock' position to start writing to it. */ + if (jeb->free_size > min_free(c) && + (!c->nextblock || c->nextblock->free_size < jeb->free_size)) { + /* Better candidate for the next writes to go to */ + if (c->nextblock) { + ret = file_dirty(c, c->nextblock); + if (ret) + goto out; + /* deleting summary information of the old nextblock */ + jffs2_sum_reset_collected(c->summary); + } + /* update collected summary information for the current nextblock */ + jffs2_sum_move_collected(c, s); + jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n", + __func__, jeb->offset); + c->nextblock = jeb; + } else { + ret = file_dirty(c, jeb); + if (ret) + goto out; + } + break; + + case BLK_STATE_ALLDIRTY: + /* Nothing valid - not even a clean marker. Needs erasing. */ + /* For now we just put it on the erasing list. We'll start the erases later */ + jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n", + jeb->offset); + list_add(&jeb->list, &c->erase_pending_list); + c->nr_erasing_blocks++; + break; + + case BLK_STATE_BADBLOCK: + jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset); + list_add(&jeb->list, &c->bad_list); + c->bad_size += c->sector_size; + c->free_size -= c->sector_size; + bad_blocks++; + break; + default: + pr_warn("%s(): unknown block state\n", __func__); + BUG(); + } + } + + /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ + if (c->nextblock && (c->nextblock->dirty_size)) { + c->nextblock->wasted_size += c->nextblock->dirty_size; + c->wasted_size += c->nextblock->dirty_size; + c->dirty_size -= c->nextblock->dirty_size; + c->nextblock->dirty_size = 0; + } +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { + /* If we're going to start writing into a block which already + contains data, and the end of the data isn't page-aligned, + skip a little and align it. */ + + uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; + + jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n", + __func__, skip); + jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); + jffs2_scan_dirty_space(c, c->nextblock, skip); + } +#endif + if (c->nr_erasing_blocks) { + if (!c->used_size && !c->unchecked_size && + ((c->nr_free_blocks+empty_blocks+bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) { + pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); + pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n", + empty_blocks, bad_blocks, c->nr_blocks); + ret = -EIO; + goto out; + } + spin_lock(&c->erase_completion_lock); + jffs2_garbage_collect_trigger(c); + spin_unlock(&c->erase_completion_lock); + } + ret = 0; + out: + jffs2_sum_reset_collected(s); + kfree(s); + out_buf: + if (buf_size) + kfree(flashbuf); +#ifndef __ECOS + else + mtd_unpoint(c->mtd, 0, c->mtd->size); +#endif + return ret; +} + +static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf, + uint32_t ofs, uint32_t len) +{ + int ret; + size_t retlen; + + ret = jffs2_flash_read(c, ofs, len, &retlen, buf); + if (ret) { + jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n", + len, ofs, ret); + return ret; + } + if (retlen < len) { + jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n", + ofs, retlen); + return -EIO; + } + return 0; +} + +int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) +{ + if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size + && (!jeb->first_node || !ref_next(jeb->first_node)) ) + return BLK_STATE_CLEANMARKER; + + /* move blocks with max 4 byte dirty space to cleanlist */ + else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { + c->dirty_size -= jeb->dirty_size; + c->wasted_size += jeb->dirty_size; + jeb->wasted_size += jeb->dirty_size; + jeb->dirty_size = 0; + return BLK_STATE_CLEAN; + } else if (jeb->used_size || jeb->unchecked_size) + return BLK_STATE_PARTDIRTY; + else + return BLK_STATE_ALLDIRTY; +} + +#ifdef CONFIG_JFFS2_FS_XATTR +static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_xattr *rx, uint32_t ofs, + struct jffs2_summary *s) +{ + struct jffs2_xattr_datum *xd; + uint32_t xid, version, totlen, crc; + int err; + + crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4); + if (crc != je32_to_cpu(rx->node_crc)) { + JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", + ofs, je32_to_cpu(rx->node_crc), crc); + if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) + return err; + return 0; + } + + xid = je32_to_cpu(rx->xid); + version = je32_to_cpu(rx->version); + + totlen = PAD(sizeof(struct jffs2_raw_xattr) + + rx->name_len + 1 + je16_to_cpu(rx->value_len)); + if (totlen != je32_to_cpu(rx->totlen)) { + JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n", + ofs, je32_to_cpu(rx->totlen), totlen); + if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen)))) + return err; + return 0; + } + + xd = jffs2_setup_xattr_datum(c, xid, version); + if (IS_ERR(xd)) + return PTR_ERR(xd); + + if (xd->version > version) { + struct jffs2_raw_node_ref *raw + = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL); + raw->next_in_ino = xd->node->next_in_ino; + xd->node->next_in_ino = raw; + } else { + xd->version = version; + xd->xprefix = rx->xprefix; + xd->name_len = rx->name_len; + xd->value_len = je16_to_cpu(rx->value_len); + xd->data_crc = je32_to_cpu(rx->data_crc); + + jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd); + } + + if (jffs2_sum_active()) + jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset); + dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n", + ofs, xd->xid, xd->version); + return 0; +} + +static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_xref *rr, uint32_t ofs, + struct jffs2_summary *s) +{ + struct jffs2_xattr_ref *ref; + uint32_t crc; + int err; + + crc = crc32(0, rr, sizeof(*rr) - 4); + if (crc != je32_to_cpu(rr->node_crc)) { + JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n", + ofs, je32_to_cpu(rr->node_crc), crc); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen))))) + return err; + return 0; + } + + if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) { + JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n", + ofs, je32_to_cpu(rr->totlen), + PAD(sizeof(struct jffs2_raw_xref))); + if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen)))) + return err; + return 0; + } + + ref = jffs2_alloc_xattr_ref(); + if (!ref) + return -ENOMEM; + + /* BEFORE jffs2_build_xattr_subsystem() called, + * and AFTER xattr_ref is marked as a dead xref, + * ref->xid is used to store 32bit xid, xd is not used + * ref->ino is used to store 32bit inode-number, ic is not used + * Thoes variables are declared as union, thus using those + * are exclusive. In a similar way, ref->next is temporarily + * used to chain all xattr_ref object. It's re-chained to + * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly. + */ + ref->ino = je32_to_cpu(rr->ino); + ref->xid = je32_to_cpu(rr->xid); + ref->xseqno = je32_to_cpu(rr->xseqno); + if (ref->xseqno > c->highest_xseqno) + c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER); + ref->next = c->xref_temp; + c->xref_temp = ref; + + jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref); + + if (jffs2_sum_active()) + jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset); + dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n", + ofs, ref->xid, ref->ino); + return 0; +} +#endif + +/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into + the flash, XIP-style */ +static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { + struct jffs2_unknown_node *node; + struct jffs2_unknown_node crcnode; + uint32_t ofs, prevofs, max_ofs; + uint32_t hdr_crc, buf_ofs, buf_len; + int err; + int noise = 0; + + +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + int cleanmarkerfound = 0; +#endif + + ofs = jeb->offset; + prevofs = jeb->offset - 1; + + jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs); + +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + if (jffs2_cleanmarker_oob(c)) { + int ret; + + if (mtd_block_isbad(c->mtd, jeb->offset)) + return BLK_STATE_BADBLOCK; + + ret = jffs2_check_nand_cleanmarker(c, jeb); + jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret); + + /* Even if it's not found, we still scan to see + if the block is empty. We use this information + to decide whether to erase it or not. */ + switch (ret) { + case 0: cleanmarkerfound = 1; break; + case 1: break; + default: return ret; + } + } +#endif + + if (jffs2_sum_active()) { + struct jffs2_sum_marker *sm; + void *sumptr = NULL; + uint32_t sumlen; + + if (!buf_size) { + /* XIP case. Just look, point at the summary if it's there */ + sm = (void *)buf + c->sector_size - sizeof(*sm); + if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { + sumptr = buf + je32_to_cpu(sm->offset); + sumlen = c->sector_size - je32_to_cpu(sm->offset); + } + } else { + /* If NAND flash, read a whole page of it. Else just the end */ + if (c->wbuf_pagesize) + buf_len = c->wbuf_pagesize; + else + buf_len = sizeof(*sm); + + /* Read as much as we want into the _end_ of the preallocated buffer */ + err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, + jeb->offset + c->sector_size - buf_len, + buf_len); + if (err) + return err; + + sm = (void *)buf + buf_size - sizeof(*sm); + if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) { + sumlen = c->sector_size - je32_to_cpu(sm->offset); + sumptr = buf + buf_size - sumlen; + + /* sm->offset maybe wrong but MAGIC maybe right */ + if (sumlen > c->sector_size) + goto full_scan; + + /* Now, make sure the summary itself is available */ + if (sumlen > buf_size) { + /* Need to kmalloc for this. */ + sumptr = kmalloc(sumlen, GFP_KERNEL); + if (!sumptr) + return -ENOMEM; + memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len); + } + if (buf_len < sumlen) { + /* Need to read more so that the entire summary node is present */ + err = jffs2_fill_scan_buf(c, sumptr, + jeb->offset + c->sector_size - sumlen, + sumlen - buf_len); + if (err) { + if (sumlen > buf_size) + kfree(sumptr); + return err; + } + } + } + + } + + if (sumptr) { + err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random); + + if (buf_size && sumlen > buf_size) + kfree(sumptr); + /* If it returns with a real error, bail. + If it returns positive, that's a block classification + (i.e. BLK_STATE_xxx) so return that too. + If it returns zero, fall through to full scan. */ + if (err) + return err; + } + } + +full_scan: + buf_ofs = jeb->offset; + + if (!buf_size) { + /* This is the XIP case -- we're reading _directly_ from the flash chip */ + buf_len = c->sector_size; + } else { + buf_len = EMPTY_SCAN_SIZE(c->sector_size); + err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); + if (err) + return err; + } + + /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ + ofs = 0; + max_ofs = EMPTY_SCAN_SIZE(c->sector_size); + /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */ + while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) + ofs += 4; + + if (ofs == max_ofs) { +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + if (jffs2_cleanmarker_oob(c)) { + /* scan oob, take care of cleanmarker */ + int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); + jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n", + ret); + switch (ret) { + case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; + case 1: return BLK_STATE_ALLDIRTY; + default: return ret; + } + } +#endif + jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n", + jeb->offset); + if (c->cleanmarker_size == 0) + return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ + else + return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ + } + if (ofs) { + jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset, + jeb->offset + ofs); + if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1))) + return err; + if ((err = jffs2_scan_dirty_space(c, jeb, ofs))) + return err; + } + + /* Now ofs is a complete physical flash offset as it always was... */ + ofs += jeb->offset; + + noise = 10; + + dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); + +scan_more: + while(ofs < jeb->offset + c->sector_size) { + + jffs2_dbg_acct_paranoia_check_nolock(c, jeb); + + /* Make sure there are node refs available for use */ + err = jffs2_prealloc_raw_node_refs(c, jeb, 2); + if (err) + return err; + + cond_resched(); + + if (ofs & 3) { + pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs); + ofs = PAD(ofs); + continue; + } + if (ofs == prevofs) { + pr_warn("ofs 0x%08x has already been seen. Skipping\n", + ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + prevofs = ofs; + + if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { + jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", + sizeof(struct jffs2_unknown_node), + jeb->offset, c->sector_size, ofs, + sizeof(*node)); + if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs))) + return err; + break; + } + + if (buf_ofs + buf_len < ofs + sizeof(*node)) { + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", + sizeof(struct jffs2_unknown_node), + buf_len, ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + } + + node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; + + if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { + uint32_t inbuf_ofs; + uint32_t empty_start, scan_end; + + empty_start = ofs; + ofs += 4; + scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); + + jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs); + more_empty: + inbuf_ofs = ofs - buf_ofs; + while (inbuf_ofs < scan_end) { + if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { + pr_warn("Empty flash at 0x%08x ends at 0x%08x\n", + empty_start, ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) + return err; + goto scan_more; + } + + inbuf_ofs+=4; + ofs += 4; + } + /* Ran off end. */ + jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n", + ofs); + + /* If we're only checking the beginning of a block with a cleanmarker, + bail now */ + if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && + c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) { + jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n", + EMPTY_SCAN_SIZE(c->sector_size)); + return BLK_STATE_CLEANMARKER; + } + if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ + scan_end = buf_len; + goto more_empty; + } + + /* See how much more there is to read in this eraseblock... */ + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + if (!buf_len) { + /* No more to read. Break out of main loop without marking + this range of empty space as dirty (because it's not) */ + jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n", + empty_start); + break; + } + /* point never reaches here */ + scan_end = buf_len; + jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n", + buf_len, ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + goto more_empty; + } + + if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { + pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", + ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { + jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { + pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs); + pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n"); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { + /* OK. We're out of possibilities. Whinge and move on */ + noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", + __func__, + JFFS2_MAGIC_BITMASK, ofs, + je16_to_cpu(node->magic)); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + /* We seem to have a node of sorts. Check the CRC */ + crcnode.magic = node->magic; + crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); + crcnode.totlen = node->totlen; + hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); + + if (hdr_crc != je32_to_cpu(node->hdr_crc)) { + noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n", + __func__, + ofs, je16_to_cpu(node->magic), + je16_to_cpu(node->nodetype), + je32_to_cpu(node->totlen), + je32_to_cpu(node->hdr_crc), + hdr_crc); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + + if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) { + /* Eep. Node goes over the end of the erase block. */ + pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", + ofs, je32_to_cpu(node->totlen)); + pr_warn("Perhaps the file system was created with the wrong erase size?\n"); + if ((err = jffs2_scan_dirty_space(c, jeb, 4))) + return err; + ofs += 4; + continue; + } + + if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { + /* Wheee. This is an obsoleted node */ + jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n", + ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + continue; + } + + switch(je16_to_cpu(node->nodetype)) { + case JFFS2_NODETYPE_INODE: + if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", + sizeof(struct jffs2_raw_inode), + buf_len, ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + node = (void *)buf; + } + err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); + if (err) return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + + case JFFS2_NODETYPE_DIRENT: + if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", + je32_to_cpu(node->totlen), buf_len, + ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + node = (void *)buf; + } + err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); + if (err) return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + +#ifdef CONFIG_JFFS2_FS_XATTR + case JFFS2_NODETYPE_XATTR: + if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n", + je32_to_cpu(node->totlen), buf_len, + ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + node = (void *)buf; + } + err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s); + if (err) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + case JFFS2_NODETYPE_XREF: + if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { + buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); + jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n", + je32_to_cpu(node->totlen), buf_len, + ofs); + err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); + if (err) + return err; + buf_ofs = ofs; + node = (void *)buf; + } + err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s); + if (err) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; +#endif /* CONFIG_JFFS2_FS_XATTR */ + + case JFFS2_NODETYPE_CLEANMARKER: + jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs); + if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { + pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", + ofs, je32_to_cpu(node->totlen), + c->cleanmarker_size); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) + return err; + ofs += PAD(sizeof(struct jffs2_unknown_node)); + } else if (jeb->first_node) { + pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", + ofs, jeb->offset); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node))))) + return err; + ofs += PAD(sizeof(struct jffs2_unknown_node)); + } else { + jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL); + + ofs += PAD(c->cleanmarker_size); + } + break; + + case JFFS2_NODETYPE_PADDING: + if (jffs2_sum_active()) + jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + + default: + switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { + case JFFS2_FEATURE_ROCOMPAT: + pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", + je16_to_cpu(node->nodetype), ofs); + c->flags |= JFFS2_SB_FLAG_RO; + if (!(jffs2_is_readonly(c))) + return -EROFS; + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + + case JFFS2_FEATURE_INCOMPAT: + pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n", + je16_to_cpu(node->nodetype), ofs); + return -EINVAL; + + case JFFS2_FEATURE_RWCOMPAT_DELETE: + jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", + je16_to_cpu(node->nodetype), ofs); + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen))))) + return err; + ofs += PAD(je32_to_cpu(node->totlen)); + break; + + case JFFS2_FEATURE_RWCOMPAT_COPY: { + jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", + je16_to_cpu(node->nodetype), ofs); + + jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL); + + /* We can't summarise nodes we don't grok */ + jffs2_sum_disable_collecting(s); + ofs += PAD(je32_to_cpu(node->totlen)); + break; + } + } + } + } + + if (jffs2_sum_active()) { + if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { + dbg_summary("There is not enough space for " + "summary information, disabling for this jeb!\n"); + jffs2_sum_disable_collecting(s); + } + } + + jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n", + jeb->offset, jeb->free_size, jeb->dirty_size, + jeb->unchecked_size, jeb->used_size, jeb->wasted_size); + + /* mark_node_obsolete can add to wasted !! */ + if (jeb->wasted_size) { + jeb->dirty_size += jeb->wasted_size; + c->dirty_size += jeb->wasted_size; + c->wasted_size -= jeb->wasted_size; + jeb->wasted_size = 0; + } + + return jffs2_scan_classify_jeb(c, jeb); +} + +struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) +{ + struct jffs2_inode_cache *ic; + + ic = jffs2_get_ino_cache(c, ino); + if (ic) + return ic; + + if (ino > c->highest_ino) + c->highest_ino = ino; + + ic = jffs2_alloc_inode_cache(); + if (!ic) { + pr_notice("%s(): allocation of inode cache failed\n", __func__); + return NULL; + } + memset(ic, 0, sizeof(*ic)); + + ic->ino = ino; + ic->nodes = (void *)ic; + jffs2_add_ino_cache(c, ic); + if (ino == 1) + ic->pino_nlink = 1; + return ic; +} + +static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) +{ + struct jffs2_inode_cache *ic; + uint32_t crc, ino = je32_to_cpu(ri->ino); + + jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); + + /* We do very little here now. Just check the ino# to which we should attribute + this node; we can do all the CRC checking etc. later. There's a tradeoff here -- + we used to scan the flash once only, reading everything we want from it into + memory, then building all our in-core data structures and freeing the extra + information. Now we allow the first part of the mount to complete a lot quicker, + but we have to go _back_ to the flash in order to finish the CRC checking, etc. + Which means that the _full_ amount of time to get to proper write mode with GC + operational may actually be _longer_ than before. Sucks to be me. */ + + /* Check the node CRC in any case. */ + crc = crc32(0, ri, sizeof(*ri)-8); + if (crc != je32_to_cpu(ri->node_crc)) { + pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", + __func__, ofs, je32_to_cpu(ri->node_crc), crc); + /* + * We believe totlen because the CRC on the node + * _header_ was OK, just the node itself failed. + */ + return jffs2_scan_dirty_space(c, jeb, + PAD(je32_to_cpu(ri->totlen))); + } + + ic = jffs2_get_ino_cache(c, ino); + if (!ic) { + ic = jffs2_scan_make_ino_cache(c, ino); + if (!ic) + return -ENOMEM; + } + + /* Wheee. It worked */ + jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic); + + jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n", + je32_to_cpu(ri->ino), je32_to_cpu(ri->version), + je32_to_cpu(ri->offset), + je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)); + + pseudo_random += je32_to_cpu(ri->version); + + if (jffs2_sum_active()) { + jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); + } + + return 0; +} + +static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, + struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) +{ + struct jffs2_full_dirent *fd; + struct jffs2_inode_cache *ic; + uint32_t checkedlen; + uint32_t crc; + int err; + + jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs); + + /* We don't get here unless the node is still valid, so we don't have to + mask in the ACCURATE bit any more. */ + crc = crc32(0, rd, sizeof(*rd)-8); + + if (crc != je32_to_cpu(rd->node_crc)) { + pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", + __func__, ofs, je32_to_cpu(rd->node_crc), crc); + /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) + return err; + return 0; + } + + pseudo_random += je32_to_cpu(rd->version); + + /* Should never happen. Did. (OLPC trac #4184)*/ + checkedlen = strnlen(rd->name, rd->nsize); + if (checkedlen < rd->nsize) { + pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n", + ofs, checkedlen); + } + fd = jffs2_alloc_full_dirent(checkedlen+1); + if (!fd) { + return -ENOMEM; + } + memcpy(&fd->name, rd->name, checkedlen); + fd->name[checkedlen] = 0; + + crc = crc32(0, fd->name, checkedlen); + if (crc != je32_to_cpu(rd->name_crc)) { + pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", + __func__, ofs, je32_to_cpu(rd->name_crc), crc); + jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n", + fd->name, je32_to_cpu(rd->ino)); + jffs2_free_full_dirent(fd); + /* FIXME: Why do we believe totlen? */ + /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ + if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen))))) + return err; + return 0; + } + ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); + if (!ic) { + jffs2_free_full_dirent(fd); + return -ENOMEM; + } + + fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd), + PAD(je32_to_cpu(rd->totlen)), ic); + + fd->next = NULL; + fd->version = je32_to_cpu(rd->version); + fd->ino = je32_to_cpu(rd->ino); + fd->nhash = full_name_hash(NULL, fd->name, checkedlen); + fd->type = rd->type; + jffs2_add_fd_to_list(c, fd, &ic->scan_dents); + + if (jffs2_sum_active()) { + jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); + } + + return 0; +} + +static int count_list(struct list_head *l) +{ + uint32_t count = 0; + struct list_head *tmp; + + list_for_each(tmp, l) { + count++; + } + return count; +} + +/* Note: This breaks if list_empty(head). I don't care. You + might, if you copy this code and use it elsewhere :) */ +static void rotate_list(struct list_head *head, uint32_t count) +{ + struct list_head *n = head->next; + + list_del(head); + while(count--) { + n = n->next; + } + list_add(head, n); +} + +void jffs2_rotate_lists(struct jffs2_sb_info *c) +{ + uint32_t x; + uint32_t rotateby; + + x = count_list(&c->clean_list); + if (x) { + rotateby = pseudo_random % x; + rotate_list((&c->clean_list), rotateby); + } + + x = count_list(&c->very_dirty_list); + if (x) { + rotateby = pseudo_random % x; + rotate_list((&c->very_dirty_list), rotateby); + } + + x = count_list(&c->dirty_list); + if (x) { + rotateby = pseudo_random % x; + rotate_list((&c->dirty_list), rotateby); + } + + x = count_list(&c->erasable_list); + if (x) { + rotateby = pseudo_random % x; + rotate_list((&c->erasable_list), rotateby); + } + + if (c->nr_erasing_blocks) { + rotateby = pseudo_random % c->nr_erasing_blocks; + rotate_list((&c->erase_pending_list), rotateby); + } + + if (c->nr_free_blocks) { + rotateby = pseudo_random % c->nr_free_blocks; + rotate_list((&c->free_list), rotateby); + } +} |