patch-2.4.0-test3 linux/fs/jffs/intrep.c
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- Lines: 2560
- Date:
Thu Jul 6 01:22:24 2000
- Orig file:
v2.4.0-test2/linux/fs/jffs/intrep.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.0-test2/linux/fs/jffs/intrep.c linux/fs/jffs/intrep.c
@@ -0,0 +1,2559 @@
+/*
+ * JFFS -- Journaling Flash File System, Linux implementation.
+ *
+ * Copyright (C) 1999, 2000 Axis Communications, Inc.
+ *
+ * Created by Finn Hakansson <finn@axis.com>.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * $Id: intrep.c,v 1.15 2000/06/27 15:33:43 dwmw2 Exp $
+ *
+ * Ported to Linux 2.3.x and MTD:
+ * Copyright (C) 2000 Alexander Larsson (alex@cendio.se), Cendio Systems AB
+ *
+ */
+
+/* This file contains the code for the internal structure of the
+ Journaling Flash File System, JFFS. */
+
+/*
+ * Todo list:
+ *
+ * memcpy_to_flash() and memcpy_from_flash()-functions.
+ *
+ * Implementation of hard links.
+ *
+ * Organize the source code in a better way. Against the VFS we could
+ * have jffs_ext.c, and against the block device jffs_int.c.
+ * A better file-internal organization too.
+ *
+ * A better checksum algorithm.
+ *
+ * Consider endianness stuff. ntohl() etc.
+ *
+ * Are we handling the atime, mtime, ctime members of the inode right?
+ *
+ * Remove some duplicated code. Take a look at jffs_write_node() and
+ * jffs_rewrite_data() for instance.
+ *
+ * Implement more meaning of the nlink member in various data structures.
+ * nlink could be used in conjunction with hard links for instance.
+ *
+ * Fix the rename stuff. (I.e. if we have two files `a' and `b' and we
+ * do a `mv b a'.) Half of this is already implemented.
+ *
+ * Better memory management. Allocate data structures in larger chunks
+ * if possible.
+ *
+ * If too much meta data is stored, a garbage collect should be issued.
+ * We have experienced problems with too much meta data with for instance
+ * log files.
+ *
+ * Improve the calls to jffs_ioctl(). We would like to retrieve more
+ * information to be able to debug (or to supervise) JFFS during run-time.
+ *
+ */
+#define __NO_VERSION__
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/malloc.h>
+#include <linux/jffs.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/pagemap.h>
+#include <linux/locks.h>
+#include <asm/semaphore.h>
+#include <asm/byteorder.h>
+#include <linux/version.h>
+
+#include "intrep.h"
+#include "jffs_fm.h"
+
+#if LINUX_VERSION_CODE < 0x20300
+#define set_current_state(x) do{current->state = x;} while (0)
+#endif
+
+#if defined(CONFIG_JFFS_FS_VERBOSE) && CONFIG_JFFS_FS_VERBOSE
+#define D(x) x
+#else
+#define D(x)
+#endif
+#define D1(x) D(x)
+#define D2(x)
+#define D3(x)
+#define ASSERT(x) x
+
+#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
+long no_jffs_file = 0;
+long no_jffs_node = 0;
+long no_jffs_control = 0;
+long no_jffs_raw_inode = 0;
+long no_jffs_node_ref = 0;
+long no_jffs_fm = 0;
+long no_jffs_fmcontrol = 0;
+long no_hash = 0;
+long no_name = 0;
+#endif
+
+static int jffs_scan_flash(struct jffs_control *c);
+static int jffs_update_file(struct jffs_file *f, struct jffs_node *node);
+static __u8 flash_read_u8(struct mtd_info *mtd, loff_t from);
+
+#if 1
+#define _U 01
+#define _L 02
+#define _N 04
+#define _S 010
+#define _P 020
+#define _C 040
+#define _X 0100
+#define _B 0200
+
+const unsigned char jffs_ctype_[1 + 256] = {
+ 0,
+ _C, _C, _C, _C, _C, _C, _C, _C,
+ _C, _C|_S, _C|_S, _C|_S, _C|_S, _C|_S, _C, _C,
+ _C, _C, _C, _C, _C, _C, _C, _C,
+ _C, _C, _C, _C, _C, _C, _C, _C,
+ _S|_B, _P, _P, _P, _P, _P, _P, _P,
+ _P, _P, _P, _P, _P, _P, _P, _P,
+ _N, _N, _N, _N, _N, _N, _N, _N,
+ _N, _N, _P, _P, _P, _P, _P, _P,
+ _P, _U|_X, _U|_X, _U|_X, _U|_X, _U|_X, _U|_X, _U,
+ _U, _U, _U, _U, _U, _U, _U, _U,
+ _U, _U, _U, _U, _U, _U, _U, _U,
+ _U, _U, _U, _P, _P, _P, _P, _P,
+ _P, _L|_X, _L|_X, _L|_X, _L|_X, _L|_X, _L|_X, _L,
+ _L, _L, _L, _L, _L, _L, _L, _L,
+ _L, _L, _L, _L, _L, _L, _L, _L,
+ _L, _L, _L, _P, _P, _P, _P, _C
+};
+
+#define jffs_isalpha(c) ((jffs_ctype_+1)[(int)c]&(_U|_L))
+#define jffs_isupper(c) ((jffs_ctype_+1)[(int)c]&_U)
+#define jffs_islower(c) ((jffs_ctype_+1)[(int)c]&_L)
+#define jffs_isdigit(c) ((jffs_ctype_+1)[(int)c]&_N)
+#define jffs_isxdigit(c) ((jffs_ctype_+1)[(int)c]&(_X|_N))
+#define jffs_isspace(c) ((jffs_ctype_+1)[(int)c]&_S)
+#define jffs_ispunct(c) ((jffs_ctype_+1)[(int)c]&_P)
+#define jffs_isalnum(c) ((jffs_ctype_+1)[(int)c]&(_U|_L|_N))
+#define jffs_isprint(c) ((jffs_ctype_+1)[(int)c]&(_P|_U|_L|_N|_B))
+#define jffs_isgraph(c) ((jffs_ctype_+1)[(int)c]&(_P|_U|_L|_N))
+#define jffs_iscntrl(c) ((jffs_ctype_+1)[(int)c]&_C)
+
+void
+jffs_hexdump(struct mtd_info *mtd, loff_t pos, int size)
+{
+ char line[16];
+ int j = 0;
+
+ while (size > 0) {
+ int i;
+
+ printk("%ld:", (long) pos);
+ for (j = 0; j < 16; j++) {
+ line[j] = flash_read_u8(mtd, pos++);
+ }
+ for (i = 0; i < j; i++) {
+ if (!(i & 1)) {
+ printk(" %.2x", line[i] & 0xff);
+ }
+ else {
+ printk("%.2x", line[i] & 0xff);
+ }
+ }
+
+ /* Print empty space */
+ for (; i < 16; i++) {
+ if (!(i & 1)) {
+ printk(" ");
+ }
+ else {
+ printk(" ");
+ }
+ }
+ printk(" ");
+
+ for (i = 0; i < j; i++) {
+ if (jffs_isgraph(line[i])) {
+ printk("%c", line[i]);
+ }
+ else {
+ printk(".");
+ }
+ }
+ printk("\n");
+ size -= 16;
+ }
+}
+#endif
+
+#define flash_safe_acquire(arg)
+#define flash_safe_release(arg)
+
+static int
+flash_safe_read(struct mtd_info *mtd, loff_t from,
+ u_char *buf, size_t count)
+{
+ size_t retlen;
+
+ MTD_READ(mtd, from, count, &retlen, buf);
+ if (retlen != count) {
+ printk("Didn't read all bytes in flash_safe_read()\n");
+ }
+ return retlen;
+}
+
+static __u32
+flash_read_u32(struct mtd_info *mtd, loff_t from)
+{
+ size_t retlen;
+ __u32 ret;
+
+ MTD_READ(mtd, from, 4, &retlen, (unsigned char *)&ret);
+ if (retlen != 4) {
+ printk("Didn't read all bytes in flash_read_u32()\n");
+ return 0;
+ }
+
+ return ret;
+}
+
+static __u8
+flash_read_u8(struct mtd_info *mtd, loff_t from)
+{
+ size_t retlen;
+ __u8 ret;
+
+ MTD_READ(mtd, from, 1, &retlen, &ret);
+ if (retlen != 1) {
+ printk("Didn't read all bytes in flash_read_u32()\n");
+ return 0;
+ }
+
+ return ret;
+}
+
+
+static int
+flash_safe_write(struct mtd_info *mtd, loff_t to,
+ const u_char *buf, size_t count)
+{
+ size_t retlen;
+
+ MTD_WRITE(mtd, to, count, &retlen, buf);
+ if (retlen != count) {
+ printk("Didn't write all bytes in flash_safe_write()\n");
+ }
+ return retlen;
+}
+
+static int
+flash_memset(struct mtd_info *mtd, loff_t to,
+ const u_char c, size_t size)
+{
+ static unsigned char pattern[16];
+ int i;
+
+ /* fill up pattern */
+
+ for(i = 0; i < 16; i++)
+ pattern[i] = c;
+
+ /* write as many 16-byte chunks as we can */
+
+ while(size >= 16) {
+ flash_safe_write(mtd, to, pattern, 16);
+ size -= 16;
+ to += 16;
+ }
+
+ /* and the rest */
+
+ if(size)
+ flash_safe_write(mtd, to, pattern, size);
+
+ return size;
+}
+
+static void intrep_erase_callback(struct erase_info *done)
+{
+ wait_queue_head_t *wait_q;
+
+ wait_q = (wait_queue_head_t *)done->priv;
+
+ wake_up(wait_q);
+}
+
+static int
+flash_erase_region(struct mtd_info *mtd, loff_t start,
+ size_t size)
+{
+ struct erase_info *erase;
+ DECLARE_WAITQUEUE(wait, current);
+ wait_queue_head_t wait_q;
+
+ erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
+ if (!erase)
+ return -ENOMEM;
+
+ init_waitqueue_head(&wait_q);
+
+ erase->mtd = mtd;
+ erase->callback = intrep_erase_callback;
+ erase->addr = start;
+ erase->len = size;
+ erase->priv = (u_long)&wait_q;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&wait_q, &wait);
+
+ if (MTD_ERASE(mtd, erase) < 0) {
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&wait_q, &wait);
+ kfree(erase);
+
+ printk(KERN_WARNING "flash: erase of region [0x%ld, 0x%ld] totally failed\n",
+ (long)start, (long)start + size);
+
+ return -1;
+ }
+
+ schedule(); /* Wait for flash to finish. */
+ /* FIXME: We could have been interrupted here. We don't deal with it */
+ remove_wait_queue(&wait_q, &wait);
+
+ kfree(erase);
+
+ return 0;
+}
+
+inline int
+jffs_min(int a, int b)
+{
+ return (a < b ? a : b);
+}
+
+
+inline int
+jffs_max(int a, int b)
+{
+ return (a > b ? a : b);
+}
+
+
+/* This routine calculates checksums in JFFS. */
+__u32
+jffs_checksum(const void *data, int size)
+{
+ __u32 sum = 0;
+ __u8 *ptr = (__u8 *)data;
+ while (size-- > 0) {
+ sum += *ptr++;
+ }
+ D3(printk(", result: 0x%08x\n", sum));
+ return sum;
+}
+
+__u32
+jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size)
+{
+ __u32 sum = 0;
+ loff_t ptr = start;
+ while (size-- > 0) {
+ sum += flash_read_u8(mtd, ptr++);
+ }
+ D3(printk("checksum result: 0x%08x\n", sum));
+ return sum;
+}
+
+/* Create and initialize a new struct jffs_file. */
+static struct jffs_file *
+jffs_create_file(struct jffs_control *c,
+ const struct jffs_raw_inode *raw_inode)
+{
+ struct jffs_file *f;
+
+ if (!(f = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
+ GFP_KERNEL))) {
+ D(printk("jffs_create_file(): Failed!\n"));
+ return 0;
+ }
+ DJM(no_jffs_file++);
+ memset(f, 0, sizeof(struct jffs_file));
+ f->ino = raw_inode->ino;
+ f->pino = raw_inode->pino;
+ f->nlink = raw_inode->nlink;
+ f->deleted = raw_inode->deleted;
+ f->c = c;
+
+ return f;
+}
+
+
+/* Build a control block for the file system. */
+static struct jffs_control *
+jffs_create_control(kdev_t dev)
+{
+ struct jffs_control *c;
+ register int s = sizeof(struct jffs_control);
+ int i;
+ D(char *t = 0);
+
+ D2(printk("jffs_create_control()\n"));
+
+ if (!(c = (struct jffs_control *)kmalloc(s, GFP_KERNEL))) {
+ goto fail_control;
+ }
+ DJM(no_jffs_control++);
+ c->root = 0;
+ c->hash_len = JFFS_HASH_SIZE;
+ s = sizeof(struct list_head) * c->hash_len;
+ if (!(c->hash = (struct list_head *)kmalloc(s, GFP_KERNEL))) {
+ goto fail_hash;
+ }
+ DJM(no_hash++);
+ for (i=0;i<c->hash_len;i++)
+ INIT_LIST_HEAD(&c->hash[i]);
+ if (!(c->fmc = jffs_build_begin(c, dev))) {
+ goto fail_fminit;
+ }
+ c->next_ino = JFFS_MIN_INO + 1;
+ return c;
+
+fail_fminit:
+ D(t = "c->fmc");
+fail_hash:
+ kfree(c);
+ DJM(no_jffs_control--);
+ D(t = t ? t : "c->hash");
+fail_control:
+ D(t = t ? t : "control");
+ D(printk("jffs_create_control(): Allocation failed: (%s)\n", t));
+ return (struct jffs_control *)0;
+}
+
+
+/* Clean up all data structures associated with the file system. */
+void
+jffs_cleanup_control(struct jffs_control *c)
+{
+ D2(printk("jffs_cleanup_control()\n"));
+
+ if (!c) {
+ D(printk("jffs_cleanup_control(): c == NULL !!!\n"));
+ return;
+ }
+
+ /* Free all files and nodes. */
+ if (c->hash) {
+ jffs_foreach_file(c, jffs_free_node_list);
+ kfree(c->hash);
+ DJM(no_hash--);
+ }
+ jffs_cleanup_fmcontrol(c->fmc);
+ kfree(c);
+ DJM(no_jffs_control--);
+ D3(printk("jffs_cleanup_control(): Leaving...\n"));
+}
+
+
+/* This function adds a virtual root node to the in-RAM representation.
+ Called by jffs_build_fs(). */
+static int
+jffs_add_virtual_root(struct jffs_control *c)
+{
+ struct jffs_file *root;
+ struct jffs_node *node;
+
+ D2(printk("jffs_add_virtual_root(): "
+ "Creating a virtual root directory.\n"));
+
+ if (!(root = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
+ GFP_KERNEL))) {
+ return -ENOMEM;
+ }
+ DJM(no_jffs_file++);
+ if (!(node = (struct jffs_node *)kmalloc(sizeof(struct jffs_node),
+ GFP_KERNEL))) {
+ kfree(root);
+ DJM(no_jffs_file--);
+ return -ENOMEM;
+ }
+ DJM(no_jffs_node++);
+ memset(node, 0, sizeof(struct jffs_node));
+ node->ino = JFFS_MIN_INO;
+ memset(root, 0, sizeof(struct jffs_file));
+ root->ino = JFFS_MIN_INO;
+ root->mode = S_IFDIR | S_IRWXU | S_IRGRP
+ | S_IXGRP | S_IROTH | S_IXOTH;
+ root->atime = root->mtime = root->ctime = CURRENT_TIME;
+ root->nlink = 1;
+ root->c = c;
+ root->version_head = root->version_tail = node;
+ jffs_insert_file_into_hash(root);
+ return 0;
+}
+
+
+/* This is where the file system is built and initialized. */
+int
+jffs_build_fs(struct super_block *sb)
+{
+ struct jffs_control *c;
+ int err = 0;
+
+ D2(printk("jffs_build_fs()\n"));
+
+ if (!(c = jffs_create_control(sb->s_dev))) {
+ return -ENOMEM;
+ }
+ c->building_fs = 1;
+ c->sb = sb;
+ if ((err = jffs_scan_flash(c)) < 0) {
+ goto jffs_build_fs_fail;
+ }
+
+ /* Add a virtual root node if no one exists. */
+ if (!jffs_find_file(c, JFFS_MIN_INO)) {
+ if ((err = jffs_add_virtual_root(c)) < 0) {
+ goto jffs_build_fs_fail;
+ }
+ }
+
+ /* Remove deleted nodes. */
+ if ((err = jffs_foreach_file(c, jffs_possibly_delete_file)) < 0) {
+ printk(KERN_ERR "JFFS: Failed to remove deleted nodes.\n");
+ goto jffs_build_fs_fail;
+ }
+ /* Remove redundant nodes. (We are not interested in the
+ return value in this case.) */
+ jffs_foreach_file(c, jffs_remove_redundant_nodes);
+ /* Try to build a tree from all the nodes. */
+ if ((err = jffs_foreach_file(c, jffs_insert_file_into_tree)) < 0) {
+ printk("JFFS: Failed to build tree.\n");
+ goto jffs_build_fs_fail;
+ }
+ /* Compute the sizes of all files in the filesystem. Adjust if
+ necessary. */
+ if ((err = jffs_foreach_file(c, jffs_build_file)) < 0) {
+ printk("JFFS: Failed to build file system.\n");
+ goto jffs_build_fs_fail;
+ }
+ sb->u.generic_sbp = (void *)c;
+ c->building_fs = 0;
+
+ D1(jffs_print_hash_table(c));
+ D1(jffs_print_tree(c->root, 0));
+
+ return 0;
+
+jffs_build_fs_fail:
+ jffs_cleanup_control(c);
+ return err;
+} /* jffs_build_fs() */
+
+
+/* Scan the whole flash memory in order to find all nodes in the
+ file systems. */
+static int
+jffs_scan_flash(struct jffs_control *c)
+{
+ char name[JFFS_MAX_NAME_LEN + 2];
+ struct jffs_raw_inode raw_inode;
+ struct jffs_node *node = 0;
+ struct jffs_fmcontrol *fmc = c->fmc;
+ __u32 checksum;
+ __u8 tmp_accurate;
+ __u16 tmp_chksum;
+ loff_t pos = fmc->flash_start;
+ loff_t start;
+ loff_t end = fmc->flash_start + fmc->flash_size;
+
+ D1(printk("jffs_scan_flash(): start pos = 0x%ld, end = 0x%ld\n",
+ (long)pos, (long)end));
+
+ flash_safe_acquire(fmc->mtd);
+
+ /* Start the scan. */
+ while (pos < end) {
+
+ /* Remember the position from where we started this scan. */
+ start = pos;
+
+ switch (flash_read_u32(fmc->mtd, pos)) {
+ case JFFS_EMPTY_BITMASK:
+ /* We have found 0xff on this block. We have to
+ scan the rest of the block to be sure it is
+ filled with 0xff. */
+ D1(printk("jffs_scan_flash(): 0xff at pos 0x%ld.\n",
+ (long)pos));
+ for (; pos < end
+ && JFFS_EMPTY_BITMASK == flash_read_u32(fmc->mtd, pos);
+ pos += 4);
+ D1(printk("jffs_scan_flash(): 0xff ended at "
+ "pos 0x%ld.\n", (long)pos));
+ continue;
+
+ case JFFS_DIRTY_BITMASK:
+ /* We have found 0x00 on this block. We have to
+ scan as far as possible to find out how much
+ is dirty. */
+ D1(printk("jffs_scan_flash(): 0x00 at pos 0x%ld.\n",
+ (long)pos));
+ for (; pos < end
+ && JFFS_DIRTY_BITMASK == flash_read_u32(fmc->mtd, pos);
+ pos += 4);
+ D1(printk("jffs_scan_flash(): 0x00 ended at "
+ "pos 0x%ld.\n", (long)pos));
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start), 0);
+ continue;
+
+ case JFFS_MAGIC_BITMASK:
+ /* We have probably found a new raw inode. */
+ break;
+
+ default:
+ bad_inode:
+ /* We're f*cked. This is not solved yet. We have
+ to scan for the magic pattern. */
+ D1(printk("*************** Dirty flash memory or bad inode: "
+ "hexdump(pos = 0x%ld, len = 128):\n",
+ (long)pos));
+ D1(jffs_hexdump(fmc->mtd, pos, 128));
+ for (pos += 4; pos < end; pos += 4) {
+ switch (flash_read_u32(fmc->mtd, pos)) {
+ case JFFS_MAGIC_BITMASK:
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start),
+ 0);
+ goto cont_scan;
+ default:
+ break;
+ }
+ }
+ cont_scan:
+ continue;
+ }
+
+ /* We have found the beginning of an inode. Create a
+ node for it. */
+ if (!node) {
+ if (!(node = (struct jffs_node *)
+ kmalloc(sizeof(struct jffs_node),
+ GFP_KERNEL))) {
+ flash_safe_release(fmc->mtd);
+ return -ENOMEM;
+ }
+ DJM(no_jffs_node++);
+ }
+
+ /* Read the next raw inode. */
+
+ flash_safe_read(fmc->mtd, pos, (u_char *) &raw_inode, sizeof(struct jffs_raw_inode));
+
+ /* When we compute the checksum for the inode, we never
+ count the 'accurate' or the 'checksum' fields. */
+ tmp_accurate = raw_inode.accurate;
+ tmp_chksum = raw_inode.chksum;
+ raw_inode.accurate = 0;
+ raw_inode.chksum = 0;
+ checksum = jffs_checksum(&raw_inode,
+ sizeof(struct jffs_raw_inode));
+ raw_inode.accurate = tmp_accurate;
+ raw_inode.chksum = tmp_chksum;
+
+ D3(printk("*** We have found this raw inode at pos 0x%ld "
+ "on the flash:\n", (long)pos));
+ D3(jffs_print_raw_inode(&raw_inode));
+
+ if (checksum != raw_inode.chksum) {
+ D1(printk("jffs_scan_flash(): Bad checksum: "
+ "checksum = %u, "
+ "raw_inode.chksum = %u\n",
+ checksum, raw_inode.chksum));
+ pos += sizeof(struct jffs_raw_inode);
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start), 0);
+ /* Reuse this unused struct jffs_node. */
+ continue;
+ }
+
+ /* Check the raw inode read so far. Start with the
+ maximum length of the filename. */
+ if (raw_inode.nsize > JFFS_MAX_NAME_LEN) {
+ goto bad_inode;
+ }
+ /* The node's data segment should not exceed a
+ certain length. */
+ if (raw_inode.dsize > fmc->max_chunk_size) {
+ goto bad_inode;
+ }
+
+ pos += sizeof(struct jffs_raw_inode);
+
+ /* This shouldn't be necessary because a node that
+ violates the flash boundaries shouldn't be written
+ in the first place. */
+ if (pos >= end) {
+ goto check_node;
+ }
+
+ /* Read the name. */
+ *name = 0;
+ if (raw_inode.nsize) {
+ flash_safe_read(fmc->mtd, pos, name, raw_inode.nsize);
+ name[raw_inode.nsize] = '\0';
+ pos += raw_inode.nsize
+ + JFFS_GET_PAD_BYTES(raw_inode.nsize);
+ D3(printk("name == \"%s\"\n", name));
+ checksum = jffs_checksum(name, raw_inode.nsize);
+ if (checksum != raw_inode.nchksum) {
+ D1(printk("jffs_scan_flash(): Bad checksum: "
+ "checksum = %u, "
+ "raw_inode.nchksum = %u\n",
+ checksum, raw_inode.nchksum));
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start), 0);
+ /* Reuse this unused struct jffs_node. */
+ continue;
+ }
+ if (pos >= end) {
+ goto check_node;
+ }
+ }
+
+ /* Read the data in order to be sure it matches the
+ checksum. */
+ checksum = jffs_checksum_flash(fmc->mtd, pos, raw_inode.dsize);
+ pos += raw_inode.dsize + JFFS_GET_PAD_BYTES(raw_inode.dsize);
+
+ if (checksum != raw_inode.dchksum) {
+ D1(printk("jffs_scan_flash(): Bad checksum: "
+ "checksum = %u, "
+ "raw_inode.dchksum = %u\n",
+ checksum, raw_inode.dchksum));
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start), 0);
+ /* Reuse this unused struct jffs_node. */
+ continue;
+ }
+
+ check_node:
+
+ /* Remember the highest inode number in the whole file
+ system. This information will be used when assigning
+ new files new inode numbers. */
+ if (c->next_ino <= raw_inode.ino) {
+ c->next_ino = raw_inode.ino + 1;
+ }
+
+ if (raw_inode.accurate) {
+ int err;
+ node->data_offset = raw_inode.offset;
+ node->data_size = raw_inode.dsize;
+ node->removed_size = raw_inode.rsize;
+ /* Compute the offset to the actual data in the
+ on-flash node. */
+ node->fm_offset
+ = sizeof(struct jffs_raw_inode)
+ + raw_inode.nsize
+ + JFFS_GET_PAD_BYTES(raw_inode.nsize);
+ node->fm = jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start),
+ node);
+ if (!node->fm) {
+ D(printk("jffs_scan_flash(): !node->fm\n"));
+ kfree(node);
+ DJM(no_jffs_node--);
+ flash_safe_release(fmc->mtd);
+ return -ENOMEM;
+ }
+ if ((err = jffs_insert_node(c, 0, &raw_inode,
+ name, node)) < 0) {
+ printk("JFFS: Failed to handle raw inode. "
+ "(err = %d)\n", err);
+ break;
+ }
+ D3(jffs_print_node(node));
+ node = 0; /* Don't free the node! */
+ }
+ else {
+ jffs_fmalloced(fmc, (__u32) start,
+ (__u32) (pos - start), 0);
+ D3(printk("jffs_scan_flash(): Just found an obsolete "
+ "raw_inode. Continuing the scan...\n"));
+ /* Reuse this unused struct jffs_node. */
+ }
+ }
+
+ if (node) {
+ kfree(node);
+ DJM(no_jffs_node--);
+ }
+ jffs_build_end(fmc);
+ D3(printk("jffs_scan_flash(): Leaving...\n"));
+ flash_safe_release(fmc->mtd);
+ return 0;
+} /* jffs_scan_flash() */
+
+
+/* Insert any kind of node into the file system. Take care of data
+ insertions and deletions. Also remove redundant information. The
+ memory allocated for the `name' is regarded as "given away" in the
+ caller's perspective. */
+int
+jffs_insert_node(struct jffs_control *c, struct jffs_file *f,
+ const struct jffs_raw_inode *raw_inode,
+ const char *name, struct jffs_node *node)
+{
+ int update_name = 0;
+ int insert_into_tree = 0;
+
+ D2(printk("jffs_insert_node(): ino = %u, version = %u, name = \"%s\"\n",
+ raw_inode->ino, raw_inode->version,
+ ((name && *name) ? name : "")));
+
+ /* If there doesn't exist an associated jffs_file, then
+ create, initialize and insert one into the file system. */
+ if (!f && !(f = jffs_find_file(c, raw_inode->ino))) {
+ if (!(f = jffs_create_file(c, raw_inode))) {
+ return -ENOMEM;
+ }
+ jffs_insert_file_into_hash(f);
+ insert_into_tree = 1;
+ }
+
+ node->ino = raw_inode->ino;
+ node->version = raw_inode->version;
+ node->data_size = raw_inode->dsize;
+ node->fm_offset = sizeof(struct jffs_raw_inode) + raw_inode->nsize
+ + JFFS_GET_PAD_BYTES(raw_inode->nsize);
+ node->name_size = raw_inode->nsize;
+
+ /* Now insert the node at the correct position into the file's
+ version list. */
+ if (!f->version_head) {
+ /* This is the first node. */
+ f->version_head = node;
+ f->version_tail = node;
+ node->version_prev = 0;
+ node->version_next = 0;
+ f->highest_version = node->version;
+ update_name = 1;
+ f->mode = raw_inode->mode;
+ f->uid = raw_inode->uid;
+ f->gid = raw_inode->gid;
+ f->atime = raw_inode->atime;
+ f->mtime = raw_inode->mtime;
+ f->ctime = raw_inode->ctime;
+ f->deleted = raw_inode->deleted;
+ }
+ else if ((f->highest_version < node->version)
+ || (node->version == 0)) {
+ /* Insert at the end of the list. I.e. this node is the
+ oldest one so far. */
+ node->version_prev = f->version_tail;
+ node->version_next = 0;
+ f->version_tail->version_next = node;
+ f->version_tail = node;
+ f->highest_version = node->version;
+ update_name = 1;
+ f->pino = raw_inode->pino;
+ f->mode = raw_inode->mode;
+ f->uid = raw_inode->uid;
+ f->gid = raw_inode->gid;
+ f->atime = raw_inode->atime;
+ f->mtime = raw_inode->mtime;
+ f->ctime = raw_inode->ctime;
+ f->deleted = raw_inode->deleted;
+ }
+ else if (f->version_head->version > node->version) {
+ /* Insert at the bottom of the list. */
+ node->version_prev = 0;
+ node->version_next = f->version_head;
+ f->version_head->version_prev = node;
+ f->version_head = node;
+ if (!f->name) {
+ update_name = 1;
+ }
+ if (raw_inode->deleted) {
+ f->deleted = raw_inode->deleted;
+ }
+ }
+ else {
+ struct jffs_node *n;
+ int newer_name = 0;
+ /* Search for the insertion position starting from
+ the tail (newest node). */
+ for (n = f->version_tail; n; n = n->version_prev) {
+ if (n->version < node->version) {
+ node->version_prev = n;
+ node->version_next = n->version_next;
+ node->version_next->version_prev = node;
+ n->version_next = node;
+ if (!newer_name) {
+ update_name = 1;
+ }
+ break;
+ }
+ if (n->name_size) {
+ newer_name = 1;
+ }
+ }
+ }
+
+ /* Perhaps update the name. */
+ if (raw_inode->nsize && update_name && name && *name && (name != f->name)) {
+ if (f->name) {
+ kfree(f->name);
+ DJM(no_name--);
+ }
+ if (!(f->name = (char *) kmalloc(raw_inode->nsize + 1,
+ GFP_KERNEL))) {
+ return -ENOMEM;
+ }
+ DJM(no_name++);
+ memcpy(f->name, name, raw_inode->nsize);
+ f->name[raw_inode->nsize] = '\0';
+ f->nsize = raw_inode->nsize;
+ D3(printk("jffs_insert_node(): Updated the name of "
+ "the file to \"%s\".\n", name));
+ }
+
+ if (!c->building_fs) {
+ D3(printk("jffs_insert_node(): ---------------------------"
+ "------------------------------------------- 1\n"));
+ if (insert_into_tree) {
+ jffs_insert_file_into_tree(f);
+ }
+ if (f->deleted) {
+ /* Mark all versions of the node as obsolete. */
+ jffs_possibly_delete_file(f);
+ }
+ else {
+ if (node->data_size || node->removed_size) {
+ jffs_update_file(f, node);
+ }
+ jffs_remove_redundant_nodes(f);
+ }
+#ifdef USE_GC
+ if (!c->fmc->no_call_gc) {
+ jffs_garbage_collect(c);
+ }
+#endif
+ D3(printk("jffs_insert_node(): ---------------------------"
+ "------------------------------------------- 2\n"));
+ }
+
+ return 0;
+} /* jffs_insert_node() */
+
+
+/* Unlink a jffs_node from the version list it is in. */
+static inline void
+jffs_unlink_node_from_version_list(struct jffs_file *f,
+ struct jffs_node *node)
+{
+ if (node->version_prev) {
+ node->version_prev->version_next = node->version_next;
+ } else {
+ f->version_head = node->version_next;
+ }
+ if (node->version_next) {
+ node->version_next->version_prev = node->version_prev;
+ } else {
+ f->version_tail = node->version_prev;
+ }
+}
+
+
+/* Unlink a jffs_node from the range list it is in. */
+static inline void
+jffs_unlink_node_from_range_list(struct jffs_file *f, struct jffs_node *node)
+{
+ if (node->range_prev) {
+ node->range_prev->range_next = node->range_next;
+ }
+ else {
+ f->range_head = node->range_next;
+ }
+ if (node->range_next) {
+ node->range_next->range_prev = node->range_prev;
+ }
+ else {
+ f->range_tail = node->range_prev;
+ }
+}
+
+
+/* Function used by jffs_remove_redundant_nodes() below. This function
+ classifies what kind of information a node adds to a file. */
+static inline __u8
+jffs_classify_node(struct jffs_node *node)
+{
+ __u8 mod_type = JFFS_MODIFY_INODE;
+
+ if (node->name_size) {
+ mod_type |= JFFS_MODIFY_NAME;
+ }
+ if (node->data_size || node->removed_size) {
+ mod_type |= JFFS_MODIFY_DATA;
+ }
+ return mod_type;
+}
+
+
+/* Remove redundant nodes from a file. Mark the on-flash memory
+ as dirty. */
+int
+jffs_remove_redundant_nodes(struct jffs_file *f)
+{
+ struct jffs_node *newest_node;
+ struct jffs_node *cur;
+ struct jffs_node *prev;
+ __u8 newest_type;
+ __u8 mod_type;
+ __u8 node_with_name_later = 0;
+
+ if (!(newest_node = f->version_tail)) {
+ return 0;
+ }
+
+ /* What does the `newest_node' modify? */
+ newest_type = jffs_classify_node(newest_node);
+ node_with_name_later = newest_type & JFFS_MODIFY_NAME;
+
+ D3(printk("jffs_remove_redundant_nodes(): ino: %u, name: \"%s\", "
+ "newest_type: %u\n", f->ino, (f->name ? f->name : ""),
+ newest_type));
+
+ /* Traverse the file's nodes and determine which of them that are
+ superfluous. Yeah, this might look very complex at first
+ glance but it is actually very simple. */
+ for (cur = newest_node->version_prev; cur; cur = prev) {
+ prev = cur->version_prev;
+ mod_type = jffs_classify_node(cur);
+ if ((mod_type <= JFFS_MODIFY_INODE)
+ || ((newest_type & JFFS_MODIFY_NAME)
+ && (mod_type
+ <= (JFFS_MODIFY_INODE + JFFS_MODIFY_NAME)))
+ || (cur->data_size == 0 && cur->removed_size
+ && !cur->version_prev && node_with_name_later)) {
+ /* Yes, this node is redundant. Remove it. */
+ D2(printk("jffs_remove_redundant_nodes(): "
+ "Removing node: ino: %u, version: %u, "
+ "mod_type: %u\n", cur->ino, cur->version,
+ mod_type));
+ jffs_unlink_node_from_version_list(f, cur);
+ jffs_fmfree(f->c->fmc, cur->fm, cur);
+ kfree(cur);
+ DJM(no_jffs_node--);
+ }
+ else {
+ node_with_name_later |= (mod_type & JFFS_MODIFY_NAME);
+ }
+ }
+
+ return 0;
+}
+
+
+/* Insert a file into the hash table. */
+int
+jffs_insert_file_into_hash(struct jffs_file *f)
+{
+ int i = f->ino % f->c->hash_len;
+
+ D3(printk("jffs_insert_file_into_hash(): f->ino: %u\n", f->ino));
+
+ list_add(&f->hash, &f->c->hash[i]);
+ return 0;
+}
+
+
+/* Insert a file into the file system tree. */
+int
+jffs_insert_file_into_tree(struct jffs_file *f)
+{
+ struct jffs_file *parent;
+
+ D3(printk("jffs_insert_file_into_tree(): name: \"%s\"\n",
+ (f->name ? f->name : "")));
+
+ if (!(parent = jffs_find_file(f->c, f->pino))) {
+ if (f->pino == 0) {
+ f->c->root = f;
+ f->parent = 0;
+ f->sibling_prev = 0;
+ f->sibling_next = 0;
+ return 0;
+ }
+ else {
+ D1(printk("jffs_insert_file_into_tree(): Found "
+ "inode with no parent and pino == %u\n",
+ f->pino));
+ return -1;
+ }
+ }
+ f->parent = parent;
+ f->sibling_next = parent->children;
+ if (f->sibling_next) {
+ f->sibling_next->sibling_prev = f;
+ }
+ f->sibling_prev = 0;
+ parent->children = f;
+ return 0;
+}
+
+
+/* Remove a file from the hash table. */
+int
+jffs_unlink_file_from_hash(struct jffs_file *f)
+{
+ D3(printk("jffs_unlink_file_from_hash(): f: 0x%p, "
+ "ino %u\n", f, f->ino));
+
+ list_del(&f->hash);
+ return 0;
+}
+
+
+/* Just remove the file from the parent's children. Don't free
+ any memory. */
+int
+jffs_unlink_file_from_tree(struct jffs_file *f)
+{
+ D3(printk("jffs_unlink_file_from_tree(): ino: %d, pino: %d, name: "
+ "\"%s\"\n", f->ino, f->pino, (f->name ? f->name : "")));
+
+ if (f->sibling_prev) {
+ f->sibling_prev->sibling_next = f->sibling_next;
+ }
+ else if (f->parent) {
+ D3(printk("f->parent=%p\n", f->parent));
+ f->parent->children = f->sibling_next;
+ }
+ if (f->sibling_next) {
+ f->sibling_next->sibling_prev = f->sibling_prev;
+ }
+ return 0;
+}
+
+
+/* Find a file with its inode number. */
+struct jffs_file *
+jffs_find_file(struct jffs_control *c, __u32 ino)
+{
+ struct jffs_file *f;
+ int i = ino % c->hash_len;
+ struct list_head *tmp;
+
+ D3(printk("jffs_find_file(): ino: %u\n", ino));
+
+ for (tmp = c->hash[i].next; tmp != &c->hash[i]; tmp = tmp->next) {
+ f = list_entry(tmp, struct jffs_file, hash);
+ if (ino != f->ino)
+ continue;
+ D3(printk("jffs_find_file(): Found file with ino "
+ "%u. (name: \"%s\")\n",
+ ino, (f->name ? f->name : ""));
+ );
+ return f;
+ }
+ D3(printk("jffs_find_file(): Didn't find file "
+ "with ino %u.\n", ino);
+ );
+ return NULL;
+}
+
+
+/* Find a file in a directory. We are comparing the names. */
+struct jffs_file *
+jffs_find_child(struct jffs_file *dir, const char *name, int len)
+{
+ struct jffs_file *f;
+
+ D3(printk("jffs_find_child()\n"));
+
+ for (f = dir->children; f; f = f->sibling_next) {
+ if (f->name
+ && !strncmp(f->name, name, len)
+ && f->name[len] == '\0') {
+ break;
+ }
+ }
+
+ D3(if (f) {
+ printk("jffs_find_child(): Found \"%s\".\n", f->name);
+ }
+ else {
+ char *copy = (char *) kmalloc(len + 1, GFP_KERNEL);
+ if (copy) {
+ memcpy(copy, name, len);
+ copy[len] = '\0';
+ }
+ printk("jffs_find_child(): Didn't find the file \"%s\".\n",
+ (copy ? copy : ""));
+ if (copy) {
+ kfree(copy);
+ }
+ });
+
+ return f;
+}
+
+
+/* Write a raw inode that takes up a certain amount of space in the flash
+ memory. At the end of the flash device, there is often space that is
+ impossible to use. At these times we want to mark this space as not
+ used. In the cases when the amount of space is greater or equal than
+ a struct jffs_raw_inode, we write a "dummy node" that takes up this
+ space. The space after the raw inode, if it exists, is left as it is.
+ Since this space after the raw inode contains JFFS_EMPTY_BITMASK bytes,
+ we can compute the checksum of it; we don't have to manipulate it any
+ further.
+
+ If the space left on the device is less than the size of a struct
+ jffs_raw_inode, this space is filled with JFFS_DIRTY_BITMASK bytes.
+ No raw inode is written this time. */
+static int
+jffs_write_dummy_node(struct jffs_control *c, struct jffs_fm *dirty_fm)
+{
+ struct jffs_fmcontrol *fmc = c->fmc;
+ int err;
+
+ D1(printk("jffs_write_dummy_node(): dirty_fm->offset = 0x%08x, "
+ "dirty_fm->size = %u\n",
+ dirty_fm->offset, dirty_fm->size));
+
+ if (dirty_fm->size >= sizeof(struct jffs_raw_inode)) {
+ struct jffs_raw_inode raw_inode;
+ memset(&raw_inode, 0, sizeof(struct jffs_raw_inode));
+ raw_inode.magic = JFFS_MAGIC_BITMASK;
+ raw_inode.dsize = dirty_fm->size
+ - sizeof(struct jffs_raw_inode);
+ raw_inode.dchksum = raw_inode.dsize * 0xff;
+ raw_inode.chksum
+ = jffs_checksum(&raw_inode, sizeof(struct jffs_raw_inode));
+
+ if ((err = flash_safe_write(fmc->mtd,
+ dirty_fm->offset,
+ (u_char *)&raw_inode,
+ sizeof(struct jffs_raw_inode)))
+ < 0) {
+ printk(KERN_ERR "JFFS: jffs_write_dummy_node: "
+ "flash_safe_write failed!\n");
+ return err;
+ }
+ }
+ else {
+ flash_safe_acquire(fmc->mtd);
+ flash_memset(fmc->mtd, dirty_fm->offset, 0, dirty_fm->size);
+ flash_safe_release(fmc->mtd);
+ }
+
+ D3(printk("jffs_write_dummy_node(): Leaving...\n"));
+ return 0;
+}
+
+/* Write a raw inode, possibly its name and possibly some data. */
+int
+jffs_write_node(struct jffs_control *c, struct jffs_node *node,
+ struct jffs_raw_inode *raw_inode,
+ const char *name, const unsigned char *data)
+{
+ struct jffs_fmcontrol *fmc = c->fmc;
+ struct jffs_fm *fm;
+ __u32 pos;
+ int err;
+ __u32 total_name_size = raw_inode->nsize
+ + JFFS_GET_PAD_BYTES(raw_inode->nsize);
+ __u32 total_data_size = raw_inode->dsize
+ + JFFS_GET_PAD_BYTES(raw_inode->dsize);
+ __u32 total_size = sizeof(struct jffs_raw_inode)
+ + total_name_size + total_data_size;
+
+ /* Fire the retrorockets and shoot the fruiton torpedoes, sir! */
+
+ ASSERT(if (!node) {
+ printk("jffs_write_node(): node == NULL\n");
+ return -EINVAL;
+ });
+ ASSERT(if (raw_inode && raw_inode->nsize && !name) {
+ printk("*** jffs_write_node(): nsize = %u but name == NULL\n",
+ raw_inode->nsize);
+ return -EINVAL;
+ });
+
+ D1(printk("jffs_write_node(): filename = \"%s\", ino = %u, "
+ "version = %u, total_size = %u\n",
+ (name ? name : ""), raw_inode->ino,
+ raw_inode->version, total_size));
+
+ /* First try to allocate some flash memory. */
+ if ((err = jffs_fmalloc(fmc, total_size, node, &fm)) < 0) {
+ D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) "
+ "failed!\n", fmc, total_size));
+ return err;
+ }
+ else if (!fm->nodes) {
+ /* The jffs_fm struct that we got is not good enough.
+ Make that space dirty. */
+ if ((err = jffs_write_dummy_node(c, fm)) < 0) {
+ D(printk("jffs_write_node(): "
+ "jffs_write_dummy_node(): Failed!\n"));
+ kfree(fm);
+ DJM(no_jffs_fm--);
+ return err;
+ }
+ /* Get a new one. */
+ if ((err = jffs_fmalloc(fmc, total_size, node, &fm)) < 0) {
+ D(printk("jffs_write_node(): Second "
+ "jffs_fmalloc(0x%p, %u) failed!\n",
+ fmc, total_size));
+ return err;
+ }
+ }
+ node->fm = fm;
+
+ ASSERT(if (fm->nodes == 0) {
+ printk(KERN_ERR "jffs_write_node(): fm->nodes == 0\n");
+ });
+
+ pos = node->fm->offset;
+
+ /* Compute the checksum for the data and name chunks. */
+ raw_inode->dchksum = jffs_checksum(data, raw_inode->dsize);
+ raw_inode->nchksum = jffs_checksum(name, raw_inode->nsize);
+
+ /* The checksum is calculated without the chksum and accurate
+ fields so set them to zero first. */
+ raw_inode->accurate = 0;
+ raw_inode->chksum = 0;
+ raw_inode->chksum = jffs_checksum(raw_inode,
+ sizeof(struct jffs_raw_inode));
+ raw_inode->accurate = 0xff;
+
+ D3(printk("jffs_write_node(): About to write this raw inode to the "
+ "flash at pos 0x%ld:\n", (long)pos));
+ D3(jffs_print_raw_inode(raw_inode));
+
+ /* Step 1: Write the raw jffs inode to the flash. */
+ if ((err = flash_safe_write(fmc->mtd, pos,
+ (u_char *)raw_inode,
+ sizeof(struct jffs_raw_inode))) < 0) {
+ jffs_fmfree_partly(fmc, fm,
+ total_name_size + total_data_size);
+ printk(KERN_ERR "JFFS: jffs_write_node: Failed to write "
+ "raw_inode.\n");
+ return err;
+ }
+ pos += sizeof(struct jffs_raw_inode);
+
+ /* Step 2: Write the name, if there is any. */
+ if (raw_inode->nsize) {
+ if ((err = flash_safe_write(fmc->mtd, pos,
+ (u_char *)name,
+ raw_inode->nsize)) < 0) {
+ jffs_fmfree_partly(fmc, fm, total_data_size);
+ printk(KERN_ERR "JFFS: jffs_write_node: Failed to "
+ "write the name.\n");
+ return err;
+ }
+ pos += total_name_size;
+ }
+
+ /* Step 3: Append the actual data, if any. */
+ if (raw_inode->dsize) {
+ if ((err = flash_safe_write(fmc->mtd, pos, data,
+ raw_inode->dsize)) < 0) {
+ jffs_fmfree_partly(fmc, fm, 0);
+ printk(KERN_ERR "JFFS: jffs_write_node: Failed to "
+ "write the data.\n");
+ return err;
+ }
+ }
+
+ D3(printk("jffs_write_node(): Leaving...\n"));
+ return raw_inode->dsize;
+} /* jffs_write_node() */
+
+
+/* Read data from the node and write it to the buffer. 'node_offset'
+ is how much we have read from this particular node before and which
+ shouldn't be read again. 'max_size' is how much space there is in
+ the buffer. */
+static int
+jffs_get_node_data(struct jffs_file *f, struct jffs_node *node, char *buf,
+ __u32 node_offset, __u32 max_size, kdev_t dev)
+{
+ struct jffs_fmcontrol *fmc = f->c->fmc;
+ __u32 pos = node->fm->offset + node->fm_offset + node_offset;
+ __u32 avail = node->data_size - node_offset;
+ __u32 r;
+
+ D2(printk(" jffs_get_node_data(): file: \"%s\", ino: %u, "
+ "version: %u, node_offset: %u\n",
+ f->name, node->ino, node->version, node_offset));
+
+ r = jffs_min(avail, max_size);
+ flash_safe_read(fmc->mtd, pos, buf, r);
+
+ D3(printk(" jffs_get_node_data(): Read %u byte%s.\n",
+ r, (r == 1 ? "" : "s")));
+
+ return r;
+}
+
+
+/* Read data from the file's nodes. Write the data to the buffer
+ 'buf'. 'read_offset' tells how much data we should skip. */
+int
+jffs_read_data(struct jffs_file *f, char *buf, __u32 read_offset, __u32 size)
+{
+ struct jffs_node *node;
+ __u32 read_data = 0; /* Total amount of read data. */
+ __u32 node_offset = 0;
+ __u32 pos = 0; /* Number of bytes traversed. */
+
+ D1(printk("jffs_read_data(): file = \"%s\", read_offset = %d, "
+ "size = %u\n",
+ (f->name ? f->name : ""), read_offset, size));
+
+ if (read_offset >= f->size) {
+ D(printk(" f->size: %d\n", f->size));
+ return 0;
+ }
+
+ /* First find the node to read data from. */
+ node = f->range_head;
+ while (pos <= read_offset) {
+ node_offset = read_offset - pos;
+ if (node_offset >= node->data_size) {
+ pos += node->data_size;
+ node = node->range_next;
+ }
+ else {
+ break;
+ }
+ }
+
+ /* "Cats are living proof that not everything in nature
+ has to be useful."
+ - Garrison Keilor ('97) */
+
+ /* Fill the buffer. */
+ while (node && (read_data < size)) {
+ int r;
+ if (!node->fm) {
+ /* This node does not refer to real data. */
+ r = jffs_min(size - read_data,
+ node->data_size - node_offset);
+ memset(&buf[read_data], 0, r);
+ }
+ else if ((r = jffs_get_node_data(f, node, &buf[read_data],
+ node_offset,
+ size - read_data,
+ f->c->sb->s_dev)) < 0) {
+ return r;
+ }
+ read_data += r;
+ node_offset = 0;
+ node = node->range_next;
+ }
+ D3(printk(" jffs_read_data(): Read %u bytes.\n", read_data));
+ return read_data;
+}
+
+
+/* Used for traversing all nodes in the hash table. */
+int
+jffs_foreach_file(struct jffs_control *c, int (*func)(struct jffs_file *))
+{
+ int pos;
+ int r;
+ int result = 0;
+
+ for (pos = 0; pos < c->hash_len; pos++) {
+ struct list_head *p, *next;
+ for (p = c->hash[pos].next; p != &c->hash[pos]; p = next) {
+ /* We need a reference to the next file in the
+ list because `func' might remove the current
+ file `f'. */
+ next = p->next;
+ r = func(list_entry(p, struct jffs_file, hash));
+ if (r < 0)
+ return r;
+ result += r;
+ }
+ }
+
+ return result;
+}
+
+
+/* Free all memory associated with a file. */
+int
+jffs_free_node_list(struct jffs_file *f)
+{
+ struct jffs_node *node;
+ struct jffs_node *p;
+
+ D3(printk("jffs_free_node_list(): f #%u, \"%s\"\n",
+ f->ino, (f->name ? f->name : "")));
+ node = f->version_head;
+ while (node) {
+ p = node;
+ node = node->version_next;
+ kfree(p);
+ DJM(no_jffs_node--);
+ }
+ return 0;
+}
+
+
+/* See if a file is deleted. If so, mark that file's nodes as obsolete. */
+int
+jffs_possibly_delete_file(struct jffs_file *f)
+{
+ struct jffs_node *n;
+
+ D3(printk("jffs_possibly_delete_file(): ino: %u\n",
+ f->ino));
+
+ ASSERT(if (!f) {
+ printk(KERN_ERR "jffs_possibly_delete_file(): f == NULL\n");
+ return -1;
+ });
+
+ if (f->deleted) {
+ /* First try to remove all older versions. */
+ for (n = f->version_head; n; n = n->version_next) {
+ if (!n->fm) {
+ continue;
+ }
+ if (jffs_fmfree(f->c->fmc, n->fm, n) < 0) {
+ break;
+ }
+ }
+ /* Unlink the file from the filesystem. */
+ jffs_unlink_file_from_tree(f);
+ jffs_unlink_file_from_hash(f);
+ jffs_free_node_list(f);
+ if (f->name) {
+ kfree(f->name);
+ DJM(no_name--);
+ }
+ kfree(f);
+ DJM(no_jffs_file--);
+ }
+ return 0;
+}
+
+
+/* Used in conjunction with jffs_foreach_file() to count the number
+ of files in the file system. */
+int
+jffs_file_count(struct jffs_file *f)
+{
+ return 1;
+}
+
+
+/* Build up a file's range list from scratch by going through the
+ version list. */
+int
+jffs_build_file(struct jffs_file *f)
+{
+ struct jffs_node *n;
+
+ D3(printk("jffs_build_file(): ino: %u, name: \"%s\"\n",
+ f->ino, (f->name ? f->name : "")));
+
+ for (n = f->version_head; n; n = n->version_next) {
+ jffs_update_file(f, n);
+ }
+ return 0;
+}
+
+
+/* Remove an amount of data from a file. If this amount of data is
+ zero, that could mean that a node should be split in two parts.
+ We remove or change the appropriate nodes in the lists.
+
+ Starting offset of area to be removed is node->data_offset,
+ and the length of the area is in node->removed_size. */
+static void
+jffs_delete_data(struct jffs_file *f, struct jffs_node *node)
+{
+ struct jffs_node *n;
+ __u32 offset = node->data_offset;
+ __u32 remove_size = node->removed_size;
+
+ D3(printk("jffs_delete_data(): offset = %u, remove_size = %u\n",
+ offset, remove_size));
+
+ if (remove_size == 0
+ && f->range_tail
+ && f->range_tail->data_offset + f->range_tail->data_size
+ == offset) {
+ /* A simple append; nothing to remove or no node to split. */
+ return;
+ }
+
+ /* Find the node where we should begin the removal. */
+ for (n = f->range_head; n; n = n->range_next) {
+ if (n->data_offset + n->data_size > offset) {
+ break;
+ }
+ }
+ if (!n) {
+ /* If there's no data in the file there's no data to
+ remove either. */
+ return;
+ }
+
+ if (n->data_offset > offset) {
+ /* XXX: Not implemented yet. */
+ printk(KERN_WARNING "JFFS: An unexpected situation "
+ "occurred in jffs_delete_data.\n");
+ }
+ else if (n->data_offset < offset) {
+ /* See if the node has to be split into two parts. */
+ if (n->data_offset + n->data_size < offset + remove_size) {
+ /* Do the split. */
+ struct jffs_node *new_node;
+ D3(printk("jffs_delete_data(): Split node with "
+ "version number %u.\n", n->version));
+
+ if (!(new_node = (struct jffs_node *)
+ kmalloc(sizeof(struct jffs_node),
+ GFP_KERNEL))) {
+ D(printk("jffs_delete_data(): -ENOMEM\n"));
+ return;
+ }
+ DJM(no_jffs_node++);
+
+ new_node->ino = n->ino;
+ new_node->version = n->version;
+ new_node->data_offset = offset;
+ new_node->data_size = n->data_size
+ - (remove_size
+ + (offset - n->data_offset));
+ new_node->fm_offset = n->fm_offset + n->data_size
+ + remove_size;
+ new_node->name_size = n->name_size;
+ new_node->fm = n->fm;
+ new_node->version_prev = n;
+ new_node->version_next = n->version_next;
+ if (new_node->version_next) {
+ new_node->version_next->version_prev
+ = new_node;
+ }
+ else {
+ f->version_tail = new_node;
+ }
+ n->version_next = new_node;
+ new_node->range_prev = n;
+ new_node->range_next = n->range_next;
+ if (new_node->range_next) {
+ new_node->range_next->range_prev = new_node;
+ }
+ else {
+ f->range_tail = new_node;
+ }
+ /* A very interesting can of worms. */
+ n->range_next = new_node;
+ n->data_size = offset - n->data_offset;
+ jffs_add_node(new_node);
+ n = new_node->range_next;
+ remove_size = 0;
+ }
+ else {
+ /* No. No need to split the node. Just remove
+ the end of the node. */
+ int r = jffs_min(n->data_offset + n->data_size
+ - offset, remove_size);
+ n->data_size -= r;
+ remove_size -= r;
+ n = n->range_next;
+ }
+ }
+
+ /* Remove as many nodes as necessary. */
+ while (n && remove_size) {
+ if (n->data_size <= remove_size) {
+ struct jffs_node *p = n;
+ remove_size -= n->data_size;
+ n = n->range_next;
+ D3(printk("jffs_delete_data(): Removing node: "
+ "ino: %u, version: %u\n",
+ p->ino, p->version));
+ if (p->fm) {
+ jffs_fmfree(f->c->fmc, p->fm, p);
+ }
+ jffs_unlink_node_from_range_list(f, p);
+ jffs_unlink_node_from_version_list(f, p);
+ kfree(p);
+ DJM(no_jffs_node--);
+ }
+ else {
+ n->data_size -= remove_size;
+ n->fm_offset += remove_size;
+ n->data_offset -= (node->removed_size - remove_size);
+ n = n->range_next;
+ break;
+ }
+ }
+
+ /* Adjust the following nodes' information about offsets etc. */
+ while (n && node->removed_size) {
+ n->data_offset -= node->removed_size;
+ n = n->range_next;
+ }
+
+ f->size -= node->removed_size;
+ D3(printk("jffs_delete_data(): f->size = %d\n", f->size));
+} /* jffs_delete_data() */
+
+
+/* Insert some data into a file. Prior to the call to this function,
+ jffs_delete_data() should be called. */
+static void
+jffs_insert_data(struct jffs_file *f, struct jffs_node *node)
+{
+ D3(printk("jffs_insert_data(): node->data_offset = %u, "
+ "node->data_size = %u, f->size = %u\n",
+ node->data_offset, node->data_size, f->size));
+
+ /* Find the position where we should insert data. */
+
+ if (node->data_offset == f->size) {
+ /* A simple append. This is the most common operation. */
+ node->range_next = 0;
+ node->range_prev = f->range_tail;
+ if (node->range_prev) {
+ node->range_prev->range_next = node;
+ }
+ f->range_tail = node;
+ f->size += node->data_size;
+ if (!f->range_head) {
+ f->range_head = node;
+ }
+ }
+ else if (node->data_offset < f->size) {
+ /* Trying to insert data into the middle of the file. This
+ means no problem because jffs_delete_data() has already
+ prepared the range list for us. */
+ struct jffs_node *n;
+
+ /* Find the correct place for the insertion and then insert
+ the node. */
+ for (n = f->range_head; n; n = n->range_next) {
+ D1(printk("Cool stuff's happening!\n"));
+
+ if (n->data_offset == node->data_offset) {
+ node->range_prev = n->range_prev;
+ if (node->range_prev) {
+ node->range_prev->range_next = node;
+ }
+ else {
+ f->range_head = node;
+ }
+ node->range_next = n;
+ n->range_prev = node;
+ break;
+ }
+ ASSERT(else if (n->data_offset + n->data_size >
+ node->data_offset) {
+ printk(KERN_ERR "jffs_insert_data(): "
+ "Couldn't find a place to insert "
+ "the data!\n");
+ return;
+ });
+ }
+
+ /* Adjust later nodes' offsets etc. */
+ n = node->range_next;
+ while (n) {
+ n->data_offset += node->data_size;
+ n = n->range_next;
+ }
+ f->size += node->data_size;
+ }
+ else if (node->data_offset > f->size) {
+ /* Not implemented yet. */
+#if 0
+ /* Below is some example code for future use if we decide
+ to implement it. */
+ /* This is code that isn't supported by VFS. So there aren't
+ really any reasons to implement it yet. */
+ if (!f->range_head) {
+ if (node->data_offset > f->size) {
+ if (!(nn = jffs_alloc_node())) {
+ D(printk("jffs_insert_data(): "
+ "Allocation failed.\n"));
+ return;
+ }
+ nn->version = JFFS_MAGIC_BITMASK;
+ nn->data_offset = 0;
+ nn->data_size = node->data_offset;
+ nn->removed_size = 0;
+ nn->fm_offset = 0;
+ nn->name_size = 0;
+ nn->fm = 0; /* This is a virtual data holder. */
+ nn->version_prev = 0;
+ nn->version_next = 0;
+ nn->range_prev = 0;
+ nn->range_next = 0;
+ nh->range_head = nn;
+ nh->range_tail = nn;
+ }
+ }
+#endif
+ }
+
+ D3(printk("jffs_insert_data(): f->size = %d\n", f->size));
+}
+
+
+/* A new node (with data) has been added to the file and now the range
+ list has to be modified. */
+static int
+jffs_update_file(struct jffs_file *f, struct jffs_node *node)
+{
+ D3(printk("jffs_update_file(): ino: %u, version: %u\n",
+ f->ino, node->version));
+
+ if (node->data_size == 0) {
+ if (node->removed_size == 0) {
+ /* data_offset == X */
+ /* data_size == 0 */
+ /* remove_size == 0 */
+ }
+ else {
+ /* data_offset == X */
+ /* data_size == 0 */
+ /* remove_size != 0 */
+ jffs_delete_data(f, node);
+ }
+ }
+ else {
+ /* data_offset == X */
+ /* data_size != 0 */
+ /* remove_size == Y */
+ jffs_delete_data(f, node);
+ jffs_insert_data(f, node);
+ }
+ return 0;
+}
+
+
+/* Print the contents of a node. */
+void
+jffs_print_node(struct jffs_node *n)
+{
+ D(printk("jffs_node: 0x%p\n", n));
+ D(printk("{\n"));
+ D(printk(" 0x%08x, /* version */\n", n->version));
+ D(printk(" 0x%08x, /* data_offset */\n", n->data_offset));
+ D(printk(" 0x%08x, /* data_size */\n", n->data_size));
+ D(printk(" 0x%08x, /* removed_size */\n", n->removed_size));
+ D(printk(" 0x%08x, /* fm_offset */\n", n->fm_offset));
+ D(printk(" 0x%02x, /* name_size */\n", n->name_size));
+ D(printk(" 0x%p, /* fm, fm->offset: %u */\n",
+ n->fm, n->fm->offset));
+ D(printk(" 0x%p, /* version_prev */\n", n->version_prev));
+ D(printk(" 0x%p, /* version_next */\n", n->version_next));
+ D(printk(" 0x%p, /* range_prev */\n", n->range_prev));
+ D(printk(" 0x%p, /* range_next */\n", n->range_next));
+ D(printk("}\n"));
+}
+
+
+/* Print the contents of a raw inode. */
+void
+jffs_print_raw_inode(struct jffs_raw_inode *raw_inode)
+{
+ D(printk("jffs_raw_inode: inode number: %u\n", raw_inode->ino));
+ D(printk("{\n"));
+ D(printk(" 0x%08x, /* magic */\n", raw_inode->magic));
+ D(printk(" 0x%08x, /* ino */\n", raw_inode->ino));
+ D(printk(" 0x%08x, /* pino */\n", raw_inode->pino));
+ D(printk(" 0x%08x, /* version */\n", raw_inode->version));
+ D(printk(" 0x%08x, /* mode */\n", raw_inode->mode));
+ D(printk(" 0x%04x, /* uid */\n", raw_inode->uid));
+ D(printk(" 0x%04x, /* gid */\n", raw_inode->gid));
+ D(printk(" 0x%08x, /* atime */\n", raw_inode->atime));
+ D(printk(" 0x%08x, /* mtime */\n", raw_inode->mtime));
+ D(printk(" 0x%08x, /* ctime */\n", raw_inode->ctime));
+ D(printk(" 0x%08x, /* offset */\n", raw_inode->offset));
+ D(printk(" 0x%08x, /* dsize */\n", raw_inode->dsize));
+ D(printk(" 0x%08x, /* rsize */\n", raw_inode->rsize));
+ D(printk(" 0x%02x, /* nsize */\n", raw_inode->nsize));
+ D(printk(" 0x%02x, /* nlink */\n", raw_inode->nlink));
+ D(printk(" 0x%02x, /* spare */\n",
+ raw_inode->spare));
+ D(printk(" %u, /* rename */\n",
+ raw_inode->rename));
+ D(printk(" %u, /* deleted */\n",
+ raw_inode->deleted));
+ D(printk(" 0x%02x, /* accurate */\n",
+ raw_inode->accurate));
+ D(printk(" 0x%08x, /* dchksum */\n", raw_inode->dchksum));
+ D(printk(" 0x%04x, /* nchksum */\n", raw_inode->nchksum));
+ D(printk(" 0x%04x, /* chksum */\n", raw_inode->chksum));
+ D(printk("}\n"));
+}
+
+
+/* Print the contents of a file. */
+int
+jffs_print_file(struct jffs_file *f)
+{
+ D(int i);
+ D(printk("jffs_file: 0x%p\n", f));
+ D(printk("{\n"));
+ D(printk(" 0x%08x, /* ino */\n", f->ino));
+ D(printk(" 0x%08x, /* pino */\n", f->pino));
+ D(printk(" 0x%08x, /* mode */\n", f->mode));
+ D(printk(" 0x%04x, /* uid */\n", f->uid));
+ D(printk(" 0x%04x, /* gid */\n", f->gid));
+ D(printk(" 0x%08x, /* atime */\n", f->atime));
+ D(printk(" 0x%08x, /* mtime */\n", f->mtime));
+ D(printk(" 0x%08x, /* ctime */\n", f->ctime));
+ D(printk(" 0x%02x, /* nsize */\n", f->nsize));
+ D(printk(" 0x%02x, /* nlink */\n", f->nlink));
+ D(printk(" 0x%02x, /* deleted */\n", f->deleted));
+ D(printk(" \"%s\", ", (f->name ? f->name : "")));
+ D(for (i = strlen(f->name ? f->name : ""); i < 8; ++i) {
+ printk(" ");
+ });
+ D(printk("/* name */\n"));
+ D(printk(" 0x%08x, /* size */\n", f->size));
+ D(printk(" 0x%08x, /* highest_version */\n",
+ f->highest_version));
+ D(printk(" 0x%p, /* c */\n", f->c));
+ D(printk(" 0x%p, /* parent */\n", f->parent));
+ D(printk(" 0x%p, /* children */\n", f->children));
+ D(printk(" 0x%p, /* sibling_prev */\n", f->sibling_prev));
+ D(printk(" 0x%p, /* sibling_next */\n", f->sibling_next));
+ D(printk(" 0x%p, /* hash_prev */\n", f->hash.prev));
+ D(printk(" 0x%p, /* hash_next */\n", f->hash.next));
+ D(printk(" 0x%p, /* range_head */\n", f->range_head));
+ D(printk(" 0x%p, /* range_tail */\n", f->range_tail));
+ D(printk(" 0x%p, /* version_head */\n", f->version_head));
+ D(printk(" 0x%p, /* version_tail */\n", f->version_tail));
+ D(printk("}\n"));
+ return 0;
+}
+
+
+void
+jffs_print_hash_table(struct jffs_control *c)
+{
+ int i;
+
+ printk("JFFS: Dumping the file system's hash table...\n");
+ for (i = 0; i < c->hash_len; i++) {
+ struct list_head *p;
+ for (p = c->hash[i].next; p != &c->hash[i]; p = p->next) {
+ struct jffs_file *f=list_entry(p,struct jffs_file,hash);
+ printk("*** c->hash[%u]: \"%s\" "
+ "(ino: %u, pino: %u)\n",
+ i, (f->name ? f->name : ""),
+ f->ino, f->pino);
+ }
+ }
+}
+
+
+void
+jffs_print_tree(struct jffs_file *first_file, int indent)
+{
+ struct jffs_file *f;
+ char *space;
+
+ if (!first_file) {
+ return;
+ }
+
+ if (!(space = (char *) kmalloc(indent + 1, GFP_KERNEL))) {
+ printk("jffs_print_tree(): Out of memory!\n");
+ return;
+ }
+
+ memset(space, ' ', indent);
+ space[indent] = '\0';
+
+ for (f = first_file; f; f = f->sibling_next) {
+ printk("%s%s (ino: %u, highest_version: %u, size: %u)\n",
+ space, (f->name ? f->name : "/"),
+ f->ino, f->highest_version, f->size);
+ if (S_ISDIR(f->mode)) {
+ jffs_print_tree(f->children, indent + 2);
+ }
+ }
+
+ kfree(space);
+}
+
+
+#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
+void
+jffs_print_memory_allocation_statistics(void)
+{
+ static long printout = 0;
+ printk("________ Memory printout #%ld ________\n", ++printout);
+ printk("no_jffs_file = %ld\n", no_jffs_file);
+ printk("no_jffs_node = %ld\n", no_jffs_node);
+ printk("no_jffs_control = %ld\n", no_jffs_control);
+ printk("no_jffs_raw_inode = %ld\n", no_jffs_raw_inode);
+ printk("no_jffs_node_ref = %ld\n", no_jffs_node_ref);
+ printk("no_jffs_fm = %ld\n", no_jffs_fm);
+ printk("no_jffs_fmcontrol = %ld\n", no_jffs_fmcontrol);
+ printk("no_hash = %ld\n", no_hash);
+ printk("no_name = %ld\n", no_name);
+ printk("\n");
+}
+#endif
+
+
+/* Rewrite `size' bytes, and begin at `node'. */
+int
+jffs_rewrite_data(struct jffs_file *f, struct jffs_node *node, int size)
+{
+ struct jffs_control *c = f->c;
+ struct jffs_fmcontrol *fmc = c->fmc;
+ struct jffs_raw_inode raw_inode;
+ struct jffs_node *new_node;
+ struct jffs_fm *fm;
+ __u32 pos;
+ __u32 pos_dchksum;
+ __u32 total_name_size;
+ __u32 total_data_size;
+ __u32 total_size;
+ int err;
+
+ D1(printk("***jffs_rewrite_data(): node: %u, name: \"%s\", size: %u\n",
+ f->ino, (f->name ? f->name : ""), size));
+
+ /* Create and initialize the new node. */
+ if (!(new_node = (struct jffs_node *)
+ kmalloc(sizeof(struct jffs_node), GFP_KERNEL))) {
+ D(printk("jffs_rewrite_data(): "
+ "Failed to allocate node.\n"));
+ return -ENOMEM;
+ }
+ DJM(no_jffs_node++);
+ new_node->data_offset = node->data_offset;
+ new_node->data_size = size;
+ new_node->removed_size = size;
+ total_name_size = f->nsize + JFFS_GET_PAD_BYTES(f->nsize);
+ total_data_size = size + JFFS_GET_PAD_BYTES(size);
+ total_size = sizeof(struct jffs_raw_inode)
+ + total_name_size + total_data_size;
+ new_node->fm_offset = sizeof(struct jffs_raw_inode)
+ + total_name_size;
+
+ if ((err = jffs_fmalloc(fmc, total_size, new_node, &fm)) < 0) {
+ D(printk("jffs_rewrite_data(): Failed to allocate fm.\n"));
+ kfree(new_node);
+ DJM(no_jffs_node--);
+ return err;
+ }
+ else if (!fm->nodes) {
+ /* The jffs_fm struct that we got is not good enough. */
+ if ((err = jffs_write_dummy_node(c, fm)) < 0) {
+ D(printk("jffs_rewrite_data(): "
+ "jffs_write_dummy_node() Failed!\n"));
+ kfree(fm);
+ DJM(no_jffs_fm--);
+ return err;
+ }
+ /* Get a new one. */
+ if ((err = jffs_fmalloc(fmc, total_size, node, &fm)) < 0) {
+ D(printk("jffs_rewrite_data(): Second "
+ "jffs_fmalloc(0x%p, %u) failed!\n",
+ fmc, total_size));
+ return err;
+ }
+ }
+ new_node->fm = fm;
+
+ ASSERT(if (new_node->fm->nodes == 0) {
+ printk(KERN_ERR "jffs_rewrite_data(): "
+ "new_node->fm->nodes == 0\n");
+ });
+
+ /* Initialize the raw inode. */
+ raw_inode.magic = JFFS_MAGIC_BITMASK;
+ raw_inode.ino = f->ino;
+ raw_inode.pino = f->pino;
+ raw_inode.version = f->highest_version + 1;
+ raw_inode.mode = f->mode;
+ raw_inode.uid = f->uid;
+ raw_inode.gid = f->gid;
+ raw_inode.atime = f->atime;
+ raw_inode.mtime = f->mtime;
+ raw_inode.ctime = f->ctime;
+ raw_inode.offset = node->data_offset;
+ raw_inode.dsize = size;
+ raw_inode.rsize = size;
+ raw_inode.nsize = f->nsize;
+ raw_inode.nlink = f->nlink;
+ raw_inode.spare = 0;
+ raw_inode.rename = 0;
+ raw_inode.deleted = 0;
+ raw_inode.accurate = 0xff;
+ raw_inode.dchksum = 0;
+ raw_inode.nchksum = 0;
+
+ pos = new_node->fm->offset;
+ pos_dchksum = pos +JFFS_RAW_INODE_DCHKSUM_OFFSET;
+
+ D3(printk("jffs_rewrite_data(): Writing this raw inode "
+ "to pos 0x%ul.\n", pos));
+ D3(jffs_print_raw_inode(&raw_inode));
+
+ if ((err = flash_safe_write(fmc->mtd, pos,
+ (u_char *) &raw_inode,
+ sizeof(struct jffs_raw_inode)
+ - sizeof(__u32)
+ - sizeof(__u16) - sizeof(__u16))) < 0) {
+ printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
+ "rewrite. (raw inode)\n");
+ jffs_fmfree_partly(fmc, fm,
+ total_name_size + total_data_size);
+ return err;
+ }
+ pos += sizeof(struct jffs_raw_inode);
+
+ /* Write the name to the flash memory. */
+ if (f->nsize) {
+ D3(printk("jffs_rewrite_data(): Writing name \"%s\" to "
+ "pos 0x%ul.\n", f->name, (long)pos));
+ if ((err = flash_safe_write(fmc->mtd, pos,
+ (u_char *)f->name,
+ f->nsize)) < 0) {
+ printk(KERN_ERR "JFFS: jffs_rewrite_data: Write "
+ "error during rewrite. (name)\n");
+ jffs_fmfree_partly(fmc, fm, total_data_size);
+ return err;
+ }
+ pos += total_name_size;
+ raw_inode.nchksum = jffs_checksum(f->name, f->nsize);
+ }
+
+ /* Write the data. */
+ if (size) {
+ int r;
+ unsigned char *page;
+ __u32 offset = node->data_offset;
+
+ if (!(page = (unsigned char *)__get_free_page(GFP_KERNEL))) {
+ jffs_fmfree_partly(fmc, fm, 0);
+ return -1;
+ }
+
+ while (size) {
+ __u32 s = jffs_min(size, PAGE_SIZE);
+ if ((r = jffs_read_data(f, (char *)page,
+ offset, s)) < s) {
+ printk(KERN_ERR "JFFS: jffs_rewrite_data: "
+ "jffs_read_data() "
+ "failed! (r = %d)\n", r);
+ jffs_fmfree_partly(fmc, fm, 0);
+ return -1;
+ }
+ if ((err = flash_safe_write(fmc->mtd,
+ pos, page, r)) < 0) {
+ printk(KERN_ERR "JFFS: jffs_rewrite_data: "
+ "Write error during rewrite. "
+ "(data)\n");
+ free_page((unsigned long)page);
+ jffs_fmfree_partly(fmc, fm, 0);
+ return err;
+ }
+ pos += r;
+ size -= r;
+ offset += r;
+ raw_inode.dchksum += jffs_checksum(page, r);
+ }
+
+ free_page((unsigned long)page);
+ }
+
+ raw_inode.accurate = 0;
+ raw_inode.chksum = jffs_checksum(&raw_inode,
+ sizeof(struct jffs_raw_inode)
+ - sizeof(__u16));
+
+ /* Add the checksum. */
+ if ((err
+ = flash_safe_write(fmc->mtd, pos_dchksum,
+ &((u_char *)
+ &raw_inode)[JFFS_RAW_INODE_DCHKSUM_OFFSET],
+ sizeof(__u32) + sizeof(__u16)
+ + sizeof(__u16))) < 0) {
+ printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
+ "rewrite. (checksum)\n");
+ jffs_fmfree_partly(fmc, fm, 0);
+ return err;
+ }
+
+ /* Now make the file system aware of the newly written node. */
+ jffs_insert_node(c, f, &raw_inode, f->name, new_node);
+
+ D3(printk("jffs_rewrite_data(): Leaving...\n"));
+ return 0;
+} /* jffs_rewrite_data() */
+
+
+/* jffs_garbage_collect_next implements one step in the garbage collect
+ process and is often called multiple times at each occasion of a
+ garbage collect. */
+int
+jffs_garbage_collect_next(struct jffs_control *c)
+{
+ struct jffs_fmcontrol *fmc = c->fmc;
+ struct jffs_node *node;
+ struct jffs_file *f;
+ int size;
+ int data_size;
+ int total_name_size;
+ int free_size = fmc->flash_size - (fmc->used_size + fmc->dirty_size);
+ __u32 free_chunk_size1 = jffs_free_size1(fmc);
+ D2(__u32 free_chunk_size2 = jffs_free_size2(fmc));
+
+ /* Get the oldest node in the flash. */
+ node = jffs_get_oldest_node(fmc);
+ ASSERT(if (!node) {
+ printk(KERN_ERR "JFFS: jffs_garbage_collect_next: "
+ "No oldest node found!\n");
+ return -1;
+ });
+
+ /* Find its corresponding file too. */
+ f = jffs_find_file(c, node->ino);
+ ASSERT(if (!f) {
+ printk(KERN_ERR "JFFS: jffs_garbage_collect_next: "
+ "No file to garbage collect! "
+ "(ino = 0x%08x)\n", node->ino);
+ return -1;
+ });
+
+ D1(printk("jffs_garbage_collect_next(): \"%s\", "
+ "ino: %u, version: %u\n",
+ (f->name ? f->name : ""), node->ino, node->version));
+
+ /* Compute how much we want to rewrite at the moment. */
+ data_size = f->size - node->data_offset;
+ total_name_size = f->nsize + JFFS_GET_PAD_BYTES(f->nsize);
+ size = sizeof(struct jffs_raw_inode) + total_name_size
+ + data_size + JFFS_GET_PAD_BYTES(data_size);
+
+ D2(printk(" total_name_size: %u\n", total_name_size));
+ D2(printk(" data_size: %u\n", data_size));
+ D2(printk(" size: %u\n", size));
+ D2(printk(" f->nsize: %u\n", f->nsize));
+ D2(printk(" f->size: %u\n", f->size));
+ D2(printk(" free_chunk_size1: %u\n", free_chunk_size1));
+ D2(printk(" free_chunk_size2: %u\n", free_chunk_size2));
+
+ if (size > fmc->max_chunk_size) {
+ size = fmc->max_chunk_size;
+ data_size = size - sizeof(struct jffs_raw_inode)
+ - total_name_size;
+ }
+ if (size > free_chunk_size1) {
+
+ if (free_chunk_size1 <
+ (sizeof(struct jffs_raw_inode) + f->nsize + BLOCK_SIZE)) {
+ /* The space left is too small to be of any
+ use really. */
+ struct jffs_fm *dirty_fm
+ = jffs_fmalloced(fmc,
+ fmc->tail->offset + fmc->tail->size,
+ free_chunk_size1, NULL);
+ if (!dirty_fm) {
+ printk(KERN_ERR "JFFS: "
+ "jffs_garbage_collect_next: "
+ "Failed to allocate `dirty' "
+ "flash memory!\n");
+ return -1;
+ }
+ jffs_write_dummy_node(c, dirty_fm);
+ goto jffs_garbage_collect_next_end;
+ }
+
+ size = free_chunk_size1;
+ data_size = size - sizeof(struct jffs_raw_inode)
+ - total_name_size;
+ }
+
+ D2(printk(" size: %u (again)\n", size));
+
+ if (free_size - size < fmc->sector_size) {
+ /* Just rewrite that node (or even less). */
+ jffs_rewrite_data(f, node,
+ jffs_min(node->data_size, data_size));
+ }
+ else {
+ size -= (sizeof(struct jffs_raw_inode) + f->nsize);
+ jffs_rewrite_data(f, node, data_size);
+ }
+
+jffs_garbage_collect_next_end:
+ D3(printk("jffs_garbage_collect_next: Leaving...\n"));
+ return 0;
+} /* jffs_garbage_collect_next */
+
+
+/* If an obsolete node is partly going to be erased due to garbage
+ collection, the part that isn't going to be erased must be filled
+ with zeroes so that the scan of the flash will work smoothly next
+ time.
+ There are two phases in this procedure: First, the clearing of
+ the name and data parts of the node. Second, possibly also clearing
+ a part of the raw inode as well. If the box is power cycled during
+ the first phase, only the checksum of this node-to-be-cleared-at-
+ the-end will be wrong. If the box is power cycled during, or after,
+ the clearing of the raw inode, the information like the length of
+ the name and data parts are zeroed. The next time the box is
+ powered up, the scanning algorithm manages this faulty data too
+ because:
+
+ - The checksum is invalid and thus the raw inode must be discarded
+ in any case.
+ - If the lengths of the data part or the name part are zeroed, the
+ scanning just continues after the raw inode. But after the inode
+ the scanning procedure just finds zeroes which is the same as
+ dirt.
+
+ So, in the end, this could never fail. :-) Even if it does fail,
+ the scanning algorithm should manage that too. */
+
+static int
+jffs_clear_end_of_node(struct jffs_control *c, __u32 erase_size)
+{
+ struct jffs_fm *fm;
+ struct jffs_fmcontrol *fmc = c->fmc;
+ __u32 zero_offset;
+ __u32 zero_size;
+ __u32 zero_offset_data;
+ __u32 zero_size_data;
+ __u32 cutting_raw_inode = 0;
+
+ if (!(fm = jffs_cut_node(fmc, erase_size))) {
+ D3(printk("jffs_clear_end_of_node(): fm == NULL\n"));
+ return 0;
+ }
+
+ /* Where and how much shall we clear? */
+ zero_offset = fmc->head->offset + erase_size;
+ zero_size = fm->offset + fm->size - zero_offset;
+
+ /* Do we have to clear the raw_inode explicitly? */
+ if (fm->size - zero_size < sizeof(struct jffs_raw_inode)) {
+ cutting_raw_inode = sizeof(struct jffs_raw_inode)
+ - (fm->size - zero_size);
+ }
+
+ /* First, clear the name and data fields. */
+ zero_offset_data = zero_offset + cutting_raw_inode;
+ zero_size_data = zero_size - cutting_raw_inode;
+ flash_safe_acquire(fmc->mtd);
+ flash_memset(fmc->mtd, zero_offset_data, 0, zero_size_data);
+ flash_safe_release(fmc->mtd);
+
+ /* Should we clear a part of the raw inode? */
+ if (cutting_raw_inode) {
+ /* I guess it is ok to clear the raw inode in this order. */
+ flash_safe_acquire(fmc->mtd);
+ flash_memset(fmc->mtd, zero_offset, 0,
+ cutting_raw_inode);
+ flash_safe_release(fmc->mtd);
+ }
+
+ return 0;
+} /* jffs_clear_end_of_node() */
+
+/* Try to erase as much as possible of the dirt in the flash memory. */
+long
+jffs_try_to_erase(struct jffs_control *c)
+{
+ struct jffs_fmcontrol *fmc = c->fmc;
+ long erase_size;
+ int err;
+ __u32 offset;
+
+ D3(printk("jffs_try_to_erase()\n"));
+
+ erase_size = jffs_erasable_size(fmc);
+
+ D2(printk("jffs_try_to_erase(): erase_size = %ld\n", erase_size));
+
+ if (erase_size == 0) {
+ return 0;
+ }
+ else if (erase_size < 0) {
+ printk(KERN_ERR "JFFS: jffs_try_to_erase: "
+ "jffs_erasable_size returned %ld.\n", erase_size);
+ return erase_size;
+ }
+
+ if ((err = jffs_clear_end_of_node(c, erase_size)) < 0) {
+ printk(KERN_ERR "JFFS: jffs_try_to_erase: "
+ "Clearing of node failed.\n");
+ return err;
+ }
+
+ offset = fmc->head->offset - fmc->flash_start;
+
+ /* Now, let's try to do the erase. */
+ if ((err = flash_erase_region(fmc->mtd,
+ offset, erase_size)) < 0) {
+ printk(KERN_ERR "JFFS: Erase of flash failed. "
+ "offset = %u, erase_size = %ld\n",
+ offset, erase_size);
+ /* XXX: Here we should allocate this area as dirty
+ with jffs_fmalloced or something similar. Now
+ we just report the error. */
+ return err;
+ }
+
+#if 0
+ /* Check if the erased sectors really got erased. */
+ {
+ __u32 pos;
+ __u32 end;
+
+ pos = (__u32)flash_get_direct_pointer(c->sb->s_dev, offset);
+ end = pos + erase_size;
+
+ D2(printk("JFFS: Checking erased sector(s)...\n"));
+
+ flash_safe_acquire(fmc->mtd);
+
+ for (; pos < end; pos += 4) {
+ if (*(__u32 *)pos != JFFS_EMPTY_BITMASK) {
+ printk("JFFS: Erase failed! pos = 0x%ld\n",
+ (long)pos);
+ jffs_hexdump(fmc->mtd, pos,
+ jffs_min(256, end - pos));
+ err = -1;
+ break;
+ }
+ }
+
+ flash_safe_release(fmc->mtd);
+
+ if (!err) {
+ D2(printk("JFFS: Erase succeeded.\n"));
+ }
+ else {
+ /* XXX: Here we should allocate the memory
+ with jffs_fmalloced() in order to prevent
+ JFFS from using this area accidentally. */
+ return err;
+ }
+ }
+#endif
+
+ /* Update the flash memory data structures. */
+ jffs_sync_erase(fmc, erase_size);
+
+ return erase_size;
+}
+
+
+/* There are different criteria that should trigger a garbage collect:
+
+ 1. There is too much dirt in the memory.
+ 2. The free space is becoming small.
+ 3. There are many versions of a node.
+
+ The garbage collect should always be done in a manner that guarantees
+ that future garbage collects cannot be locked. E.g. Rewritten chunks
+ should not be too large (span more than one sector in the flash memory
+ for exemple). Of course there is a limit on how intelligent this garbage
+ collection can be. */
+int
+jffs_garbage_collect(struct jffs_control *c)
+{
+ struct jffs_fmcontrol *fmc = c->fmc;
+ long erased_total = 0;
+ long erased;
+ int result = 0;
+ D1(int i = 1);
+
+ D2(printk("***jffs_garbage_collect(): fmc->dirty_size = %u\n",
+ fmc->dirty_size));
+ D2(jffs_print_fmcontrol(fmc));
+
+ c->fmc->no_call_gc = 1;
+
+ /* While there is too much dirt left and it is possible
+ to garbage collect, do so. */
+
+ while (fmc->dirty_size >= fmc->sector_size) {
+
+ D1(printk("***jffs_garbage_collect(): round #%u, "
+ "fmc->dirty_size = %u\n", i++, fmc->dirty_size));
+ D2(jffs_print_fmcontrol(fmc));
+
+ /* At least one sector should be able to free now. */
+ if ((erased = jffs_try_to_erase(c)) < 0) {
+ printk(KERN_WARNING "JFFS: Error in "
+ "garbage collector.\n");
+ result = erased;
+ goto gc_end;
+ }
+ else if (erased == 0) {
+ __u32 free_size = fmc->flash_size
+ - (fmc->used_size
+ + fmc->dirty_size);
+
+ if (free_size > 0) {
+ /* Let's dare to make a garbage collect. */
+ if ((result = jffs_garbage_collect_next(c))
+ < 0) {
+ printk(KERN_ERR "JFFS: Something "
+ "has gone seriously wrong "
+ "with a garbage collect.\n");
+ goto gc_end;
+ }
+ }
+ else {
+ /* What should we do here? */
+ D(printk(" jffs_garbage_collect(): "
+ "erased: %ld, free_size: %u\n",
+ erased, free_size));
+ result = -1;
+ goto gc_end;
+ }
+ }
+
+ D1(printk(" jffs_garbage_collect(): erased: %ld\n", erased));
+ erased_total += erased;
+ DJM(jffs_print_memory_allocation_statistics());
+ }
+
+
+gc_end:
+ c->fmc->no_call_gc = 0;
+
+ D3(printk(" jffs_garbage_collect(): Leaving...\n"));
+ D1(if (erased_total) {
+ printk("erased_total = %ld\n", erased_total);
+ jffs_print_fmcontrol(fmc);
+ });
+ return result;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)