diff options
Diffstat (limited to 'fs/jffs/intrep.c')
| -rw-r--r-- | fs/jffs/intrep.c | 3457 |
1 files changed, 3457 insertions, 0 deletions
diff --git a/fs/jffs/intrep.c b/fs/jffs/intrep.c new file mode 100644 index 000000000000..8cc6893fc56c --- /dev/null +++ b/fs/jffs/intrep.c @@ -0,0 +1,3457 @@ +/* + * 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 1.102 2001/09/23 23:28:36 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. + * + * 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. + * + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/jffs.h> +#include <linux/fs.h> +#include <linux/stat.h> +#include <linux/pagemap.h> +#include <asm/semaphore.h> +#include <asm/byteorder.h> +#include <linux/smp_lock.h> +#include <linux/time.h> +#include <linux/ctype.h> + +#include "intrep.h" +#include "jffs_fm.h" + +long no_jffs_node = 0; +static long no_jffs_file = 0; +#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG +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 int jffs_build_file(struct jffs_file *f); +static int jffs_free_file(struct jffs_file *f); +static int jffs_free_node_list(struct jffs_file *f); +static int jffs_garbage_collect_now(struct jffs_control *c); +static int jffs_insert_file_into_hash(struct jffs_file *f); +static int jffs_remove_redundant_nodes(struct jffs_file *f); + +/* Is there enough space on the flash? */ +static inline int JFFS_ENOUGH_SPACE(struct jffs_control *c, __u32 space) +{ + struct jffs_fmcontrol *fmc = c->fmc; + + while (1) { + if ((fmc->flash_size - (fmc->used_size + fmc->dirty_size)) + >= fmc->min_free_size + space) { + return 1; + } + if (fmc->dirty_size < fmc->sector_size) + return 0; + + if (jffs_garbage_collect_now(c)) { + D1(printk("JFFS_ENOUGH_SPACE: jffs_garbage_collect_now() failed.\n")); + return 0; + } + } +} + +#if CONFIG_JFFS_FS_VERBOSE > 0 +static __u8 +flash_read_u8(struct mtd_info *mtd, loff_t from) +{ + size_t retlen; + __u8 ret; + int res; + + res = MTD_READ(mtd, from, 1, &retlen, &ret); + if (retlen != 1) { + printk("Didn't read a byte in flash_read_u8(). Returned %d\n", res); + return 0; + } + + return ret; +} + +static 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 (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; + int res; + + D3(printk(KERN_NOTICE "flash_safe_read(%p, %08x, %p, %08x)\n", + mtd, (unsigned int) from, buf, count)); + + res = MTD_READ(mtd, from, count, &retlen, buf); + if (retlen != count) { + panic("Didn't read all bytes in flash_safe_read(). Returned %d\n", res); + } + return res?res:retlen; +} + + +static __u32 +flash_read_u32(struct mtd_info *mtd, loff_t from) +{ + size_t retlen; + __u32 ret; + int res; + + res = MTD_READ(mtd, from, 4, &retlen, (unsigned char *)&ret); + if (retlen != 4) { + printk("Didn't read all bytes in flash_read_u32(). Returned %d\n", res); + 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; + int res; + + D3(printk(KERN_NOTICE "flash_safe_write(%p, %08x, %p, %08x)\n", + mtd, (unsigned int) to, buf, count)); + + res = MTD_WRITE(mtd, to, count, &retlen, buf); + if (retlen != count) { + printk("Didn't write all bytes in flash_safe_write(). Returned %d\n", res); + } + return res?res:retlen; +} + + +static int +flash_safe_writev(struct mtd_info *mtd, const struct kvec *vecs, + unsigned long iovec_cnt, loff_t to) +{ + size_t retlen, retlen_a; + int i; + int res; + + D3(printk(KERN_NOTICE "flash_safe_writev(%p, %08x, %p)\n", + mtd, (unsigned int) to, vecs)); + + if (mtd->writev) { + res = MTD_WRITEV(mtd, vecs, iovec_cnt, to, &retlen); + return res ? res : retlen; + } + /* Not implemented writev. Repeatedly use write - on the not so + unreasonable assumption that the mtd driver doesn't care how + many write cycles we use. */ + res=0; + retlen=0; + + for (i=0; !res && i<iovec_cnt; i++) { + res = MTD_WRITE(mtd, to, vecs[i].iov_len, &retlen_a, vecs[i].iov_base); + if (retlen_a != vecs[i].iov_len) { + printk("Didn't write all bytes in flash_safe_writev(). Returned %d\n", res); + if (i != iovec_cnt-1) + return -EIO; + } + /* If res is non-zero, retlen_a is undefined, but we don't + care because in that case it's not going to be + returned anyway. + */ + to += retlen_a; + retlen += retlen_a; + } + return res?res:retlen; +} + + +static int +flash_memset(struct mtd_info *mtd, loff_t to, + const u_char c, size_t size) +{ + static unsigned char pattern[64]; + int i; + + /* fill up pattern */ + + for(i = 0; i < 64; i++) + pattern[i] = c; + + /* write as many 64-byte chunks as we can */ + + while (size >= 64) { + flash_safe_write(mtd, to, pattern, 64); + size -= 64; + to += 64; + } + + /* 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; + + /* FIXME: Use TASK_INTERRUPTIBLE and deal with being interrupted */ + set_current_state(TASK_UNINTERRUPTIBLE); + 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%lx, 0x%lx] " + "totally failed\n", (long)start, (long)start + size); + + return -1; + } + + schedule(); /* Wait for flash to finish. */ + remove_wait_queue(&wait_q, &wait); + + kfree(erase); + + return 0; +} + +/* This routine calculates checksums in JFFS. */ +static __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; +} + + +static int +jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size, __u32 *result) +{ + __u32 sum = 0; + loff_t ptr = start; + __u8 *read_buf; + int i, length; + + /* Allocate read buffer */ + read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL); + if (!read_buf) { + printk(KERN_NOTICE "kmalloc failed in jffs_checksum_flash()\n"); + return -ENOMEM; + } + /* Loop until checksum done */ + while (size) { + /* Get amount of data to read */ + if (size < 4096) + length = size; + else + length = 4096; + + /* Perform flash read */ + D3(printk(KERN_NOTICE "jffs_checksum_flash\n")); + flash_safe_read(mtd, ptr, &read_buf[0], length); + + /* Compute checksum */ + for (i=0; i < length ; i++) + sum += read_buf[i]; + + /* Update pointer and size */ + size -= length; + ptr += length; + } + + /* Free read buffer */ + kfree (read_buf); + + /* Return result */ + D3(printk("checksum result: 0x%08x\n", sum)); + *result = sum; + return 0; +} + +static __inline__ void jffs_fm_write_lock(struct jffs_fmcontrol *fmc) +{ + // down(&fmc->wlock); +} + +static __inline__ void jffs_fm_write_unlock(struct jffs_fmcontrol *fmc) +{ + // up(&fmc->wlock); +} + + +/* 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 NULL; + } + 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(struct super_block *sb) +{ + 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 = NULL; + c->gc_task = NULL; + 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, MINOR(sb->s_dev)))) { + goto fail_fminit; + } + c->next_ino = JFFS_MIN_INO + 1; + c->delete_list = (struct jffs_delete_list *) 0; + 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; + } + + while (c->delete_list) { + struct jffs_delete_list *delete_list_element; + delete_list_element = c->delete_list; + c->delete_list = c->delete_list->next; + kfree(delete_list_element); + } + + /* Free all files and nodes. */ + if (c->hash) { + jffs_foreach_file(c, jffs_free_node_list); + jffs_foreach_file(c, jffs_free_file); + 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; + } + no_jffs_file++; + if (!(node = jffs_alloc_node())) { + kfree(root); + 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 = get_seconds(); + 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))) { + return -ENOMEM; + } + c->building_fs = 1; + c->sb = sb; + if ((err = jffs_scan_flash(c)) < 0) { + if(err == -EAGAIN){ + /* scan_flash() wants us to try once more. A flipping + bits sector was detect in the middle of the scan flash. + Clean up old allocated memory before going in. + */ + D1(printk("jffs_build_fs: Cleaning up all control structures," + " reallocating them and trying mount again.\n")); + jffs_cleanup_control(c); + if (!(c = jffs_create_control(sb))) { + return -ENOMEM; + } + c->building_fs = 1; + c->sb = sb; + + if ((err = jffs_scan_flash(c)) < 0) { + goto jffs_build_fs_fail; + } + }else{ + 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; + } + } + + while (c->delete_list) { + struct jffs_file *f; + struct jffs_delete_list *delete_list_element; + + if ((f = jffs_find_file(c, c->delete_list->ino))) { + f->deleted = 1; + } + delete_list_element = c->delete_list; + c->delete_list = c->delete_list->next; + kfree(delete_list_element); + } + + /* 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->s_fs_info = (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() */ + + +/* + This checks for sectors that were being erased in their previous + lifetimes and for some reason or the other (power fail etc.), + the erase cycles never completed. + As the flash array would have reverted back to read status, + these sectors are detected by the symptom of the "flipping bits", + i.e. bits being read back differently from the same location in + flash if read multiple times. + The only solution to this is to re-erase the entire + sector. + Unfortunately detecting "flipping bits" is not a simple exercise + as a bit may be read back at 1 or 0 depending on the alignment + of the stars in the universe. + The level of confidence is in direct proportion to the number of + scans done. By power fail testing I (Vipin) have been able to + proove that reading twice is not enough. + Maybe 4 times? Change NUM_REREADS to a higher number if you want + a (even) higher degree of confidence in your mount process. + A higher number would of course slow down your mount. +*/ +static int check_partly_erased_sectors(struct jffs_fmcontrol *fmc){ + +#define NUM_REREADS 4 /* see note above */ +#define READ_AHEAD_BYTES 4096 /* must be a multiple of 4, + usually set to kernel page size */ + + __u8 *read_buf1; + __u8 *read_buf2; + + int err = 0; + int retlen; + int i; + int cnt; + __u32 offset; + loff_t pos = 0; + loff_t end = fmc->flash_size; + + + /* Allocate read buffers */ + read_buf1 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL); + if (!read_buf1) + return -ENOMEM; + + read_buf2 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL); + if (!read_buf2) { + kfree(read_buf1); + return -ENOMEM; + } + + CHECK_NEXT: + while(pos < end){ + + D1(printk("check_partly_erased_sector():checking sector which contains" + " offset 0x%x for flipping bits..\n", (__u32)pos)); + + retlen = flash_safe_read(fmc->mtd, pos, + &read_buf1[0], READ_AHEAD_BYTES); + retlen &= ~3; + + for(cnt = 0; cnt < NUM_REREADS; cnt++){ + (void)flash_safe_read(fmc->mtd, pos, + &read_buf2[0], READ_AHEAD_BYTES); + + for (i=0 ; i < retlen ; i+=4) { + /* buffers MUST match, double word for word! */ + if(*((__u32 *) &read_buf1[i]) != + *((__u32 *) &read_buf2[i]) + ){ + /* flipping bits detected, time to erase sector */ + /* This will help us log some statistics etc. */ + D1(printk("Flipping bits detected in re-read round:%i of %i\n", + cnt, NUM_REREADS)); + D1(printk("check_partly_erased_sectors:flipping bits detected" + " @offset:0x%x(0x%x!=0x%x)\n", + (__u32)pos+i, *((__u32 *) &read_buf1[i]), + *((__u32 *) &read_buf2[i]))); + + /* calculate start of present sector */ + offset = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size; + + D1(printk("check_partly_erased_sector():erasing sector starting 0x%x.\n", + offset)); + + if (flash_erase_region(fmc->mtd, + offset, fmc->sector_size) < 0) { + printk(KERN_ERR "JFFS: Erase of flash failed. " + "offset = %u, erase_size = %d\n", + offset , fmc->sector_size); + + err = -EIO; + goto returnBack; + + }else{ + D1(printk("JFFS: Erase of flash sector @0x%x successful.\n", + offset)); + /* skip ahead to the next sector */ + pos = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size; + pos += fmc->sector_size; + goto CHECK_NEXT; + } + } + } + } + pos += READ_AHEAD_BYTES; + } + + returnBack: + kfree(read_buf1); + kfree(read_buf2); + + D2(printk("check_partly_erased_sector():Done checking all sectors till offset 0x%x for flipping bits.\n", + (__u32)pos)); + + return err; + +}/* end check_partly_erased_sectors() */ + + + +/* 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 = NULL; + struct jffs_fmcontrol *fmc = c->fmc; + __u32 checksum; + __u8 tmp_accurate; + __u16 tmp_chksum; + __u32 deleted_file; + loff_t pos = 0; + loff_t start; + loff_t test_start; + loff_t end = fmc->flash_size; + __u8 *read_buf; + int i, len, retlen; + __u32 offset; + + __u32 free_chunk_size1; + __u32 free_chunk_size2; + + +#define NUMFREEALLOWED 2 /* 2 chunks of at least erase size space allowed */ + int num_free_space = 0; /* Flag err if more than TWO + free blocks found. This is NOT allowed + by the current jffs design. + */ + int num_free_spc_not_accp = 0; /* For debugging purposed keep count + of how much free space was rejected and + marked dirty + */ + + D1(printk("jffs_scan_flash(): start pos = 0x%lx, end = 0x%lx\n", + (long)pos, (long)end)); + + flash_safe_acquire(fmc->mtd); + + /* + check and make sure that any sector does not suffer + from the "partly erased, bit flipping syndrome" (TM Vipin :) + If so, offending sectors will be erased. + */ + if(check_partly_erased_sectors(fmc) < 0){ + + flash_safe_release(fmc->mtd); + return -EIO; /* bad, bad, bad error. Cannot continue.*/ + } + + /* Allocate read buffer */ + read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL); + if (!read_buf) { + flash_safe_release(fmc->mtd); + return -ENOMEM; + } + + /* Start the scan. */ + while (pos < end) { + deleted_file = 0; + + /* 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 0xffffffff at this position. We have to + scan the rest of the flash till the end or till + something else than 0xffffffff is found. + Keep going till we do not find JFFS_EMPTY_BITMASK + anymore */ + + D1(printk("jffs_scan_flash(): 0xffffffff at pos 0x%lx.\n", + (long)pos)); + + while(pos < end){ + + len = end - pos < 4096 ? end - pos : 4096; + + retlen = flash_safe_read(fmc->mtd, pos, + &read_buf[0], len); + + retlen &= ~3; + + for (i=0 ; i < retlen ; i+=4, pos += 4) { + if(*((__u32 *) &read_buf[i]) != + JFFS_EMPTY_BITMASK) + break; + } + if (i == retlen) + continue; + else + break; + } + + D1(printk("jffs_scan_flash():0xffffffff ended at pos 0x%lx.\n", + (long)pos)); + + /* If some free space ends in the middle of a sector, + treat it as dirty rather than clean. + This is to handle the case where one thread + allocated space for a node, but didn't get to + actually _write_ it before power was lost, leaving + a gap in the log. Shifting all node writes into + a single kernel thread will fix the original problem. + */ + if ((__u32) pos % fmc->sector_size) { + /* If there was free space in previous + sectors, don't mark that dirty too - + only from the beginning of this sector + (or from start) + */ + + test_start = pos & ~(fmc->sector_size-1); /* end of last sector */ + + if (start < test_start) { + + /* free space started in the previous sector! */ + + if((num_free_space < NUMFREEALLOWED) && + ((unsigned int)(test_start - start) >= fmc->sector_size)){ + + /* + Count it in if we are still under NUMFREEALLOWED *and* it is + at least 1 erase sector in length. This will keep us from + picking any little ole' space as "free". + */ + + D1(printk("Reducing end of free space to 0x%x from 0x%x\n", + (unsigned int)test_start, (unsigned int)pos)); + + D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n", + (unsigned int) start, + (unsigned int)(test_start - start))); + + /* below, space from "start" to "pos" will be marked dirty. */ + start = test_start; + + /* Being in here means that we have found at least an entire + erase sector size of free space ending on a sector boundary. + Keep track of free spaces accepted. + */ + num_free_space++; + }else{ + num_free_spc_not_accp++; + D1(printk("Free space (#%i) found but *Not* accepted: Starting" + " 0x%x for 0x%x bytes\n", + num_free_spc_not_accp, (unsigned int)start, + (unsigned int)((unsigned int)(pos & ~(fmc->sector_size-1)) - (unsigned int)start))); + + } + + } + if((((__u32)(pos - start)) != 0)){ + + D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n", + (unsigned int) start, (unsigned int) (pos - start))); + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), NULL); + }else{ + /* "Flipping bits" detected. This means that our scan for them + did not catch this offset. See check_partly_erased_sectors() for + more info. + */ + + D1(printk("jffs_scan_flash():wants to allocate dirty flash " + "space for 0 bytes.\n")); + D1(printk("jffs_scan_flash(): Flipping bits! We will free " + "all allocated memory, erase this sector and remount\n")); + + /* calculate start of present sector */ + offset = (((__u32)pos)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size; + + D1(printk("jffs_scan_flash():erasing sector starting 0x%x.\n", + offset)); + + if (flash_erase_region(fmc->mtd, + offset, fmc->sector_size) < 0) { + printk(KERN_ERR "JFFS: Erase of flash failed. " + "offset = %u, erase_size = %d\n", + offset , fmc->sector_size); + + flash_safe_release(fmc->mtd); + kfree (read_buf); + return -1; /* bad, bad, bad! */ + + } + flash_safe_release(fmc->mtd); + kfree (read_buf); + + return -EAGAIN; /* erased offending sector. Try mount one more time please. */ + } + }else{ + /* Being in here means that we have found free space that ends on an erase sector + boundary. + Count it in if we are still under NUMFREEALLOWED *and* it is at least 1 erase + sector in length. This will keep us from picking any little ole' space as "free". + */ + if((num_free_space < NUMFREEALLOWED) && + ((unsigned int)(pos - start) >= fmc->sector_size)){ + /* We really don't do anything to mark space as free, except *not* + mark it dirty and just advance the "pos" location pointer. + It will automatically be picked up as free space. + */ + num_free_space++; + D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n", + (unsigned int) start, (unsigned int) (pos - start))); + }else{ + num_free_spc_not_accp++; + D1(printk("Free space (#%i) found but *Not* accepted: Starting " + "0x%x for 0x%x bytes\n", num_free_spc_not_accp, + (unsigned int) start, + (unsigned int) (pos - start))); + + /* Mark this space as dirty. We already have our free space. */ + D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n", + (unsigned int) start, (unsigned int) (pos - start))); + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), NULL); + } + + } + if(num_free_space > NUMFREEALLOWED){ + printk(KERN_WARNING "jffs_scan_flash(): Found free space " + "number %i. Only %i free space is allowed.\n", + num_free_space, NUMFREEALLOWED); + } + continue; + + case JFFS_DIRTY_BITMASK: + /* We have found 0x00000000 at this position. Scan as far + as possible to find out how much is dirty. */ + D1(printk("jffs_scan_flash(): 0x00000000 at pos 0x%lx.\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%lx.\n", (long)pos)); + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), NULL); + 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%lx, 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: + case JFFS_EMPTY_BITMASK: + /* handle these in the main switch() loop */ + goto cont_scan; + + default: + break; + } + } + + cont_scan: + /* First, mark as dirty the region + which really does contain crap. */ + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), + NULL); + + continue; + }/* switch */ + + /* We have found the beginning of an inode. Create a + node for it unless there already is one available. */ + if (!node) { + if (!(node = jffs_alloc_node())) { + /* Free read buffer */ + kfree (read_buf); + + /* Release the flash device */ + 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%lx " + "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), NULL); + /* 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) { + printk(KERN_WARNING "jffs_scan_flash: Found a " + "JFFS node with name too large\n"); + goto bad_inode; + } + + if (raw_inode.rename && raw_inode.dsize != sizeof(__u32)) { + printk(KERN_WARNING "jffs_scan_flash: Found a " + "rename node with dsize %u.\n", + raw_inode.dsize); + jffs_print_raw_inode(&raw_inode); + goto bad_inode; + } + + /* The node's data segment should not exceed a + certain length. */ + if (raw_inode.dsize > fmc->max_chunk_size) { + printk(KERN_WARNING "jffs_scan_flash: Found a " + "JFFS node with dsize (0x%x) > max_chunk_size (0x%x)\n", + 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), NULL); + /* Reuse this unused struct jffs_node. */ + continue; + } + if (pos >= end) { + goto check_node; + } + } + + /* Read the data, if it exists, in order to be sure it + matches the checksum. */ + if (raw_inode.dsize) { + if (raw_inode.rename) { + deleted_file = flash_read_u32(fmc->mtd, pos); + } + if (jffs_checksum_flash(fmc->mtd, pos, raw_inode.dsize, &checksum)) { + printk("jffs_checksum_flash() failed to calculate a checksum\n"); + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), NULL); + /* Reuse this unused struct jffs_node. */ + continue; + } + 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), NULL); + /* 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")); + jffs_free_node(node); + DJM(no_jffs_node--); + + /* Free read buffer */ + kfree (read_buf); + + /* Release the flash device */ + flash_safe_release(fmc->mtd); + + return -ENOMEM; + } + if ((err = jffs_insert_node(c, NULL, &raw_inode, + name, node)) < 0) { + printk("JFFS: Failed to handle raw inode. " + "(err = %d)\n", err); + break; + } + if (raw_inode.rename) { + struct jffs_delete_list *dl + = (struct jffs_delete_list *) + kmalloc(sizeof(struct jffs_delete_list), + GFP_KERNEL); + if (!dl) { + D(printk("jffs_scan_flash: !dl\n")); + jffs_free_node(node); + DJM(no_jffs_node--); + + /* Release the flash device */ + flash_safe_release(fmc->flash_part); + + /* Free read buffer */ + kfree (read_buf); + + return -ENOMEM; + } + dl->ino = deleted_file; + dl->next = c->delete_list; + c->delete_list = dl; + node->data_size = 0; + } + D3(jffs_print_node(node)); + node = NULL; /* Don't free the node! */ + } + else { + jffs_fmalloced(fmc, (__u32) start, + (__u32) (pos - start), NULL); + D3(printk("jffs_scan_flash(): Just found an obsolete " + "raw_inode. Continuing the scan...\n")); + /* Reuse this unused struct jffs_node. */ + } + } + + if (node) { + jffs_free_node(node); + DJM(no_jffs_node--); + } + jffs_build_end(fmc); + + /* Free read buffer */ + kfree (read_buf); + + if(!num_free_space){ + printk(KERN_WARNING "jffs_scan_flash(): Did not find even a single " + "chunk of free space. This is BAD!\n"); + } + + /* Return happy */ + D3(printk("jffs_scan_flash(): Leaving...\n")); + flash_safe_release(fmc->mtd); + + /* This is to trap the "free size accounting screwed error. */ + free_chunk_size1 = jffs_free_size1(fmc); + free_chunk_size2 = jffs_free_size2(fmc); + + if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) { + + printk(KERN_WARNING "jffs_scan_falsh():Free size accounting screwed\n"); + printk(KERN_WARNING "jfffs_scan_flash():free_chunk_size1 == 0x%x, " + "free_chunk_size2 == 0x%x, fmc->free_size == 0x%x\n", + free_chunk_size1, free_chunk_size2, fmc->free_size); + + return -1; /* Do NOT mount f/s so that we can inspect what happened. + Mounting this screwed up f/s will screw us up anyway. + */ + } + + return 0; /* as far as we are concerned, we are happy! */ +} /* 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\", deleted = %d\n", + raw_inode->ino, raw_inode->version, + ((name && *name) ? name : ""), raw_inode->deleted)); + + /* 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 = NULL; + node->version_next = NULL; + 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; + } + else if ((f->highest_version < node->version) + || (node->version == 0)) { + /* Insert at the end of the list. I.e. this node is the + newest one so far. */ + node->version_prev = f->version_tail; + node->version_next = NULL; + 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; + } + else if (f->version_head->version > node->version) { + /* Insert at the bottom of the list. */ + node->version_prev = NULL; + node->version_next = f->version_head; + f->version_head->version_prev = node; + f->version_head = node; + if (!f->name) { + update_name = 1; + } + } + 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; + } + } + } + + /* Deletion is irreversible. If any 'deleted' node is ever + written, the file is deleted */ + if (raw_inode->deleted) + f->deleted = raw_inode->deleted; + + /* 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); + } + /* Once upon a time, we would call jffs_possibly_delete_file() + here. That causes an oops if someone's still got the file + open, so now we only do it in jffs_delete_inode() + -- dwmw2 + */ + if (node->data_size || node->removed_size) { + jffs_update_file(f, node); + } + jffs_remove_redundant_nodes(f); + + jffs_garbage_collect_trigger(c); + + 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. */ +static 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); + jffs_free_node(cur); + DJM(no_jffs_node--); + } + else { + node_with_name_later |= (mod_type & JFFS_MODIFY_NAME); + } + } + + return 0; +} + + +/* Insert a file into the hash table. */ +static 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 = NULL; + f->sibling_prev = NULL; + f->sibling_next = NULL; + 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 = NULL; + parent->children = f; + return 0; +} + + +/* Remove a file from the hash table. */ +static 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->deleted && 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, + int recoverable, + struct jffs_file *f) +{ + struct jffs_fmcontrol *fmc = c->fmc; + struct jffs_fm *fm; + struct kvec node_iovec[4]; + unsigned long iovec_cnt; + + __u32 pos; + int err; + __u32 slack = 0; + + __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; + + /* If this node isn't something that will eventually let + GC free even more space, then don't allow it unless + there's at least max_chunk_size space still available + */ + if (!recoverable) + slack = fmc->max_chunk_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, " + "total_size = %u\n", + (name ? name : ""), raw_inode->ino, + total_size)); + + jffs_fm_write_lock(fmc); + +retry: + fm = NULL; + err = 0; + while (!fm) { + + /* Deadlocks suck. */ + while(fmc->free_size < fmc->min_free_size + total_size + slack) { + jffs_fm_write_unlock(fmc); + if (!JFFS_ENOUGH_SPACE(c, total_size + slack)) + return -ENOSPC; + jffs_fm_write_lock(fmc); + } + + /* First try to allocate some flash memory. */ + err = jffs_fmalloc(fmc, total_size, node, &fm); + + if (err == -ENOSPC) { + /* Just out of space. GC and try again */ + if (fmc->dirty_size < fmc->sector_size) { + D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) " + "failed, no dirty space to GC\n", fmc, + total_size)); + return err; + } + + D1(printk(KERN_INFO "jffs_write_node(): Calling jffs_garbage_collect_now()\n")); + jffs_fm_write_unlock(fmc); + if ((err = jffs_garbage_collect_now(c))) { + D(printk("jffs_write_node(): jffs_garbage_collect_now() failed\n")); + return err; + } + jffs_fm_write_lock(fmc); + continue; + } + + if (err < 0) { + jffs_fm_write_unlock(fmc); + + D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) " + "failed!\n", fmc, total_size)); + return err; + } + + if (!fm->nodes) { + /* The jffs_fm struct that we got is not good enough. + Make that space dirty and try again */ + if ((err = jffs_write_dummy_node(c, fm)) < 0) { + kfree(fm); + DJM(no_jffs_fm--); + jffs_fm_write_unlock(fmc); + D(printk("jffs_write_node(): " + "jffs_write_dummy_node(): Failed!\n")); + return err; + } + fm = NULL; + } + } /* while(!fm) */ + node->fm = fm; + + ASSERT(if (fm->nodes == 0) { + printk(KERN_ERR "jffs_write_node(): fm->nodes == 0\n"); + }); + + pos = node->fm->offset; + + /* Increment the version number here. We can't let the caller + set it beforehand, because we might have had to do GC on a node + of this file - and we'd end up reusing version numbers. + */ + if (f) { + raw_inode->version = f->highest_version + 1; + D1(printk (KERN_NOTICE "jffs_write_node(): setting version of %s to %d\n", f->name, raw_inode->version)); + + /* if the file was deleted, set the deleted bit in the raw inode */ + if (f->deleted) + raw_inode->deleted = 1; + } + + /* 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%lx:\n", (long)pos)); + D3(jffs_print_raw_inode(raw_inode)); + + /* The actual raw JFFS node */ + node_iovec[0].iov_base = (void *) raw_inode; + node_iovec[0].iov_len = (size_t) sizeof(struct jffs_raw_inode); + iovec_cnt = 1; + + /* Get name and size if there is one */ + if (raw_inode->nsize) { + node_iovec[iovec_cnt].iov_base = (void *) name; + node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->nsize; + iovec_cnt++; + + if (JFFS_GET_PAD_BYTES(raw_inode->nsize)) { + static char allff[3]={255,255,255}; + /* Add some extra padding if necessary */ + node_iovec[iovec_cnt].iov_base = allff; + node_iovec[iovec_cnt].iov_len = + JFFS_GET_PAD_BYTES(raw_inode->nsize); + iovec_cnt++; + } + } + + /* Get data and size if there is any */ + if (raw_inode->dsize) { + node_iovec[iovec_cnt].iov_base = (void *) data; + node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->dsize; + iovec_cnt++; + /* No need to pad this because we're not actually putting + anything after it. + */ + } + + if ((err = flash_safe_writev(fmc->mtd, node_iovec, iovec_cnt, + pos)) < 0) { + jffs_fmfree_partly(fmc, fm, 0); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_write_node: Failed to write, " + "requested %i, wrote %i\n", total_size, err); + goto retry; + } + if (raw_inode->deleted) + f->deleted = 1; + + jffs_fm_write_unlock(fmc); + 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, + unsigned char *buf,__u32 node_offset, __u32 max_size) +{ + 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 = min(avail, max_size); + D3(printk(KERN_NOTICE "jffs_get_node_data\n")); + 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, unsigned 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. */ + + D2(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 = 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)) < 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 nodes associated with a file. */ +static 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; + jffs_free_node(p); + DJM(no_jffs_node--); + } + return 0; +} + + +/* Free a file and its name. */ +static int +jffs_free_file(struct jffs_file *f) +{ + D3(printk("jffs_free_file: f #%u, \"%s\"\n", + f->ino, (f->name ? f->name : ""))); + + if (f->name) { + kfree(f->name); + DJM(no_name--); + } + kfree(f); + no_jffs_file--; + return 0; +} + +static long +jffs_get_file_count(void) +{ + return no_jffs_file; +} + +/* 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. Commence with + the oldest node. */ + 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. */ + if (!f->c->building_fs) { + jffs_unlink_file_from_tree(f); + } + jffs_unlink_file_from_hash(f); + jffs_free_node_list(f); + jffs_free_file(f); + } + 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. */ +static 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 int +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 0; + } + + /* 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 0; + } + + 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 = jffs_alloc_node())) { + D(printk("jffs_delete_data(): -ENOMEM\n")); + return -ENOMEM; + } + 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 + (remove_size + (offset - n->data_offset)); + 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; + if (new_node->fm) + jffs_add_node(new_node); + else { + D1(printk(KERN_WARNING "jffs_delete_data(): Splitting an empty node (file hold).\n!")); + D1(printk(KERN_WARNING "FIXME: Did dwmw2 do the right thing here?\n")); + } + 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 = 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%s\n", + p->ino, p->version, + (p->fm ? "" : " (virtual)"))); + 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); + jffs_free_node(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; + } + + if (node->removed_size > (f->size - node->data_offset)) { + /* It's possible that the removed_size is in fact + * greater than the amount of data we actually thought + * were present in the first place - some of the nodes + * which this node originally obsoleted may already have + * been deleted from the flash by subsequent garbage + * collection. + * + * If this is the case, don't let f->size go negative. + * Bad things would happen :) + */ + f->size = node->data_offset; + } else { + f->size -= node->removed_size; + } + D3(printk("jffs_delete_data(): f->size = %d\n", f->size)); + return 0; +} /* jffs_delete_data() */ + + +/* Insert some data into a file. Prior to the call to this function, + jffs_delete_data should be called. */ +static int +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. */ + retry: + if (node->data_offset == f->size) { + /* A simple append. This is the most common operation. */ + node->range_next = NULL; + 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) { + D2(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 -1; + }); + } + + /* 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) { + /* Okay. This is tricky. This means that we want to insert + data at a place that is beyond the limits of the file as + it is constructed right now. This is actually a common + event that for instance could occur during the mounting + of the file system if a large file have been truncated, + rewritten and then only partially garbage collected. */ + + struct jffs_node *n; + + /* We need a place holder for the data that is missing in + front of this insertion. This "virtual node" will not + be associated with any space on the flash device. */ + struct jffs_node *virtual_node; + if (!(virtual_node = jffs_alloc_node())) { + return -ENOMEM; + } + + D(printk("jffs_insert_data: Inserting a virtual node.\n")); + D(printk(" node->data_offset = %u\n", node->data_offset)); + D(printk(" f->size = %u\n", f->size)); + + virtual_node->ino = node->ino; + virtual_node->version = node->version; + virtual_node->removed_size = 0; + virtual_node->fm_offset = 0; + virtual_node->name_size = 0; + virtual_node->fm = NULL; /* This is a virtual data holder. */ + virtual_node->version_prev = NULL; + virtual_node->version_next = NULL; + virtual_node->range_next = NULL; + + /* Are there any data at all in the file yet? */ + if (f->range_head) { + virtual_node->data_offset + = f->range_tail->data_offset + + f->range_tail->data_size; + virtual_node->data_size + = node->data_offset - virtual_node->data_offset; + virtual_node->range_prev = f->range_tail; + f->range_tail->range_next = virtual_node; + } + else { + virtual_node->data_offset = 0; + virtual_node->data_size = node->data_offset; + virtual_node->range_prev = NULL; + f->range_head = virtual_node; + } + + f->range_tail = virtual_node; + f->size += virtual_node->data_size; + + /* Insert this virtual node in the version list as well. */ + for (n = f->version_head; n ; n = n->version_next) { + if (n->version == virtual_node->version) { + virtual_node->version_prev = n->version_prev; + n->version_prev = virtual_node; + if (virtual_node->version_prev) { + virtual_node->version_prev + ->version_next = virtual_node; + } + else { + f->version_head = virtual_node; + } + virtual_node->version_next = n; + break; + } + } + + D(jffs_print_node(virtual_node)); + + /* Make a new try to insert the node. */ + goto retry; + } + + D3(printk("jffs_insert_data(): f->size = %d\n", f->size)); + return 0; +} + + +/* 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) +{ + int err; + + 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 */ + if ((err = jffs_delete_data(f, node)) < 0) { + return err; + } + } + } + else { + /* data_offset == X */ + /* data_size != 0 */ + /* remove_size == Y */ + if ((err = jffs_delete_data(f, node)) < 0) { + return err; + } + if ((err = jffs_insert_data(f, node)) < 0) { + return err; + } + } + 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 ? n->fm->offset : 0))); + 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. */ +#if 0 +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; +} +#endif /* 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; + int dir; + + 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) { + dir = S_ISDIR(f->mode); + printk("%s%s%s (ino: %u, highest_version: %u, size: %u)\n", + space, (f->name ? f->name : ""), (dir ? "/" : ""), + f->ino, f->highest_version, f->size); + if (dir) { + 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; + 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'. */ +static int +jffs_rewrite_data(struct jffs_file *f, struct jffs_node *node, __u32 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 : "(null)"), size)); + + /* Create and initialize the new node. */ + if (!(new_node = jffs_alloc_node())) { + 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->removed_size = size; + total_name_size = JFFS_PAD(f->nsize); + total_data_size = JFFS_PAD(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; + +retry: + jffs_fm_write_lock(fmc); + err = 0; + + if ((err = jffs_fmalloc(fmc, total_size, new_node, &fm)) < 0) { + DJM(no_jffs_node--); + jffs_fm_write_unlock(fmc); + D(printk("jffs_rewrite_data(): Failed to allocate fm.\n")); + jffs_free_node(new_node); + return err; + } + else if (!fm->nodes) { + /* The jffs_fm struct that we got is not big enough. */ + /* This should never happen, because we deal with this case + in jffs_garbage_collect_next().*/ + printk(KERN_WARNING "jffs_rewrite_data(): Allocated node is too small (%d bytes of %d)\n", fm->size, total_size); + if ((err = jffs_write_dummy_node(c, fm)) < 0) { + D(printk("jffs_rewrite_data(): " + "jffs_write_dummy_node() Failed!\n")); + } else { + err = -ENOSPC; + } + DJM(no_jffs_fm--); + jffs_fm_write_unlock(fmc); + kfree(fm); + + return err; + } + new_node->fm = fm; + + /* 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 = f->deleted; + 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) { + jffs_fmfree_partly(fmc, fm, + total_name_size + total_data_size); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during " + "rewrite. (raw inode)\n"); + printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying " + "rewrite. (raw inode)\n"); + goto retry; + } + 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, (unsigned int) pos)); + if ((err = flash_safe_write(fmc->mtd, pos, + (u_char *)f->name, + f->nsize)) < 0) { + jffs_fmfree_partly(fmc, fm, total_data_size); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_rewrite_data: Write " + "error during rewrite. (name)\n"); + printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying " + "rewrite. (name)\n"); + goto retry; + } + 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 = min(size, (__u32)PAGE_SIZE); + if ((r = jffs_read_data(f, (char *)page, + offset, s)) < s) { + free_page((unsigned long)page); + jffs_fmfree_partly(fmc, fm, 0); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_rewrite_data: " + "jffs_read_data() " + "failed! (r = %d)\n", r); + return -1; + } + if ((err = flash_safe_write(fmc->mtd, + pos, page, r)) < 0) { + free_page((unsigned long)page); + jffs_fmfree_partly(fmc, fm, 0); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_rewrite_data: " + "Write error during rewrite. " + "(data)\n"); + goto retry; + } + 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) { + jffs_fmfree_partly(fmc, fm, 0); + jffs_fm_write_unlock(fmc); + printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during " + "rewrite. (checksum)\n"); + goto retry; + } + + /* Now make the file system aware of the newly written node. */ + jffs_insert_node(c, f, &raw_inode, f->name, new_node); + jffs_fm_write_unlock(fmc); + + 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. */ + +static int +jffs_garbage_collect_next(struct jffs_control *c) +{ + struct jffs_fmcontrol *fmc = c->fmc; + struct jffs_node *node; + struct jffs_file *f; + int err = 0; + __u32 size; + __u32 data_size; + __u32 total_name_size; + __u32 extra_available; + __u32 space_needed; + __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"); + err = -1; + goto jffs_garbage_collect_next_end; + + + }); + + /* Find its corresponding file too. */ + f = jffs_find_file(c, node->ino); + + if (!f) { + printk (KERN_ERR "JFFS: jffs_garbage_collect_next: " + "No file to garbage collect! " + "(ino = 0x%08x)\n", node->ino); + /* FIXME: Free the offending node and recover. */ + err = -1; + goto jffs_garbage_collect_next_end; + } + + /* We always write out the name. Theoretically, we don't need + to, but for now it's easier - because otherwise we'd have + to keep track of how many times the current name exists on + the flash and make sure it never reaches zero. + + The current approach means that would be possible to cause + the GC to end up eating its tail by writing lots of nodes + with no name for it to garbage-collect. Hence the change in + inode.c to write names with _every_ node. + + It sucks, but it _should_ work. + */ + total_name_size = JFFS_PAD(f->nsize); + + D1(printk("jffs_garbage_collect_next(): \"%s\", " + "ino: %u, version: %u, location 0x%x, dsize %u\n", + (f->name ? f->name : ""), node->ino, node->version, + node->fm->offset, node->data_size)); + + /* Compute how many data it's possible to rewrite at the moment. */ + data_size = f->size - node->data_offset; + + /* And from that, the total size of the chunk we want to write */ + size = sizeof(struct jffs_raw_inode) + total_name_size + + data_size + JFFS_GET_PAD_BYTES(data_size); + + /* If that's more than max_chunk_size, reduce it accordingly */ + if (size > fmc->max_chunk_size) { + size = fmc->max_chunk_size; + data_size = size - sizeof(struct jffs_raw_inode) + - total_name_size; + } + + /* If we're asking to take up more space than free_chunk_size1 + but we _could_ fit in it, shrink accordingly. + */ + if (size > free_chunk_size1) { + + if (free_chunk_size1 < + (sizeof(struct jffs_raw_inode) + total_name_size + 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"); + err = -1; + goto jffs_garbage_collect_next_end; + } + D1(printk("Dirtying end of flash - too small\n")); + jffs_write_dummy_node(c, dirty_fm); + err = 0; + goto jffs_garbage_collect_next_end; + } + D1(printk("Reducing size of new node from %d to %d to avoid " + " exceeding free_chunk_size1\n", + size, free_chunk_size1)); + + size = free_chunk_size1; + data_size = size - sizeof(struct jffs_raw_inode) + - total_name_size; + } + + + /* Calculate the amount of space needed to hold the nodes + which are remaining in the tail */ + space_needed = fmc->min_free_size - (node->fm->offset % fmc->sector_size); + + /* From that, calculate how much 'extra' space we can use to + increase the size of the node we're writing from the size + of the node we're obsoleting + */ + if (space_needed > fmc->free_size) { + /* If we've gone below min_free_size for some reason, + don't fuck up. This is why we have + min_free_size > sector_size. Whinge about it though, + just so I can convince myself my maths is right. + */ + D1(printk(KERN_WARNING "jffs_garbage_collect_next(): " + "space_needed %d exceeded free_size %d\n", + space_needed, fmc->free_size)); + extra_available = 0; + } else { + extra_available = fmc->free_size - space_needed; + } + + /* Check that we don't use up any more 'extra' space than + what's available */ + if (size > JFFS_PAD(node->data_size) + total_name_size + + sizeof(struct jffs_raw_inode) + extra_available) { + D1(printk("Reducing size of new node from %d to %ld to avoid " + "catching our tail\n", size, + (long) (JFFS_PAD(node->data_size) + JFFS_PAD(node->name_size) + + sizeof(struct jffs_raw_inode) + extra_available))); + D1(printk("space_needed = %d, extra_available = %d\n", + space_needed, extra_available)); + + size = JFFS_PAD(node->data_size) + total_name_size + + sizeof(struct jffs_raw_inode) + extra_available; + data_size = size - sizeof(struct jffs_raw_inode) + - total_name_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(" node->data_offset: %u\n", node->data_offset)); + D2(printk(" free_chunk_size1: %u\n", free_chunk_size1)); + D2(printk(" free_chunk_size2: %u\n", free_chunk_size2)); + D2(printk(" node->fm->offset: 0x%08x\n", node->fm->offset)); + + if ((err = jffs_rewrite_data(f, node, data_size))) { + printk(KERN_WARNING "jffs_rewrite_data() failed: %d\n", err); + return err; + } + +jffs_garbage_collect_next_end: + D3(printk("jffs_garbage_collect_next: Leaving...\n")); + return err; +} /* 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. (The data in the file could for instance be a JFFS image + which could cause enormous confusion during a scan of the flash + device if we didn't do this.) + 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. */ +static 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; + + /* 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(to_kdev_t(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%lx\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. */ + + +static int +jffs_garbage_collect_now(struct jffs_control *c) +{ + struct jffs_fmcontrol *fmc = c->fmc; + long erased = 0; + int result = 0; + D1(int i = 1); + D2(printk("***jffs_garbage_collect_now(): fmc->dirty_size = %u, fmc->free_size = 0x%x\n, fcs1=0x%x, fcs2=0x%x", + fmc->dirty_size, fmc->free_size, jffs_free_size1(fmc), jffs_free_size2(fmc))); + D2(jffs_print_fmcontrol(fmc)); + + // down(&fmc->gclock); + + /* If it is possible to garbage collect, do so. */ + + while (erased == 0) { + D1(printk("***jffs_garbage_collect_now(): round #%u, " + "fmc->dirty_size = %u\n", i++, fmc->dirty_size)); + D2(jffs_print_fmcontrol(fmc)); + + if ((erased = jffs_try_to_erase(c)) < 0) { + printk(KERN_WARNING "JFFS: Error in " + "garbage collector.\n"); + result = erased; + goto gc_end; + } + if (erased) + break; + + if (fmc->free_size == 0) { + /* Argh */ + printk(KERN_ERR "jffs_garbage_collect_now(): free_size == 0. This is BAD.\n"); + result = -ENOSPC; + break; + } + + if (fmc->dirty_size < fmc->sector_size) { + /* Actually, we _may_ have been able to free some, + * if there are many overlapping nodes which aren't + * actually marked dirty because they still have + * some valid data in each. + */ + result = -ENOSPC; + break; + } + + /* 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; + } + + D1(printk(" jffs_garbage_collect_now(): erased: %ld\n", erased)); + DJM(jffs_print_memory_allocation_statistics()); + } + +gc_end: + // up(&fmc->gclock); + + D3(printk(" jffs_garbage_collect_now(): Leaving...\n")); + D1(if (erased) { + printk("jffs_g_c_now(): erased = %ld\n", erased); + jffs_print_fmcontrol(fmc); + }); + + if (!erased && !result) + return -ENOSPC; + + return result; +} /* jffs_garbage_collect_now() */ + + +/* Determine if it is reasonable to start garbage collection. + We start a gc pass if either: + - The number of free bytes < MIN_FREE_BYTES && at least one + block is dirty, OR + - The number of dirty bytes > MAX_DIRTY_BYTES +*/ +static inline int thread_should_wake (struct jffs_control *c) +{ + D1(printk (KERN_NOTICE "thread_should_wake(): free=%d, dirty=%d, blocksize=%d.\n", + c->fmc->free_size, c->fmc->dirty_size, c->fmc->sector_size)); + + /* If there's not enough dirty space to free a block, there's no point. */ + if (c->fmc->dirty_size < c->fmc->sector_size) { + D2(printk(KERN_NOTICE "thread_should_wake(): Not waking. Insufficient dirty space\n")); + return 0; + } +#if 1 + /* If there is too much RAM used by the various structures, GC */ + if (jffs_get_node_inuse() > (c->fmc->used_size/c->fmc->max_chunk_size * 5 + jffs_get_file_count() * 2 + 50)) { + /* FIXME: Provide proof that this test can be satisfied. We + don't want a filesystem doing endless GC just because this + condition cannot ever be false. + */ + D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to number of nodes\n")); + return 1; + } +#endif + /* If there are fewer free bytes than the threshold, GC */ + if (c->fmc->free_size < c->gc_minfree_threshold) { + D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to insufficent free space\n")); + return 1; + } + /* If there are more dirty bytes than the threshold, GC */ + if (c->fmc->dirty_size > c->gc_maxdirty_threshold) { + D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to excessive dirty space\n")); + return 1; + } + /* FIXME: What about the "There are many versions of a node" condition? */ + + return 0; +} + + +void jffs_garbage_collect_trigger(struct jffs_control *c) +{ + /* NOTE: We rely on the fact that we have the BKL here. + * Otherwise, the gc_task could go away between the check + * and the wake_up_process() + */ + if (c->gc_task && thread_should_wake(c)) + send_sig(SIGHUP, c->gc_task, 1); +} + + +/* Kernel threads take (void *) as arguments. Thus we pass + the jffs_control data as a (void *) and then cast it. */ +int +jffs_garbage_collect_thread(void *ptr) +{ + struct jffs_control *c = (struct jffs_control *) ptr; + struct jffs_fmcontrol *fmc = c->fmc; + long erased; + int result = 0; + D1(int i = 1); + + daemonize("jffs_gcd"); + + c->gc_task = current; + + lock_kernel(); + init_completion(&c->gc_thread_comp); /* barrier */ + spin_lock_irq(¤t->sighand->siglock); + siginitsetinv (¤t->blocked, sigmask(SIGHUP) | sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT)); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): Starting infinite loop.\n")); + + for (;;) { + + /* See if we need to start gc. If we don't, go to sleep. + + Current implementation is a BAD THING(tm). If we try + to unmount the FS, the unmount operation will sleep waiting + for this thread to exit. We need to arrange to send it a + sig before the umount process sleeps. + */ + + if (!thread_should_wake(c)) + set_current_state (TASK_INTERRUPTIBLE); + + schedule(); /* Yes, we do this even if we want to go + on immediately - we're a low priority + background task. */ + + /* Put_super will send a SIGKILL and then wait on the sem. + */ + while (signal_pending(current)) { + siginfo_t info; + unsigned long signr = 0; + + spin_lock_irq(¤t->sighand->siglock); + signr = dequeue_signal(current, ¤t->blocked, &info); + spin_unlock_irq(¤t->sighand->siglock); + + switch(signr) { + case SIGSTOP: + D1(printk("jffs_garbage_collect_thread(): SIGSTOP received.\n")); + set_current_state(TASK_STOPPED); + schedule(); + break; + + case SIGKILL: + D1(printk("jffs_garbage_collect_thread(): SIGKILL received.\n")); + c->gc_task = NULL; + complete_and_exit(&c->gc_thread_comp, 0); + } + } + + + D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): collecting.\n")); + + D3(printk (KERN_NOTICE "g_c_thread(): down biglock\n")); + down(&fmc->biglock); + + D1(printk("***jffs_garbage_collect_thread(): round #%u, " + "fmc->dirty_size = %u\n", i++, fmc->dirty_size)); + D2(jffs_print_fmcontrol(fmc)); + + if ((erased = jffs_try_to_erase(c)) < 0) { + printk(KERN_WARNING "JFFS: Error in " + "garbage collector: %ld.\n", erased); + } + + if (erased) + goto gc_end; + + if (fmc->free_size == 0) { + /* Argh. Might as well commit suicide. */ + printk(KERN_ERR "jffs_garbage_collect_thread(): free_size == 0. This is BAD.\n"); + send_sig(SIGQUIT, c->gc_task, 1); + // panic() + goto gc_end; + } + + /* 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: %d\n", result); + } + + gc_end: + D3(printk (KERN_NOTICE "g_c_thread(): up biglock\n")); + up(&fmc->biglock); + } /* for (;;) */ +} /* jffs_garbage_collect_thread() */ |
