diff options
Diffstat (limited to 'fs/jffs/jffs_fm.c')
| -rw-r--r-- | fs/jffs/jffs_fm.c | 798 |
1 files changed, 0 insertions, 798 deletions
diff --git a/fs/jffs/jffs_fm.c b/fs/jffs/jffs_fm.c deleted file mode 100644 index 5a95fbdd6fd..00000000000 --- a/fs/jffs/jffs_fm.c +++ /dev/null @@ -1,798 +0,0 @@ -/* - * JFFS -- Journaling Flash File System, Linux implementation. - * - * Copyright (C) 1999, 2000 Axis Communications AB. - * - * 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: jffs_fm.c,v 1.27 2001/09/20 12:29:47 dwmw2 Exp $ - * - * Ported to Linux 2.3.x and MTD: - * Copyright (C) 2000 Alexander Larsson (alex@cendio.se), Cendio Systems AB - * - */ -#include <linux/slab.h> -#include <linux/err.h> -#include <linux/blkdev.h> -#include <linux/jffs.h> -#include "jffs_fm.h" -#include "intrep.h" - -#if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE -static int jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset); -#endif - -static struct jffs_fm *jffs_alloc_fm(void); -static void jffs_free_fm(struct jffs_fm *n); - -extern struct kmem_cache *fm_cache; -extern struct kmem_cache *node_cache; - -#if CONFIG_JFFS_FS_VERBOSE > 0 -void -jffs_print_fmcontrol(struct jffs_fmcontrol *fmc) -{ - D(printk("struct jffs_fmcontrol: 0x%p\n", fmc)); - D(printk("{\n")); - D(printk(" %u, /* flash_size */\n", fmc->flash_size)); - D(printk(" %u, /* used_size */\n", fmc->used_size)); - D(printk(" %u, /* dirty_size */\n", fmc->dirty_size)); - D(printk(" %u, /* free_size */\n", fmc->free_size)); - D(printk(" %u, /* sector_size */\n", fmc->sector_size)); - D(printk(" %u, /* min_free_size */\n", fmc->min_free_size)); - D(printk(" %u, /* max_chunk_size */\n", fmc->max_chunk_size)); - D(printk(" 0x%p, /* mtd */\n", fmc->mtd)); - D(printk(" 0x%p, /* head */ " - "(head->offset = 0x%08x)\n", - fmc->head, (fmc->head ? fmc->head->offset : 0))); - D(printk(" 0x%p, /* tail */ " - "(tail->offset + tail->size = 0x%08x)\n", - fmc->tail, - (fmc->tail ? fmc->tail->offset + fmc->tail->size : 0))); - D(printk(" 0x%p, /* head_extra */\n", fmc->head_extra)); - D(printk(" 0x%p, /* tail_extra */\n", fmc->tail_extra)); - D(printk("}\n")); -} -#endif /* CONFIG_JFFS_FS_VERBOSE > 0 */ - -#if CONFIG_JFFS_FS_VERBOSE > 2 -static void -jffs_print_fm(struct jffs_fm *fm) -{ - D(printk("struct jffs_fm: 0x%p\n", fm)); - D(printk("{\n")); - D(printk(" 0x%08x, /* offset */\n", fm->offset)); - D(printk(" %u, /* size */\n", fm->size)); - D(printk(" 0x%p, /* prev */\n", fm->prev)); - D(printk(" 0x%p, /* next */\n", fm->next)); - D(printk(" 0x%p, /* nodes */\n", fm->nodes)); - D(printk("}\n")); -} -#endif /* CONFIG_JFFS_FS_VERBOSE > 2 */ - -#if 0 -void -jffs_print_node_ref(struct jffs_node_ref *ref) -{ - D(printk("struct jffs_node_ref: 0x%p\n", ref)); - D(printk("{\n")); - D(printk(" 0x%p, /* node */\n", ref->node)); - D(printk(" 0x%p, /* next */\n", ref->next)); - D(printk("}\n")); -} -#endif /* 0 */ - -/* This function creates a new shiny flash memory control structure. */ -struct jffs_fmcontrol * -jffs_build_begin(struct jffs_control *c, int unit) -{ - struct jffs_fmcontrol *fmc; - struct mtd_info *mtd; - - D3(printk("jffs_build_begin()\n")); - fmc = kmalloc(sizeof(*fmc), GFP_KERNEL); - if (!fmc) { - D(printk("jffs_build_begin(): Allocation of " - "struct jffs_fmcontrol failed!\n")); - return (struct jffs_fmcontrol *)0; - } - DJM(no_jffs_fmcontrol++); - - mtd = get_mtd_device(NULL, unit); - - if (IS_ERR(mtd)) { - kfree(fmc); - DJM(no_jffs_fmcontrol--); - return NULL; - } - - /* Retrieve the size of the flash memory. */ - fmc->flash_size = mtd->size; - D3(printk(" fmc->flash_size = %d bytes\n", fmc->flash_size)); - - fmc->used_size = 0; - fmc->dirty_size = 0; - fmc->free_size = mtd->size; - fmc->sector_size = mtd->erasesize; - fmc->max_chunk_size = fmc->sector_size >> 1; - /* min_free_size: - 1 sector, obviously. - + 1 x max_chunk_size, for when a nodes overlaps the end of a sector - + 1 x max_chunk_size again, which ought to be enough to handle - the case where a rename causes a name to grow, and GC has - to write out larger nodes than the ones it's obsoleting. - We should fix it so it doesn't have to write the name - _every_ time. Later. - + another 2 sectors because people keep getting GC stuck and - we don't know why. This scares me - I want formal proof - of correctness of whatever number we put here. dwmw2. - */ - fmc->min_free_size = fmc->sector_size << 2; - fmc->mtd = mtd; - fmc->c = c; - fmc->head = NULL; - fmc->tail = NULL; - fmc->head_extra = NULL; - fmc->tail_extra = NULL; - mutex_init(&fmc->biglock); - return fmc; -} - - -/* When the flash memory scan has completed, this function should be called - before use of the control structure. */ -void -jffs_build_end(struct jffs_fmcontrol *fmc) -{ - D3(printk("jffs_build_end()\n")); - - if (!fmc->head) { - fmc->head = fmc->head_extra; - fmc->tail = fmc->tail_extra; - } - else if (fmc->head_extra) { - fmc->tail_extra->next = fmc->head; - fmc->head->prev = fmc->tail_extra; - fmc->head = fmc->head_extra; - } - fmc->head_extra = NULL; /* These two instructions should be omitted. */ - fmc->tail_extra = NULL; - D3(jffs_print_fmcontrol(fmc)); -} - - -/* Call this function when the file system is unmounted. This function - frees all memory used by this module. */ -void -jffs_cleanup_fmcontrol(struct jffs_fmcontrol *fmc) -{ - if (fmc) { - struct jffs_fm *next = fmc->head; - while (next) { - struct jffs_fm *cur = next; - next = next->next; - jffs_free_fm(cur); - } - put_mtd_device(fmc->mtd); - kfree(fmc); - DJM(no_jffs_fmcontrol--); - } -} - - -/* This function returns the size of the first chunk of free space on the - flash memory. This function will return something nonzero if the flash - memory contains any free space. */ -__u32 -jffs_free_size1(struct jffs_fmcontrol *fmc) -{ - __u32 head; - __u32 tail; - __u32 end = fmc->flash_size; - - if (!fmc->head) { - /* There is nothing on the flash. */ - return fmc->flash_size; - } - - /* Compute the beginning and ending of the contents of the flash. */ - head = fmc->head->offset; - tail = fmc->tail->offset + fmc->tail->size; - if (tail == end) { - tail = 0; - } - ASSERT(else if (tail > end) { - printk(KERN_WARNING "jffs_free_size1(): tail > end\n"); - tail = 0; - }); - - if (head <= tail) { - return end - tail; - } - else { - return head - tail; - } -} - -/* This function will return something nonzero in case there are two free - areas on the flash. Like this: - - +----------------+------------------+----------------+ - | FREE 1 | USED / DIRTY | FREE 2 | - +----------------+------------------+----------------+ - fmc->head -----^ - fmc->tail ------------------------^ - - The value returned, will be the size of the first empty area on the - flash, in this case marked "FREE 1". */ -__u32 -jffs_free_size2(struct jffs_fmcontrol *fmc) -{ - if (fmc->head) { - __u32 head = fmc->head->offset; - __u32 tail = fmc->tail->offset + fmc->tail->size; - if (tail == fmc->flash_size) { - tail = 0; - } - - if (tail >= head) { - return head; - } - } - return 0; -} - - -/* Allocate a chunk of flash memory. If there is enough space on the - device, a reference to the associated node is stored in the jffs_fm - struct. */ -int -jffs_fmalloc(struct jffs_fmcontrol *fmc, __u32 size, struct jffs_node *node, - struct jffs_fm **result) -{ - struct jffs_fm *fm; - __u32 free_chunk_size1; - __u32 free_chunk_size2; - - D2(printk("jffs_fmalloc(): fmc = 0x%p, size = %d, " - "node = 0x%p\n", fmc, size, node)); - - *result = NULL; - - if (!(fm = jffs_alloc_fm())) { - D(printk("jffs_fmalloc(): kmalloc() failed! (fm)\n")); - return -ENOMEM; - } - - 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 "Free size accounting screwed\n"); - printk(KERN_WARNING "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); - } - - D3(printk("jffs_fmalloc(): free_chunk_size1 = %u, " - "free_chunk_size2 = %u\n", - free_chunk_size1, free_chunk_size2)); - - if (size <= free_chunk_size1) { - if (!(fm->nodes = (struct jffs_node_ref *) - kmalloc(sizeof(struct jffs_node_ref), - GFP_KERNEL))) { - D(printk("jffs_fmalloc(): kmalloc() failed! " - "(node_ref)\n")); - jffs_free_fm(fm); - return -ENOMEM; - } - DJM(no_jffs_node_ref++); - fm->nodes->node = node; - fm->nodes->next = NULL; - if (fmc->tail) { - fm->offset = fmc->tail->offset + fmc->tail->size; - if (fm->offset == fmc->flash_size) { - fm->offset = 0; - } - ASSERT(else if (fm->offset > fmc->flash_size) { - printk(KERN_WARNING "jffs_fmalloc(): " - "offset > flash_end\n"); - fm->offset = 0; - }); - } - else { - /* There don't have to be files in the file - system yet. */ - fm->offset = 0; - } - fm->size = size; - fmc->free_size -= size; - fmc->used_size += size; - } - else if (size > free_chunk_size2) { - printk(KERN_WARNING "JFFS: Tried to allocate a too " - "large flash memory chunk. (size = %u)\n", size); - jffs_free_fm(fm); - return -ENOSPC; - } - else { - fm->offset = fmc->tail->offset + fmc->tail->size; - fm->size = free_chunk_size1; - fm->nodes = NULL; - fmc->free_size -= fm->size; - fmc->dirty_size += fm->size; /* Changed by simonk. This seemingly fixes a - bug that caused infinite garbage collection. - It previously set fmc->dirty_size to size (which is the - size of the requested chunk). - */ - } - - fm->next = NULL; - if (!fmc->head) { - fm->prev = NULL; - fmc->head = fm; - fmc->tail = fm; - } - else { - fm->prev = fmc->tail; - fmc->tail->next = fm; - fmc->tail = fm; - } - - D3(jffs_print_fmcontrol(fmc)); - D3(jffs_print_fm(fm)); - *result = fm; - return 0; -} - - -/* The on-flash space is not needed anymore by the passed node. Remove - the reference to the node from the node list. If the data chunk in - the flash memory isn't used by any more nodes anymore (fm->nodes == 0), - then mark that chunk as dirty. */ -int -jffs_fmfree(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, struct jffs_node *node) -{ - struct jffs_node_ref *ref; - struct jffs_node_ref *prev; - ASSERT(int del = 0); - - D2(printk("jffs_fmfree(): node->ino = %u, node->version = %u\n", - node->ino, node->version)); - - ASSERT(if (!fmc || !fm || !fm->nodes) { - printk(KERN_ERR "jffs_fmfree(): fmc: 0x%p, fm: 0x%p, " - "fm->nodes: 0x%p\n", - fmc, fm, (fm ? fm->nodes : NULL)); - return -1; - }); - - /* Find the reference to the node that is going to be removed - and remove it. */ - for (ref = fm->nodes, prev = NULL; ref; ref = ref->next) { - if (ref->node == node) { - if (prev) { - prev->next = ref->next; - } - else { - fm->nodes = ref->next; - } - kfree(ref); - DJM(no_jffs_node_ref--); - ASSERT(del = 1); - break; - } - prev = ref; - } - - /* If the data chunk in the flash memory isn't used anymore - just mark it as obsolete. */ - if (!fm->nodes) { - /* No node uses this chunk so let's remove it. */ - fmc->used_size -= fm->size; - fmc->dirty_size += fm->size; -#if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE - if (jffs_mark_obsolete(fmc, fm->offset) < 0) { - D1(printk("jffs_fmfree(): Failed to mark an on-flash " - "node obsolete!\n")); - return -1; - } -#endif - } - - ASSERT(if (!del) { - printk(KERN_WARNING "***jffs_fmfree(): " - "Didn't delete any node reference!\n"); - }); - - return 0; -} - - -/* This allocation function is used during the initialization of - the file system. */ -struct jffs_fm * -jffs_fmalloced(struct jffs_fmcontrol *fmc, __u32 offset, __u32 size, - struct jffs_node *node) -{ - struct jffs_fm *fm; - - D3(printk("jffs_fmalloced()\n")); - - if (!(fm = jffs_alloc_fm())) { - D(printk("jffs_fmalloced(0x%p, %u, %u, 0x%p): failed!\n", - fmc, offset, size, node)); - return NULL; - } - fm->offset = offset; - fm->size = size; - fm->prev = NULL; - fm->next = NULL; - fm->nodes = NULL; - if (node) { - /* `node' exists and it should be associated with the - jffs_fm structure `fm'. */ - if (!(fm->nodes = (struct jffs_node_ref *) - kmalloc(sizeof(struct jffs_node_ref), - GFP_KERNEL))) { - D(printk("jffs_fmalloced(): !fm->nodes\n")); - jffs_free_fm(fm); - return NULL; - } - DJM(no_jffs_node_ref++); - fm->nodes->node = node; - fm->nodes->next = NULL; - fmc->used_size += size; - fmc->free_size -= size; - } - else { - /* If there is no node, then this is just a chunk of dirt. */ - fmc->dirty_size += size; - fmc->free_size -= size; - } - - if (fmc->head_extra) { - fm->prev = fmc->tail_extra; - fmc->tail_extra->next = fm; - fmc->tail_extra = fm; - } - else if (!fmc->head) { - fmc->head = fm; - fmc->tail = fm; - } - else if (fmc->tail->offset + fmc->tail->size < offset) { - fmc->head_extra = fm; - fmc->tail_extra = fm; - } - else { - fm->prev = fmc->tail; - fmc->tail->next = fm; - fmc->tail = fm; - } - D3(jffs_print_fmcontrol(fmc)); - D3(jffs_print_fm(fm)); - return fm; -} - - -/* Add a new node to an already existing jffs_fm struct. */ -int -jffs_add_node(struct jffs_node *node) -{ - struct jffs_node_ref *ref; - - D3(printk("jffs_add_node(): ino = %u\n", node->ino)); - - ref = kmalloc(sizeof(*ref), GFP_KERNEL); - if (!ref) - return -ENOMEM; - - DJM(no_jffs_node_ref++); - ref->node = node; - ref->next = node->fm->nodes; - node->fm->nodes = ref; - return 0; -} - - -/* Free a part of some allocated space. */ -void -jffs_fmfree_partly(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, __u32 size) -{ - D1(printk("***jffs_fmfree_partly(): fm = 0x%p, fm->nodes = 0x%p, " - "fm->nodes->node->ino = %u, size = %u\n", - fm, (fm ? fm->nodes : 0), - (!fm ? 0 : (!fm->nodes ? 0 : fm->nodes->node->ino)), size)); - - if (fm->nodes) { - kfree(fm->nodes); - DJM(no_jffs_node_ref--); - fm->nodes = NULL; - } - fmc->used_size -= fm->size; - if (fm == fmc->tail) { - fm->size -= size; - fmc->free_size += size; - } - fmc->dirty_size += fm->size; -} - - -/* Find the jffs_fm struct that contains the end of the data chunk that - begins at the logical beginning of the flash memory and spans `size' - bytes. If we want to erase a sector of the flash memory, we use this - function to find where the sector limit cuts a chunk of data. */ -struct jffs_fm * -jffs_cut_node(struct jffs_fmcontrol *fmc, __u32 size) -{ - struct jffs_fm *fm; - __u32 pos = 0; - - if (size == 0) { - return NULL; - } - - ASSERT(if (!fmc) { - printk(KERN_ERR "jffs_cut_node(): fmc == NULL\n"); - return NULL; - }); - - fm = fmc->head; - - while (fm) { - pos += fm->size; - if (pos < size) { - fm = fm->next; - } - else if (pos > size) { - break; - } - else { - fm = NULL; - break; - } - } - - return fm; -} - - -/* Move the head of the fmc structures and delete the obsolete parts. */ -void -jffs_sync_erase(struct jffs_fmcontrol *fmc, int erased_size) -{ - struct jffs_fm *fm; - struct jffs_fm *del; - - ASSERT(if (!fmc) { - printk(KERN_ERR "jffs_sync_erase(): fmc == NULL\n"); - return; - }); - - fmc->dirty_size -= erased_size; - fmc->free_size += erased_size; - - for (fm = fmc->head; fm && (erased_size > 0);) { - if (erased_size >= fm->size) { - erased_size -= fm->size; - del = fm; - fm = fm->next; - fm->prev = NULL; - fmc->head = fm; - jffs_free_fm(del); - } - else { - fm->size -= erased_size; - fm->offset += erased_size; - break; - } - } -} - - -/* Return the oldest used node in the flash memory. */ -struct jffs_node * -jffs_get_oldest_node(struct jffs_fmcontrol *fmc) -{ - struct jffs_fm *fm; - struct jffs_node_ref *nref; - struct jffs_node *node = NULL; - - ASSERT(if (!fmc) { - printk(KERN_ERR "jffs_get_oldest_node(): fmc == NULL\n"); - return NULL; - }); - - for (fm = fmc->head; fm && !fm->nodes; fm = fm->next); - - if (!fm) { - return NULL; - } - - /* The oldest node is the last one in the reference list. This list - shouldn't be too long; just one or perhaps two elements. */ - for (nref = fm->nodes; nref; nref = nref->next) { - node = nref->node; - } - - D2(printk("jffs_get_oldest_node(): ino = %u, version = %u\n", - (node ? node->ino : 0), (node ? node->version : 0))); - - return node; -} - - -#if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE - -/* Mark an on-flash node as obsolete. - - Note that this is just an optimization that isn't necessary for the - filesystem to work. */ - -static int -jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset) -{ - /* The `accurate_pos' holds the position of the accurate byte - in the jffs_raw_inode structure that we are going to mark - as obsolete. */ - __u32 accurate_pos = fm_offset + JFFS_RAW_INODE_ACCURATE_OFFSET; - unsigned char zero = 0x00; - size_t len; - - D3(printk("jffs_mark_obsolete(): accurate_pos = %u\n", accurate_pos)); - ASSERT(if (!fmc) { - printk(KERN_ERR "jffs_mark_obsolete(): fmc == NULL\n"); - return -1; - }); - - /* Write 0x00 to the raw inode's accurate member. Don't care - about the return value. */ - MTD_WRITE(fmc->mtd, accurate_pos, 1, &len, &zero); - return 0; -} - -#endif /* JFFS_MARK_OBSOLETE */ - -/* check if it's possible to erase the wanted range, and if not, return - * the range that IS erasable, or a negative error code. - */ -static long -jffs_flash_erasable_size(struct mtd_info *mtd, __u32 offset, __u32 size) -{ - u_long ssize; - - /* assume that sector size for a partition is constant even - * if it spans more than one chip (you usually put the same - * type of chips in a system) - */ - - ssize = mtd->erasesize; - - if (offset % ssize) { - printk(KERN_WARNING "jffs_flash_erasable_size() given non-aligned offset %x (erasesize %lx)\n", offset, ssize); - /* The offset is not sector size aligned. */ - return -1; - } - else if (offset > mtd->size) { - printk(KERN_WARNING "jffs_flash_erasable_size given offset off the end of device (%x > %x)\n", offset, mtd->size); - return -2; - } - else if (offset + size > mtd->size) { - printk(KERN_WARNING "jffs_flash_erasable_size() given length which runs off the end of device (ofs %x + len %x = %x, > %x)\n", offset,size, offset+size, mtd->size); - return -3; - } - - return (size / ssize) * ssize; -} - - -/* How much dirty flash memory is possible to erase at the moment? */ -long -jffs_erasable_size(struct jffs_fmcontrol *fmc) -{ - struct jffs_fm *fm; - __u32 size = 0; - long ret; - - ASSERT(if (!fmc) { - printk(KERN_ERR "jffs_erasable_size(): fmc = NULL\n"); - return -1; - }); - - if (!fmc->head) { - /* The flash memory is totally empty. No nodes. No dirt. - Just return. */ - return 0; - } - - /* Calculate how much space that is dirty. */ - for (fm = fmc->head; fm && !fm->nodes; fm = fm->next) { - if (size && fm->offset == 0) { - /* We have reached the beginning of the flash. */ - break; - } - size += fm->size; - } - - /* Someone's signature contained this: - There's a fine line between fishing and just standing on - the shore like an idiot... */ - ret = jffs_flash_erasable_size(fmc->mtd, fmc->head->offset, size); - - ASSERT(if (ret < 0) { - printk("jffs_erasable_size: flash_erasable_size() " - "returned something less than zero (%ld).\n", ret); - printk("jffs_erasable_size: offset = 0x%08x\n", - fmc->head->offset); - }); - - /* If there is dirt on the flash (which is the reason to why - this function was called in the first place) but no space is - possible to erase right now, the initial part of the list of - jffs_fm structs, that hold place for dirty space, could perhaps - be shortened. The list's initial "dirty" elements are merged - into just one large dirty jffs_fm struct. This operation must - only be performed if nothing is possible to erase. Otherwise, - jffs_clear_end_of_node() won't work as expected. */ - if (ret == 0) { - struct jffs_fm *head = fmc->head; - struct jffs_fm *del; - /* While there are two dirty nodes beside each other.*/ - while (head->nodes == 0 - && head->next - && head->next->nodes == 0) { - del = head->next; - head->size += del->size; - head->next = del->next; - if (del->next) { - del->next->prev = head; - } - jffs_free_fm(del); - } - } - - return (ret >= 0 ? ret : 0); -} - -static struct jffs_fm *jffs_alloc_fm(void) -{ - struct jffs_fm *fm; - - fm = kmem_cache_alloc(fm_cache,GFP_KERNEL); - DJM(if (fm) no_jffs_fm++;); - - return fm; -} - -static void jffs_free_fm(struct jffs_fm *n) -{ - kmem_cache_free(fm_cache,n); - DJM(no_jffs_fm--); -} - - - -struct jffs_node *jffs_alloc_node(void) -{ - struct jffs_node *n; - - n = (struct jffs_node *)kmem_cache_alloc(node_cache,GFP_KERNEL); - if(n != NULL) - no_jffs_node++; - return n; -} - -void jffs_free_node(struct jffs_node *n) -{ - kmem_cache_free(node_cache,n); - no_jffs_node--; -} - - -int jffs_get_node_inuse(void) -{ - return no_jffs_node; -} |