packages/fs/jffs2/v2_0/src/file-ecos.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001, 2002 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  * $Id$
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/crc32.h>
  17 #include "nodelist.h"
  18
  19 int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
  20 {
  21         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
  22         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
  23         unsigned char *pg_buf;
  24         int ret;
  25
  26         D1(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
  27
  28         if (!PageLocked(pg))
  29                 PAGE_BUG(pg);
  30
  31         pg_buf = (char *)kmap(pg);
  32         /* FIXME: Can kmap fail? */
  33
  34         ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
  35
  36         if (ret) {
  37                 ClearPageUptodate(pg);
  38                 SetPageError(pg);
  39         } else {
  40                 SetPageUptodate(pg);
  41                 ClearPageError(pg);
  42         }
  43
  44         flush_dcache_page(pg);
  45         kunmap(pg);
  46
  47         D1(printk(KERN_DEBUG "readpage finished\n"));
  48         return 0;
  49 }
  50
  51 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
  52 {
  53         int ret = jffs2_do_readpage_nolock(inode, pg);
  54         UnlockPage(pg);
  55         return ret;
  56 }
  57
  58
  59 //int jffs2_readpage (struct file *filp, struct page *pg)
  60 int jffs2_readpage (struct inode *d_inode, struct page *pg)
  61 {
  62         //      struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode);
  63         int ret;
  64
  65         //      down(&f->sem);
  66         ret = jffs2_do_readpage_unlock(d_inode, pg);
  67         //      up(&f->sem);
  68         return ret;
  69 }
  70
  71 //int jffs2_prepare_write (struct file *filp, struct page *pg, unsigned start, unsigned end)
  72 int jffs2_prepare_write (struct inode *d_inode, struct page *pg, unsigned start, unsigned end)
  73 {
  74         struct inode *inode = d_inode;
  75         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
  76         uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
  77         int ret = 0;
  78
  79         D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
  80
  81         if (pageofs > inode->i_size) {
  82                 /* Make new hole frag from old EOF to new page */
  83                 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
  84                 struct jffs2_raw_inode ri;
  85                 struct jffs2_full_dnode *fn;
  86                 uint32_t phys_ofs, alloc_len;
  87
  88                 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
  89                           (unsigned int)inode->i_size, pageofs));
  90
  91                 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
  92                 if (ret)
  93                         return ret;
  94
  95                 down(&f->sem);
  96                 memset(&ri, 0, sizeof(ri));
  97
  98                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  99                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
 100                 ri.totlen = cpu_to_je32(sizeof(ri));
 101                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
 102
 103                 ri.ino = cpu_to_je32(f->inocache->ino);
 104                 ri.version = cpu_to_je32(++f->highest_version);
 105                 ri.mode = cpu_to_jemode(inode->i_mode);
 106                 ri.uid = cpu_to_je16(inode->i_uid);
 107                 ri.gid = cpu_to_je16(inode->i_gid);
 108
 109                 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
 110                 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(cyg_timestamp());
 111                 ri.offset = cpu_to_je32(inode->i_size);
 112                 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
 113                 ri.csize = cpu_to_je32(0);
 114                 ri.compr = JFFS2_COMPR_ZERO;
 115                 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
 116                 ri.data_crc = cpu_to_je32(0);
 117
 118                 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, NULL);
 119                 jffs2_complete_reservation(c);
 120                 if (IS_ERR(fn)) {
 121                         ret = PTR_ERR(fn);
 122                         up(&f->sem);
 123                         return ret;
 124                 }
 125                 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
 126                 if (f->metadata) {
 127                         jffs2_mark_node_obsolete(c, f->metadata->raw);
 128                         jffs2_free_full_dnode(f->metadata);
 129                         f->metadata = NULL;
 130                 }
 131                 if (ret) {
 132                         D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
 133                         jffs2_mark_node_obsolete(c, fn->raw);
 134                         jffs2_free_full_dnode(fn);
 135                         up(&f->sem);
 136                         return ret;
 137                 }
 138                 inode->i_size = pageofs;
 139                 up(&f->sem);
 140         }
 141
 142
 143         /* Read in the page if it wasn't already present, unless it's a whole page */
 144         // eCos has no concept of uptodate and by default always reads pages afresh
 145         if (!Page_Uptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
 146                 down(&f->sem);
 147                 ret = jffs2_do_readpage_nolock(inode, pg);
 148                 up(&f->sem);
 149         }
 150         D1(printk(KERN_DEBUG "end prepare_write()\n"));
 151         return ret;
 152 }
 153
 154 //int jffs2_commit_write (struct file *filp, struct page *pg, unsigned start, unsigned end)
 155 int jffs2_commit_write (struct inode *d_inode, struct page *pg, unsigned start, unsigned end)
 156 {
 157         /* Actually commit the write from the page cache page we're looking at.
 158          * For now, we write the full page out each time. It sucks, but it's simple
 159          */
 160         struct inode *inode = d_inode;
 161         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 162         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 163         struct jffs2_raw_inode *ri;
 164         int ret = 0;
 165         uint32_t writtenlen = 0;
 166
 167         D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d\n",
 168                   inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end));
 169
 170
 171         ri = jffs2_alloc_raw_inode();
 172         if (!ri) {
 173                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
 174                 return -ENOMEM;
 175         }
 176
 177         /* Set the fields that the generic jffs2_write_inode_range() code can't find */
 178         ri->ino = cpu_to_je32(inode->i_ino);
 179         ri->mode = cpu_to_jemode(inode->i_mode);
 180         ri->uid = cpu_to_je16(inode->i_uid);
 181         ri->gid = cpu_to_je16(inode->i_gid);
 182         ri->isize = cpu_to_je32((uint32_t)inode->i_size);
 183         ri->atime = ri->ctime = ri->mtime = cpu_to_je32(cyg_timestamp());
 184
 185         ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + start,
 186                                       (pg->index << PAGE_CACHE_SHIFT) + start,
 187                                       end - start, &writtenlen);
 188
 189         if (ret) {
 190                 /* There was an error writing. */
 191                 SetPageError(pg);
 192         }
 193
 194         if (writtenlen) {
 195                 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
 196                         inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
 197                         inode->i_ctime = inode->i_mtime = je32_to_cpu(ri->ctime);
 198                 }
 199         }
 200
 201         jffs2_free_raw_inode(ri);
 202
 203         if (start+writtenlen < end) {
 204                 /* generic_file_write has written more to the page cache than we've
 205                    actually written to the medium. Mark the page !Uptodate so that
 206                    it gets reread */
 207                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
 208                 SetPageError(pg);
 209                 ClearPageUptodate(pg);
 210         }
 211
 212         D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret));
 213         return writtenlen?writtenlen:ret;
 214 }