[JFFS2] Core changes required to support JFFS2-on-Dataflash devices.

DataFlash page-sizes are not a power of two (they're multiples of 528
bytes).  There are a few places in JFFS2 code where sector_size is used
as a bitmask.  A new macro (SECTOR_ADDR) was defined to calculate these
sector addresses. For non-DataFlash devices, the original (faster)
bitmask operation is still used.

In scan.c, the EMPTY_SCAN_SIZE was a constant of 1024.
Since this could be larger than the sector size of the DataFlash, this
is now basically set to MIN(sector_size, 1024).

Addition of a jffs2_is_writebuffered() macro.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 31 insertions, 32 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 79414abadd5e..894dea88678d 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -9,7 +9,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: wbuf.c,v 1.86 2005/02/05 18:23:37 hammache Exp $
+ * $Id: wbuf.c,v 1.87 2005/02/09 09:09:02 pavlov Exp $
  *
  */
 
@@ -415,9 +415,9 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
         int ret;
         size_t retlen;
 
-        /* Nothing to do if not NAND flash. In particular, we shouldn't
+        /* Nothing to do if not write-buffering the flash. In particular, we shouldn't
            del_timer() the timer we never initialised. */
-        if (jffs2_can_mark_obsolete(c))
+        if (!jffs2_is_writebuffered(c))
                 return 0;
 
         if (!down_trylock(&c->alloc_sem)) {
@@ -426,7 +426,7 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
                 BUG();
         }
 
-        if(!c->wbuf || !c->wbuf_len)
+        if (!c->wbuf_len)       /* already checked c->wbuf above */
                 return 0;
 
         /* claim remaining space on the page
@@ -620,7 +620,7 @@ int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs, unsig
         uint32_t outvec_to = to;
 
         /* If not NAND flash, don't bother */
-        if (!c->wbuf)
+        if (!jffs2_is_writebuffered(c))
                 return jffs2_flash_direct_writev(c, invecs, count, to, retlen);
         
         down_write(&c->wbuf_sem);
@@ -649,7 +649,7 @@ int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs, unsig
            erase block. Anything else, and you die.
            New block starts at xxx000c (0-b = block header)
         */
-        if ( (to & ~(c->sector_size-1)) != (c->wbuf_ofs & ~(c->sector_size-1)) ) {
+        if (SECTOR_ADDR(to) != SECTOR_ADDR(c->wbuf_ofs)) {
                 /* It's a write to a new block */
                 if (c->wbuf_len) {
                         D1(printk(KERN_DEBUG "jffs2_flash_writev() to 0x%lx causes flush of wbuf at 0x%08x\n", (unsigned long)to, c->wbuf_ofs));
@@ -847,7 +847,7 @@ int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *r
 {
         struct kvec vecs[1];
 
-        if (jffs2_can_mark_obsolete(c))
+        if (!jffs2_is_writebuffered(c))
                 return c->mtd->write(c->mtd, ofs, len, retlen, buf);
 
         vecs[0].iov_base = (unsigned char *) buf;
@@ -863,38 +863,37 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re
         loff_t  orbf = 0, owbf = 0, lwbf = 0;
         int     ret;
 
-        /* Read flash */
-        if (!jffs2_can_mark_obsolete(c)) {
-
-                if (jffs2_cleanmarker_oob(c))
-                        ret = c->mtd->read_ecc(c->mtd, ofs, len, retlen, buf, NULL, c->oobinfo);
-                else
-                        ret = c->mtd->read(c->mtd, ofs, len, retlen, buf);
-
-                if ( (ret == -EBADMSG) && (*retlen == len) ) {
-                        printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx) returned ECC error\n",
-                               len, ofs);
-                        /* 
-                         * We have the raw data without ECC correction in the buffer, maybe 
-                         * we are lucky and all data or parts are correct. We check the node.
-                         * If data are corrupted node check will sort it out.
-                         * We keep this block, it will fail on write or erase and the we
-                         * mark it bad. Or should we do that now? But we should give him a chance.
-                         * Maybe we had a system crash or power loss before the ecc write or  
-                         * a erase was completed.
-                         * So we return success. :)
-                         */
-                        ret = 0;
-                 }      
-        } else
+        if (!jffs2_is_writebuffered(c))
                 return c->mtd->read(c->mtd, ofs, len, retlen, buf);
 
+        /* Read flash */
+        if (jffs2_cleanmarker_oob(c))
+                ret = c->mtd->read_ecc(c->mtd, ofs, len, retlen, buf, NULL, c->oobinfo);
+        else
+                ret = c->mtd->read(c->mtd, ofs, len, retlen, buf);
+
+        if ( (ret == -EBADMSG) && (*retlen == len) ) {
+                printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx) returned ECC error\n",
+                       len, ofs);
+                /* 
+                 * We have the raw data without ECC correction in the buffer, maybe 
+                 * we are lucky and all data or parts are correct. We check the node.
+                 * If data are corrupted node check will sort it out.
+                 * We keep this block, it will fail on write or erase and the we
+                 * mark it bad. Or should we do that now? But we should give him a chance.
+                 * Maybe we had a system crash or power loss before the ecc write or  
+                 * a erase was completed.
+                 * So we return success. :)
+                 */
+                ret = 0;
+        }       
+
         /* if no writebuffer available or write buffer empty, return */
         if (!c->wbuf_pagesize || !c->wbuf_len)
                 return ret;;
 
         /* if we read in a different block, return */
-        if ( (ofs & ~(c->sector_size-1)) != (c->wbuf_ofs & ~(c->sector_size-1)) ) 
+        if (SECTOR_ADDR(ofs) != SECTOR_ADDR(c->wbuf_ofs))
                 return ret;
 
         /* Lock only if we have reason to believe wbuf contains relevant data,