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-rw-r--r--fs/jffs2/readinode.c98
1 files changed, 33 insertions, 65 deletions
diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index 717a48c..1298848 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -421,49 +421,38 @@ static inline int read_unknown(struct jffs2_sb_info *c, struct jffs2_raw_node_re
* negative error code on failure.
*/
static int read_more(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref,
- int right_size, int *rdlen, unsigned char *buf, unsigned char *bufstart)
+ int needed_len, int *rdlen, unsigned char *buf)
{
- int right_len, err, len;
+ int err, to_read = needed_len - *rdlen;
size_t retlen;
uint32_t offs;
if (jffs2_is_writebuffered(c)) {
- right_len = c->wbuf_pagesize - (bufstart - buf);
- if (right_size + (int)(bufstart - buf) > c->wbuf_pagesize)
- right_len += c->wbuf_pagesize;
- } else
- right_len = right_size;
+ int rem = to_read % c->wbuf_pagesize;
- if (*rdlen == right_len)
- return 0;
+ if (rem)
+ to_read += c->wbuf_pagesize - rem;
+ }
/* We need to read more data */
offs = ref_offset(ref) + *rdlen;
- if (jffs2_is_writebuffered(c)) {
- bufstart = buf + c->wbuf_pagesize;
- len = c->wbuf_pagesize;
- } else {
- bufstart = buf + *rdlen;
- len = right_size - *rdlen;
- }
- dbg_readinode("read more %d bytes\n", len);
+ dbg_readinode("read more %d bytes\n", to_read);
- err = jffs2_flash_read(c, offs, len, &retlen, bufstart);
+ err = jffs2_flash_read(c, offs, to_read, &retlen, buf + *rdlen);
if (err) {
JFFS2_ERROR("can not read %d bytes from 0x%08x, "
- "error code: %d.\n", len, offs, err);
+ "error code: %d.\n", to_read, offs, err);
return err;
}
- if (retlen < len) {
+ if (retlen < to_read) {
JFFS2_ERROR("short read at %#08x: %zu instead of %d.\n",
- offs, retlen, len);
+ offs, retlen, to_read);
return -EIO;
}
- *rdlen = right_len;
-
+ *rdlen += to_read;
return 0;
}
@@ -486,27 +475,9 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
dbg_readinode("ino #%u\n", f->inocache->ino);
- if (jffs2_is_writebuffered(c)) {
- /*
- * If we have the write buffer, we assume the minimal I/O unit
- * is c->wbuf_pagesize. We implement some optimizations which in
- * this case and we need a temporary buffer of size =
- * 2*c->wbuf_pagesize bytes (see comments in read_dnode()).
- * Basically, we want to read not only the node header, but the
- * whole wbuf (NAND page in case of NAND) or 2, if the node
- * header overlaps the border between the 2 wbufs.
- */
- len = 2*c->wbuf_pagesize;
- } else {
- /*
- * When there is no write buffer, the size of the temporary
- * buffer is the size of the larges node header.
- */
- len = sizeof(union jffs2_node_union);
- }
-
/* FIXME: in case of NOR and available ->point() this
* needs to be fixed. */
+ len = sizeof(union jffs2_node_union) + c->wbuf_pagesize;
buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -516,8 +487,6 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
if (!valid_ref && f->inocache->ino != 1)
JFFS2_WARNING("Eep. No valid nodes for ino #%u.\n", f->inocache->ino);
while (valid_ref) {
- unsigned char *bufstart;
-
/* We can hold a pointer to a non-obsolete node without the spinlock,
but _obsolete_ nodes may disappear at any time, if the block
they're in gets erased. So if we mark 'ref' obsolete while we're
@@ -533,32 +502,31 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
/*
* At this point we don't know the type of the node we're going
* to read, so we do not know the size of its header. In order
- * to minimize the amount of flash IO we assume the node has
- * size = JFFS2_MIN_NODE_HEADER.
+ * to minimize the amount of flash IO we assume the header is
+ * of size = JFFS2_MIN_NODE_HEADER.
*/
+ len = JFFS2_MIN_NODE_HEADER;
if (jffs2_is_writebuffered(c)) {
+ int end, rem;
+
/*
- * We treat 'buf' as 2 adjacent wbufs. We want to
- * adjust bufstart such as it points to the
- * beginning of the node within this wbuf.
+ * We are about to read JFFS2_MIN_NODE_HEADER bytes,
+ * but this flash has some minimal I/O unit. It is
+ * possible that we'll need to read more soon, so read
+ * up to the next min. I/O unit, in order not to
+ * re-read the same min. I/O unit twice.
*/
- bufstart = buf + (ref_offset(ref) % c->wbuf_pagesize);
- /* We will read either one wbuf or 2 wbufs. */
- len = c->wbuf_pagesize - (bufstart - buf);
- if (JFFS2_MIN_NODE_HEADER + (int)(bufstart - buf) > c->wbuf_pagesize) {
- /* The header spans the border of the first wbuf */
- len += c->wbuf_pagesize;
- }
- } else {
- bufstart = buf;
- len = JFFS2_MIN_NODE_HEADER;
+ end = ref_offset(ref) + len;
+ rem = end % c->wbuf_pagesize;
+ if (rem)
+ end += c->wbuf_pagesize - rem;
+ len = end - ref_offset(ref);
}
dbg_readinode("read %d bytes at %#08x(%d).\n", len, ref_offset(ref), ref_flags(ref));
/* FIXME: point() */
- err = jffs2_flash_read(c, ref_offset(ref), len,
- &retlen, bufstart);
+ err = jffs2_flash_read(c, ref_offset(ref), len, &retlen, buf);
if (err) {
JFFS2_ERROR("can not read %d bytes from 0x%08x, " "error code: %d.\n", len, ref_offset(ref), err);
goto free_out;
@@ -570,7 +538,7 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
goto free_out;
}
- node = (union jffs2_node_union *)bufstart;
+ node = (union jffs2_node_union *)buf;
/* No need to mask in the valid bit; it shouldn't be invalid */
if (je32_to_cpu(node->u.hdr_crc) != crc32(0, node, sizeof(node->u)-4)) {
@@ -596,7 +564,7 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
case JFFS2_NODETYPE_DIRENT:
if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_raw_dirent)) {
- err = read_more(c, ref, sizeof(struct jffs2_raw_dirent), &len, buf, bufstart);
+ err = read_more(c, ref, sizeof(struct jffs2_raw_dirent), &len, buf);
if (unlikely(err))
goto free_out;
}
@@ -616,7 +584,7 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
case JFFS2_NODETYPE_INODE:
if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_raw_inode)) {
- err = read_more(c, ref, sizeof(struct jffs2_raw_inode), &len, buf, bufstart);
+ err = read_more(c, ref, sizeof(struct jffs2_raw_inode), &len, buf);
if (unlikely(err))
goto free_out;
}
@@ -635,7 +603,7 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf
default:
if (JFFS2_MIN_NODE_HEADER < sizeof(struct jffs2_unknown_node)) {
- err = read_more(c, ref, sizeof(struct jffs2_unknown_node), &len, buf, bufstart);
+ err = read_more(c, ref, sizeof(struct jffs2_unknown_node), &len, buf);
if (unlikely(err))
goto free_out;
}
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