Hi Alex,
I tested your patch on my system with a 20TB device, but some tests
failed. Looking at the code, I saw that the support of 48-bit block
number in extents is lacking.
I made some changes in the code (see the patch in attachment) and now
all my tests are OK.
The patch is not complete, I didn't update calls to wb_debug() which
dump "ee_start".
Hope this helps.
Valérie
Index: linux-2.6.20-rc1/fs/ext4/writeback.c
===================================================================
--- linux-2.6.20-rc1.orig/fs/ext4/writeback.c 2007-01-09 18:41:27.000000000 +0100
+++ linux-2.6.20-rc1/fs/ext4/writeback.c 2007-01-11 13:25:38.000000000 +0100
@@ -274,7 +274,8 @@ static int ext4_wb_submit_extent(struct
struct inode *inode = wc->mapping->host;
int blkbits = inode->i_blkbits;
struct page *page;
- unsigned long blk, off, len, remain;
+ ext4_fsblk_t off;
+ unsigned long blk, len, remain;
unsigned long pstart, plen, prev;
struct bio *bio = NULL;
int nr_pages;
@@ -332,6 +333,7 @@ alloc_new_bio:
nr_pages = (ex->ee_len - (blk - ex->ee_block));
nr_pages = (nr_pages >> (PAGE_CACHE_SHIFT - blkbits));
off = ex->ee_start + (blk - ex->ee_block);
+ off |= (ext4_fsblk_t) ex->ee_start_hi << 32;
bio = ext4_wb_bio_alloc(inode, off, nr_pages + 2);
if (bio == NULL)
return -ENOMEM;
@@ -377,7 +379,9 @@ ext4_wb_find_goal(struct inode *inode, s
/* try to predict block placement */
if ((ex = path[depth].p_ext))
- return ex->ee_start + (block - ex->ee_block);
+ return ((ex->ee_start
+ | ((ext4_fsblk_t) ex->ee_start_hi << 32))
+ + (block - ex->ee_block);
/* it looks index is empty
* try to find starting from index itself */
@@ -416,7 +420,8 @@ static int ext4_wb_handle_extent(struct
(unsigned) ec->ec_block,
(unsigned) ec->ec_len,
(unsigned) ec->ec_start);
- nex.ee_start = ec->ec_start;
+ nex.ee_start = ec->ec_start & 0xffffffff;
+ nex.ee_start_hi = (ec->ec_start >> 32) & 0xffff;
nex.ee_block = ec->ec_block;
nex.ee_len = ec->ec_len;
err = ext4_wb_submit_extent(wc, NULL, &nex, 0);
@@ -488,8 +493,8 @@ static int ext4_wb_handle_extent(struct
pblock, count, inode->i_ino, ec->ec_len);
/* insert new extent */
- nex.ee_start = pblock;
- nex.ee_start_hi = 0;
+ nex.ee_start = pblock & 0xffffffff;
+ nex.ee_start_hi = (pblock >> 32) & 0xffff;
nex.ee_len = count;
nex.ee_block = ec->ec_block;
err = ext4_ext_insert_extent(handle, inode, path, &nex);
@@ -520,7 +525,9 @@ static int ext4_wb_handle_extent(struct
/* block have been allocated for data, so time to drop dirty
* in correspondend buffer_heads to prevent corruptions */
for (i = 0; i < nex.ee_len; i++)
- unmap_underlying_metadata(sb->s_bdev, nex.ee_start + i);
+ unmap_underlying_metadata(sb->s_bdev,
+ ((ext4_fsblk_t) nex.ee_start_hi << 32)
+ + nex.ee_start + i);
/* correct on-disk inode size */
if (nex.ee_len > 0) {
