As you pointed out offline, the -ac kernels fixed the problem using
*both* approaches. Here's a 2.4.18-pre1 version. generic_file_write()
is getting rather icky.
Please let me know if this looks like the way to proceed, and I'll
find a way to actually test the thing.
--- linux-2.4.18-pre1/fs/buffer.c Fri Dec 21 11:19:14 2001
+++ linux-akpm/fs/buffer.c Sat Dec 29 22:46:21 2001
@@ -1639,6 +1639,17 @@ static int __block_prepare_write(struct
}
return 0;
out:
+ bh = head;
+ block_start = 0;
+ do {
+ if (buffer_new(bh) && !buffer_uptodate(bh)) {
+ memset(kaddr+block_start, 0, bh->b_size);
+ set_bit(BH_Uptodate, &bh->b_state);
+ mark_buffer_dirty(bh);
+ }
+ block_start += bh->b_size;
+ bh = bh->b_this_page;
+ } while (bh != head);
return err;
}
--- linux-2.4.18-pre1/mm/filemap.c Wed Dec 26 11:47:41 2001
+++ linux-akpm/mm/filemap.c Sat Dec 29 23:04:29 2001
@@ -2856,6 +2856,7 @@ generic_file_write(struct file *file,con
ssize_t written;
long status = 0;
int err;
+ int prepare_write_failed = 0;
unsigned bytes;
if ((ssize_t) count < 0)
@@ -3003,8 +3004,10 @@ generic_file_write(struct file *file,con
kaddr = kmap(page);
status = mapping->a_ops->prepare_write(file, page, offset, offset+bytes);
- if (status)
+ if (status) {
+ prepare_write_failed = 1;
goto unlock;
+ }
page_fault = __copy_from_user(kaddr+offset, buf, bytes);
flush_dcache_page(page);
status = mapping->a_ops->commit_write(file, page, offset, offset+bytes);
@@ -3026,8 +3029,18 @@ unlock:
UnlockPage(page);
page_cache_release(page);
- if (status < 0)
+ if (status < 0) {
+ if (prepare_write_failed) {
+ /*
+ * If blocksize < pagesize, prepare_write() may have
+ * instantiated a few blocks outside i_size. Trim
+ * these off again.
+ */
+ if (pos + bytes > inode->i_size)
+ vmtruncate(inode, inode->i_size);
+ }
break;
+ }
} while (count);
*ppos = pos;
-
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This archive was generated by hypermail 2b29 : Mon Dec 31 2001 - 21:00:22 EST