lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

GFS2: fix block allocation check for fallocate

Browse Source 
GFS2 fallocate wasn't properly checking if a blocks were already allocated.
In write_empty_blocks(), if a page didn't have buffer_heads attached, GFS2
was always treating it as if there were no blocks allocated for that page.
GFS2 now calls gfs2_block_map() to check if the blocks are allocated before
writing them out.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Benjamin Marzinski 2011-03-11 00:49:09 -06:00 committed by Steven Whitehouse
parent fa1bbdea30
commit e4a7b7b0c9
1 changed files with 33 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
fs/gfs2/file.c
View File

@ -622,8 +622,7 @@ static void empty_write_end(struct page *page, unsigned from,
{
struct gfs2_inode *ip = GFS2_I(page->mapping->host);
page_zero_new_buffers(page, from, to);
flush_dcache_page(page);
zero_user(page, from, to-from);
mark_page_accessed(page);
if (!gfs2_is_writeback(ip))
@ -632,36 +631,43 @@ static void empty_write_end(struct page *page, unsigned from,
block_commit_write(page, from, to);
}
static int needs_empty_write(sector_t block, struct inode *inode)
{
int error;
struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
bh_map.b_size = 1 << inode->i_blkbits;
error = gfs2_block_map(inode, block, &bh_map, 0);
if (unlikely(error))
return error;
return !buffer_mapped(&bh_map);
}
static int write_empty_blocks(struct page *page, unsigned from, unsigned to)
{
unsigned start, end, next;
struct buffer_head *bh, *head;
int error;
struct inode *inode = page->mapping->host;
unsigned start, end, next, blksize;
sector_t block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
int ret;
if (!page_has_buffers(page)) {
error = __block_write_begin(page, from, to - from, gfs2_block_map);
if (unlikely(error))
return error;
empty_write_end(page, from, to);
return 0;
}
bh = head = page_buffers(page);
blksize = 1 << inode->i_blkbits;
next = end = 0;
while (next < from) {
next += bh->b_size;
bh = bh->b_this_page;
next += blksize;
block++;
}
start = next;
do {
next += bh->b_size;
if (buffer_mapped(bh)) {
next += blksize;
ret = needs_empty_write(block, inode);
if (unlikely(ret < 0))
return ret;
if (ret == 0) {
if (end) {
error = __block_write_begin(page, start, end - start,
gfs2_block_map);
if (unlikely(error))
return error;
ret = __block_write_begin(page, start, end - start,
gfs2_block_map);
if (unlikely(ret))
return ret;
empty_write_end(page, start, end);
end = 0;
}
@ -669,13 +675,13 @@ static int write_empty_blocks(struct page *page, unsigned from, unsigned to)
}
else
end = next;
bh = bh->b_this_page;
block++;
} while (next < to);
if (end) {
error = __block_write_begin(page, start, end - start, gfs2_block_map);
if (unlikely(error))
return error;
ret = __block_write_begin(page, start, end - start, gfs2_block_map);
if (unlikely(ret))
return ret;
empty_write_end(page, start, end);
}