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Date: Fri, 16 May 2014 17:14:47 +0800
From: Chao Yu <chao2.yu@...sung.com>
To: Jaegeuk Kim <jaegeuk.kim@...sung.com>
Cc: linux-f2fs-devel@...ts.sourceforge.net,
linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [f2fs-dev][PATCH] f2fs: avoid crash when trace f2fs_submit_page_mbio
event in ra_sum_pages
Previously we allocate pages with no mapping in ra_sum_pages(), so we may
encounter a crash in event trace of f2fs_submit_page_mbio where we access
mapping data of the page.
We'd better allocate pages in bd_inode mapping and invalidate these pages after
we restore data from pages. It could avoid crash in above scenario.
Call Trace:
[<f1031630>] ? ftrace_raw_event_f2fs_write_checkpoint+0x80/0x80 [f2fs]
[<f10377bb>] f2fs_submit_page_mbio+0x1cb/0x200 [f2fs]
[<f103c5da>] restore_node_summary+0x13a/0x280 [f2fs]
[<f103e22d>] build_curseg+0x2bd/0x620 [f2fs]
[<f104043b>] build_segment_manager+0x1cb/0x920 [f2fs]
[<f1032c85>] f2fs_fill_super+0x535/0x8e0 [f2fs]
[<c115b66a>] mount_bdev+0x16a/0x1a0
[<f102f63f>] f2fs_mount+0x1f/0x30 [f2fs]
[<c115c096>] mount_fs+0x36/0x170
[<c1173635>] vfs_kern_mount+0x55/0xe0
[<c1175388>] do_mount+0x1e8/0x900
[<c1175d72>] SyS_mount+0x82/0xc0
[<c16059cc>] sysenter_do_call+0x12/0x22
Signed-off-by: Chao Yu <chao2.yu@...sung.com>
---
fs/f2fs/node.c | 49 ++++++++++++++++++++++++++++---------------------
1 file changed, 28 insertions(+), 21 deletions(-)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 3d60d3d..b5cd814 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1658,13 +1658,16 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
/*
* ra_sum_pages() merge contiguous pages into one bio and submit.
- * these pre-readed pages are linked in pages list.
+ * these pre-readed pages are alloced in bd_inode's mapping tree.
*/
-static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
+static int ra_sum_pages(struct f2fs_sb_info *sbi, struct page **pages,
int start, int nrpages)
{
struct page *page;
+ struct inode *inode = sbi->sb->s_bdev->bd_inode;
+ struct address_space *mapping = inode->i_mapping;
int page_idx = start;
+ int alloced, readed;
struct f2fs_io_info fio = {
.type = META,
.rw = READ_SYNC | REQ_META | REQ_PRIO
@@ -1672,21 +1675,23 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
for (; page_idx < start + nrpages; page_idx++) {
/* alloc temporal page for read node summary info*/
- page = alloc_page(GFP_F2FS_ZERO);
+ page = grab_cache_page(mapping, page_idx);
if (!page)
break;
-
- lock_page(page);
- page->index = page_idx;
- list_add_tail(&page->lru, pages);
+ page_cache_release(page);
}
- list_for_each_entry(page, pages, lru)
- f2fs_submit_page_mbio(sbi, page, page->index, &fio);
+ alloced = page_idx - start;
+ readed = find_get_pages_contig(mapping, start, alloced, pages);
+ BUG_ON(alloced != readed);
+
+ for (page_idx = 0; page_idx < readed; page_idx++)
+ f2fs_submit_page_mbio(sbi, pages[page_idx],
+ pages[page_idx]->index, &fio);
f2fs_submit_merged_bio(sbi, META, READ);
- return page_idx - start;
+ return readed;
}
int restore_node_summary(struct f2fs_sb_info *sbi,
@@ -1694,11 +1699,11 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
{
struct f2fs_node *rn;
struct f2fs_summary *sum_entry;
- struct page *page, *tmp;
+ struct inode *inode = sbi->sb->s_bdev->bd_inode;
block_t addr;
int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
- int i, last_offset, nrpages, err = 0;
- LIST_HEAD(page_list);
+ struct page *pages[bio_blocks];
+ int i, index, last_offset, nrpages, err = 0;
/* scan the node segment */
last_offset = sbi->blocks_per_seg;
@@ -1709,29 +1714,31 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
nrpages = min(last_offset - i, bio_blocks);
/* read ahead node pages */
- nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
+ nrpages = ra_sum_pages(sbi, pages, addr, nrpages);
if (!nrpages)
return -ENOMEM;
- list_for_each_entry_safe(page, tmp, &page_list, lru) {
+ for (index = 0; index < nrpages; index++) {
if (err)
goto skip;
- lock_page(page);
- if (unlikely(!PageUptodate(page))) {
+ lock_page(pages[index]);
+ if (unlikely(!PageUptodate(pages[index]))) {
err = -EIO;
} else {
- rn = F2FS_NODE(page);
+ rn = F2FS_NODE(pages[index]);
sum_entry->nid = rn->footer.nid;
sum_entry->version = 0;
sum_entry->ofs_in_node = 0;
sum_entry++;
}
- unlock_page(page);
+ unlock_page(pages[index]);
skip:
- list_del(&page->lru);
- __free_pages(page, 0);
+ page_cache_release(pages[index]);
}
+
+ invalidate_mapping_pages(inode->i_mapping, addr,
+ addr + nrpages);
}
return err;
}
--
1.7.10.4
--
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