shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-03-25 20:10:23 +09:00
Code Issues Packages Projects Releases Wiki Activity

UPSTREAM: squashfs: fix extending readahead beyond end of file

Browse Source 
The readahead code will try to extend readahead to the entire size of the
Squashfs data block.

But, it didn't take into account that the last block at the end of the
file may not be a whole block.  In this case, the code would extend
readahead to beyond the end of the file, leaving trailing pages.

Fix this by only requesting the expected number of pages.

Link: https://lkml.kernel.org/r/20221020223616.7571-3-phillip@squashfs.org.uk
Fixes: 8fc78b6fe2 ("squashfs: implement readahead")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Bug: 290900323
(cherry picked from commit c9199de82b)
Change-Id: Ic2d449471ab6caa8acbde2eba48b781d47ad0e2a
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
This commit is contained in:
Phillip Lougher
2022-10-20 23:36:15 +01:00
committed by Lecopzer Chen
parent dec4ef3ce4
commit 813c3dec23
1 changed files with 7 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
fs/squashfs/file.c
View File

@@ -557,6 +557,12 @@ static void squashfs_readahead(struct readahead_control *ractl)
unsigned int expected;
struct page *last_page;
expected = start >> msblk->block_log == file_end ?
(i_size_read(inode) & (msblk->block_size - 1)) :
msblk->block_size;
max_pages = (expected + PAGE_SIZE - 1) >> PAGE_SHIFT;
nr_pages = __readahead_batch(ractl, pages, max_pages);
if (!nr_pages)
break;
@@ -565,13 +571,10 @@ static void squashfs_readahead(struct readahead_control *ractl)
goto skip_pages;
index = pages[0]->index >> shift;
if ((pages[nr_pages - 1]->index >> shift) != index)
goto skip_pages;
expected = index == file_end ?
(i_size_read(inode) & (msblk->block_size - 1)) :
msblk->block_size;
if (index == file_end && squashfs_i(inode)->fragment_block !=
SQUASHFS_INVALID_BLK) {
res = squashfs_readahead_fragment(pages, nr_pages,