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path: root/fs/exfat/balloc.c
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2022-05-23exfat: check if cluster num is validTadeusz Struk1-2/+6
Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap. This was triggered by reproducer calling truncute with size 0, which causes the following trace: BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 Read of size 8 at addr ffff888115aa9508 by task syz-executor251/365 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3c0 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181 __exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217 exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243 exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339 notify_change+0xb76/0xe10 fs/attr.c:336 do_truncate+0x1ea/0x2d0 fs/open.c:65 Move the is_valid_cluster() helper from fatent.c to a common header to make it reusable in other *.c files. And add is_valid_cluster() to validate if cluster number is within valid range in exfat_clear_bitmap() and exfat_set_bitmap(). Link: https://syzkaller.appspot.com/bug?id=50381fc73821ecae743b8cf24b4c9a04776f767c Reported-by: syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-01-10exfat: remove argument 'sector' from exfat_get_dentry()Yuezhang.Mo1-1/+1
No any function uses argument 'sector', remove it. Reviewed-by: Andy.Wu <Andy.Wu@sony.com> Reviewed-by: Aoyama, Wataru <wataru.aoyama@sony.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Yuezhang.Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2021-04-27exfat: improve write performance when dirsync enabledHyeongseok Kim1-2/+2
Degradation of write speed caused by frequent disk access for cluster bitmap update on every cluster allocation could be improved by selective syncing bitmap buffer. Change to flush bitmap buffer only for the directory related operations. Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27exfat: add support ioctl and FITRIM functionHyeongseok Kim1-0/+80
Add FITRIM ioctl to enable discarding unused blocks while mounted. As current exFAT doesn't have generic ioctl handler, add empty ioctl function first, and add FITRIM handler. Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-04-27exfat: fix erroneous discard when clear cluster bitHyeongseok Kim1-10/+1
If mounted with discard option, exFAT issues discard command when clear cluster bit to remove file. But the input parameter of cluster-to-sector calculation is abnormally added by reserved cluster size which is 2, leading to discard unrelated sectors included in target+2 cluster. With fixing this, remove the wrong comments in set/clear/find bitmap functions. Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2021-02-22exfat: improve performance of exfat_free_cluster when using dirsync mount optionHyeongseok Kim1-2/+2
There are stressful update of cluster allocation bitmap when using dirsync mount option which is doing sync buffer on every cluster bit clearing. This could result in performance degradation when deleting big size file. Fix to update only when the bitmap buffer index is changed would make less disk access, improving performance especially for truncate operation. Testing with Samsung 256GB sdcard, mounted with dirsync option (mount -t exfat /dev/block/mmcblk0p1 /temp/mount -o dirsync) Remove 4GB file, blktrace result. [Before] : 39 secs. Total (blktrace): Reads Queued: 0, 0KiB Writes Queued: 32775, 16387KiB Read Dispatches: 0, 0KiB Write Dispatches: 32775, 16387KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 32775, 16387KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB IO unplugs: 2 Timer unplugs: 0 [After] : 1 sec. Total (blktrace): Reads Queued: 0, 0KiB Writes Queued: 13, 6KiB Read Dispatches: 0, 0KiB Write Dispatches: 13, 6KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 13, 6KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB IO unplugs: 1 Timer unplugs: 0 Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com> Acked-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: remove EXFAT_SB_DIRTY flagTetsuhiro Kohada1-2/+2
This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid sync_blockdev(). - exfat_put_super(): Before calling this, the VFS has already called sync_filesystem(), so sync is never performed here. - exfat_sync_fs(): After calling this, the VFS calls sync_blockdev(), so, it is meaningless to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here. Remove the EXFAT_SB_DIRTY check to ensure synchronization. And remove the code related to the flag. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: Use a more common logging styleJoe Perches1-5/+3
Remove the direct use of KERN_<LEVEL> in functions by creating separate exfat_<level> macros. Miscellanea: o Remove several unnecessary terminating newlines in formats o Realign arguments and fit to 80 columns where appropriate Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-04-22exfat: Unify access to the boot sectorTetsuhiro Kohada1-3/+0
Unify access to boot sector via 'sbi->pbr_bh'. This fixes vol_flags inconsistency at read failed in fs_set_vol_flags(), and buffer_head leak in __exfat_fill_super(). Signed-off-by: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-03-05exfat: add bitmap operationsNamjae Jeon1-0/+280
This adds the implementation of bitmap operations for exfat. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>