user/sven/linux.git/fs/f2fs/debug.c, branch v4.4.294

f2fs: set ->owner for debugfs status file's file_operations

2017-01-06T10:16:13Z

commit 05e6ea2685c964db1e675a24a4f4e2adc22d2388 upstream. The struct file_operations instance serving the f2fs/status debugfs file lacks an initialization of its ->owner. This means that although that file might have been opened, the f2fs module can still get removed. Any further operation on that opened file, releasing included, will cause accesses to unmapped memory. Indeed, Mike Marshall reported the following: BUG: unable to handle kernel paging request at ffffffffa0307430 IP: [] full_proxy_release+0x24/0x90 <...> Call Trace: [] __fput+0xdf/0x1d0 [] ____fput+0xe/0x10 [] task_work_run+0x8e/0xc0 [] do_exit+0x2ae/0xae0 [] ? __audit_syscall_entry+0xae/0x100 [] ? syscall_trace_enter+0x1ca/0x310 [] do_group_exit+0x44/0xc0 [] SyS_exit_group+0x14/0x20 [] do_syscall_64+0x61/0x150 [] entry_SYSCALL64_slow_path+0x25/0x25 <...> ---[ end trace f22ae883fa3ea6b8 ]--- Fixing recursive fault but reboot is needed! Fix this by initializing the f2fs/status file_operations' ->owner with THIS_MODULE. This will allow debugfs to grab a reference to the f2fs module upon any open on that file, thus preventing it from getting removed. Fixes: 902829aa0b72 ("f2fs: move proc files to debugfs") Reported-by: Mike Marshall Reported-by: Martin Brandenburg Signed-off-by: Nicolai Stange Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: use atomic64_t for extent cache hit stat

2015-10-09T23:20:55Z

Our hit stat of extent cache will increase all the time until remount, and we use atomic_t type for the stat variable, so it may easily incur overflow when we query extent cache frequently in a long time running fs. So to avoid that, this patch uses atomic64_t for hit stat variables. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix incorrect bimodal calculation

2015-10-09T23:20:53Z

In update_sit_info, we use div_u64 to handle 'u64 divide u64' case, but div_u64 can only handle 32-bits divisor, so our divisor with u64 type passed to div_u64 will overflow, result in the wrong calculation when show debug info of f2fs as below: BDF: 464, avg. vblocks: 23509 (BDF should never exceed 100) So change to use div64_u64 to handle this case correctly. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix overflow of size calculation

2015-10-09T23:20:50Z

We have potential overflow issue when calculating size of object, when we left shift index with PAGE_CACHE_SHIFT bits, if type of index has only 32-bits space in 32-bit architecture, left shifting will incur overflow, i.e: pgoff_t index = 0xFFFFFFFF; loff_t size = index << PAGE_CACHE_SHIFT; size: 0xFFFFF000 So we should cast index with 64-bits type to avoid this issue. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: adjust showing of extent cache stat

2015-08-22T05:45:16Z

This patch alters to replace total hit stat with rbtree hit stat, and then adjust showing of extent cache stat: Hit Count: L1-1: for largest node hit count; L1-2: for last cached node hit count; L2: for extent node hit after lookuping in rbtree. Hit Ratio: ratio (hit count / total lookup count) Inner Struct Count: tree count, node count. Before: Extent Hit Ratio: 0 / 2 Extent Tree Count: 3 Extent Node Count: 2 Patched: Exten Cacache: - Hit Count: L1-1:4871 L1-2:2074 L2:208 - Hit Ratio: 1% (7153 / 550751) - Inner Struct Count: tree: 26560, node: 11824 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: add largest/cached stat in extent cache

2015-08-22T05:45:15Z

This patch adds to stat the hit count of largest/cached node for showing in debugfs. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: use atomic_t to record hit ratio info of extent cache

2015-08-05T15:08:06Z

Variables for recording extent cache ratio info were updated without protection, this patch tries to alter them to atomic_t type for more accurate stat. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: stat inline xattr inode number

2015-08-05T15:08:05Z

This patch adds to stat the number of inline xattr inode for showing in debugfs. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix building on 32-bit architectures

2015-06-01T23:20:53Z

A bug fix to the debug output extended the type of some local variables to 64-bit, which now causes the kernel to fail building because of missing 64-bit division functions: ERROR: "__aeabi_uldivmod" [fs/f2fs/f2fs.ko] undefined! In the kernel, we have to use div_u64 or do_div to do this, in order to annotate that this is an expensive operation. As the function is only called for debug out, we know this is not performance critical, so it is safe to use div_u64. Signed-off-by: Arnd Bergmann Fixes: d1f85bd38db19 ("f2fs: avoid value overflow in showing current status") Signed-off-by: Jaegeuk Kim

f2fs: avoid value overflow in showing current status

2015-05-28T22:41:44Z

This patch fixes overflow when do cat /sys/kernel/debug/f2fs/status. If a section is relatively large, dist value can be overflowed. Reported-by: Yossi Goldfill Signed-off-by: Jaegeuk Kim