forked from luck/tmp_suning_uos_patched
7bfac9ecf0
There's a possible deadlock in generic_file_splice_write(), splice_from_pipe() and ocfs2_file_splice_write(): - task A calls generic_file_splice_write() - this calls inode_double_lock(), which locks i_mutex on both pipe->inode and target inode - ordering depends on inode pointers, can happen that pipe->inode is locked first - __splice_from_pipe() needs more data, calls pipe_wait() - this releases lock on pipe->inode, goes to interruptible sleep - task B calls generic_file_splice_write(), similarly to the first - this locks pipe->inode, then tries to lock inode, but that is already held by task A - task A is interrupted, it tries to lock pipe->inode, but fails, as it is already held by task B - ABBA deadlock Fix this by explicitly ordering locks: the outer lock must be on target inode and the inner lock (which is later unlocked and relocked) must be on pipe->inode. This is OK, pipe inodes and target inodes form two nonoverlapping sets, generic_file_splice_write() and friends are not called with a target which is a pipe. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: Jens Axboe <jens.axboe@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|---|---|---|
| .. | ||
| cluster | ||
| dlm | ||
| acl.c | ||
| acl.h | ||
| alloc.c | ||
| alloc.h | ||
| aops.c | ||
| aops.h | ||
| blockcheck.c | ||
| blockcheck.h | ||
| buffer_head_io.c | ||
| buffer_head_io.h | ||
| dcache.c | ||
| dcache.h | ||
| dir.c | ||
| dir.h | ||
| dlmglue.c | ||
| dlmglue.h | ||
| export.c | ||
| export.h | ||
| extent_map.c | ||
| extent_map.h | ||
| file.c | ||
| file.h | ||
| heartbeat.c | ||
| heartbeat.h | ||
| inode.c | ||
| inode.h | ||
| ioctl.c | ||
| ioctl.h | ||
| journal.c | ||
| journal.h | ||
| Kconfig | ||
| localalloc.c | ||
| localalloc.h | ||
| locks.c | ||
| locks.h | ||
| Makefile | ||
| mmap.c | ||
| mmap.h | ||
| namei.c | ||
| namei.h | ||
| ocfs1_fs_compat.h | ||
| ocfs2_fs.h | ||
| ocfs2_lockid.h | ||
| ocfs2_lockingver.h | ||
| ocfs2.h | ||
| quota_global.c | ||
| quota_local.c | ||
| quota.h | ||
| resize.c | ||
| resize.h | ||
| slot_map.c | ||
| slot_map.h | ||
| stack_o2cb.c | ||
| stack_user.c | ||
| stackglue.c | ||
| stackglue.h | ||
| suballoc.c | ||
| suballoc.h | ||
| super.c | ||
| super.h | ||
| symlink.c | ||
| symlink.h | ||
| sysfile.c | ||
| sysfile.h | ||
| uptodate.c | ||
| uptodate.h | ||
| ver.c | ||
| ver.h | ||
| xattr.c | ||
| xattr.h | ||