mm/shmem.c: fix unlikely() test of info->seals to test only for WRITE and GROW
Running my likely/unlikely profiler, I discovered that the test in shmem_write_begin() that tests for info->seals as unlikely, is always incorrect. This is because shmem_get_inode() sets info->seals to have F_SEAL_SEAL set by default, and it is unlikely to be cleared when shmem_write_begin() is called. Thus, the if statement is very likely. But as the if statement block only cares about F_SEAL_WRITE and F_SEAL_GROW, change the test to only test those two bits. Link: http://lkml.kernel.org/r/20170203105656.7aec6237@gandalf.local.home Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
c2f83143f1
commit
3f472cc978
|
@ -2331,7 +2331,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
|
|||
pgoff_t index = pos >> PAGE_SHIFT;
|
||||
|
||||
/* i_mutex is held by caller */
|
||||
if (unlikely(info->seals)) {
|
||||
if (unlikely(info->seals & (F_SEAL_WRITE | F_SEAL_GROW))) {
|
||||
if (info->seals & F_SEAL_WRITE)
|
||||
return -EPERM;
|
||||
if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size)
|
||||
|
|
Loading…
Reference in a new issue