From 1fd36adcd98c14d2fd97f545293c488775cb2823 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 16 Feb 2012 17:49:54 +0000 Subject: Replace the fd_sets in struct fdtable with an array of unsigned longs Replace the fd_sets in struct fdtable with an array of unsigned longs and then use the standard non-atomic bit operations rather than the FD_* macros. This: (1) Removes the abuses of struct fd_set: (a) Since we don't want to allocate a full fd_set the vast majority of the time, we actually, in effect, just allocate a just-big-enough array of unsigned longs and cast it to an fd_set type - so why bother with the fd_set at all? (b) Some places outside of the core fdtable handling code (such as SELinux) want to look inside the array of unsigned longs hidden inside the fd_set struct for more efficient iteration over the entire set. (2) Eliminates the use of FD_*() macros in the kernel completely. (3) Permits the __FD_*() macros to be deleted entirely where not exposed to userspace. Signed-off-by: David Howells Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin Cc: Al Viro --- fs/select.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/select.c') diff --git a/fs/select.c b/fs/select.c index d33418fdc858..2e7fbe8a092c 100644 --- a/fs/select.c +++ b/fs/select.c @@ -348,7 +348,7 @@ static int max_select_fd(unsigned long n, fd_set_bits *fds) set = ~(~0UL << (n & (__NFDBITS-1))); n /= __NFDBITS; fdt = files_fdtable(current->files); - open_fds = fdt->open_fds->fds_bits+n; + open_fds = fdt->open_fds + n; max = 0; if (set) { set &= BITS(fds, n); -- cgit v1.2.3