diff options
| author | David Howells <dhowells@redhat.com> | 2012-02-16 17:49:42 +0000 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2012-02-19 10:30:52 -0800 |
| commit | 1dce27c5aa6770e9d195f2bb7db1db3d4dde5591 (patch) | |
| tree | 4ad3ffeee95cb5b10e047b7cb9bdbb48cfc734e0 /fs/fcntl.c | |
| parent | 8b3d1cda4f5ff0d7c2ae910ea8fd03493996912f (diff) | |
Wrap accesses to the fd_sets in struct fdtable
Wrap accesses to the fd_sets in struct fdtable (for recording open files and
close-on-exec flags) so that we can move away from using fd_sets since we
abuse the fd_set structs by not allocating the full-sized structure under
normal circumstances and by non-core code looking at the internals of the
fd_sets.
The first abuse means that use of FD_ZERO() on these fd_sets is not permitted,
since that cannot be told about their abnormal lengths.
This introduces six wrapper functions for setting, clearing and testing
close-on-exec flags and fd-is-open flags:
void __set_close_on_exec(int fd, struct fdtable *fdt);
void __clear_close_on_exec(int fd, struct fdtable *fdt);
bool close_on_exec(int fd, const struct fdtable *fdt);
void __set_open_fd(int fd, struct fdtable *fdt);
void __clear_open_fd(int fd, struct fdtable *fdt);
bool fd_is_open(int fd, const struct fdtable *fdt);
Note that I've prepended '__' to the names of the set/clear functions because
they require the caller to hold a lock to use them.
Note also that I haven't added wrappers for looking behind the scenes at the
the array. Possibly that should exist too.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 22764c7c838..75e7c1f3a08 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -32,20 +32,20 @@ void set_close_on_exec(unsigned int fd, int flag) spin_lock(&files->file_lock); fdt = files_fdtable(files); if (flag) - FD_SET(fd, fdt->close_on_exec); + __set_close_on_exec(fd, fdt); else - FD_CLR(fd, fdt->close_on_exec); + __clear_close_on_exec(fd, fdt); spin_unlock(&files->file_lock); } -static int get_close_on_exec(unsigned int fd) +static bool get_close_on_exec(unsigned int fd) { struct files_struct *files = current->files; struct fdtable *fdt; - int res; + bool res; rcu_read_lock(); fdt = files_fdtable(files); - res = FD_ISSET(fd, fdt->close_on_exec); + res = close_on_exec(fd, fdt); rcu_read_unlock(); return res; } @@ -90,15 +90,15 @@ SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags) err = -EBUSY; fdt = files_fdtable(files); tofree = fdt->fd[newfd]; - if (!tofree && FD_ISSET(newfd, fdt->open_fds)) + if (!tofree && fd_is_open(newfd, fdt)) goto out_unlock; get_file(file); rcu_assign_pointer(fdt->fd[newfd], file); - FD_SET(newfd, fdt->open_fds); + __set_open_fd(newfd, fdt); if (flags & O_CLOEXEC) - FD_SET(newfd, fdt->close_on_exec); + __set_close_on_exec(newfd, fdt); else - FD_CLR(newfd, fdt->close_on_exec); + __clear_close_on_exec(newfd, fdt); spin_unlock(&files->file_lock); if (tofree) |