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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/open.c | |
parent | 8b3d1cda4f5ff0d7c2ae910ea8fd03493996912f (diff) | |
download | linux-1dce27c5aa6770e9d195f2bb7db1db3d4dde5591.tar.bz2 |
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/open.c')
-rw-r--r-- | fs/open.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c index 77becc041149..5720854156db 100644 --- a/fs/open.c +++ b/fs/open.c @@ -836,7 +836,7 @@ EXPORT_SYMBOL(dentry_open); static void __put_unused_fd(struct files_struct *files, unsigned int fd) { struct fdtable *fdt = files_fdtable(files); - __FD_CLR(fd, fdt->open_fds); + __clear_open_fd(fd, fdt); if (fd < files->next_fd) files->next_fd = fd; } @@ -1080,7 +1080,7 @@ SYSCALL_DEFINE1(close, unsigned int, fd) if (!filp) goto out_unlock; rcu_assign_pointer(fdt->fd[fd], NULL); - FD_CLR(fd, fdt->close_on_exec); + __clear_close_on_exec(fd, fdt); __put_unused_fd(files, fd); spin_unlock(&files->file_lock); retval = filp_close(filp, files); |