While here also cleanup some surrounding code; particularly
drop some malloc() casts.
Found with devel/coccinelle.
Reviewed by: bde (previous version - all new bugs are mine)
- In the unionfs case, opendir() and fdopendir() read the directory's full
contents and cache it. This cache is not refreshed when rewinddir() is
called, so rewinddir() will not notice updates to a directory. Fix this
by splitting the code to fetch a directory's contents out of
__opendir_common() into a new _filldir() function and call this from
rewinddir() when operating on a unionfs directory.
- If rewinddir() is called on a directory opened with fdopendir() before
any directory entries are fetched, rewinddir() will not adjust the seek
location of the backing file descriptor. If the file descriptor passed
to fdopendir() had a non-zero offset, the rewinddir() will not rewind to
the beginning. Fix this by always seeking back to 0 in rewinddir().
This means the dd_rewind hack can also be removed.
While here, add missing locking to rewinddir().
CR: https://phabric.freebsd.org/D312
Reviewed by: jilles
MFC after: 1 week
* Reopen the directory using openat(fd, ".", ...) instead of opening the
pathname again. This fixes a race condition where the meaning of the
pathname changes and allows a reopen with fdopendir().
* Always reopen the directory for union stacks, not only when DTF_REWIND
is passed. Applications should be able to fchdir(dirfd(dir)) and
*at(dirfd(dir), ...). DTF_REWIND now does nothing.
This fixes a race condition where another thread may fork() before CLOEXEC
is set, unintentionally passing the descriptor to the child process.
This commit only adds O_CLOEXEC flags to open() or openat() calls where no
fcntl(fd, F_SETFD, FD_CLOEXEC) follows. The separate fcntl() call still
leaves a race window so it should be fixed later.
Introduce dirfd() libc exported symbol replacing macro with same name,
preserve _dirfd() macro for internal use.
Replace dirp->dd_fd with dirfd() call. Avoid using dirfd as variable
name to prevent shadowing global symbol.
Sponsored by: Google Summer Of Code 2011
They were made excessive in r205424 by opening with O_DIRECTORY.
Also eliminated the fcntl() call used to set FD_CLOEXEC by opening
with O_CLOEXEC.
(fdopendir() still checks that the passed descriptor is a directory,
and sets FD_CLOEXEC on it.)
Reviewed by: ed
POSIX 2008 and XSI 7require strcoll() for opendir() is not true.
I can't find such requirement in POSIX 2008 and XSI 7.
So, back out that part of my commit, returning old strcmp(), and remove
this misleading comment.
It also matches now how our 'ls' works for years.
b) Remove comment expressed 2 fears:
1) One just simple describe how strcoll() works in _any_ context,
not for directories only. Are we plan to remove strcoll() from everything
just because it is little more complex than strcmp()? I doubt, and
directories give nothing different here. Moreover, strcoll() used
in 'ls' for years and nobody complaints yet.
2) Plain wrong statement about undefined strcoll() behaviour. strcoll()
always gives predictable results, falling back to strcmp() on any
trouble, see strcoll(3).
No objections from -current list discussion.
alphasort-like interface to the comparision function required by
qsort() and qsort_r().
For opendir() thunk and alphasort(), comment on why we deviated from
POSIX by using strcmp() instead of strcoll().
Requested and reviewed by: bde
MFC after: 2 weeks
Std 1003.1-2008. Both Linux and Solaris conforms to the new definitions,
so we better follow too (older glibc used old BSDish alphasort prototype
and corresponding type of the comparision function for scandir). While
there, change the definitions of the functions to ANSI C and fix several
style issues nearby.
Remove requirement for "sys/types.h" include for functions from manpage.
POSIX also requires that alphasort(3) sorts as if strcoll(3) was used,
but leave the strcmp(3) call in the function for now.
Adapt in-tree callers of scandir(3) to new declaration. The fact that
select_sections() from catman(1) could modify supplied struct dirent is
a bug.
PR: standards/142255
MFC after: 2 weeks
deals with the usual __opendir2() calls, and the rest part with an interface
translator to expose fdopendir(3) functionality. Manual page was obtained from
kib@'s work for *at(2) system calls.
Fixes a problem where directory entries could show up twice: once
on the top layer of the union stack, and once on the bottom layer.
Approved by: re (rwatson)
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.
Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo
Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.
Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.
Remove uneeded includes of <errno.h> from a few files.
Add $FreeBSD$ to a few files in order to pass commitprep.
Approved by: -arch
telldir positions. This will allow (future) locking on a
per-DIR basis (for MT-safety). For now, this change does
the following:
o Remove the hash table from telldir.c. Recode to use queue
macros.
o Remove 'const' from 'telldir(const DIR *)'.
o Remove 'register' variables as suggested in a recent
thread.
No response from: -current
just use _foo() <-- foo(). In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate. In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().
Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().
Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().
Make thread cancellation fully POSIX-compliant.
Suggested by: deischen
points. For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep(). The arrows represent weak aliases. For
system calls, the pattern is _read() <-- _libc_read() <-- read().
In some cases replace if (a == null) a = malloc(x); else a =
realloc(a, x); with simple reallocf(a, x). Per ANSI-C, this is
guaranteed to be the same thing.
I've been running these on my system here w/o ill effects for some
time. However, the CTM-express is at part 6 of 34 for the CAM
changes, so I've not been able to do a build world with the CAM in the
tree with these changes. Shouldn't impact anything, but...
My changes to preserve errno across free() and close() and to report
fstat() errors properly were blown away.
Updated the FreeBSD changes to match the Lite2 style fixes.
- it succeeded on non-directories (see POSIX 5.1.2.4).
- it hung on (non-open) named pipes.
- it leaked memory if the second malloc() failed.
- it didn't preserve errno across errors in close().
