commit 10bc8e4af65946b727728d7479c028742321b60a upstream.
Commit 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs
copies") removed fallback to generic_copy_file_range() for cross-fs
cases inside vfs_copy_file_range().
To preserve behavior of nfsd and ksmbd server-side-copy, the fallback to
generic_copy_file_range() was added in nfsd and ksmbd code, but that
call is missing sb_start_write(), fsnotify hooks and more.
Ideally, nfsd and ksmbd would pass a flag to vfs_copy_file_range() that
will take care of the fallback, but that code would be subtle and we got
vfs_copy_file_range() logic wrong too many times already.
Instead, add a flag to explicitly request vfs_copy_file_range() to
perform only generic_copy_file_range() and let nfsd and ksmbd use this
flag only in the fallback path.
This choise keeps the logic changes to minimum in the non-nfsd/ksmbd code
paths to reduce the risk of further regressions.
Fixes: 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs copies")
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[backport comments for v5.15: - sb_write_started() is missing - assert was dropped ]
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bdeb77bc2c405fa9f954c20269db175a0bd2793f upstream.
sendfile has to return EAGAIN if out_fd is nonblocking and the write into
it would block.
Here is a small reproducer for the problem:
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/sendfile.h>
#define FILE_SIZE (1UL << 30)
int main(int argc, char **argv) {
int p[2], fd;
if (pipe2(p, O_NONBLOCK))
return 1;
fd = open(argv[1], O_RDWR | O_TMPFILE, 0666);
if (fd < 0)
return 1;
ftruncate(fd, FILE_SIZE);
if (sendfile(p[1], fd, 0, FILE_SIZE) == -1) {
fprintf(stderr, "FAIL\n");
}
if (sendfile(p[1], fd, 0, FILE_SIZE) != -1 || errno != EAGAIN) {
fprintf(stderr, "FAIL\n");
}
return 0;
}
It worked before b964bf53e540, it is stuck after b964bf53e540, and it
works again with this fix.
This regression occurred because do_splice_direct() calls pipe_write
that handles O_NONBLOCK. Here is a trace log from the reproducer:
1) | __x64_sys_sendfile64() {
1) | do_sendfile() {
1) | __fdget()
1) | rw_verify_area()
1) | __fdget()
1) | rw_verify_area()
1) | do_splice_direct() {
1) | rw_verify_area()
1) | splice_direct_to_actor() {
1) | do_splice_to() {
1) | rw_verify_area()
1) | generic_file_splice_read()
1) + 74.153 us | }
1) | direct_splice_actor() {
1) | iter_file_splice_write() {
1) | __kmalloc()
1) 0.148 us | pipe_lock();
1) 0.153 us | splice_from_pipe_next.part.0();
1) 0.162 us | page_cache_pipe_buf_confirm();
... 16 times
1) 0.159 us | page_cache_pipe_buf_confirm();
1) | vfs_iter_write() {
1) | do_iter_write() {
1) | rw_verify_area()
1) | do_iter_readv_writev() {
1) | pipe_write() {
1) | mutex_lock()
1) 0.153 us | mutex_unlock();
1) 1.368 us | }
1) 1.686 us | }
1) 5.798 us | }
1) 6.084 us | }
1) 0.174 us | kfree();
1) 0.152 us | pipe_unlock();
1) + 14.461 us | }
1) + 14.783 us | }
1) 0.164 us | page_cache_pipe_buf_release();
... 16 times
1) 0.161 us | page_cache_pipe_buf_release();
1) | touch_atime()
1) + 95.854 us | }
1) + 99.784 us | }
1) ! 107.393 us | }
1) ! 107.699 us | }
Link: https://lkml.kernel.org/r/20220415005015.525191-1-avagin@gmail.com
Fixes: b964bf53e540 ("teach sendfile(2) to handle send-to-pipe directly")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 868f9f2f8e004bfe0d3935b1976f625b2924893b upstream.
A regression has been reported by Nicolas Boichat, found while using the
copy_file_range syscall to copy a tracefs file.
Before commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across
devices") the kernel would return -EXDEV to userspace when trying to
copy a file across different filesystems. After this commit, the
syscall doesn't fail anymore and instead returns zero (zero bytes
copied), as this file's content is generated on-the-fly and thus reports
a size of zero.
Another regression has been reported by He Zhe - the assertion of
WARN_ON_ONCE(ret == -EOPNOTSUPP) can be triggered from userspace when
copying from a sysfs file whose read operation may return -EOPNOTSUPP.
Since we do not have test coverage for copy_file_range() between any two
types of filesystems, the best way to avoid these sort of issues in the
future is for the kernel to be more picky about filesystems that are
allowed to do copy_file_range().
This patch restores some cross-filesystem copy restrictions that existed
prior to commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across
devices"), namely, cross-sb copy is not allowed for filesystems that do
not implement ->copy_file_range().
Filesystems that do implement ->copy_file_range() have full control of
the result - if this method returns an error, the error is returned to
the user. Before this change this was only true for fs that did not
implement the ->remap_file_range() operation (i.e. nfsv3).
Filesystems that do not implement ->copy_file_range() still fall-back to
the generic_copy_file_range() implementation when the copy is within the
same sb. This helps the kernel can maintain a more consistent story
about which filesystems support copy_file_range().
nfsd and ksmbd servers are modified to fall-back to the
generic_copy_file_range() implementation in case vfs_copy_file_range()
fails with -EOPNOTSUPP or -EXDEV, which preserves behavior of
server-side-copy.
fall-back to generic_copy_file_range() is not implemented for the smb
operation FSCTL_DUPLICATE_EXTENTS_TO_FILE, which is arguably a correct
change of behavior.
Fixes: 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices")
Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@chromium.org/
Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/
Link: https://lore.kernel.org/linux-fsdevel/20210630161320.29006-1-lhenriques@suse.de/
Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Fixes: 64bf5ff58dff ("vfs: no fallback for ->copy_file_range")
Link: https://lore.kernel.org/linux-fsdevel/20f17f64-88cb-4e80-07c1-85cb96c83619@windriver.com/
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3efee0567b4a ("fs: remove mandatory file locking support") removes
some operations in functions rw_verify_area().
As these functions are now simplified, do some syntactic clean-up as
follow-up to the removal as well, which was pointed out by compiler
warnings and static analysis.
No functional change.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it off in Fedora and RHEL8. Several other distros have followed suit. I've heard of one problem in all that time: Someone migrated from an older distro that supported "-o mand" to one that didn't, and the host had a fstab entry with "mand" in it which broke on reboot. They didn't actually _use_ mandatory locking so they just removed the mount option and moved on. This patch rips out mandatory locking support wholesale from the kernel, along with the Kconfig option and the Documentation file. It also changes the mount code to ignore the "mand" mount option instead of erroring out, and to throw a big, ugly warning. Signed-off-by: Jeff Layton <jlayton@kernel.org>
no point going through the intermediate pipe Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull clone/dedupe/remap code refactoring from Darrick Wong: "Move the generic file range remap (aka reflink and dedupe) functions out of mm/filemap.c and fs/read_write.c and into fs/remap_range.c to reduce clutter in the first two files" * tag 'vfs-5.10-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: vfs: move the generic write and copy checks out of mm vfs: move the remap range helpers to remap_range.c vfs: move generic_remap_checks out of mm
Pull initial set_fs() removal from Al Viro:
"Christoph's set_fs base series + fixups"
* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Allow a NULL pos pointer to __kernel_read
fs: Allow a NULL pos pointer to __kernel_write
powerpc: remove address space overrides using set_fs()
powerpc: use non-set_fs based maccess routines
x86: remove address space overrides using set_fs()
x86: make TASK_SIZE_MAX usable from assembly code
x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
lkdtm: remove set_fs-based tests
test_bitmap: remove user bitmap tests
uaccess: add infrastructure for kernel builds with set_fs()
fs: don't allow splice read/write without explicit ops
fs: don't allow kernel reads and writes without iter ops
sysctl: Convert to iter interfaces
proc: add a read_iter method to proc proc_ops
proc: cleanup the compat vs no compat file ops
proc: remove a level of indentation in proc_get_inode
Match the behaviour of new_sync_read() and __kernel_write(). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linus prefers that callers be allowed to pass in a NULL pointer for ppos like new_sync_write(). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>