kernel/linux.git/fs/read_write.c, branch v5.10.257

vfs: fix copy_file_range() averts filesystem freeze protection

2022-12-19T11:27:30+00:00

commit 10bc8e4af65946b727728d7479c028742321b60a upstream. [backport comments for pre v5.15: - ksmbd mentions are irrelevant - ksmbd hunks were dropped - sb_write_started() is missing - assert was dropped ] 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 Tested-by: Luis Henriques Signed-off-by: Amir Goldstein Signed-off-by: Al Viro Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman

vfs: fix copy_file_range() regression in cross-fs copies

2022-12-19T11:27:30+00:00

commit 868f9f2f8e004bfe0d3935b1976f625b2924893b upstream. [backport comments for pre v5.15: - This commit has a bug fixed by commit 10bc8e4af659 ("vfs: fix copy_file_range() averts filesystem freeze protection") - ksmbd mentions are irrelevant - ksmbd hunks were dropped ] 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 Reported-by: kernel test robot Signed-off-by: Luis Henriques 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 Tested-by: Namjae Jeon Tested-by: Luis Henriques Signed-off-by: Amir Goldstein Signed-off-by: Linus Torvalds Link: https://bugzilla.kernel.org/show_bug.cgi?id=216800 Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman

Merge tag 'vfs-5.10-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2020-10-23T18:33:41+00:00

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

Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-22T16:59:21+00:00

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

fs: Allow a NULL pos pointer to __kernel_read

2020-10-15T18:20:42+00:00

Match the behaviour of new_sync_read() and __kernel_write(). Reviewed-by: Christoph Hellwig Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Al Viro

fs: Allow a NULL pos pointer to __kernel_write

2020-10-15T18:20:41+00:00

Linus prefers that callers be allowed to pass in a NULL pointer for ppos like new_sync_write(). Reviewed-by: Christoph Hellwig Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Al Viro

vfs: move the generic write and copy checks out of mm

2020-10-15T16:50:01+00:00

The generic write check helpers also don't have much to do with the page cache, so move them to the vfs. Signed-off-by: Darrick J. Wong

vfs: move the remap range helpers to remap_range.c

2020-10-15T16:48:49+00:00

Complete the migration by moving the file remapping helper functions out of read_write.c and into remap_range.c. This reduces the clutter in the first file and (eventually) will make it so that we can compile out the second file if it isn't needed. Signed-off-by: Darrick J. Wong

Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-12T23:35:51+00:00

Pull compat iovec cleanups from Al Viro: "Christoph's series around import_iovec() and compat variant thereof" * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: security/keys: remove compat_keyctl_instantiate_key_iov mm: remove compat_process_vm_{readv,writev} fs: remove compat_sys_vmsplice fs: remove the compat readv/writev syscalls fs: remove various compat readv/writev helpers iov_iter: transparently handle compat iovecs in import_iovec iov_iter: refactor rw_copy_check_uvector and import_iovec iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c compat.h: fix a spelling error in

fs: remove the compat readv/writev syscalls

2020-10-03T04:02:14+00:00

Now that import_iovec handles compat iovecs, the native readv and writev syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro