kernel/linux.git/fs/fuse/file.c, branch linux-6.0.y

fuse: lock inode unconditionally in fuse_fallocate()

2022-12-02T16:43:16+00:00

commit 44361e8cf9ddb23f17bdcc40ca944abf32e83e79 upstream. file_modified() must be called with inode lock held. fuse_fallocate() didn't lock the inode in case of just FALLOC_KEEP_SIZE flags value, which resulted in a kernel Warning in notify_change(). Lock the inode unconditionally, like all other fallocate implementations do. Reported-by: Pengfei Xu Reported-and-tested-by: syzbot+462da39f0667b357c4b6@syzkaller.appspotmail.com Fixes: 4a6f278d4827 ("fuse: add file_modified() to fallocate") Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: add file_modified() to fallocate

2022-11-10T17:17:33+00:00

commit 4a6f278d4827b59ba26ceae0ff4529ee826aa258 upstream. Add missing file_modified() call to fuse_file_fallocate(). Without this fallocate on fuse failed to clear privileges. Fixes: 05ba1f082300 ("fuse: add FALLOCATE operation") Cc: Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-08-09T03:04:35+00:00

Pull more iov_iter updates from Al Viro: - more new_sync_{read,write}() speedups - ITER_UBUF introduction - ITER_PIPE cleanups - unification of iov_iter_get_pages/iov_iter_get_pages_alloc and switching them to advancing semantics - making ITER_PIPE take high-order pages without splitting them - handling copy_page_from_iter() for high-order pages properly * tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) fix copy_page_from_iter() for compound destinations hugetlbfs: copy_page_to_iter() can deal with compound pages copy_page_to_iter(): don't split high-order page in case of ITER_PIPE expand those iov_iter_advance()... pipe_get_pages(): switch to append_pipe() get rid of non-advancing variants ceph: switch the last caller of iov_iter_get_pages_alloc() 9p: convert to advancing variant of iov_iter_get_pages_alloc() af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages() iter_to_pipe(): switch to advancing variant of iov_iter_get_pages() block: convert to advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: saner helper for page array allocation fold __pipe_get_pages() into pipe_get_pages() ITER_XARRAY: don't open-code DIV_ROUND_UP() unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts unify xarray_get_pages() and xarray_get_pages_alloc() unify pipe_get_pages() and pipe_get_pages_alloc() iov_iter_get_pages(): sanity-check arguments iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper ...

iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()

2022-08-09T02:37:22+00:00

Most of the users immediately follow successful iov_iter_get_pages() with advancing by the amount it had returned. Provide inline wrappers doing that, convert trivial open-coded uses of those. BTW, iov_iter_get_pages() never returns more than it had been asked to; such checks in cifs ought to be removed someday... Reviewed-by: Jeff Layton Signed-off-by: Al Viro

new iov_iter flavour - ITER_UBUF

2022-08-09T02:37:15+00:00

Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro

Merge tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2022-08-08T18:10:02+00:00

Pull fuse updates from Miklos Szeredi: - Fix an issue with reusing the bdi in case of block based filesystems - Allow root (in init namespace) to access fuse filesystems in user namespaces if expicitly enabled with a module param - Misc fixes * tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: retire block-device-based superblock on force unmount vfs: function to prevent re-use of block-device-based superblocks virtio_fs: Modify format for virtio_fs_direct_access virtiofs: delete unused parameter for virtio_fs_cleanup_vqs fuse: Add module param for CAP_SYS_ADMIN access bypassing allow_other fuse: Remove the control interface for virtio-fs fuse: ioctl: translate ENOSYS fuse: limit nsec fuse: avoid unnecessary spinlock bump fuse: fix deadlock between atomic O_TRUNC and page invalidation fuse: write inode in fuse_release()

fuse: fix deadlock between atomic O_TRUNC and page invalidation

2022-07-21T14:02:45+00:00

fuse_finish_open() will be called with FUSE_NOWRITE set in case of atomic O_TRUNC open(), so commit 76224355db75 ("fuse: truncate pagecache on atomic_o_trunc") replaced invalidate_inode_pages2() by truncate_pagecache() in such a case to avoid the A-A deadlock. However, we found another A-B-B-A deadlock related to the case above, which will cause the xfstests generic/464 testcase hung in our virtio-fs test environment. For example, consider two processes concurrently open one same file, one with O_TRUNC and another without O_TRUNC. The deadlock case is described below, if open(O_TRUNC) is already set_nowrite(acquired A), and is trying to lock a page (acquiring B), open() could have held the page lock (acquired B), and waiting on the page writeback (acquiring A). This would lead to deadlocks. open(O_TRUNC) ---------------------------------------------------------------- fuse_open_common inode_lock [C acquire] fuse_set_nowrite [A acquire] fuse_finish_open truncate_pagecache lock_page [B acquire] truncate_inode_page unlock_page [B release] fuse_release_nowrite [A release] inode_unlock [C release] ---------------------------------------------------------------- open() ---------------------------------------------------------------- fuse_open_common fuse_finish_open invalidate_inode_pages2 lock_page [B acquire] fuse_launder_page fuse_wait_on_page_writeback [A acquire & release] unlock_page [B release] ---------------------------------------------------------------- Besides this case, all calls of invalidate_inode_pages2() and invalidate_inode_pages2_range() in fuse code also can deadlock with open(O_TRUNC). Fix by moving the truncate_pagecache() call outside the nowrite protected region. The nowrite protection is only for delayed writeback (writeback_cache) case, where inode lock does not protect against truncation racing with writes on the server. Write syscalls racing with page cache truncation still get the inode lock protection. This patch also changes the order of filemap_invalidate_lock() vs. fuse_set_nowrite() in fuse_open_common(). This new order matches the order found in fuse_file_fallocate() and fuse_do_setattr(). Reported-by: Jiachen Zhang Tested-by: Jiachen Zhang Fixes: e4648309b85a ("fuse: truncate pending writes on O_TRUNC") Cc: Signed-off-by: Miklos Szeredi

fuse: write inode in fuse_release()

2022-07-21T14:02:45+00:00

A race between write(2) and close(2) allows pages to be dirtied after fuse_flush -> write_inode_now(). If these pages are not flushed from fuse_release(), then there might not be a writable open file later. So any remaining dirty pages must be written back before the file is released. This is a partial revert of the blamed commit. Reported-by: syzbot+6e1efbd8efaaa6860e91@syzkaller.appspotmail.com Fixes: 36ea23374d1f ("fuse: write inode in fuse_vma_close() instead of fuse_release()") Cc: # v5.16 Signed-off-by: Miklos Szeredi

iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC

2022-06-10T20:05:15+00:00

New helper to be used instead of direct checks for IOCB_DSYNC: iocb_is_dsync(iocb). Checks converted, which allows to avoid the IS_SYNC(iocb->ki_filp->f_mapping->host) part (4 cache lines) from iocb_flags() - it's checked in iocb_is_dsync() instead Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Al Viro

fuse: Convert fuse to read_folio

2022-05-09T20:21:45+00:00

This is a "weak" conversion which converts straight back to using pages. A full conversion should be performed at some point, hopefully by someone familiar with the filesystem. Signed-off-by: Matthew Wilcox (Oracle)