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2021-11-25fuse: release pipe buf after last useMiklos Szeredi
Checking buf->flags should be done before the pipe_buf_release() is called on the pipe buffer, since releasing the buffer might modify the flags. This is exactly what page_cache_pipe_buf_release() does, and which results in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was trying to fix. Reported-by: Justin Forbes <jmforbes@linuxtx.org> Fixes: 712a951025c0 ("fuse: fix page stealing") Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-09Merge tag 'fuse-update-5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Fix a possible of deadlock in case inode writeback is in progress during dentry reclaim - Fix a crash in case of page stealing - Selectively invalidate cached attributes, possibly improving performance - Allow filesystems to disable data flushing from ->flush() - Misc fixes and cleanups * tag 'fuse-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (23 commits) fuse: fix page stealing virtiofs: use strscpy for copying the queue name fuse: add FOPEN_NOFLUSH fuse: only update necessary attributes fuse: take cache_mask into account in getattr fuse: add cache_mask fuse: move reverting attributes to fuse_change_attributes() fuse: simplify local variables holding writeback cache state fuse: cleanup code conditional on fc->writeback_cache fuse: fix attr version comparison in fuse_read_update_size() fuse: always invalidate attributes after writes fuse: rename fuse_write_update_size() fuse: don't bump attr_version in cached write fuse: selective attribute invalidation fuse: don't increment nlink in link() fuse: decrement nlink on overwriting rename fuse: simplify __fuse_write_file_get() fuse: move fuse_invalidate_attr() into fuse_update_ctime() fuse: delete redundant code fuse: use kmap_local_page() ...
2021-11-02Merge tag 'gfs2-v5.15-rc5-mmap-fault' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher: "Functions gfs2_file_read_iter and gfs2_file_write_iter are both accessing the user buffer to write to or read from while holding the inode glock. In the most basic deadlock scenario, that buffer will not be resident and it will be mapped to the same file. Accessing the buffer will trigger a page fault, and gfs2 will deadlock trying to take the same inode glock again while trying to handle that fault. Fix that and similar, more complex scenarios by disabling page faults while accessing user buffers. To make this work, introduce a small amount of new infrastructure and fix some bugs that didn't trigger so far, with page faults enabled" * tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix mmap + page fault deadlocks for direct I/O iov_iter: Introduce nofault flag to disable page faults gup: Introduce FOLL_NOFAULT flag to disable page faults iomap: Add done_before argument to iomap_dio_rw iomap: Support partial direct I/O on user copy failures iomap: Fix iomap_dio_rw return value for user copies gfs2: Fix mmap + page fault deadlocks for buffered I/O gfs2: Eliminate ip->i_gh gfs2: Move the inode glock locking to gfs2_file_buffered_write gfs2: Introduce flag for glock holder auto-demotion gfs2: Clean up function may_grant gfs2: Add wrapper for iomap_file_buffered_write iov_iter: Introduce fault_in_iov_iter_writeable iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} powerpc/kvm: Fix kvm_use_magic_page iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value
2021-11-02fuse: fix page stealingMiklos Szeredi
It is possible to trigger a crash by splicing anon pipe bufs to the fuse device. The reason for this is that anon_pipe_buf_release() will reuse buf->page if the refcount is 1, but that page might have already been stolen and its flags modified (e.g. PG_lru added). This happens in the unlikely case of fuse_dev_splice_write() getting around to calling pipe_buf_release() after a page has been stolen, added to the page cache and removed from the page cache. Fix by calling pipe_buf_release() right after the page was inserted into the page cache. In this case the page has an elevated refcount so any release function will know that the page isn't reusable. Reported-by: Frank Dinoff <fdinoff@google.com> Link: https://lore.kernel.org/r/CAAmZXrsGg2xsP1CK+cbuEMumtrqdvD-NKnWzhNcvn71RV3c1yw@mail.gmail.com/ Fixes: dd3bb14f44a6 ("fuse: support splice() writing to fuse device") Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-02virtiofs: use strscpy for copying the queue nameMiklos Szeredi
Always null terminate fsvq->name. Reported-by: kernel test robot <lkp@intel.com> Fixes: b43b7e81eb2b ("virtiofs: provide a helper function for virtqueue initialization") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-01Merge tag 'for-5.16/ki_complete-2021-10-29' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull kiocb->ki_complete() cleanup from Jens Axboe: "This removes the res2 argument from kiocb->ki_complete(). Only the USB gadget code used it, everybody else passes 0. The USB guys checked the user gadget code they could find, and everybody just uses res as expected for the async interface" * tag 'for-5.16/ki_complete-2021-10-29' of git://git.kernel.dk/linux-block: fs: get rid of the res2 iocb->ki_complete argument usb: remove res2 argument from gadget code completions
2021-10-28fuse: add FOPEN_NOFLUSHAmir Goldstein
Add flag returned by FUSE_OPEN and FUSE_CREATE requests to avoid flushing data cache on close. Different filesystems implement ->flush() is different ways: - Most disk filesystems do not implement ->flush() at all - Some network filesystem (e.g. nfs) flush local write cache of FMODE_WRITE file and send a "flush" command to server - Some network filesystem (e.g. cifs) flush local write cache of FMODE_WRITE file without sending an additional command to server FUSE flushes local write cache of ANY file, even non FMODE_WRITE and sends a "flush" command to server (if server implements it). The FUSE implementation of ->flush() seems over agressive and arbitrary and does not make a lot of sense when writeback caching is disabled. Instead of deciding on another arbitrary implementation that makes sense, leave the choice of per-file flush behavior in the hands of the server. Link: https://lore.kernel.org/linux-fsdevel/CAJfpegspE8e6aKd47uZtSYX8Y-1e1FWS0VL0DH2Skb9gQP5RJQ@mail.gmail.com/ Suggested-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: only update necessary attributesMiklos Szeredi
fuse_update_attributes() refreshes metadata for internal use. Each use needs a particular set of attributes to be refreshed, but currently that cannot be expressed and all but atime are refreshed. Add a mask argument, which lets fuse_update_get_attr() to decide based on the cache_mask and the inval_mask whether a GETATTR call is needed or not. Reported-by: Yongji Xie <xieyongji@bytedance.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: take cache_mask into account in getattrMiklos Szeredi
When deciding to send a GETATTR request take into account the cache mask (which attributes are always valid). The cache mask takes precedence over the invalid mask. This results in the GETATTR request not being sent unnecessarily. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: add cache_maskMiklos Szeredi
If writeback_cache is enabled, then the size, mtime and ctime attributes of regular files are always valid in the kernel's cache. They are retrieved from userspace only when the inode is freshly looked up. Add a more generic "cache_mask", that indicates which attributes are currently valid in cache. This patch doesn't change behavior. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: move reverting attributes to fuse_change_attributes()Miklos Szeredi
In case of writeback_cache fuse_fillattr() would revert the queried attributes to the cached version. Move this to fuse_change_attributes() in order to manage the writeback logic in a central helper. This will be necessary for patches that follow. Only fuse_do_getattr() -> fuse_fillattr() uses the attributes after calling fuse_change_attributes(), so this should not change behavior. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: simplify local variables holding writeback cache stateMiklos Szeredi
There are two instances of "bool is_wb = fc->writeback_cache" where the actual use mostly involves checking "is_wb && S_ISREG(inode->i_mode)". Clean up these cases by storing the second condition in the local variable. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: cleanup code conditional on fc->writeback_cacheMiklos Szeredi
It's safe to call file_update_time() if writeback cache is not enabled, since S_NOCMTIME is set in this case. This part is purely a cleanup. __fuse_copy_file_range() also calls fuse_write_update_attr() only in the writeback cache case. This is inconsistent with other callers, where it's called unconditionally. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: fix attr version comparison in fuse_read_update_size()Miklos Szeredi
A READ request returning a short count is taken as indication of EOF, and the cached file size is modified accordingly. Fix the attribute version checking to allow for changes to fc->attr_version on other inodes. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: always invalidate attributes after writesMiklos Szeredi
Extend the fuse_write_update_attr() helper to invalidate cached attributes after a write. This has already been done in all cases except in fuse_notify_store(), so this is mostly a cleanup. fuse_direct_write_iter() calls fuse_direct_IO() which already calls fuse_write_update_attr(), so don't repeat that again in the former. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: rename fuse_write_update_size()Miklos Szeredi
This function already updates the attr_version in fuse_inode, regardless of whether the size was changed or not. Rename the helper to fuse_write_update_attr() to reflect the more generic nature. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: don't bump attr_version in cached writeMiklos Szeredi
The attribute version in fuse_inode should be updated whenever the attributes might have changed on the server. In case of cached writes this is not the case, so updating the attr_version is unnecessary and could possibly affect performance. Open code the remaining part of fuse_write_update_size(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: selective attribute invalidationMiklos Szeredi
Only invalidate attributes that the operation might have changed. Introduce two constants for common combinations of changed attributes: FUSE_STATX_MODIFY: file contents are modified but not size FUSE_STATX_MODSIZE: size and/or file contents modified Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: don't increment nlink in link()Miklos Szeredi
The fuse_iget() call in create_new_entry() already updated the inode with all the new attributes and incremented the attribute version. Incrementing the nlink will result in the wrong count. This wasn't noticed because the attributes were invalidated right after this. Updating ctime is still needed for the writeback case when the ctime is not refreshed. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-25fs: get rid of the res2 iocb->ki_complete argumentJens Axboe
The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-22fuse: decrement nlink on overwriting renameMiklos Szeredi
Rename didn't decrement/clear nlink on overwritten target inode. Create a common helper fuse_entry_unlinked() that handles this for unlink, rmdir and rename. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: simplify __fuse_write_file_get()Miklos Szeredi
Use list_first_entry_or_null() instead of list_empty() + list_entry(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: move fuse_invalidate_attr() into fuse_update_ctime()Miklos Szeredi
Logically it belongs there since attributes are invalidated due to the updated ctime. This is a cleanup and should not change behavior. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: delete redundant codePeng Hao
'ia->io=io' has been set in fuse_io_alloc. Signed-off-by: Peng Hao <flyingpeng@tencent.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: use kmap_local_page()Peng Hao
Due to the introduction of kmap_local_*, the storage of slots used for short-term mapping has changed from per-CPU to per-thread. kmap_atomic() disable preemption, while kmap_local_*() only disable migration. There is no need to disable preemption in several kamp_atomic places used in fuse. Link: https://lwn.net/Articles/836144/ Signed-off-by: Peng Hao <flyingpeng@tencent.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: annotate lock in fuse_reverse_inval_entry()Miklos Szeredi
Add missing inode lock annotatation; found by syzbot. Reported-and-tested-by: syzbot+9f747458f5990eaa8d43@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: write inode in fuse_vma_close() instead of fuse_release()Miklos Szeredi
Fuse ->release() is otherwise asynchronous for the reason that it can happen in contexts unrelated to close/munmap. Inode is already written back from fuse_flush(). Add it to fuse_vma_close() as well to make sure inode dirtying from mmaps also get written out before the file is released. Also add error handling. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: make sure reclaim doesn't write the inodeMiklos Szeredi
In writeback cache mode mtime/ctime updates are cached, and flushed to the server using the ->write_inode() callback. Closing the file will result in a dirty inode being immediately written, but in other cases the inode can remain dirty after all references are dropped. This result in the inode being written back from reclaim, which can deadlock on a regular allocation while the request is being served. The usual mechanisms (GFP_NOFS/PF_MEMALLOC*) don't work for FUSE, because serving a request involves unrelated userspace process(es). Instead do the same as for dirty pages: make sure the inode is written before the last reference is gone. - fallocate(2)/copy_file_range(2): these call file_update_time() or file_modified(), so flush the inode before returning from the call - unlink(2), link(2) and rename(2): these call fuse_update_ctime(), so flush the ctime directly from this helper Reported-by: chenguanyou <chenguanyou@xiaomi.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21fuse: clean up error exits in fuse_fill_super()Miklos Szeredi
Instead of "goto err", return error directly, since there's no error cleanup to do now. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21fuse: always initialize sb->s_fs_infoMiklos Szeredi
Syzkaller reports a null pointer dereference in fuse_test_super() that is caused by sb->s_fs_info being NULL. This is due to the fact that fuse_fill_super() is initializing s_fs_info, which is too late, it's already on the fs_supers list. The initialization needs to be done in sget_fc() with the sb_lock held. Move allocation of fuse_mount and fuse_conn from fuse_fill_super() into fuse_get_tree(). After this ->kill_sb() will always be called with non-NULL ->s_fs_info, hence fuse_mount_destroy() can drop the test for non-NULL "fm". Reported-by: syzbot+74a15f02ccb51f398601@syzkaller.appspotmail.com Fixes: 5d5b74aa9c76 ("fuse: allow sharing existing sb") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21fuse: clean up fuse_mount destructionMiklos Szeredi
1. call fuse_mount_destroy() for open coded variants 2. before deactivate_locked_super() don't need fuse_mount destruction since that will now be done (if ->s_fs_info is not cleared) 3. rearrange fuse_mount setup in fuse_get_tree_submount() so that the regular pattern can be used Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21fuse: get rid of fuse_put_super()Miklos Szeredi
The ->put_super callback is called from generic_shutdown_super() in case of a fully initialized sb. This is called from kill_***_super(), which is called from ->kill_sb instances. Fuse uses ->put_super to destroy the fs specific fuse_mount and drop the reference to the fuse_conn, while it does the same on each error case during sb setup. This patch moves the destruction from fuse_put_super() to fuse_mount_destroy(), called at the end of all ->kill_sb instances. A follup patch will clean up the error paths. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21fuse: check s_root when destroying sbMiklos Szeredi
Checking "fm" works because currently sb->s_fs_info is cleared on error paths; however, sb->s_root is what generic_shutdown_super() checks to determine whether the sb was fully initialized or not. This change will allow cleanup of sb setup error paths. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-18iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readableAndreas Gruenbacher
Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in, similar to copy_to_user, instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in as well as new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure this change doesn't silently break things. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-09-07Merge tag 'fuse-update-5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Allow mounting an active fuse device. Previously the fuse device would always be mounted during initialization, and sharing a fuse superblock was only possible through mount or namespace cloning - Fix data flushing in syncfs (virtiofs only) - Fix data flushing in copy_file_range() - Fix a possible deadlock in atomic O_TRUNC - Misc fixes and cleanups * tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: remove unused arg in fuse_write_file_get() fuse: wait for writepages in syncfs fuse: flush extending writes fuse: truncate pagecache on atomic_o_trunc fuse: allow sharing existing sb fuse: move fget() to fuse_get_tree() fuse: move option checking into fuse_fill_super() fuse: name fs_context consistently fuse: fix use after free in fuse_read_interrupt()
2021-09-06fuse: remove unused arg in fuse_write_file_get()Miklos Szeredi
The struct fuse_conn argument is not used and can be removed. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-09-06fuse: wait for writepages in syncfsMiklos Szeredi
In case of fuse the MM subsystem doesn't guarantee that page writeback completes by the time ->sync_fs() is called. This is because fuse completes page writeback immediately to prevent DoS of memory reclaim by the userspace file server. This means that fuse itself must ensure that writes are synced before sending the SYNCFS request to the server. Introduce sync buckets, that hold a counter for the number of outstanding write requests. On syncfs replace the current bucket with a new one and wait until the old bucket's counter goes down to zero. It is possible to have multiple syncfs calls in parallel, in which case there could be more than one waited-on buckets. Descendant buckets must not complete until the parent completes. Add a count to the child (new) bucket until the (parent) old bucket completes. Use RCU protection to dereference the current bucket and to wake up an emptied bucket. Use fc->lock to protect against parallel assignments to the current bucket. This leaves just the counter to be a possible scalability issue. The fc->num_waiting counter has a similar issue, so both should be addressed at the same time. Reported-by: Amir Goldstein <amir73il@gmail.com> Fixes: 2d82ab251ef0 ("virtiofs: propagate sync() to file server") Cc: <stable@vger.kernel.org> # v5.14 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-09-02Merge tag 'ovl-update-5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: - Copy up immutable/append/sync/noatime attributes (Amir Goldstein) - Improve performance by enabling RCU lookup. - Misc fixes and improvements The reason this touches so many files is that the ->get_acl() method now gets a "bool rcu" argument. The ->get_acl() API was updated based on comments from Al and Linus: Link: https://lore.kernel.org/linux-fsdevel/CAJfpeguQxpd6Wgc0Jd3ks77zcsAv_bn0q17L3VNnnmPKu11t8A@mail.gmail.com/ * tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: enable RCU'd ->get_acl() vfs: add rcu argument to ->get_acl() callback ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup() ovl: use kvalloc in xattr copy-up ovl: update ctime when changing fileattr ovl: skip checking lower file's i_writecount on truncate ovl: relax lookup error on mismatch origin ftype ovl: do not set overlay.opaque for new directories ovl: add ovl_allow_offline_changes() helper ovl: disable decoding null uuid with redirect_dir ovl: consistent behavior for immutable/append-only inodes ovl: copy up sync/noatime fileattr flags ovl: pass ovl_fs to ovl_check_setxattr() fs: add generic helper for filling statx attribute flags
2021-08-31fuse: flush extending writesMiklos Szeredi
Callers of fuse_writeback_range() assume that the file is ready for modification by the server in the supplied byte range after the call returns. If there's a write that extends the file beyond the end of the supplied range, then the file needs to be extended to at least the end of the range, but currently that's not done. There are at least two cases where this can cause problems: - copy_file_range() will return short count if the file is not extended up to end of the source range. - FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE will not extend the file, hence the region may not be fully allocated. Fix by flushing writes from the start of the range up to the end of the file. This could be optimized if the writes are non-extending, etc, but it's probably not worth the trouble. Fixes: a2bc92362941 ("fuse: fix copy_file_range() in the writeback case") Fixes: 6b1bdb56b17c ("fuse: allow fallocate(FALLOC_FL_ZERO_RANGE)") Cc: <stable@vger.kernel.org> # v5.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-30Merge tag 'hole_punch_for_v5.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fs hole punching vs cache filling race fixes from Jan Kara: "Fix races leading to possible data corruption or stale data exposure in multiple filesystems when hole punching races with operations such as readahead. This is the series I was sending for the last merge window but with your objection fixed - now filemap_fault() has been modified to take invalidate_lock only when we need to create new page in the page cache and / or bring it uptodate" * tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: filesystems/locking: fix Malformed table warning cifs: Fix race between hole punch and page fault ceph: Fix race between hole punch and page fault fuse: Convert to using invalidate_lock f2fs: Convert to using invalidate_lock zonefs: Convert to using invalidate_lock xfs: Convert double locking of MMAPLOCK to use VFS helpers xfs: Convert to use invalidate_lock xfs: Refactor xfs_isilocked() ext2: Convert to using invalidate_lock ext4: Convert to use mapping->invalidate_lock mm: Add functions to lock invalidate_lock for two mappings mm: Protect operations adding pages to page cache with invalidate_lock documentation: Sync file_operations members with reality mm: Fix comments mentioning i_mutex
2021-08-18vfs: add rcu argument to ->get_acl() callbackMiklos Szeredi
Add a rcu argument to the ->get_acl() callback to allow get_cached_acl_rcu() to call the ->get_acl() method in the next patch. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-17fuse: truncate pagecache on atomic_o_truncMiklos Szeredi
fuse_finish_open() will be called with FUSE_NOWRITE in case of atomic O_TRUNC. This can deadlock with fuse_wait_on_page_writeback() in fuse_launder_page() triggered by invalidate_inode_pages2(). Fix by replacing invalidate_inode_pages2() in fuse_finish_open() with a truncate_pagecache() call. This makes sense regardless of FOPEN_KEEP_CACHE or fc->writeback cache, so do it unconditionally. Reported-by: Xie Yongji <xieyongji@bytedance.com> Reported-and-tested-by: syzbot+bea44a5189836d956894@syzkaller.appspotmail.com Fixes: e4648309b85a ("fuse: truncate pending writes on O_TRUNC") Cc: <stable@vger.kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-11Merge branch 'for-5.14/dax' into libnvdimm-fixesDan Williams
Pick up some small dax cleanups that make some of Ira's follow on work easier.
2021-08-05fuse: allow sharing existing sbMiklos Szeredi
Make it possible to create a new mount from a already working server. Here's a detailed description of the problem from Jakob: "The background for this question is occasional problems we see with our fuse filesystem [1] and mount namespaces. On a usual client, we have system-wide, autofs managed mountpoints. When a new mount namespace is created (which can be done unprivileged in combination with user namespaces), it can happen that a mountpoint is used inside the new namespace but idle in the root mount namespace. So autofs unmounts the parent, system-wide mountpoint. But the fuse module stays active and still serves mountpoint in the child mount namespace. Because the fuse daemon also blocks other system wide resources corresponding to the mountpoint, this situation effectively prevents new mounts until the child mount namespaces closes. [1] https://github.com/cvmfs/cvmfs" Reported-by: Jakob Blomer <jblomer@cern.ch> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-05fuse: move fget() to fuse_get_tree()Miklos Szeredi
Affected call chains: fuse_get_tree -> get_tree_(bdev|nodev) -> fuse_fill_super Needed for following patch. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04fuse: move option checking into fuse_fill_super()Miklos Szeredi
Checking whether the "fd=", "rootmode=", "user_id=" and "group_id=" mount options are present can be moved from fuse_get_tree() into fuse_fill_super() where the value of the options are consumed. This relaxes semantics of reusing a fuse blockdev mount using the device name. Before this patch presence of these options were enforced but values ignored, after this patch these options are completely ignored in this case. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04fuse: name fs_context consistentlyMiklos Szeredi
Naming convention under fs/fuse/: struct fuse_conn *fc; struct fs_context *fsc; Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04fuse: fix use after free in fuse_read_interrupt()Miklos Szeredi
There is a potential race between fuse_read_interrupt() and fuse_request_end(). TASK1 in fuse_read_interrupt(): delete req->intr_entry (while holding fiq->lock) TASK2 in fuse_request_end(): req->intr_entry is empty -> skip fiq->lock wake up TASK3 TASK3 request is freed TASK1 in fuse_read_interrupt(): dereference req->in.h.unique ***BAM*** Fix by always grabbing fiq->lock if the request was ever interrupted (FR_INTERRUPTED set) thereby serializing with concurrent fuse_read_interrupt() calls. FR_INTERRUPTED is set before the request is queued on fiq->interrupts. Dequeing the request is done with list_del_init() but FR_INTERRUPTED is not cleared in this case. Reported-by: lijiazi <lijiazi@xiaomi.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-07-13fuse: Convert to using invalidate_lockJan Kara
Use invalidate_lock instead of fuse's private i_mmap_sem. The intended purpose is exactly the same. By this conversion we fix a long standing race between hole punching and read(2) / readahead(2) paths that can lead to stale page cache contents. CC: Miklos Szeredi <miklos@szeredi.hu> Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-07fs/fuse: Remove unneeded kaddr parameterIra Weiny
fuse_dax_mem_range_init() does not need the address or the pfn of the memory requested in dax_direct_access(). It is only calling direct access to get the number of pages. Remove the unused variables and stop requesting the kaddr and pfn from dax_direct_access(). Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/20210525172428.3634316-2-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>