starfive-tech/linux.git/fs/fuse, branch VF2_v3.4.5

fuse: clean up error exits in fuse_fill_super()

2021-10-21T08:01:39+00:00

Instead of "goto err", return error directly, since there's no error cleanup to do now. Signed-off-by: Miklos Szeredi

fuse: always initialize sb->s_fs_info

2021-10-21T08:01:39+00:00

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

fuse: clean up fuse_mount destruction

2021-10-21T08:01:39+00:00

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

fuse: get rid of fuse_put_super()

2021-10-21T08:01:38+00:00

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

fuse: check s_root when destroying sb

2021-10-21T08:01:38+00:00

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

Merge tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2021-09-07T19:18:29+00:00

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()

fuse: remove unused arg in fuse_write_file_get()

2021-09-06T11:37:10+00:00

The struct fuse_conn argument is not used and can be removed. Signed-off-by: Miklos Szeredi

fuse: wait for writepages in syncfs

2021-09-06T11:37:02+00:00

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 Fixes: 2d82ab251ef0 ("virtiofs: propagate sync() to file server") Cc: # v5.14 Signed-off-by: Miklos Szeredi

Merge tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

2021-09-02T16:21:27+00:00

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

fuse: flush extending writes

2021-08-31T12:18:08+00:00

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: # v5.2 Signed-off-by: Miklos Szeredi