kernel/git/stable/linux.git/fs/fuse/file.c, branch linux-4.4.y

fuse: Fix parameter for FS_IOC_{GET,SET}FLAGS

2020-07-22T07:10:06+00:00

commit 31070f6ccec09f3bd4f1e28cd1e592fa4f3ba0b6 upstream. The ioctl encoding for this parameter is a long but the documentation says it should be an int and the kernel drivers expect it to be an int. If the fuse driver treats this as a long it might end up scribbling over the stack of a userspace process that only allocated enough space for an int. This was previously discussed in [1] and a patch for fuse was proposed in [2]. From what I can tell the patch in [2] was nacked in favor of adding new, "fixed" ioctls and using those from userspace. However there is still no "fixed" version of these ioctls and the fact is that it's sometimes infeasible to change all userspace to use the new one. Handling the ioctls specially in the fuse driver seems like the most pragmatic way for fuse servers to support them without causing crashes in userspace applications that call them. [1]: https://lore.kernel.org/linux-fsdevel/20131126200559.GH20559@hall.aurel32.net/T/ [2]: https://sourceforge.net/p/fuse/mailman/message/31771759/ Signed-off-by: Chirantan Ekbote Fixes: 59efec7b9039 ("fuse: implement ioctl support") Cc: Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: truncate pending writes on O_TRUNC

2019-11-06T11:09:18+00:00

commit e4648309b85a78f8c787457832269a8712a8673e upstream. Make sure cached writes are not reordered around open(..., O_TRUNC), with the obvious wrong results. Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on") Cc: # v3.15+ Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: fix missing unlock_page in fuse_writepage()

2019-10-05T10:27:52+00:00

commit d5880c7a8620290a6c90ced7a0e8bd0ad9419601 upstream. unlock_page() was missing in case of an already in-flight write against the same page. Signed-off-by: Vasily Averin Fixes: ff17be086477 ("fuse: writepage: skip already in flight") Cc: # v3.13 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: Add FOPEN_STREAM to use stream_open()

2019-06-11T10:24:13+00:00

commit bbd84f33652f852ce5992d65db4d020aba21f882 upstream. Starting from commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") files opened even via nonseekable_open gate read and write via lock and do not allow them to be run simultaneously. This can create read vs write deadlock if a filesystem is trying to implement a socket-like file which is intended to be simultaneously used for both read and write from filesystem client. See commit 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock") for details and e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") for a similar deadlock example on /proc/xen/xenbus. To avoid such deadlock it was tempting to adjust fuse_finish_open to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. Add another flag (FOPEN_STREAM) for filesystem servers to indicate that the opened handler is having stream-like semantics; does not use file position and thus the kernel is free to issue simultaneous read and write request on opened file handle. This patch together with stream_open() should be added to stable kernels starting from v3.14+. This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in open handler and this way avoid the deadlock on all kernel versions. This should work because fuse_finish_open ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Kirill Smelkov Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: fallocate: fix return with locked inode

2019-06-11T10:24:13+00:00

commit 35d6fcbb7c3e296a52136347346a698a35af3fda upstream. Do the proper cleanup in case the size check fails. Tested with xfstests:generic/228 Reported-by: kbuild test robot Reported-by: Dan Carpenter Fixes: 0cbade024ba5 ("fuse: honor RLIMIT_FSIZE in fuse_file_fallocate") Cc: Liu Bo Cc: # v3.5 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: honor RLIMIT_FSIZE in fuse_file_fallocate

2019-06-11T10:23:46+00:00

commit 0cbade024ba501313da3b7e5dd2a188a6bc491b5 upstream. fstests generic/228 reported this failure that fuse fallocate does not honor what 'ulimit -f' has set. This adds the necessary inode_newsize_ok() check. Signed-off-by: Liu Bo Fixes: 05ba1f082300 ("fuse: add FALLOCATE operation") Cc: # v3.5 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: fix writepages on 32bit

2019-06-11T10:23:46+00:00

commit 9de5be06d0a89ca97b5ab902694d42dfd2bb77d2 upstream. Writepage requests were cropped to i_size & 0xffffffff, which meant that mmaped writes to any file larger than 4G might be silently discarded. Fix by storing the file size in a properly sized variable (loff_t instead of size_t). Reported-by: Antonio SJ Musumeci Fixes: 6eaf4782eb09 ("fuse: writepages: crop secondary requests") Cc: # v3.13 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: decrement NR_WRITEBACK_TEMP on the right page

2019-02-20T09:13:16+00:00

commit a2ebba824106dabe79937a9f29a875f837e1b6d4 upstream. NR_WRITEBACK_TEMP is accounted on the temporary page in the request, not the page cache page. Fixes: 8b284dc47291 ("fuse: writepages: handle same page rewrites") Cc: # v3.13 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: Dont call set_page_dirty_lock() for ITER_BVEC pages for async_dio

2018-11-10T15:41:37+00:00

[ Upstream commit 61c12b49e1c9c77d7a1bcc161de540d0fd21cf0c ] Commit 8fba54aebbdf ("fuse: direct-io: don't dirty ITER_BVEC pages") fixes the ITER_BVEC page deadlock for direct io in fuse by checking in fuse_direct_io(), whether the page is a bvec page or not, before locking it. However, this check is missed when the "async_dio" mount option is enabled. In this case, set_page_dirty_lock() is called from the req->end callback in request_end(), when the fuse thread is returning from userspace to respond to the read request. This will cause the same deadlock because the bvec condition is not checked in this path. Here is the stack of the deadlocked thread, while returning from userspace: [13706.656686] INFO: task glusterfs:3006 blocked for more than 120 seconds. [13706.657808] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [13706.658788] glusterfs D ffffffff816c80f0 0 3006 1 0x00000080 [13706.658797] ffff8800d6713a58 0000000000000086 ffff8800d9ad7000 ffff8800d9ad5400 [13706.658799] ffff88011ffd5cc0 ffff8800d6710008 ffff88011fd176c0 7fffffffffffffff [13706.658801] 0000000000000002 ffffffff816c80f0 ffff8800d6713a78 ffffffff816c790e [13706.658803] Call Trace: [13706.658809] [] ? bit_wait_io_timeout+0x80/0x80 [13706.658811] [] schedule+0x3e/0x90 [13706.658813] [] schedule_timeout+0x1b5/0x210 [13706.658816] [] ? gup_pud_range+0x1db/0x1f0 [13706.658817] [] ? kvm_clock_read+0x1e/0x20 [13706.658819] [] ? kvm_clock_get_cycles+0x9/0x10 [13706.658822] [] ? ktime_get+0x52/0xc0 [13706.658824] [] io_schedule_timeout+0xa4/0x110 [13706.658826] [] bit_wait_io+0x36/0x50 [13706.658828] [] __wait_on_bit_lock+0x76/0xb0 [13706.658831] [] ? lock_request+0x46/0x70 [fuse] [13706.658834] [] __lock_page+0xaa/0xb0 [13706.658836] [] ? wake_atomic_t_function+0x40/0x40 [13706.658838] [] set_page_dirty_lock+0x58/0x60 [13706.658841] [] fuse_release_user_pages+0x58/0x70 [fuse] [13706.658844] [] ? fuse_aio_complete+0x190/0x190 [fuse] [13706.658847] [] fuse_aio_complete_req+0x29/0x90 [fuse] [13706.658849] [] request_end+0xd9/0x190 [fuse] [13706.658852] [] fuse_dev_do_write+0x336/0x490 [fuse] [13706.658854] [] fuse_dev_write+0x6e/0xa0 [fuse] [13706.658857] [] ? security_file_permission+0x23/0x90 [13706.658859] [] do_iter_readv_writev+0x60/0x90 [13706.658862] [] ? fuse_dev_splice_write+0x350/0x350 [fuse] [13706.658863] [] do_readv_writev+0x171/0x1f0 [13706.658866] [] ? try_to_wake_up+0x210/0x210 [13706.658868] [] vfs_writev+0x41/0x50 [13706.658870] [] SyS_writev+0x56/0xf0 [13706.658872] [] ? syscall_trace_leave+0xf1/0x160 [13706.658874] [] system_call_fastpath+0x12/0x71 Fix this by making should_dirty a fuse_io_priv parameter that can be checked in fuse_aio_complete_req(). Reported-by: Tiger Yang Signed-off-by: Ashish Samant Signed-off-by: Miklos Szeredi Signed-off-by: Sasha Levin

fuse: Add missed unlock_page() to fuse_readpages_fill()

2018-09-05T07:18:39+00:00

commit 109728ccc5933151c68d1106e4065478a487a323 upstream. The above error path returns with page unlocked, so this place seems also to behave the same. Fixes: f8dbdf81821b ("fuse: rework fuse_readpages()") Signed-off-by: Kirill Tkhai Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman