fuse_get_user_pages() should return error or 0. Otherwise fuse_direct_io
read will not return 0 to indicate that read has completed.
Fixes: 742f992708df ("fuse: return patrial success from fuse_direct_io()")
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a user calls writev/readv in direct io mode with partially valid data in the iovec array such that any vector other than the first one in the array contains invalid data, we currently return the error for the invalid iovec. Instead, we should return the number of bytes already written/read and not the error as we do in the non direct_io case. Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com> Signed-off-by: Ashish Samant <ashish.samant@oracle.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The 'reqs' member of fuse_io_priv serves two purposes. First is to track
the number of oustanding async requests to the server and to signal that
the io request is completed. The second is to be a reference count on the
structure to know when it can be freed.
For sync io requests these purposes can be at odds. fuse_direct_IO() wants
to block until the request is done, and since the signal is sent when
'reqs' reaches 0 it cannot keep a reference to the object. Yet it needs to
use the object after the userspace server has completed processing
requests. This leads to some handshaking and special casing that it
needlessly complicated and responsible for at least one race condition.
It's much cleaner and safer to maintain a separate reference count for the
object lifecycle and to let 'reqs' just be a count of outstanding requests
to the userspace server. Then we can know for sure when it is safe to free
the object without any handshaking or special cases.
The catch here is that most of the time these objects are stack allocated
and should not be freed. Initializing these objects with a single reference
that is never released prevents accidental attempts to free the objects.
Fixes: 9d5722b7777e ("fuse: handle synchronous iocbs internally")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
There's a race in fuse_direct_IO(), whereby is_sync_kiocb() is called on an
iocb that could have been freed if async io has already completed. The fix
in this case is simple and obvious: cache the result before starting io.
It was discovered by KASan:
kernel: ==================================================================
kernel: BUG: KASan: use after free in fuse_direct_IO+0xb1a/0xcc0 at addr ffff88036c414390
Signed-off-by: Robert Doebbelin <robert@quobyte.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: bcba24ccdc82 ("fuse: enable asynchronous processing direct IO")
Cc: <stable@vger.kernel.org> # 3.10+
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull fuse updates from Miklos Szeredi: "This adds SEEK_HOLE and SEEK_DATA support in lseek" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: add support for SEEK_HOLE and SEEK_DATA in lseek
Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs RCU symlink updates from Al Viro: "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode even if the symlink is not an embedded one. No changes since the mailbomb on Jan 1" * 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->get_link() to delayed_call, kill ->put_link() kill free_page_put_link() teach nfs_get_link() to work in RCU mode teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode teach shmem_get_link() to work in RCU mode teach page_get_link() to work in RCU mode replace ->follow_link() with new method that could stay in RCU mode don't put symlink bodies in pagecache into highmem namei: page_getlink() and page_follow_link_light() are the same thing ufs: get rid of ->setattr() for symlinks udf: don't duplicate page_symlink_inode_operations logfs: don't duplicate page_symlink_inode_operations switch befs long symlinks to page_symlink_operations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>