Commit graph

13 commits

Author SHA1 Message Date
zhengbin
cabdb4fa2f fuse: use true,false for bool variable
Fixes coccicheck warning:

fs/fuse/readdir.c:335:1-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/file.c:1398:2-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/file.c:1400:2-20: WARNING: Assignment of 0/1 to bool variable
fs/fuse/cuse.c:454:1-20: WARNING: Assignment of 0/1 to bool variable
fs/fuse/cuse.c:455:1-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:497:2-17: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:504:2-23: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:511:2-22: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:518:2-23: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:522:2-26: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:526:2-18: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:1000:1-20: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06 16:39:28 +01:00
Miklos Szeredi
eb59bd17d2 fuse: verify attributes
If a filesystem returns negative inode sizes, future reads on the file were
causing the cpu to spin on truncate_pagecache.

Create a helper to validate the attributes.  This now does two things:

 - check the file mode
 - check if the file size fits in i_size without overflowing

Reported-by: Arijit Banerjee <arijit@rubrik.com>
Fixes: d8a5ba4545 ("[PATCH] FUSE - core")
Cc: <stable@vger.kernel.org> # v2.6.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-12 11:49:04 +01:00
Tejun Heo
e5854b1cdf fuse: fix beyond-end-of-page access in fuse_parse_cache()
With DEBUG_PAGEALLOC on, the following triggers.

  BUG: unable to handle page fault for address: ffff88859367c000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 3001067 P4D 3001067 PUD 406d3a8067 PMD 406d30c067 PTE 800ffffa6c983060
  Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
  CPU: 38 PID: 3110657 Comm: python2.7
  RIP: 0010:fuse_readdir+0x88f/0xe7a [fuse]
  Code: 49 8b 4d 08 49 39 4e 60 0f 84 44 04 00 00 48 8b 43 08 43 8d 1c 3c 4d 01 7e 68 49 89 dc 48 03 5c 24 38 49 89 46 60 8b 44 24 30 <8b> 4b 10 44 29 e0 48 89 ca 48 83 c1 1f 48 83 e1 f8 83 f8 17 49 89
  RSP: 0018:ffffc90035edbde0 EFLAGS: 00010286
  RAX: 0000000000001000 RBX: ffff88859367bff0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffff88859367bfed RDI: 0000000000920907
  RBP: ffffc90035edbe90 R08: 000000000000014b R09: 0000000000000004
  R10: ffff88859367b000 R11: 0000000000000000 R12: 0000000000000ff0
  R13: ffffc90035edbee0 R14: ffff889fb8546180 R15: 0000000000000020
  FS:  00007f80b5f4a740(0000) GS:ffff889fffa00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffff88859367c000 CR3: 0000001c170c2001 CR4: 00000000003606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   iterate_dir+0x122/0x180
   __x64_sys_getdents+0xa6/0x140
   do_syscall_64+0x42/0x100
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

It's in fuse_parse_cache().  %rbx (ffff88859367bff0) is fuse_dirent
pointer - addr + offset.  FUSE_DIRENT_SIZE() is trying to dereference
namelen off of it but that derefs into the next page which is disabled
by pagealloc debug causing a PF.

This is caused by dirent->namelen being accessed before ensuring that
there's enough bytes in the page for the dirent.  Fix it by pushing
down reclen calculation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 5d7bc7e868 ("fuse: allow using readdir cache")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24 15:28:01 +02:00
Miklos Szeredi
43f5098eb8 fuse: convert readdir to simple api
The old fuse_read_fill() helper can be deleted, now that the last user is
gone.

The fuse_io_args struct is moved to fuse_i.h so it can be shared between
readdir/read code.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
3545fe2112 fuse: convert fuse_force_forget() to simple api
Move this function to the readdir.c where its only caller resides.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:48 +02:00
Kirill Tkhai
c9d8f5f069 fuse: Protect fi->nlookup with fi->lock
This continues previous patch and introduces the same protection for
nlookup field.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Miklos Szeredi
261aaba72f fuse: use iversion for readdir cache verification
Use the internal iversion counter to make sure modifications of the
directory through this filesystem are not missed by the mtime check (due to
mtime granularity).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:05 +02:00
Miklos Szeredi
7118883b44 fuse: use mtime for readdir cache verification
Store the modification time of the directory in the cache, obtained before
starting to fill the cache.

When reading the cache, verify that the directory hasn't changed, by
checking if current modification time is the same as the one stored in the
cache.

This only needs to be done when the current file position is at the
beginning of the directory, as mandated by POSIX.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi
3494927e09 fuse: add readdir cache version
Allow the cache to be invalidated when page(s) have gone missing.  In this
case increment the version of the cache and reset to an empty state.

Add a version number to the directory stream in struct fuse_file as well,
indicating the version of the cache it's supposed to be reading.  If the
cache version doesn't match the stream's version, then reset the stream to
the beginning of the cache.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi
5d7bc7e868 fuse: allow using readdir cache
The cache is only used if it's completed, not while it's still being
filled; this constraint could be lifted later, if it turns out to be
useful.

Introduce state in struct fuse_file that indicates the position within the
cache.  After a seek, reset the position to the beginning of the cache and
search the cache for the current position.  If the current position is not
found in the cache, then fall back to uncached readdir.

It can also happen that page(s) disappear from the cache, in which case we
must also fall back to uncached readdir.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi
69e3455115 fuse: allow caching readdir
This patch just adds the cache filling functions, which are invoked if
FOPEN_CACHE_DIR flag is set in the OPENDIR reply.

Cache reading and cache invalidation are added by subsequent patches.

The directory cache uses the page cache.  Directory entries are packed into
a page in the same format as in the READDIR reply.  A page only contains
whole entries, the space at the end of the page is cleared.  The page is
locked while being modified.

Multiple parallel readdirs on the same directory can fill the cache; the
only constraint is that continuity must be maintained (d_off of last entry
points to position of current entry).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi
18172b10b6 fuse: extract fuse_emit() helper
Prepare for cache filling by introducing a helper for emitting a single
directory entry.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Miklos Szeredi
d123d8e183 fuse: split out readdir.c
Directory reading code is about to grow larger, so split it out from dir.c
into a new source file.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00