new helper: fixed_size_llseek()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ecryptfs: switch ecryptfs_decode_and_decrypt_filename() from dentry to sb

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fuse: another open-coded file_inode()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

btrfs: more open-coded file_inode()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fanotify: quit wanking with FASYNC in ->release()

... especially since there's no way to get that sucker
on the list fsnotify_fasync() works with - the only thing
adding to it is fsnotify_fasync() itself and it's never
called for fanotify files while they are opened.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

comedi: quit wanking with FASYNC in ->release()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

more open-coded file_inode() calls

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kill find_inode_number()

the only remaining caller (in ncpfs) is guaranteed to return 0 -
we only hit it if we'd just checked that there's no dentry with
such name.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

coda: don't bother with find_inode_number()

the fallback it's using for dcache misses is actually the
same value we would've used for inumber anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_fill_cache(): clean up, get rid of pointless find_inode_number() use

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_fill_cache(): just make instantiate_t return int

all instances always return ERR_PTR(-E...) or NULL, anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_pid_readdir(): stop wanking with proc_fill_cache() for /proc/self

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_fill_cache(): kill pointless check

we'd just checked that child->d_inode is non-NULL, for fuck sake!

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ncpfs: don't bother with EBUSY on removal of busy directories

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

don't call file_pos_write() if vfs_{read,write}{,v}() fails

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

SELinux: Institute file_path_has_perm()

Create a file_path_has_perm() function that is like path_has_perm() but
instead takes a file struct that is the source of both the path and the
inode (rather than getting the inode from the dentry in the path).  This
is then used where appropriate.

This will be useful for situations like unionmount where it will be
possible to have an apparently-negative dentry (eg. a fallthrough) that is
open with the file struct pointing to an inode on the lower fs.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Replace a bunch of file->dentry->d_inode refs with file_inode()

Replace a bunch of file->dentry->d_inode refs with file_inode().

In __fput(), use file->f_inode instead so as not to be affected by any tricks
that file_inode() might grow.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

udf: provide ->tmpfile()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ext3 ->tmpfile() support

In this case we do need a bit more than usual, due to orphan
list handling.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

allow the temp files created by open() to be linked to

O_TMPFILE | O_CREAT => linkat() with AT_SYMLINK_FOLLOW and /proc/self/fd/<n>
as oldpath (i.e. flink()) will create a link
O_TMPFILE | O_CREAT | O_EXCL => ENOENT on attempt to link those guys

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

allow build_open_flags() to return an error

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

lift file_*_write out of do_splice_direct()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

lift file_*_write out of do_splice_from()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

do_last(): fix missing checks for LAST_BIND case

/proc/self/cwd with O_CREAT should fail with EISDIR.  /proc/self/exe, OTOH,
should fail with ENOTDIR when opened with O_DIRECTORY.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

pcm_native: switch to fdget()/fdput()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] constify ->actor

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] ->readdir() is gone

everything's converted to ->iterate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ecryptfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert coda

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ocfs2

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert fatfs

... pox upon the idiotic ioctls; life would be much easier without
those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert xfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert btrfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert hostfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert afs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ncpfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert hfsplus

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert hfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert befs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert cifs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert freevxfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert fuse

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert hpfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

reiserfs: switch reiserfs_readdir_dentry to inode

... and clean the callers up a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

reiserfs: is_privroot_deh() needs only directory inode, actually

... and that - only to get the superblock.  Privroot is a directory
and we don't allow hardlinks to those...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert reiserfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ntfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert isofs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert jffs2

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert f2fs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert 9p

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert affs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert adfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert logfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert jfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ceph

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert nfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ext4

and trim the living hell out bogosities in inline dir case

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert qnx6

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert qnx4

... and use strnlen() instead of strlen() - it's done on untrusted data,
after all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert omfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert nilfs2

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert sysfs

get rid of the kludges in sysfs_readdir()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert gfs2

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert exofs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert bfs

... and get rid of that ridiculous mutex in bfs_readdir()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert procfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert openpromfs

what the hell is op_mutex for, BTW?

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert efs

* sanity checks belong before risky operation, not after it
* don't quit as soon as we'd found an entry

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert configfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert romfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert squashfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ubifs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert udf

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] convert ext3

new helper: dir_relax(inode).  Call when you are in location that will
_not_ be invalidated by directory modifications (block boundary, in case
of ext*).  Returns whether the directory has survived (dropping i_mutex
allows rmdir to kill the sucker; if it returns false to us, ->iterate()
is obviously done)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] switch dcache_readdir() users to ->iterate()

new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx),
dir_emit_dots(file, ctx).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] simple local unixlike: switch to ->iterate()

ext2, ufs, minix, sysv

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] introduce ->iterate(), ctx->pos, dir_emit()

New method - ->iterate(file, ctx).  That's the replacement for ->readdir();
it takes callback from ctx->actor, uses ctx->pos instead of file->f_pos and
calls dir_emit(ctx, ...) instead of filldir(data, ...).  It does *not*
update file->f_pos (or look at it, for that matter); iterate_dir() does the
update.

Note that dir_emit() takes the offset from ctx->pos (and eventually
filldir_t will lose that argument).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[readdir] introduce iterate_dir() and dir_context

iterate_dir(): new helper, replacing vfs_readdir().

struct dir_context: contains the readdir callback (and will get more stuff
in it), embedded into whatever data that callback wants to deal with;
eventually, we'll be passing it to ->readdir() replacement instead of
(data,filldir) pair.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

move linux/loop.h to drivers/block

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

compat.c: LOOP_CLR_FD is taken care of in loop.c itself...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

pxa3xx: VM_IO is set by io_remap_pfn_range()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

au1100fb: VM_IO is set by io_remap_pfn_range()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

au1200fb: io_remap_pfn_range() sets VM_IO

... and single return is quite sufficient to get out of function, TYVM

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

vfio: remap_pfn_range() sets all those flags...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

i810: VM_IO is set by io_remap_pfn_range()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drm: io_remap_pfn_range() sets VM_IO...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

sparc: __pci_mmap_set_flags() is useless

io_remap_pfn_range() does all we need

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mn10300: don't bother with VM_IO

io_remap_pfn_range() sets it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

hose_mmap_page_range(): io_remap_pfn_range() will set all those flags...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

samsung: don't bother with setting VM_IO

io_remap_pfn_range() will set it just fine

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

consolidate io_remap_pfn_range definitions

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

UBIFS: fix a horrid bug

Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no
mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are
in the middle of 'ubifs_readdir()'.

This means that 'file->private_data' can be freed while 'ubifs_readdir()' uses
it, and this is a very bad bug: not only 'ubifs_readdir()' can return garbage,
but this may corrupt memory and lead to all kinds of problems like crashes an
security holes.

This patch fixes the problem by using the 'file->f_version' field, which
'->llseek()' always unconditionally sets to zero. We set it to 1 in
'ubifs_readdir()' and whenever we detect that it became 0, we know there was a
seek and it is time to clear the state saved in 'file->private_data'.

I tested this patch by writing a user-space program which runds readdir and
seek in parallell. I could easily crash the kernel without these patches, but
could not crash it with these patches.

Cc: stable@vger.kernel.org
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

UBIFS: prepare to fix a horrid bug

Al Viro pointed me to the fact that '->readdir()' and '->llseek()' have no
mutual exclusion, which means the 'ubifs_dir_llseek()' can be run while we are
in the middle of 'ubifs_readdir()'.

First of all, this means that 'file->private_data' can be freed while
'ubifs_readdir()' uses it.  But this particular patch does not fix the problem.
This patch is only a preparation, and the fix will follow next.

In this patch we make 'ubifs_readdir()' stop using 'file->f_pos' directly,
because 'file->f_pos' can be changed by '->llseek()' at any point. This may
lead 'ubifs_readdir()' to returning inconsistent data: directory entry names
may correspond to incorrect file positions.

So here we introduce a local variable 'pos', read 'file->f_pose' once at very
the beginning, and then stick to 'pos'. The result of this is that when
'ubifs_dir_llseek()' changes 'file->f_pos' while we are in the middle of
'ubifs_readdir()', the latter "wins".

Cc: stable@vger.kernel.org
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

aout32 coredump compat fix

dump_seek() does SEEK_CUR, not SEEK_SET; native binfmt_aout
handles it correctly (seeks by PAGE_SIZE - sizeof(struct user),
getting the current position to PAGE_SIZE), compat one seeks
by PAGE_SIZE and ends up at PAGE_SIZE + already written...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

splice: don't pass the address of ->f_pos to methods

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mconsole: we'd better initialize pos before passing it to vfs_read()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

lseek(fd, n, SEEK_END) does *not* go to eof - n

When you copy some code, you are supposed to read it.  If nothing else,
there's a chance to spot and fix an obvious bug instead of sharing it...

X-Song: "I Got It From Agnes", by Tom Lehrer
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[ Tom Lehrer? You're dating yourself, Al ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linux 3.10-rc6