only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

S_IFMT is obviously wrong and needs to be 0777.
We're interested in the file mode, not the type.

Fixes: b98b9102 (hostfs: No need to box and later unbox the file mode)
Reported-by: NMarkus Stenberg <markus.stenberg@iki.fi>
Signed-off-by: NRichard Weinberger <richard@nod.at>

that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Currently hostfs issues every time a seekdir(), in fact
it has to do this only upon the first call.
Also telldir() can be omitted as we can obtain the directory
offset from readdir().
Signed-off-by: NRichard Weinberger <richard@nod.at>

All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

There is really no point in having a function with 10
arguments.
Reported-by: NDaniel Walter <d.walter@0x90.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

The kernel offers a helper function for that, use it.
Signed-off-by: NRichard Weinberger <richard@nod.at>

In case of an error set the page error flag and clear the up-to-date
flag.
If the read was successful clear the error flag unconditionally.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Only initialize what we really need.
Signed-off-by: NRichard Weinberger <richard@nod.at>

...otherwise we might end up with an incorrect mode mode.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

hostfs has an "append" mount option. Report it.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Be consistent with all other functions in hostfs and just
use __getname().
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

hostfs' __dentry_name() relies on the fact that dentry_path_raw() will place
the path name at the end of the provided buffer.
While this is okay, add a BUG_ON() to detect behavior changes as soon
as possible.
Signed-off-by: NRichard Weinberger <richard@nod.at>

...to make life easier for future readers of that code.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Make sure that we return EIO if one passes an invalid st.mode
into hostfs.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Historically hostfs did not open directories on the host filesystem
for performance and memory reasons.
But it turned out that this optimization has a drawback.
Calling fsync() on a hostfs directory returns immediately
with -EINVAL as fsync is not implemented.
While this is behavior is strictly speaking correct common userspace
like dpkg(1) stumbles over that and makes it impossible to use
hostfs as root filesystem.
The fix is easy, wire up the existing host open/fsync functions
to the directory file operations.
Reported-by: NDaniel Gröber <dxld@darkboxed.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

In case of a race between to callers of hostfs_file_open()
it can happen that a file describtor is leaked.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Instead of serializing hostfs_file_open() we can use
a per inode mutex to protect ->mode.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Support RENAME_NOREPLACE and RENAME_EXCHANGE flags on hostfs if the
underlying filesystem supports it.

Since renameat2(2) is not yet in any libc, use syscall(2) to invoke the
renameat2 syscall.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

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

Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NMinchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The hostfs_*() callback functions are all only used within
hostfs_kern.c, so make them static.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: NRichard Weinberger <richard@nod.at>

Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We have to implement ->release() and trigger writeback from it.
Otherwise we might lose dirty pages at munmap().
Signed-off-by: NRichard Weinberger <richard@nod.at>

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

The inode info structure is zeroed at allocation with kzalloc, and then
all but one of the fields (including the largest, vfs_inode) are
initialised explicitly. Switch to using kmalloc and initialise the
remaining field too.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Move HOSTFS_SUPER_MAGIC to <linux/magic.h> to be with it's magical
friends from other file systems.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A "will unlock" comment was added to hostfs in the following commit,
along with a spinlock:

Commit e9193059 ("hostfs: fix races in
dentry_name() and inode_name()").

But the spinlock was subsequently removed in the following commit:

Commit ec2447c2 ("hostfs: simplify
locking").

Since the comment is no longer applicable, remove it.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Somehow I failed to add the MODULE_ALIAS_FS for cifs, hostfs, hpfs,
squashfs, and udf despite what I thought were my careful checks :(

Add them now.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

With the commit 3be2be0a we removed vmtruncate,
but actaully there is no need to call inode_newsize_ok() because the checks are
already done in inode_change_ok() at the begin of the function.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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

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

Removed vmtruncate.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>