Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.

For in-tree filesystems, this is just a mechanical change.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.

For in-tree filesystems, this is just a mechanical change.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

... and switch of the obvious get_sb_bdev() users to ->mount()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

hfsplus_delete_inode only truncates away all block allocations if
i_nlink is zero.  Make sure we properly drop the unlink count even
when doing the rename hack for open but unlinked files.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Clones an existing reference to inode; caller must already hold one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Make node look as if it was on hlist, with hlist_del()
working correctly.  Usable without any locking...

Convert a couple of places where we want to do that to
inode->i_hash.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This was supposed to be a mutex_unlock() instead of a mutex_lock().
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

We need to support -EOPNOTSUPP for attributes that are not supported to
match other filesystems and allow userspace to detect if Posix ACLs
are supported or not.  setxattr already gets this right.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Make sure the initial insertation of the catalog entry already contains
the device number by calling init_special_inode early and setting writing
out the dev field of the on-disk permission structure.  The latter is
facilitated by sharing the almost identical hfsplus_set_perms helpers
between initial catalog entry creating and ->write_inode.

Unless we crashed just after mknod this bug was harmless as the inode
is marked dirty at the end of hfsplus_mknod, and hfsplus_write_inode
will update the catalog entry to contain the correct value.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

The rootflags field in hfsplus_inode_info only caches the immutable and
append-only flags in the VFS inode, so we can easily get rid of it.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

HFS implements hardlink by using indirect catalog entries that refer to a hidden
directly.  The link target is cached in the dev field in the HFS+ specific
inode, which is also used for the device number for device files, and inside
for passing the nlink value of the indirect node from hfsplus_cat_write_inode
to a helper function.  Now if we happen to write out the indirect node while
hfsplus_link is creating the catalog entry we'll get a link pointing to the
linkid of the current nlink value.  This can easily be reproduced by a large
enough loop of local git-clone operations.

Stop abusing the dev field in the HFS+ inode for short term storage by
refactoring the way the permission structure in the catalog entry is
set up, and rename the dev field to linkid to avoid any confusion.

While we're at it also prevent creating hard links to special files, as
the HFS+ dev and linkid share the same space in the on-disk structure.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

hfs seems prone to bad things when it encounters on disk corruption.  Many
values are read from disk, and used as lengths to memcpy, as an example.
This patch fixes up several of these problematic cases.

o sanity check the on-disk maximum key lengths on mount
  (these are set to a defined value at mkfs time and shouldn't differ)
o check on-disk node keylens against the maximum key length for each tree
o fix hfs_btree_open so that going out via free_tree: doesn't wind
  up in hfs_releasepage, which wants to follow the very pointer
  we were trying to set up:
	HFS_SB(sb)->cat_tree = hfs_btree_open()
    .
  failure gets to hfs_releasepage and tries to follow HFS_SB(sb)->cat_tree

Tested with the fsfuzzer; it survives more than it used to.

[hch: ported of commit cf059462 from hfs]
[hch: added the fixes from 5581d018ed3493d226e7a4d645d9c8a5af6c36b]
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

oops and fs corruption; the latter can happen even on valid fs in case of oom.

[hch: port of commit 3d10a15d from hfs]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

A particular fsfuzzer run caused an hfs file system to crash on mount. This
is due to a corrupted MDB extent record causing a miscalculation of
HFSPLUS_I(inode)->first_blocks for the extent tree. If the extent records
are zereod out, then it won't trigger the first_blocks special case and
instead falls through to the extent code, which we're in the middle
of initializing.

This patch catches the 0 size extent records, reports the corruption,
and fails the mount.

[hch: ported of commit 47f365eb from hfs]
Reported-by: NRamon de Carvalho Valle <rcvalle@linux.vnet.ibm.com>
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

When renaming over a directory we need to use hfsplus_rmdir instead of
hfsplus_unlink to evict the victim.  This makes sure we properly error out
on non-empty directory as required by Posix (BZ #16571), and it also makes
sure we do the right thing in case i_nlink will every be set correctly for
directories on hfsplus.
Reported-by: NVlado Plaga <rechner@vlado-do.de>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

tree_lock is used as mutex so make it a mutex.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Most of the extent handling code already does proper SMP locking, but
hfsplus_write_inode was calling into hfsplus_ext_write_extent without
taking the extents_lock.  Fix this by splitting hfsplus_ext_write_extent
into an internal helper that expects the lock, and a public interface
that first acquires it.

Also add a few locking asserts and document the locking rules in
hfsplus_fs.h.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

We already have i_mutex for readdir and the namespace operations that add
entries to open_dir_list, the only thing that was missing was the removal
in hfsplus_dir_release.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

The flags in the HFS+-specific superlock do get modified during runtime,
use atomic bitops to make the modifications SMP safe.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Lock updates to the mutal fields in the volume header, and document the
locing in the hfsplus_sb_info structure.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

We never walk the list - the only reason for it is to make the resource fork
inodes appear hashed to the writeback code.  Borrow a trick from JFS to do
that without needing a list head.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

We never look at it, nor change the next_alloc field in the superblock.  So
don't bother caching it or writing it out in hfsplus_sync_fs.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

We need to free the inode again on a hfsplus_create_cat failure.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Make hfsplus_mkdir and hfsplus_create call hfsplus_mknod instead of
duplicating the code.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Add a new hfsplus_system_write_inode for writing the special system inodes
and streamline the fastpath write_inode code.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Add a new hfsplus_system_read_inode for reading the special system inodes
and streamline the fastpath iget code.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

HFSPLUS_I doesn't return a pointer to the hfsplus-specific inode
information like all other FOO_I macros, but dereference the pointer in a way
that made it look like a direct struct derefence.  This only works as long
as the HFSPLUS_I macro is used directly and prevents us from keepig a local
hfsplus_inode_info pointer.  Fix the calling convention and introduce a local
hip variable in all functions that use it constantly.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

HFSPLUS_SB doesn't return a pointer to the hfsplus-specific superblock
information like all other FOO_SB macros, but dereference the pointer in a way
that made it look like a direct struct derefence.  This only works as long
as the HFSPLUS_SB macro is used directly and prevents us from keepig a local
hfsplus_sb_info pointer.  Fix the calling convention and introduce a local
sbi variable in all functions that use it constantly.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Except for ->put_super the BKL is now gone from HFS, which means it's
superflous there too as ->put_super is serialized by the VFS.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Use alloc_mutex to protect hfsplus_sync_fs against itself and concurrent
allocations, which allows to get rid of lock_super in hfsplus.

Note that most fields in the superblock still aren't protected against
concurrent allocations, that will follow later.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Use a new per-sb alloc_mutex instead of abusing i_mutex of the alloc_file
to protect block allocations.  This gets rid of lockdep nesting warnings
and prepares for extending the scope of alloc_mutex.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Use i_mutex for protecting against concurrent setflags ioctls like in
other filesystems and get rid of the BKL in hfsplus_ioctl.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Give each ioctl command a function of it's own.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

Currenly the HFSPLUS_IOC_EXT2_GETFLAGS case never unlocks the BKL, which
can lead to easily reproduced lockups when doing multiple GETFLAGS ioctls.

Fix this by only taking the BKL for the HFSPLUS_IOC_EXT2_SETFLAGS case
as neither HFSPLUS_IOC_EXT2_GETFLAGS not the default error case needs it.
Signed-off-by: NChristoph Hellwig <hch@tuxera.com>

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

Copy and simplify in the only two users remaining.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Replace inode_setattr with opencoded variants of it in all callers.  This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.

In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:

 spufs: explicitly checks for ATTR_SIZE earlier
 btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
 ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above

In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

For the new truncate sequence every filesystem that wants to truncate on-disk
state needs a seattr method.  Convert the remaining filesystems that implement
the truncate inode operation to have its own setattr method.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>