The value passed to ufs_inode_getblock() as the 3rd argument
had lower bits ignored; the upper bits were shifted down
and used and they actually make sense - those are _lower_ bits
of index in indirect block (i.e. they form the index within
a fragment within an indirect block).
Pass those as argument. Upper bits of index (i.e. the number
of fragment within indirect block) will join them shortly.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These calling conventions are rudiments of pre-2.3 times; they
really need to be sanitized. This is the first step; next
will be _always_ returning a block number, instead of this
"return a pointer to buffer_head, except when we get to the
actual data" crap.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and massage ufs_frag_map() to take those instead of fragment number.
As it is, we duplicate the damn thing on the write side, open-coded and
bloody hard to follow.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We are holding ->truncate_mutex, so nobody else can alter our
block pointers. Rechecks/retries were needed back when we
only held BKL there, and had to cope with write_begin/writepage
and writepage/truncate races. Can't happen anymore...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There's a case when an indirect block gets dirtied for no good
reason - when there's a hole starting in the middle of area
covered by it and spanning past its end, and truncate() is done
precisely to the beginning of the hole.
The block is obviously not modified at all - all removals happen
beyond it. However, existing code ends up dirtying it just in
case. It's trivial to fix and while it's not a real bug by any
stretch of imagination, it makes the damn thing harder to follow.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Note that it's already made unreachable from the inode, so we don't have
to worry about ufs_frag_map() walking into something already freed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Have caller fetch the block number *and* remove it from wherever
it was. Pass the block number instead.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We always have 0 < depth2 <= depth in there, so
if (--depth) {
if (--depth2)
A
B
} else {
C // not using depth2
}
D // not using depth2
is equivalent to
if (--depth2)
A with s/depth/depth - 1/
if (--depth)
B
else
C
D
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For calls in __ufs_truncate_blocks() it's just a matter of not
incrementing offsets[0] and not making that call - immediately
following loop will be executed one extra time and we'll be just
fine. For recursive call in ufs_trunc_branch() itself, just
assing NULL to offsets if we would be about to make such call.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of manually checking that the array contains only zeroes,
find the position of the last non-zero (in __ufs_truncate(), where
we can conveniently do that) and use that to tell if there's
any non-zero in the array tail passed to ufs_trunc_...indirect().
The goal of all that clumsiness is to get fold these functions
together.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
rather than bitslicing the offset just formed as sum of shifted indices,
pass the array of those indices itself. NULL is used as equivalent
of "all zeroes" (== free the entire branch).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
IOW, the distance of cutoff from the begining of the branch
(in blocks).
That (and the fact that block just prior to cutoff is guaranteed to
be present) allows to tell whether to free triple indirect block
just by looking at the offset.
While we are at it, using u64 for index in the block is wrong -
those should be unsigned int.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use ufs_block_to_path() to find the cutoff path in the block pointers' tree.
For now just use the information about the depth (to bypass the fully
preserved subtrees); subsequent commits will use the information about actual
path.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
type makes no sense - those are indices in block number arrays, not
block numbers. And no, UFS is not likely to grow indirect blocks with
4Gpointers in them...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It is closely tied to block pointers handling there, can benefit
from existing helpers, etc. - no point keeping them apart.
Trimmed the trailing whitespaces in inode.c at the same time.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently - on lock_ufs(), eventually - on per-inode mutex.
lock_ufs() used to be mere BKL, which is much weaker, so it needed
those rechecks. BKL doesn't provide any exclusion once we lose CPU;
its blind replacement, OTOH, _does_. Making that per-filesystem was
an atrocity, but at least we can simplify life here. And yes, we
certainly need to make that sucker per-inode - these days inode.c and
truncate.c uses are needed only to protect the block pointers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There were 3 remaining users; in two of them we took ->s_lock immediately
after lock_ufs() and held it until just before unlock_ufs(); the third
one (statfs) could not be called from itself or from other two (remount
and sync_fs). Just use ->s_lock in statfs and don't bother with lock_ufs
at all.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* stores to block pointers are under per-inode seqlock (meta_lock) and
mutex (truncate_mutex)
* fetches of block pointers are either under truncate_mutex, or wrapped
into seqretry loop on meta_lock
* all changes of ->i_size are under truncate_mutex and i_mutex
* all changes of ->i_lastfrag are under truncate_mutex
It's similar to what ext2 is doing; the main difference is that unlike
ext2 we can't rely upon the atomicity of stores into block pointers -
on UFS2 they are 64bit. So we can't cut the corner when switching
a pointer from NULL to non-NULL as we could in ext2_splice_branch()
and need to use meta_lock on all modifications.
We use seqlock where ext2 uses rwlock; ext2 could probably also benefit
from such change...
Another non-trivial difference is that with UFS we *cannot* have reader
grab truncate_mutex in case of race - it has to keep retrying. That
might be possible to change, but not until we lift tail unpacking
several levels up in call chain.
After that commit we do *NOT* hold fs-wide serialization on accesses
to block pointers anymore. Moreover, lock_ufs() can become a normal
mutex now - it's only used on statfs, remount and sync_fs and none
of those uses are recursive. As the matter of fact, *now* it can be
collapsed with ->s_lock, and be eventually replaced with saner
per-cylinder-group spinlocks, but that's a separate story.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
right now it doesn't matter (lock_ufs() serializes everything),
but when we switch to per-inode locking, it will be needed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Broken in "[PATCH] ufs: truncate should allocate block for last byte";
all way back in 2006. ufs_setattr() hadn't been the only user of
vmtruncate() and eliminating ->truncate() method required corrections
in a bunch of places. Eventually those places had migrated into
->write_begin() failure exit and ->write_end() after short copy...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) move it inside ufs_truncate()
b) ufs_free_inode() doesn't need it - it's serialized on ->s_lock
c) ufs_write_inode() doesn't need it either (and can be called without
it anyway).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull more vfs updates from Al Viro:
"Assorted VFS fixes and related cleanups (IMO the most interesting in
that part are f_path-related things and Eric's descriptor-related
stuff). UFS regression fixes (it got broken last cycle). 9P fixes.
fs-cache series, DAX patches, Jan's file_remove_suid() work"
[ I'd say this is much more than "fixes and related cleanups". The
file_table locking rule change by Eric Dumazet is a rather big and
fundamental update even if the patch isn't huge. - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
9p: cope with bogus responses from server in p9_client_{read,write}
p9_client_write(): avoid double p9_free_req()
9p: forgetting to cancel request on interrupted zero-copy RPC
dax: bdev_direct_access() may sleep
block: Add support for DAX reads/writes to block devices
dax: Use copy_from_iter_nocache
dax: Add block size note to documentation
fs/file.c: __fget() and dup2() atomicity rules
fs/file.c: don't acquire files->file_lock in fd_install()
fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
vfs: avoid creation of inode number 0 in get_next_ino
namei: make set_root_rcu() return void
make simple_positive() public
ufs: use dir_pages instead of ufs_dir_pages()
pagemap.h: move dir_pages() over there
remove the pointless include of lglock.h
fs: cleanup slight list_entry abuse
xfs: Correctly lock inode when removing suid and file capabilities
fs: Call security_ops->inode_killpriv on truncate
fs: Provide function telling whether file_remove_privs() will do anything
...
The brd driver is the only in-tree driver that may sleep currently.
After some discussion on linux-fsdevel, we decided that any driver
may choose to sleep in its ->direct_access method. To ensure that all
callers of bdev_direct_access() are prepared for this, add a call
to might_sleep().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If a block device supports the ->direct_access methods, bypass the normal
DIO path and use DAX to go straight to memcpy() instead of allocating
a DIO and a BIO.
Includes support for the DIO_SKIP_DIO_COUNT flag in DAX, as is done in
do_blockdev_direct_IO().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When userspace does a write, there's no need for the written data to
pollute the CPU cache. This matches the original XIP code.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull scheduler fixes from Ingo Molnar:
"Debug info and other statistics fixes and related enhancements"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/numa: Fix numa balancing stats in /proc/pid/sched
sched/numa: Show numa_group ID in /proc/sched_debug task listings
sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h
sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=y
sched/stat: Simplify the sched_info accounting dependency
Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.
Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.
There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.
This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.
This set of changes also addresses an issue with how open file
descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of
/proc/<pid>/fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.
There is also a short list of issues that have not been fixed yet that
I will mention briefly.
It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.
As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
Pull Ceph updates from Sage Weil:
"We have a pile of bug fixes from Ilya, including a few patches that
sync up the CRUSH code with the latest from userspace.
There is also a long series from Zheng that fixes various issues with
snapshots, inline data, and directory fsync, some simplification and
improvement in the cap release code, and a rework of the caching of
directory contents.
To top it off there are a few small fixes and cleanups from Benoit and
Hong"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (40 commits)
rbd: use GFP_NOIO in rbd_obj_request_create()
crush: fix a bug in tree bucket decode
libceph: Fix ceph_tcp_sendpage()'s more boolean usage
libceph: Remove spurious kunmap() of the zero page
rbd: queue_depth map option
rbd: store rbd_options in rbd_device
rbd: terminate rbd_opts_tokens with Opt_err
ceph: fix ceph_writepages_start()
rbd: bump queue_max_segments
ceph: rework dcache readdir
crush: sync up with userspace
crush: fix crash from invalid 'take' argument
ceph: switch some GFP_NOFS memory allocation to GFP_KERNEL
ceph: pre-allocate data structure that tracks caps flushing
ceph: re-send flushing caps (which are revoked) in reconnect stage
ceph: send TID of the oldest pending caps flush to MDS
ceph: track pending caps flushing globally
ceph: track pending caps flushing accurately
libceph: fix wrong name "Ceph filesystem for Linux"
ceph: fix directory fsync
...
