As it is, default ->i_fop has NULL ->open() (along with all other methods).
The only case where it matters is reopening (via procfs symlink) a file that
didn't get its ->f_op from ->i_fop - anything else will have ->i_fop assigned
to something sane (default would fail on read/write/ioctl/etc.).
Unfortunately, such case exists - alloc_file() users, especially
anon_get_file() ones. There we have tons of opened files of very different
kinds sharing the same inode. As the result, attempt to reopen those via
procfs succeeds and you get a descriptor you can't do anything with.
Moreover, in case of sockets we set ->i_fop that will only be used
on such reopen attempts - and put a failing ->open() into it to make sure
those do not succeed.
It would be simpler to put such ->open() into default ->i_fop and leave
it unchanged both for anon inode (as we do anyway) and for socket ones. Result:
* everything going through do_dentry_open() works as it used to
* sock_no_open() kludge is gone
* attempts to reopen anon-inode files fail as they really ought to
* ditto for aio_private_file()
* ditto for perfmon - this one actually tried to imitate sock_no_open()
trick, but failed to set ->i_fop, so in the current tree reopens succeed and
yield completely useless descriptor. Intent clearly had been to fail with
-ENXIO on such reopens; now it actually does.
* everything else that used alloc_file() keeps working - it has ->i_fop
set for its inodes anyway
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
New pseudo-filesystem: nsfs. Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.). Files on it *are* bindable - we explicitly permit that in do_loopback().
This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot. The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).
Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present. See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.
As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) make get_proc_ns() return a pointer to struct ns_common
b) mirror ns_ops in dentry->d_fsdata of ns dentries, so that
is_mnt_ns_file() could get away with fewer dereferences.
That way struct proc_ns becomes invisible outside of fs/proc/*.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
for now - just move corresponding ->proc_inum instances over there
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull btrfs deadlock fix from Chris Mason:
"This has a fix for a long standing deadlock that we've been trying to
nail down for a while. It ended up being a bad interaction with the
fair reader/writer locks and the order btrfs reacquires locks in the
btree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix lockups from btrfs_clear_path_blocking
"The biggest change is to rename the filesystem from "overlayfs" to "overlay".
This will allow legacy overlayfs to be easily carried by distros alongside the
new mainline one. Also fix a couple of copy-up races and allow escaping comma
character in filenames."
The last bit is about commas in pathname mount options...
Check against !OVL_PATH_LOWER instead of OVL_PATH_MERGE. For a copied up
directory the two are currently equivalent.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Pass dentry into ovl_dir_read_merged() insted of upperpath and lowerpath.
This cleans up callers and paves the way for multi-layer directory reads.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Xattr operations can race with copy up. This does not matter as long as
we consistently fiter out "trunsted.overlay.opaque" attribute on upper
directories.
Previously we checked parent against OVL_PATH_MERGE. This is too general,
and prone to race with copy-up. I.e. we found the parent to be on the
lower layer but ovl_dentry_real() would return the copied-up dentry,
possibly with the "opaque" attribute.
So instead use ovl_path_real() and decide to filter the attributes based on
the actual type of the dentry we'll use.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
ovl_remove_and_whiteout() needs to check if upper dentry exists or not
after having locked upper parent directory.
Previously we used a "type" value computed before locking the upper parent
directory, which is susceptible to racing with copy-up.
There's a similar check in ovl_check_empty_and_clear(). This one is not
actually racy, since copy-up doesn't change the "emptyness" property of a
directory. Add a comment to this effect, and check the existence of upper
dentry locally to make the code cleaner.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Some distributions carry an "old" format of overlayfs while mainline has a
"new" format.
The distros will possibly want to keep the old overlayfs alongside the new
for compatibility reasons.
To make it possible to differentiate the two versions change the name of
the new one from "overlayfs" to "overlay".
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Andy Whitcroft <apw@canonical.com>
The fair reader/writer locks mean that btrfs_clear_path_blocking needs
to strictly follow lock ordering rules even when we already have
blocking locks on a given path.
Before we can clear a blocking lock on the path, we need to make sure
all of the locks have been converted to blocking. This will remove lock
inversions against anyone spinning in write_lock() against the buffers
we're trying to get read locks on. These inversions didn't exist before
the fair read/writer locks, but now we need to be more careful.
We papered over this deadlock in the past by changing
btrfs_try_read_lock() to be a true trylock against both the spinlock and
the blocking lock. This was slower, and not sufficient to fix all the
deadlocks. This patch adds a btrfs_tree_read_lock_atomic(), which
basically means get the spinlock but trylock on the blocking lock.
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reported-by: Patrick Schmid <schmid@phys.ethz.ch>
cc: stable@vger.kernel.org #v3.15+
With the isofs_hash() function removed, isofs_hash_ms() is the only user
of isofs_hash_common(), but it's defined inside of an #ifdef, which triggers
this gcc warning in ARM axm55xx_defconfig starting with v3.18-rc3:
fs/isofs/inode.c:177:1: warning: 'isofs_hash_common' defined but not used [-Wunused-function]
This patch moves the function inside of the same #ifdef section to avoid that
warning, which seems the best compromise of a relatively harmless patch for
a late -rc.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b0afd8e5db ("isofs: don't bother with ->d_op for normal case")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In "d_prune_alias(): just lock the parent and call __dentry_kill()" the old
dget + d_drop + dput has been replaced with lock_parent + __dentry_kill;
unfortunately, dput() does more than just killing dentry - it also drops the
reference to parent. New variant leaks that reference and needs dput(parent)
after killing the child off.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull the beginning of seq_file cleanup from Steven:
"I'm looking to clean up the seq_file code and to eventually merge the
trace_seq code with seq_file as well, since they basically do the same thing.
Part of this process is to remove the return code of seq_printf() and friends
as they are rather inconsistent. It is better to use the new function
seq_has_overflowed() if you want to stop processing when the buffer
is full. Note, if the buffer is full, the seq_file code will throw away
the contents, allocate a bigger buffer, and then call your code again
to fill in the data. The only thing that breaking out of the function
early does is to save a little time which is probably never noticed.
I started with patches from Joe Perches and modified them as well.
There's many more places that need to be updated before we can convert
seq_printf() and friends to return void. But this patch set introduces
the seq_has_overflowed() and does some initial updates."
This patch fixes kmemcheck warning in switch_names. The function
switch_names swaps inline names of two dentries. It swaps full arrays
d_iname, no matter how many bytes are really used by the strings. Reading
data beyond string ends results in kmemcheck warning.
We fix the bug by marking both arrays as fully initialized.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v3.15
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... for situations when we don't have any candidate in pathnames - basically,
in descriptor-based syscalls.
[Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In ->atomic_open(inode, dentry, file, opened) calling finish_no_open(file, NULL)
is equivalent to dget(dentry); return finish_no_open(file, dentry);
No need to open-code that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dentry is always hashed and negative, inode - non-error, non-NULL and
non-directory. In such conditions d_splice_alias() is equivalent to
"d_instantiate(dentry, inode) and return NULL", which simplifies the
downstream code and is consistent with the "have to create a new object"
case.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Highlights include:
- Stable patches to fix NFSv4.x delegation reclaim error paths
- Fix a bug whereby we were advertising NFSv4.1 but using NFSv4.2 features
- Fix a use-after-free problem with pNFS block layouts
- Fix a memory leak in the pNFS files O_DIRECT code
- Replace an intrusive and Oops-prone performance fix in the NFSv4 atomic
open code with a safer one-line version and revert the two original patches.
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Merge tag 'nfs-for-3.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
- stable patches to fix NFSv4.x delegation reclaim error paths
- fix a bug whereby we were advertising NFSv4.1 but using NFSv4.2
features
- fix a use-after-free problem with pNFS block layouts
- fix a memory leak in the pNFS files O_DIRECT code
- replace an intrusive and Oops-prone performance fix in the NFSv4
atomic open code with a safer one-line version and revert the two
original patches"
* tag 'nfs-for-3.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
sunrpc: fix sleeping under rcu_read_lock in gss_stringify_acceptor
NFS: Don't try to reclaim delegation open state if recovery failed
NFSv4: Ensure that we call FREE_STATEID when NFSv4.x stateids are revoked
NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return
NFSv4.1: nfs41_clear_delegation_stateid shouldn't trust NFS_DELEGATED_STATE
NFSv4: Ensure that we remove NFSv4.0 delegations when state has expired
NFS: SEEK is an NFS v4.2 feature
nfs: Fix use of uninitialized variable in nfs_getattr()
nfs: Remove bogus assignment
nfs: remove spurious WARN_ON_ONCE in write path
pnfs/blocklayout: serialize GETDEVICEINFO calls
nfs: fix pnfs direct write memory leak
Revert "NFS: nfs4_do_open should add negative results to the dcache."
Revert "NFS: remove BUG possibility in nfs4_open_and_get_state"
NFSv4: Ensure nfs_atomic_open set the dentry verifier on ENOENT
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
MAINTAINERS: add IIO include files
kernel/panic.c: update comments for print_tainted
mem-hotplug: reset node present pages when hot-adding a new pgdat
mem-hotplug: reset node managed pages when hot-adding a new pgdat
mm/debug-pagealloc: correct freepage accounting and order resetting
fanotify: fix notification of groups with inode & mount marks
mm, compaction: prevent infinite loop in compact_zone
mm: alloc_contig_range: demote pages busy message from warn to info
mm/slab: fix unalignment problem on Malta with EVA due to slab merge
mm/page_alloc: restrict max order of merging on isolated pageblock
mm/page_alloc: move freepage counting logic to __free_one_page()
mm/page_alloc: add freepage on isolate pageblock to correct buddy list
mm/page_alloc: fix incorrect isolation behavior by rechecking migratetype
mm/compaction: skip the range until proper target pageblock is met
zram: avoid kunmap_atomic() of a NULL pointer
fsnotify() needs to merge inode and mount marks lists when notifying
groups about events so that ignore masks from inode marks are reflected
in mount mark notifications and groups are notified in proper order
(according to priorities).
Currently the sorting of the lists done by fsnotify_add_inode_mark() /
fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted
ignore masks not being used in some cases.
Fix the problem by always using the same comparison function when
sorting / merging the mark lists.
Thanks to Heinrich Schuchardt for improvements of my patch.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
