Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
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: Nick Piggin <npiggin@kernel.dk>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds a new mount parameter 'ecryptfs_mount_auth_tok_only' to
force ecryptfs to use only authentication tokens which signature has
been specified at mount time with parameters 'ecryptfs_sig' and
'ecryptfs_fnek_sig'. In this way, after disabling the passthrough and
the encrypted view modes, it's possible to make available to users only
files encrypted with the specified authentication token.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
[Tyler: Clean up coding style errors found by checkpatch]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
This patch replaces the check of the 'matching_auth_tok' pointer with
the exit status of ecryptfs_find_auth_tok_for_sig().
This avoids to use authentication tokens obtained through the function
ecryptfs_keyring_auth_tok_for_sig which are not valid.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
This patch allows keys requested in the function
ecryptfs_keyring_auth_tok_for_sig()to be released when they are no
longer required. In particular keys are directly released in the same
function if the obtained authentication token is not valid.
Further, a new function parameter 'auth_tok_key' has been added to
ecryptfs_find_auth_tok_for_sig() in order to provide callers the key
pointer to be passed to key_put().
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
[Tyler: Initialize auth_tok_key to NULL in ecryptfs_parse_packet_set]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
eCryptfs was passing the LOOKUP_OPEN flag through to the lower file
system, even though ecryptfs_create() doesn't support the flag. A valid
filp for the lower filesystem could be returned in the nameidata if the
lower file system's create() function supported LOOKUP_OPEN, possibly
resulting in unencrypted writes to the lower file.
However, this is only a potential problem in filesystems (FUSE, NFS,
CIFS, CEPH, 9p) that eCryptfs isn't known to support today.
https://bugs.launchpad.net/ecryptfs/+bug/641703
Reported-by: Kevin Buhr
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Ecryptfs is a stackable filesystem which relies on lower filesystems the
ability of setting/getting extended attributes.
If there is a security module enabled on the system it updates the
'security' field of inodes according to the owned extended attribute set
with the function vfs_setxattr(). When this function is performed on a
ecryptfs filesystem the 'security' field is not updated for the lower
filesystem since the call security_inode_post_setxattr() is missing for
the lower inode.
Further, the call security_inode_setxattr() is missing for the lower inode,
leading to policy violations in the security module because specific
checks for this hook are not performed (i. e. filesystem
'associate' permission on SELinux is not checked for the lower filesystem).
This patch replaces the call of the setxattr() method of the lower inode
in the function ecryptfs_setxattr() with vfs_setxattr().
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: stable <stable@kernel.org>
Cc: Dustin Kirkland <kirkland@canonical.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
The BKL is only used in fill_super, which is protected by the superblocks
s_umount rw_semaphorei, and in fasync, which does not do anything that
could require the BKL. Therefore it is safe to remove the BKL entirely.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Fixes a regression caused by 21edad3220
When file name encryption was enabled, ecryptfs_lookup() failed to use
the encrypted and encoded version of the upper, plaintext, file name
when performing a lookup in the lower file system. This made it
impossible to lookup existing encrypted file names and any newly created
files would have plaintext file names in the lower file system.
https://bugs.launchpad.net/ecryptfs/+bug/623087
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Some ecryptfs init functions are not prefixed by __init and thus not
freed after initialization. This patch saved about 1kB in ecryptfs
module.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
In this code, 0 is returned on memory allocation failure, even though other
failures return -ENOMEM or other similar values.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression ret;
expression x,e1,e2,e3;
@@
ret = 0
... when != ret = e1
*x = \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
return ret;
}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:
- ecryptfs_statfs. This one doesn't actually need vfs_statfs but just
needs to do a caller to the lower filesystem statfs method.
- sys_ustat. Add a non-exported statfs_by_dentry helper for it which
doesn't won't be able to fill out the flags field later on.
In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make sure we check the truncate constraints early on in ->setattr by adding
those checks to inode_change_ok. Also clean up and document inode_change_ok
to make this obvious.
As a fallout we don't have to call inode_newsize_ok from simple_setsize and
simplify it down to a truncate_setsize which doesn't return an error. This
simplifies a lot of setattr implementations and means we use truncate_setsize
almost everywhere. Get rid of fat_setsize now that it's trivial and mark
ext2_setsize static to make the calling convention obvious.
Keep the inode_newsize_ok in vmtruncate for now as all callers need an
audit for its removal anyway.
Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
needs a deeper audit, but that is left for later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
I have encountered the same problem that Eric Sandeen described in
this post
http://lkml.org/lkml/fancy/2010/4/23/467
while experimenting with stackable filesystems.
The reason seems to be that ecryptfs calls lookup_one_len() to get the
lower dentry, which in turn calls the lower parent dirs d_revalidate()
with a NULL nameidata object.
If ecryptfs is the underlaying filesystem, the NULL pointer dereference
occurs, since ecryptfs is not prepared to handle a NULL nameidata.
I know that this cant happen any more, since it is no longer allowed to
mount ecryptfs upon itself.
But maybe this patch it useful nevertheless, since the problem would still
apply for an underlaying filesystem that implements d_revalidate() and is
not prepared to handle a NULL nameidata (I dont know if there actually
is such a fs).
With this patch (against 2.6.35-rc5) ecryptfs uses the vfs_lookup_path()
function instead of lookup_one_len() which ensures that the nameidata
passed to the lower filesystems d_revalidate().
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The comments in the code indicate that file_info should be released if the
function fails. This releasing is done at the label out_free, not out.
The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@
x@p1 = kmem_cache_zalloc(...);
...
if (x == NULL) S
<... when != x
when != if (...) { <+...x...+> }
(
x->f1 = E
|
(x->f1 == NULL || ...)
|
f(...,x->f1,...)
)
...>
(
return <+...x...+>;
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmem_cache_zalloc %s" % (p1[0].file,p1[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
In ecryptfs_lookup_and_interpose_lower() the lower mount is not decremented
if allocation of a dentry info struct failed. As a result the lower filesystem
cant be unmounted any more (since it is considered busy). This patch corrects
the reference counting.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Lower filesystems that only implemented unlocked_ioctl weren't being
passed ioctl calls because eCryptfs only checked for
lower_file->f_op->ioctl and returned -ENOTTY if it was NULL.
eCryptfs shouldn't implement ioctl(), since it doesn't require the BKL.
This patch introduces ecryptfs_unlocked_ioctl() and
ecryptfs_compat_ioctl(), which passes the calls on to the lower file
system.
https://bugs.launchpad.net/ecryptfs/+bug/469664
Reported-by: James Dupin <james.dupin@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Fix warning seen with "make -j24 CONFIG_DEBUG_SECTION_MISMATCH=y V=1":
fs/ecryptfs/messaging.c: In function 'ecryptfs_process_response':
fs/ecryptfs/messaging.c:276: warning: 'daemon' may be used uninitialized in this function
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The function ecryptfs_uid_hash wrongly assumes that the
second parameter to hash_long() is the number of hash
buckets instead of the number of hash bits.
This patch fixes that and renames the variable
ecryptfs_hash_buckets to ecryptfs_hash_bits to make it
clearer.
Fixes: CVE-2010-2492
Signed-off-by: Andre Osterhues <aosterhues@escrypt.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lots of filesystems calls vmtruncate despite not implementing the old
->truncate method. Switch them to use simple_setsize and add some
comments about the truncate code where it seems fitting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is a seriously simplified patch from Eric Sandeen; copy of
rationale follows:
===
mounting stacked ecryptfs on ecryptfs has been shown to lead to bugs
in testing. For crypto info in xattr, there is no mechanism for handling
this at all, and for normal file headers, we run into other trouble:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffffa015b0b3>] ecryptfs_d_revalidate+0x43/0xa0 [ecryptfs]
...
There doesn't seem to be any good usecase for this, so I'd suggest just
disallowing the configuration.
Based on a patch originally, I believe, from Mike Halcrow.
===
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.
The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
First of all, get_sb_nodev() grabs anon dev minor and we
never free it in ecryptfs ->kill_sb(). Moreover, on one
of the failure exits in ecryptfs_get_sb() we leak things -
it happens before we set ->s_root and ->put_super() won't
be called in that case. Solution: kill ->put_super(), do
all that stuff in ->kill_sb(). And use kill_anon_sb() instead
of generic_shutdown_super() to deal with anon dev leak.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Vaugue warnings about ENAMETOOLONG errors when looking up an encrypted
file name have caused many users to become concerned about their data.
Since this is a rather harmless condition, I'm moving this warning to
only be printed when the ecryptfs_verbosity module param is 1.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The timestamps and size of a lower inode involved in a link() call was
being copied to the upper parent inode. Instead, we should be
copying lower parent inode's timestamps and size to the upper parent
inode. I discovered this bug using the POSIX test suite at Tuxera.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Since tmpfs has no persistent storage, it pins all its dentries in memory
so they have d_count=1 when other file systems would have d_count=0.
->lookup is only used to create new dentries. If the caller doesn't
instantiate it, it's freed immediately at dput(). ->readdir reads
directly from the dcache and depends on the dentries being hashed.
When an ecryptfs mount is mounted, it associates the lower file and dentry
with the ecryptfs files as they're accessed. When it's umounted and
destroys all the in-memory ecryptfs inodes, it fput's the lower_files and
d_drop's the lower_dentries. Commit 4981e081 added this and a d_delete in
2008 and several months later commit caeeeecf removed the d_delete. I
believe the d_drop() needs to be removed as well.
The d_drop effectively hides any file that has been accessed via ecryptfs
from the underlying tmpfs since it depends on it being hashed for it to
be accessible. I've removed the d_drop on my development node and see no
ill effects with basic testing on both tmpfs and persistent storage.
As a side effect, after ecryptfs d_drops the dentries on tmpfs, tmpfs
BUGs on umount. This is due to the dentries being unhashed.
tmpfs->kill_sb is kill_litter_super which calls d_genocide to drop
the reference pinning the dentry. It skips unhashed and negative dentries,
but shrink_dcache_for_umount_subtree doesn't. Since those dentries
still have an elevated d_count, we get a BUG().
This patch removes the d_drop call and fixes both issues.
This issue was reported at:
https://bugzilla.novell.com/show_bug.cgi?id=567887
Reported-by: Árpád Bíró <biroa@demasz.hu>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
If the lower file system driver has extended attributes disabled,
ecryptfs' own access functions return -ENOSYS instead of -EOPNOTSUPP.
This breaks execution of programs in the ecryptfs mount, since the
kernel expects the latter error when checking for security
capabilities in xattrs.
Signed-off-by: Christian Pulvermacher <pulvermacher@gmx.de>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Create a getattr handler for eCryptfs symlinks that is capable of
reading the lower target and decrypting its path. Prior to this patch,
a stat's st_size field would represent the strlen of the encrypted path,
while readlink() would return the strlen of the decrypted path. This
could lead to confusion in some userspace applications, since the two
values should be equal.
https://bugs.launchpad.net/bugs/524919
Reported-by: Loïc Minier <loic.minier@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The ecryptfs_encrypted_view mount option provides a unified way of
viewing encrypted eCryptfs files. If the metadata is stored in a xattr,
the metadata is moved to the file header when the file is read inside
the eCryptfs mount. Because of this, we should strip the
ECRYPTFS_METADATA_IN_XATTR flag from the header's flag section. This
allows eCryptfs to treat the file as an eCryptfs file with a header
at the front.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
We initially read in the first PAGE_CACHE_SIZE of a file to if the
eCryptfs header marker can be found. If it isn't found and
ecryptfs_xattr_metadata was given as a mount option, then the
user.ecryptfs xattr is read into the same buffer. Since the data from
the first page of the file wasn't cleared, it is possible that we think
we've found a second tag 3 or tag 1 packet and then error out after the
packet contents aren't as expected. This patch clears the buffer before
filling it with metadata from the user.ecryptfs xattr.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
This patch renames the num_header_bytes_at_front variable to
metadata_size since it now contains the max size of the metadata.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Nick Piggin