While trying to track down some NFS problems with BTRFS, I kept noticing I was
getting -EACCESS for no apparent reason. Eric Paris and printk() helped me
figure out that it was SELinux that was giving me grief, with the following
denial
type=AVC msg=audit(1290013638.413:95): avc: denied { 0x800000 } for pid=1772
comm="nfsd" name="" dev=sda1 ino=256 scontext=system_u:system_r:kernel_t:s0
tcontext=system_u:object_r:unlabeled_t:s0 tclass=file
Turns out this is because in d_obtain_alias if we can't find an alias we create
one and do all the normal instantiation stuff, but we don't do the
security_d_instantiate.
Usually we are protected from getting a hashed dentry that hasn't yet run
security_d_instantiate() by the parent's i_mutex, but obviously this isn't an
option there, so in order to deal with the case that a second thread comes in
and finds our new dentry before we get to run security_d_instantiate(), we go
ahead and call it if we find a dentry already. Eric assures me that this is ok
as the code checks to see if the dentry has been initialized already so calling
security_d_instantiate() against the same dentry multiple times is ok. With
this patch I'm no longer getting errant -EACCESS values.
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Have it nested inside ->i_mutex. Instead of using follow_down()
under namespace_sem, followed by grabbing i_mutex and checking that
mountpoint to be is not dead, do the following:
grab i_mutex
check that it's not dead
grab namespace_sem
see if anything is mounted there
if not, we've won
otherwise
drop locks
put_path on what we had
replace with what's mounted
retry everything with new mountpoint to be
New helper (lock_mount()) does that. do_add_mount(), do_move_mount(),
do_loopback() and pivot_root() switched to it; in case of the last
two that eliminates a race we used to have - original code didn't
do follow_down().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't hold vfsmount_lock over the loop traversing ->mnt_parent;
do check_mnt(new.mnt) under namespace_sem instead; combined with
namespace_sem held over all that code it'll guarantee the stability
of ->mnt_parent chain all the way to the root.
Doing check_mnt() outside of namespace_sem in case of pivot_root()
is wrong anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new function: mount_fs(). Does all work done by vfs_kern_mount()
except the allocation and filling of vfsmount; returns root dentry
or ERR_PTR().
vfs_kern_mount() switched to using it and taken to fs/namespace.c,
along with its wrappers.
alloc_vfsmnt()/free_vfsmnt() made static.
functions in namespace.c slightly reordered.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1) Change from ->get_sb() to ->mount()
2) Use mount_single() instead of mount_nodev()
3) Pulled in ramfs_get_inode() & trimmed to what I need for pstore
4) Drop the ugly pstore_writefile() Just save data using kmalloc() and
provide a pstore_file_read() that uses simple_read_from_buffer().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'mnt_devname' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
vfs: bury ->get_sb()
nfs: switch NFS from ->get_sb() to ->mount()
nfs: stop mangling ->mnt_devname on NFS
vfs: new superblock methods to override /proc/*/mount{s,info}
nfs: nfs_do_{ref,sub}mount() superblock argument is redundant
nfs: make nfs_path() work without vfsmount
nfs: store devname at disconnected NFS roots
nfs: propagate devname to nfs{,4}_get_root()
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] tioca: Fix assignment from incompatible pointer warnings
[IA64] mca.c: Fix cast from integer to pointer warning
[IA64] setup.c Typo fix "Architechtuallly"
[IA64] Add CONFIG_MISC_DEVICES=y to configs that need it.
[IA64] disable interrupts at end of ia64_mca_cpe_int_handler()
[IA64] Add DMA_ERROR_CODE define.
pstore: fix build warning for unused return value from sysfs_create_file
pstore: X86 platform interface using ACPI/APEI/ERST
pstore: new filesystem interface to platform persistent storage
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: That's all, folks
fs/locks.c: Remove stale FIXME left over from BKL conversion
ipx: remove the BKL
appletalk: remove the BKL
x25: remove the BKL
ufs: remove the BKL
hpfs: remove the BKL
drivers: remove extraneous includes of smp_lock.h
tracing: don't trace the BKL
adfs: remove the big kernel lock
The last remaining instances of ->get_sb() can be converted ->mount()
now - nothing in them uses new vfsmount anymore.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) ->show_devname(m, mnt) - what to put into devname columns in mounts,
mountinfo and mountstats
b) ->show_path(m, mnt) - what to put into relative path column in mountinfo
Leaving those NULL gives old behaviour. NFS switched to using those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
part 3: now we have everything to get nfs_path() just by dentry -
just follow to (disconnected) root and pick the rest of the thing
there.
Start killing propagation of struct vfsmount * on the paths that
used to bring it to nfs_path().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.
Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.
Have ->d_release() free it when dentry goes away.
Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (33 commits)
AppArmor: kill unused macros in lsm.c
AppArmor: cleanup generated files correctly
KEYS: Add an iovec version of KEYCTL_INSTANTIATE
KEYS: Add a new keyctl op to reject a key with a specified error code
KEYS: Add a key type op to permit the key description to be vetted
KEYS: Add an RCU payload dereference macro
AppArmor: Cleanup make file to remove cruft and make it easier to read
SELinux: implement the new sb_remount LSM hook
LSM: Pass -o remount options to the LSM
SELinux: Compute SID for the newly created socket
SELinux: Socket retains creator role and MLS attribute
SELinux: Auto-generate security_is_socket_class
TOMOYO: Fix memory leak upon file open.
Revert "selinux: simplify ioctl checking"
selinux: drop unused packet flow permissions
selinux: Fix packet forwarding checks on postrouting
selinux: Fix wrong checks for selinux_policycap_netpeer
selinux: Fix check for xfrm selinux context algorithm
ima: remove unnecessary call to ima_must_measure
IMA: remove IMA imbalance checking
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: (46 commits)
fs/9p: Make the writeback_fid owned by root
fs/9p: Writeback dirty data before setattr
fs/9p: call vmtruncate before setattr 9p opeation
fs/9p: Properly update inode attributes on link
fs/9p: Prevent multiple inclusion of same header
fs/9p: Workaround vfs rename rehash bug
fs/9p: Mark directory inode invalid for many directory inode operations
fs/9p: Add . and .. dentry revalidation flag
fs/9p: mark inode attribute invalid on rename, unlink and setattr
fs/9p: Add support for marking inode attribute invalid
fs/9p: Initialize root inode number for dotl
fs/9p: Update link count correctly on different file system operations
fs/9p: Add drop_inode 9p callback
fs/9p: Add direct IO support in cached mode
fs/9p: Fix inode i_size update in file_write
fs/9p: set default readahead pages in cached mode
fs/9p: Move writeback fid to v9fs_inode
fs/9p: Add v9fs_inode
fs/9p: Don't set stat.st_blocks based on nrpages
fs/9p: Add inode hashing
...
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix build failure introduced by s/freezeable/freezable/
workqueue: add system_freezeable_wq
rds/ib: use system_wq instead of rds_ib_fmr_wq
net/9p: replace p9_poll_task with a work
net/9p: use system_wq instead of p9_mux_wq
xfs: convert to alloc_workqueue()
reiserfs: make commit_wq use the default concurrency level
ocfs2: use system_wq instead of ocfs2_quota_wq
ext4: convert to alloc_workqueue()
scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
misc/iwmc3200top: use system_wq instead of dedicated workqueues
i2o: use alloc_workqueue() instead of create_workqueue()
acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
fs/aio: aio_wq isn't used in memory reclaim path
input/tps6507x-ts: use system_wq instead of dedicated workqueue
cpufreq: use system_wq instead of dedicated workqueues
wireless/ipw2x00: use system_wq instead of dedicated workqueues
arm/omap: use system_wq in mailbox
workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
It turns out that while a maximum of 8 partitions may be what people
"should" have had, you can actually fit up to 18 entries(*) in a sector.
And some people clearly were taking advantage of that, like Michael
Cree, who had ten partitions on one of his OSF disks.
(*) The OSF partition data starts at byte offset 64 in the first sector,
and the array of 16-byte partition entries start at offset 148 in
the on-disk partition structure.
Reported-by: Michael Cree <mcree@orcon.net.nz>
Cc: stable@kernel.org (v2.6.38)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
iprune_sem is continously giving us lockdep warnings because we do take it in
read mode in the reclaim path, but we're also doing non-NOFS allocations under
it taken in write mode.
Taking a bit deeper look at it I think it's fixable quite trivially:
- for invalidate_inodes we do not need iprune_sem at all. We have an active
reference on the superblock, so the filesystem is not going away until it
has finished.
- for evict_inodes we do need it, to make sure prune_icache has done it's
work before we tear down the superblock. But there is no reason to
hold it over the actual reclaim operation - it's enough to cycle through
it after the actual reclaim to make sure we wait for any pending
prune_icache to complete. We just have to remove the WARN_ON for
otherwise busy inodes as they can actually happen now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits)
tidy the trailing symlinks traversal up
Turn resolution of trailing symlinks iterative everywhere
simplify link_path_walk() tail
Make trailing symlink resolution in path_lookupat() iterative
update nd->inode in __do_follow_link() instead of after do_follow_link()
pull handling of one pathname component into a helper
fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
readlinkat(), fchownat() and fstatat() with empty relative pathnames
Allow O_PATH for symlinks
New kind of open files - "location only".
ext4: Copy fs UUID to superblock
ext3: Copy fs UUID to superblock.
vfs: Export file system uuid via /proc/<pid>/mountinfo
unistd.h: Add new syscalls numbers to asm-generic
x86: Add new syscalls for x86_64
x86: Add new syscalls for x86_32
fs: Remove i_nlink check from file system link callback
fs: Don't allow to create hardlink for deleted file
vfs: Add open by file handle support
...
The new vfs locking scheme introduced in 2.6.38 breaks NFS sillyrename
because the latter relies on being able to determine the parent
directory of the dentry in the ->iput() callback in order to send the
appropriate unlink rpc call.
Looking at the code that cares about races with dput(), there doesn't
seem to be anything that specifically uses d_parent as a test for
whether or not there is a race:
- __d_lookup_rcu(), __d_lookup() all test for d_hashed() after d_parent
- shrink_dcache_for_umount() is safe since nothing else can rearrange
the dentries in that super block.
- have_submount(), select_parent() and d_genocide() can test for a
deletion if we set the DCACHE_DISCONNECTED flag when the dentry
is removed from the parent's d_subdirs list.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org (2.6.38, needs commit c826cb7dfc "dcache.c:
create helper function for duplicated functionality" )
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This creates a helper function for he "try to ascend into the parent
directory" case, which was written out in triplicate before. With all
the locking and subtle sequence number stuff, we really don't want to
duplicate that kind of code.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pull the handling of current->total_link_count into
__do_follow_link()
* put the common "do ->put_link() if needed and path_put() the link"
stuff into a helper (put_link(nd, link, cookie))
* rename __do_follow_link() to follow_link(), while we are at it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The last remaining place (resolution of nested symlink) converted
to the loop of the same kind we have in path_lookupat() and
path_openat().
Note that we still *do* have a recursion in pathname resolution;
can't avoid it, really. However, it's strictly for nested symlinks
now - i.e. ones in the middle of a pathname.
link_path_walk() has lost the tail now - it always walks everything
except the last component.
do_follow_link() renamed to nested_symlink() and moved down.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that link_path_walk() is called without LOOKUP_PARENT
only from do_follow_link(), we can simplify the checks in
last component handling. First of all, checking if we'd
arrived to a directory is not needed - the caller will check
it anyway. And LOOKUP_FOLLOW is guaranteed to be there,
since we only get to that place with nd->depth > 0.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new helper: walk_component(). Handles everything except symlinks;
returns negative on error, 0 on success and 1 on symlinks we decided
to follow. Drops out of RCU mode on such symlinks.
link_path_walk() and do_last() switched to using that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We don't want to allow creation of private hardlinks by different application
using the fd passed to them via SCM_RIGHTS. So limit the null relative name
usage in linkat syscall to CAP_DAC_READ_SEARCH
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Changes to make sure writeback fid is owned by root
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
change file attribute can result in making the file readonly.
So flush the dirty pages before that.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We need to call vmtruncate before 9p setattr operation, otherwise we
could write back some dirty pages between setattr with ATTR_SIZE and vmtruncate
causing some truncated pages to be written back to server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
With caching enabled, we need to make sure we don't
update inode->i_size via stat2inode because we could
have dirty data which is not yet written to the server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This is similar to what ceph, ocfs2 and nfs does
http://kerneltrap.org/mailarchive/linux-fsdevel/2008/4/18/1498534
May be we should get vfs fixed
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
One successfull directory operation we would have changed directory
inode attribute. So mark them invalid
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We need to revalidate . and .. entries also
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
rename, unlink and setattr can result in update of inode attribute.
So mark the cached copy invalid
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
