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2012-07-17pstore/ram: Add ftrace messages handlingAnton Vorontsov
The ftrace log size is configurable via ramoops.ftrace_size module option, and the log itself is available via <pstore-mount>/ftrace-ramoops file. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram: Convert to write_buf callbackAnton Vorontsov
Don't use pstore.buf directly, instead convert the code to write_buf callback which passes a pointer to a buffer as an argument. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore: Add persistent function tracingAnton Vorontsov
With this support kernel can save function call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a reset or panic. We store the log in a binary format and then decode it at read time. p.s. Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross <ccross@android.com> (according to sign-off history). I reworked the driver a little bit, and ported it to pstore. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore: Introduce write_buf backend callbackAnton Vorontsov
For function tracing we need to stop using pstore.buf directly, since in a tracing callback we can't use spinlocks, and thus we can't safely use the global buffer. With write_buf callback, backends no longer need to access pstore.buf directly, and thus we can pass any buffers (e.g. allocated on stack). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram_core: Get rid of prz->ecc enable/disable flagAnton Vorontsov
Nowadays we can use prz->ecc_size as a flag, no need for the special member in the prz struct. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram: Make ECC size configurableAnton Vorontsov
This is now pretty straightforward: instead of using bool, just pass an integer. For backwards compatibility ramoops.ecc=1 means 16 bytes ECC (using 1 byte for ECC isn't much of use anyway). Suggested-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram_core: Get rid of prz->ecc_symsize and prz->ecc_polyAnton Vorontsov
The struct members were never used anywhere outside of persistent_ram_init_ecc(), so there's actually no need for them to be in the struct. If we ever want to make polynomial or symbol size configurable, it would make more sense to just pass initialized rs_decoder to the persistent_ram init functions. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17sysfs: fail dentry revalidation after namespace change fixAndrew Morton
don't assume that KOBJ_NS_TYPE_NONE==0. Also save a test-n-branch. Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17sysfs: fail dentry revalidation after namespace changeGlauber Costa
When we change the namespace tag of a sysfs entry, the associated dentry is still kept around. readdir() will work correctly and not display the old entries, but open() will still succeed, so will reads and writes. This will no longer happen if sysfs is remounted, hinting that this is a cache-related problem. I am using the following sequence to demonstrate that: shell1: ip link add type veth unshare -nm shell2: ip link set veth1 <pid_of_shell_1> cat /sys/devices/virtual/net/veth1/ifindex Before that patch, this will succeed (fail to fail). After it, it will correctly return an error. Differently from a normal rename, which we handle fine, changing the object namespace will keep it's path intact. So this check seems necessary as well. [ v2: get type from parent, as suggested by Eric Biederman ] Signed-off-by: Glauber Costa <glommer@parallels.com> CC: Tejun Heo <tj@kernel.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16cifs: always update the inode cache with the results from a FIND_*Jeff Layton
When we get back a FIND_FIRST/NEXT result, we have some info about the dentry that we use to instantiate a new inode. We were ignoring and discarding that info when we had an existing dentry in the cache. Fix this by updating the inode in place when we find an existing dentry and the uniqueid is the same. Cc: <stable@vger.kernel.org> # .31.x Reported-and-Tested-by: Andrew Bartlett <abartlet@samba.org> Reported-by: Bill Robertson <bill_robertson@debortoli.com.au> Reported-by: Dion Edwards <dion_edwards@debortoli.com.au> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16cifs: when CONFIG_HIGHMEM is set, serialize the read/write kmapsJeff Layton
Jian found that when he ran fsx on a 32 bit arch with a large wsize the process and one of the bdi writeback kthreads would sometimes deadlock with a stack trace like this: crash> bt PID: 2789 TASK: f02edaa0 CPU: 3 COMMAND: "fsx" #0 [eed63cbc] schedule at c083c5b3 #1 [eed63d80] kmap_high at c0500ec8 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs] #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs] #4 [eed63e50] do_writepages at c04f3e32 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a #6 [eed63ea4] filemap_fdatawrite at c04e1b3e #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs] #8 [eed63ecc] do_sync_write at c052d202 #9 [eed63f74] vfs_write at c052d4ee #10 [eed63f94] sys_write at c052df4c #11 [eed63fb0] ia32_sysenter_target at c0409a98 EAX: 00000004 EBX: 00000003 ECX: abd73b73 EDX: 012a65c6 DS: 007b ESI: 012a65c6 ES: 007b EDI: 00000000 SS: 007b ESP: bf8db178 EBP: bf8db1f8 GS: 0033 CS: 0073 EIP: 40000424 ERR: 00000004 EFLAGS: 00000246 Each task would kmap part of its address array before getting stuck, but not enough to actually issue the write. This patch fixes this by serializing the marshal_iov operations for async reads and writes. The idea here is to ensure that cifs aggressively tries to populate a request before attempting to fulfill another one. As soon as all of the pages are kmapped for a request, then we can unlock and allow another one to proceed. There's no need to do this serialization on non-CONFIG_HIGHMEM arches however, so optimize all of this out when CONFIG_HIGHMEM isn't set. Cc: <stable@vger.kernel.org> Reported-by: Jian Li <jiali@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16cifs: on CONFIG_HIGHMEM machines, limit the rsize/wsize to the kmap spaceJeff Layton
We currently rely on being able to kmap all of the pages in an async read or write request. If you're on a machine that has CONFIG_HIGHMEM set then that kmap space is limited, sometimes to as low as 512 slots. With 512 slots, we can only support up to a 2M r/wsize, and that's assuming that we can get our greedy little hands on all of them. There are other users however, so it's possible we'll end up stuck with a size that large. Since we can't handle a rsize or wsize larger than that currently, cap those options at the number of kmap slots we have. We could consider capping it even lower, but we currently default to a max of 1M. Might as well allow those luddites on 32 bit arches enough rope to hang themselves. A more robust fix would be to teach the send and receive routines how to contend with an array of pages so we don't need to marshal up a kvec array at all. That's a fairly significant overhaul though, so we'll need this limit in place until that's ready. Cc: <stable@vger.kernel.org> Reported-by: Jian Li <jiali@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16Initialise mid_q_entry before putting it on the pending queueSachin Prabhu
A user reported a crash in cifs_demultiplex_thread() caused by an incorrectly set mid_q_entry->callback() function. It appears that the callback assignment made in cifs_call_async() was not flushed back to memory suggesting that a memory barrier was required here. Changing the code to make sure that the mid_q_entry structure was completely initialised before it was added to the pending queue fixes the problem. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16Merge 3.5-rc7 into driver-core-nextGreg Kroah-Hartman
This pulls in the printk fixes to the driver-core-next branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16dlm: fix missing dir removeDavid Teigland
I don't know exactly how, but in some cases, a dir record is not removed, or a new one is created when it shouldn't be. The result is that the dir node lookup returns a master node where the rsb does not exist. In this case, The master node will repeatedly return -EBADR for requests, and the lock requests will be stuck. Until all possible ways for this to happen can be eliminated, a simple and effective way to recover from this situation is for the supposed master node to send a standard remove message to the dir node when it receives a request for a resource it has no rsb for. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16dlm: fix conversion deadlock from recoveryDavid Teigland
The process of rebuilding locks on a new master during recovery could re-order the locks on the convert queue, creating an "in place" conversion deadlock that would not be resolved. Fix this by not considering queue order when granting conversions after recovery. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16dlm: use wait_event_timeoutDavid Teigland
Use wait_event_timeout to avoid using a timer directly. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16dlm: fix race between remove and lookupDavid Teigland
It was possible for a remove message on an old rsb to be sent after a lookup message on a new rsb, where the rsbs were for the same resource name. This could lead to a missing directory entry for the new rsb. It is fixed by keeping a copy of the resource name being removed until after the remove has been sent. A lookup checks if this in-progress remove matches the name it is looking up. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16dlm: use idr instead of list for recovered rsbsDavid Teigland
When a large number of resources are being recovered, a linear search of the recover_list takes a long time. Use an idr in place of a list. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16dlm: use rsbtbl as resource directoryDavid Teigland
Remove the dir hash table (dirtbl), and use the rsb hash table (rsbtbl) as the resource directory. It has always been an unnecessary duplication of information. This improves efficiency by using a single rsbtbl lookup in many cases where both rsbtbl and dirtbl lookups were needed previously. This eliminates the need to handle cases of rsbtbl and dirtbl being out of sync. In many cases there will be memory savings because the dir hash table no longer exists. Signed-off-by: David Teigland <teigland@redhat.com>
2012-07-16NFS: Clean up nfs4_proc_setclientid() and friendsChuck Lever
Add documenting comments and appropriate debugging messages. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: Treat NFS4ERR_CLID_INUSE as a fatal errorChuck Lever
For NFSv4 minor version 0, currently the cl_id_uniquifier allows the Linux client to generate a unique nfs_client_id4 string whenever a server replies with NFS4ERR_CLID_INUSE. This implementation seems to be based on a flawed reading of RFC 3530. NFS4ERR_CLID_INUSE actually means that the client has presented this nfs_client_id4 string with a different principal at some time in the past, and that lease is still in use on the server. For a Linux client this might be rather difficult to achieve: the authentication flavor is named right in the nfs_client_id4.id string. If we change flavors, we change strings automatically. So, practically speaking, NFS4ERR_CLID_INUSE means there is some other client using our string. There is not much that can be done to recover automatically. Let's make it a permanent error. Remove the recovery logic in nfs4_proc_setclientid(), and remove the cl_id_uniquifier field from the nfs_client data structure. And, remove the authentication flavor from the nfs_client_id4 string. Keeping the authentication flavor in the nfs_client_id4.id string means that we could have a separate lease for each authentication flavor used by mounts on the client. But we want just one lease for all the mounts on this client. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: When state recovery fails, waiting tasks should exitChuck Lever
NFSv4 state recovery is not always successful. Failure is signalled by setting the nfs_client.cl_cons_state to a negative (errno) value, then waking waiters. Currently this can happen only during mount processing. I'm about to add an explicit case where state recovery failure during normal operation should force all NFS requests waiting on that state recovery to exit. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16SUNRPC: Add rpcauth_list_flavors()Chuck Lever
The gss_mech_list_pseudoflavors() function provides a list of currently registered GSS pseudoflavors. This list does not include any non-GSS flavors that have been registered with the RPC client. nfs4_find_root_sec() currently adds these extra flavors by hand. Instead, nfs4_find_root_sec() should be looking at the set of flavors that have been explicitly registered via rpcauth_register(). And, other areas of code will soon need the same kind of list that contains all flavors the kernel currently knows about (see below). Rather than cloning the open-coded logic in nfs4_find_root_sec() to those new places, introduce a generic RPC function that generates a full list of registered auth flavors and pseudoflavors. A new rpc_authops method is added that lists a flavor's pseudoflavors, if it has any. I encountered an interesting module loader loop when I tried to get the RPC client to invoke gss_mech_list_pseudoflavors() by name. This patch is a pre-requisite for server trunking discovery, and a pre-requisite for fixing up the in-kernel mount client to do better automatic security flavor selection. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: nfs_getaclargs.acl_len is a size_tChuck Lever
Squelch compiler warnings: fs/nfs/nfs4proc.c: In function ‘__nfs4_get_acl_uncached’: fs/nfs/nfs4proc.c:3811:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] fs/nfs/nfs4proc.c:3818:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] Introduced by commit bf118a34 "NFSv4: include bitmap in nfsv4 get acl data", Dec 7, 2011. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: Clean up TEST_STATEID and FREE_STATEID error reportingChuck Lever
As a finishing touch, add appropriate documenting comments and some debugging printk's. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: Clean up nfs41_check_expired_stateid()Chuck Lever
Clean up: Instead of open-coded flag manipulation, use test_bit() and clear_bit() just like all other accessors of the state->flag field. This also eliminates several unnecessary implicit integer type conversions. To make it absolutely clear what is going on, a number of comments are introduced. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: State reclaim clears OPEN and LOCK stateChuck Lever
The "state->flags & flags" test in nfs41_check_expired_stateid() allows the state manager to squelch a TEST_STATEID operation when it is known for sure that a state ID is no longer valid. If the lease was purged, for example, the client already knows that state ID is now defunct. But open recovery is still needed for that inode. To force a call to nfs4_open_expired(), change the default return value for nfs41_check_expired_stateid() to force open recovery, and the default return value for nfs41_check_locks() to force lock recovery, if the requested flags are clear. Fix suggested by Bryan Schumaker. Also, the presence of a delegation state ID must not prevent normal open recovery. The delegation state ID must be cleared if it was revoked, but once cleared I don't think it's presence or absence has any bearing on whether open recovery is still needed. So the logic is adjusted to ignore the TEST_STATEID result for the delegation state ID. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: Don't free a state ID the server does not recognizeChuck Lever
The result of a TEST_STATEID operation can indicate a few different things: o If NFS_OK is returned, then the client can continue using the state ID under test, and skip recovery. o RFC 5661 says that if the state ID was revoked, then the client must perform an explicit FREE_STATEID before trying to re-open. o If the server doesn't recognize the state ID at all, then no FREE_STATEID is needed, and the client can immediately continue with open recovery. Let's err on the side of caution: if the server clearly tells us the state ID is unknown, we skip the FREE_STATEID. For any other error, we issue a FREE_STATEID. Sometimes that FREE_STATEID will be unnecessary, but leaving unused state IDs on the server needlessly ties up resources. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFS: Fix up TEST_STATEID and FREE_STATEID return code handlingChuck Lever
The TEST_STATEID and FREE_STATEID operations can return -NFS4ERR_BAD_STATEID, -NFS4ERR_OLD_STATEID, or -NFS4ERR_DEADSESSION. nfs41_{test,free}_stateid() should not pass these errors to nfs4_handle_exception() during state recovery, since that will recursively kick off state recovery again, resulting in a deadlock. In particular, when the TEST_STATEID operation returns NFS4_OK, res.status can contain one of these errors. _nfs41_test_stateid() replaces NFS4_OK with the value in res.status, which is then returned to callers. But res.status is not passed through nfs4_stat_to_errno(), and thus is a positive NFS4ERR value. Currently callers are only interested in !NFS4_OK, and nfs4_handle_exception() ignores positive values. Thus the res.status values are currently ignored by nfs4_handle_exception() and won't cause the deadlock above. Thanks to this missing negative, it is only when these operations fail (which is very rare) that a deadlock can occur. Bryan agrees the original intent was to return res.status as a negative NFS4ERR value to callers of nfs41_test_stateid(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFSv4.1 do not send LAYOUTRETURN on emtpy plh_segs listAndy Adamson
mark_matching_lsegs_invalid() resets the mds_threshold counters and can dereference the layout hdr on an initial empty plh_segs list. It returns 0 both in the case of an initial empty list and in a non-emtpy list that was cleared by calls to mark_lseg_invalid. Don't send a LAYOUTRETURN if the list was initially empty. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFSv4.1 mark layout when already returnedAndy Adamson
When the file layout driver is fencing a DS, _pnfs_return_layout can be called mulitple times per inode due to in-flight i/o referencing lsegs on it's plh_segs list. Remember that LAYOUTRETURN has been called, and do not call it again. Allow LAYOUTRETURNs after a subsequent LAYOUTGET. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFSv4.1 don't send LAYOUTCOMMIT if data resent through MDSAndy Adamson
Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16NFSv4.1 return the LAYOUT for each file with failed DS connection I/OAndy Adamson
First mark the deviceid invalid to prevent any future use. Then fence all files involved in I/O to a DS with a connection error by sending a LAYOUTRETURN. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-16Merge tag 'for-linus-v3.5-rc7' of git://oss.sgi.com/xfs/xfsLinus Torvalds
Pull xfs regression fixes from Ben Myers: - Really fix a cursor leak in xfs_alloc_ag_vextent_near - Fix a performance regression related to doing allocation in workqueues - Prevent recursion in xfs_buf_iorequest which is causing stack overflows - Don't call xfs_bdstrat_cb in xfs_buf_iodone callbacks * tag 'for-linus-v3.5-rc7' of git://oss.sgi.com/xfs/xfs: xfs: do not call xfs_bdstrat_cb in xfs_buf_iodone_callbacks xfs: prevent recursion in xfs_buf_iorequest xfs: don't defer metadata allocation to the workqueue xfs: really fix the cursor leak in xfs_alloc_ag_vextent_near
2012-07-16Merge commit '9249e17fe094d853d1ef7475dd559a2cc7e23d42' into nfs-for-3.6Trond Myklebust
Resolve conflicts with the VFS atomic open and sget changes. Conflicts: fs/nfs/nfs4proc.c
2012-07-16fifo: Do not restart open() if it already found a partnerAnders Kaseorg
If a parent and child process open the two ends of a fifo, and the child immediately exits, the parent may receive a SIGCHLD before its open() returns. In that case, we need to make sure that open() will return successfully after the SIGCHLD handler returns, instead of throwing EINTR or being restarted. Otherwise, the restarted open() would incorrectly wait for a second partner on the other end. The following test demonstrates the EINTR that was wrongly thrown from the parent’s open(). Change .sa_flags = 0 to .sa_flags = SA_RESTART to see a deadlock instead, in which the restarted open() waits for a second reader that will never come. (On my systems, this happens pretty reliably within about 5 to 500 iterations. Others report that it manages to loop ~forever sometimes; YMMV.) #include <sys/stat.h> #include <sys/types.h> #include <sys/wait.h> #include <fcntl.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #define CHECK(x) do if ((x) == -1) {perror(#x); abort();} while(0) void handler(int signum) {} int main() { struct sigaction act = {.sa_handler = handler, .sa_flags = 0}; CHECK(sigaction(SIGCHLD, &act, NULL)); CHECK(mknod("fifo", S_IFIFO | S_IRWXU, 0)); for (;;) { int fd; pid_t pid; putc('.', stderr); CHECK(pid = fork()); if (pid == 0) { CHECK(fd = open("fifo", O_RDONLY)); _exit(0); } CHECK(fd = open("fifo", O_WRONLY)); CHECK(close(fd)); CHECK(waitpid(pid, NULL, 0)); } } This is what I suspect was causing the Git test suite to fail in t9010-svn-fe.sh: http://bugs.debian.org/678852 Signed-off-by: Anders Kaseorg <andersk@mit.edu> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-14VFS: Split inode_permission()David Howells
Split inode_permission() into inode- and superblock-dependent parts. This is aimed at unionmounts where the superblock from the upper layer has to be checked rather than the superblock from the lower layer as the upper layer may be writable, thus allowing an unwritable file from the lower layer to be copied up and modified. Original-author: Valerie Aurora <vaurora@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> (Further development) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14VFS: Pass mount flags to sget()David Howells
Pass mount flags to sget() so that it can use them in initialising a new superblock before the set function is called. They could also be passed to the compare function. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14VFS: Comment mount following codeDavid Howells
Add comments describing what the directions "up" and "down" mean and ref count handling to the VFS mount following family of functions. Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author) Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errorsDavid Howells
copy_tree() can theoretically fail in a case other than ENOMEM, but always returns NULL which is interpreted by callers as -ENOMEM. Change it to return an explicit error. Also change clone_mnt() for consistency and because union mounts will add new error cases. Thanks to Andreas Gruenbacher <agruen@suse.de> for a bug fix. [AV: folded braino fix by Dan Carpenter] Original-author: Valerie Aurora <vaurora@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Valerie Aurora <valerie.aurora@gmail.com> Cc: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14VFS: Make chown() and lchown() call fchownat()David Howells
Make the chown() and lchown() syscalls jump to the fchownat() syscall with the appropriate extra arguments. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14do_dentry_open(): close the race with mark_files_ro() in failure exitAl Viro
we want to take it out of mark_files_ro() reach *before* we start checking if we ought to drop write access. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14mark_files_ro(): don't bother with mntget/mntputAl Viro
mnt_drop_write_file() is safe under any lock Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14notify_change(): check that i_mutex is heldAndrew Morton
Cc: Djalal Harouni <tixxdz@opendz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14fs: add nd_jump_linkChristoph Hellwig
Add a helper that abstracts out the jump to an already parsed struct path from ->follow_link operation from procfs. Not only does this clean up the code by moving the two sides of this game into a single helper, but it also prepares for making struct nameidata private to namei.c Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14fs: move path_put on failure out of ->follow_linkChristoph Hellwig
Currently the non-nd_set_link based versions of ->follow_link are expected to do a path_put(&nd->path) on failure. This calling convention is unexpected, undocumented and doesn't match what the nd_set_link-based instances do. Move the path_put out of the only non-nd_set_link based ->follow_link instance into the caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14debugfs: get rid of useless arguments to debugfs_{mkdir,symlink}Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14debugfs: fold debugfs_create_by_name() into the only callerAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14debugfs: make sure that debugfs_create_file() gets used only for regularsAl Viro
It, debugfs_create_dir() and debugfs_create_link() use the common helper now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>