kernel/git/stable/linux.git/fs/afs, branch linux-4.18.y

afs: Fix cell proc list

2018-11-04T13:51:51+00:00

[ Upstream commit 6b3944e42e2e554aa5a4be681ecd70dccd459114 ] Access to the list of cells by /proc/net/afs/cells has a couple of problems: (1) It should be checking against SEQ_START_TOKEN for the keying the header line. (2) It's only holding the RCU read lock, so it can't just walk over the list without following the proper RCU methods. Fix these by using an hlist instead of an ordinary list and using the appropriate accessor functions to follow it with RCU. Since the code that adds a cell to the list must also necessarily change, sort the list on insertion whilst we're at it. Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

afs: Fix clearance of reply

2018-10-18T07:18:17+00:00

commit f0a7d1883d9f78ae7bf15fc258bf9a2b20f35b76 upstream. The recent patch to fix the afs_server struct leak didn't actually fix the bug, but rather fixed some of the symptoms. The problem is that an asynchronous call that holds a resource pointed to by call->reply[0] will find the pointer cleared in the call destructor, thereby preventing the resource from being cleaned up. In the case of the server record leak, the afs_fs_get_capabilities() function in devel code sets up a call with reply[0] pointing at the server record that should be altered when the result is obtained, but this was being cleared before the destructor was called, so the put in the destructor does nothing and the record is leaked. Commit f014ffb025c1 removed the additional ref obtained by afs_install_server(), but the removal of this ref is actually used by the garbage collector to mark a server record as being defunct after the record has expired through lack of use. The offending clearance of call->reply[0] upon completion in afs_process_async_call() has been there from the origin of the code, but none of the asynchronous calls actually use that pointer currently, so it should be safe to remove (note that synchronous calls don't involve this function). Fix this by the following means: (1) Revert commit f014ffb025c1. (2) Remove the clearance of reply[0] from afs_process_async_call(). Without this, afs_manage_servers() will suffer an assertion failure if it sees a server record that didn't get used because the usage count is not 1. Fixes: f014ffb025c1 ("afs: Fix afs_server struct leak") Fixes: 08e0e7c82eea ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.") Signed-off-by: David Howells Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

afs: Fix afs_server struct leak

2018-10-18T07:18:17+00:00

commit f014ffb025c159fd51d19af8af0022a991aaa4f8 upstream. Fix a leak of afs_server structs. The routine that installs them in the various lookup lists and trees gets a ref on leaving the function, whether it added the server or a server already exists. It shouldn't increment the refcount if it added the server. The effect of this that "rmmod kafs" will hang waiting for the leaked server to become unused. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

afs: Fix cell specification to permit an empty address list

2018-10-10T06:55:57+00:00

[ Upstream commit ecfe951f0c1b169ea4b7dd6f3a404dfedd795bc2 ] Fix the cell specification mechanism to allow cells to be pre-created without having to specify at least one address (the addresses will be upcalled for). This allows the cell information preload service to avoid the need to issue loads of DNS lookups during boot to get the addresses for each cell (500+ lookups for the 'standard' cell list[*]). The lookups can be done later as each cell is accessed through the filesystem. Also remove the print statement that prints a line every time a new cell is added. [*] There are 144 cells in the list. Each cell is first looked up for an SRV record, and if that fails, for an AFSDB record. These get a list of server names, each of which then has to be looked up to get the addresses for that server. E.g.: dig srv _afs3-vlserver._udp.grand.central.org Signed-off-by: David Howells Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-06-16T07:32:04+00:00

Pull AFS updates from Al Viro: "Assorted AFS stuff - ended up in vfs.git since most of that consists of David's AFS-related followups to Christoph's procfs series" * 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: afs: Optimise callback breaking by not repeating volume lookup afs: Display manually added cells in dynamic root mount afs: Enable IPv6 DNS lookups afs: Show all of a server's addresses in /proc/fs/afs/servers afs: Handle CONFIG_PROC_FS=n proc: Make inline name size calculation automatic afs: Implement network namespacing afs: Mark afs_net::ws_cell as __rcu and set using rcu functions afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus() proc: Add a way to make network proc files writable afs: Rearrange fs/afs/proc.c to remove remaining predeclarations. afs: Rearrange fs/afs/proc.c to move the show routines up afs: Rearrange fs/afs/proc.c by moving fops and open functions down afs: Move /proc management functions to the end of the file

afs: Optimise callback breaking by not repeating volume lookup

2018-06-15T14:27:09+00:00

At the moment, afs_break_callbacks calls afs_break_one_callback() for each separate FID it was given, and the latter looks up the volume individually for each one. However, this is inefficient if two or more FIDs have the same vid as we could reuse the volume. This is complicated by cell aliasing whereby we may have multiple cells sharing a volume and can therefore have multiple callback interests for any particular volume ID. At the moment afs_break_one_callback() scans the entire list of volumes we're getting from a server and breaks the appropriate callback in every matching volume, regardless of cell. This scan is done for every FID. Optimise callback breaking by the following means: (1) Sort the FID list by vid so that all FIDs belonging to the same volume are clumped together. This is done through the use of an indirection table as we cannot do an insertion sort on the afs_callback_break array as we decode FIDs into it as we subsequently also have to decode callback info into it that corresponds by array index only. We also don't really want to bubblesort afterwards if we can avoid it. (2) Sort the server->cb_interests array by vid so that all the matching volumes are grouped together. This permits the scan to stop after finding a record that has a higher vid. (3) When breaking FIDs, we try to keep server->cb_break_lock as long as possible, caching the start point in the array for that volume group as long as possible. It might make sense to add another layer in that list and have a refcounted volume ID anchor that has the matching interests attached to it rather than being in the list. This would allow the lock to be dropped without losing the cursor. Signed-off-by: David Howells

afs: Display manually added cells in dynamic root mount

2018-06-15T14:27:09+00:00

Alter the dynroot mount so that cells created by manipulation of /proc/fs/afs/cells and /proc/fs/afs/rootcell and by specification of a root cell as a module parameter will cause directories for those cells to be created in the dynamic root superblock for the network namespace[*]. To this end: (1) Only one dynamic root superblock is now created per network namespace and this is shared between all attempts to mount it. This makes it easier to find the superblock to modify. (2) When a dynamic root superblock is created, the list of cells is walked and directories created for each cell already defined. (3) When a new cell is added, if a dynamic root superblock exists, a directory is created for it. (4) When a cell is destroyed, the directory is removed. (5) These directories are created by calling lookup_one_len() on the root dir which automatically creates them if they don't exist. [*] Inasmuch as network namespaces are currently supported here. Signed-off-by: David Howells

afs: Enable IPv6 DNS lookups

2018-06-15T14:27:09+00:00

Remove the restriction on DNS lookup upcalls that prevents ipv6 addresses from being looked up. Signed-off-by: David Howells

afs: Show all of a server's addresses in /proc/fs/afs/servers

2018-06-15T04:52:59+00:00

Show all of a server's addresses in /proc/fs/afs/servers, placing the second plus addresses on padded lines of their own. The current address is marked with a star. Signed-off-by: David Howells

afs: Handle CONFIG_PROC_FS=n

2018-06-15T04:52:55+00:00

The AFS filesystem depends at the moment on /proc for configuration and also presents information that way - however, this causes a compilation failure if procfs is disabled. Fix it so that the procfs bits aren't compiled in if procfs is disabled. This means that you can't configure the AFS filesystem directly, but it is still usable provided that an up-to-date keyutils is installed to look up cells by SRV or AFSDB DNS records. Reported-by: Al Viro Signed-off-by: David Howells