- Nov 13, 2017
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David Howells authored
Protect call->state changes against the call being prematurely terminated due to a signal. What can happen is that a signal causes afs_wait_for_call_to_complete() to abort an afs_call because it's not yet complete whilst afs_deliver_to_call() is delivering data to that call. If the data delivery causes the state to change, this may overwrite the state of the afs_call, making it not-yet-complete again - but no further notifications will be forthcoming from AF_RXRPC as the rxrpc call has been aborted and completed, so kAFS will just hang in various places waiting for that call or on page bits that need clearing by that call. A tracepoint to monitor call state changes is also provided. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Add a trace event that logs the dirtying and cleaning of pages attached to AFS inodes. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Implement shared-writeable mmap for AFS. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Get rid of the afs_writeback record that kAFS is using to match keys with writes made by that key. Instead, keep a list of keys that have a file open for writing and/or sync'ing and iterate through those. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Introduce a file-private data record for kAFS and put the key into it rather than storing the key in file->private_data. Signed-off-by:
David Howells <dhowells@redhat.com>
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Marc Dionne authored
It is not required that the afs client operate on port 7001. The port could be in use because another kernel or userspace client has already bound to it. If the port is in use, just fallback to using a dynamic port. Signed-off-by:
Marc Dionne <marc.dionne@auristor.com> Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Because parsing of the directory wasn't being done under any sort of lock, the pages holding the directory content can get invalidated whilst the parsing is ongoing. Further, the directory page check function gets called outside of the page lock, so if the page gets cleared or updated, this may return reports of bad magic numbers in the directory page. Also, the directory may change size whilst checking and parsing are ongoing, so more care needs to be taken here. Fix this by: (1) Perform the page check from the page filling function before we set PageUptodate and drop the page lock. (2) Check for the file having shrunk and the page having been abandoned before checking the page contents. (3) Lock the page whilst parsing it for the directory iterator. Whilst we're at it, add a tracepoint to report check failure. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Add a pair of tracepoints to log the sending of pages for an FS.StoreData or FS.StoreData64 operation. Tracepoint afs_send_pages notes each set of pages added to the operation. There may be several of these per operation as we get up at most 8 contiguous pages in one go because the bvec we're using is on the stack. Tracepoint afs_sent_pages notes the end of adding data from a whole run of pages to the operation and the completion of the request phase. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Add tracepoints to trace the initiation and completion of client calls within the kafs filesystem. The afs_make_vl_call tracepoint watches calls to the volume location database server. The afs_make_fs_call tracepoint watches calls to the file server. The afs_call_done tracepoint watches for call completion. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
The documentation that describes the #-prefix and the %-prefix used when specifying the source to mount is has the descriptions the wrong way round. Switch them over. Reported-by:
Marc Dionne <marc.dionne@auristor.com> Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Fix the total-length calculation in afs_make_call() when the operation being dispatched has data from a series of pages attached. Despite the patched code looking like that it should reduce mathematically to the current code, it doesn't because the 32-bit unsigned arithmetic being used to calculate the page-offset-difference doesn't correctly extend to a 64-bit value when the result is effectively negative. Without this, some FS.StoreData operations that span multiple pages fail, reporting too little or too much data. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Only progress the AFS call state at the end of Tx phase from the callback passed to rxrpc_kernel_send_data() rather than setting it before the last data send call. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
YFS VL servers offer an upgraded Volume Location service that can return IPv6 addresses to fileservers and volume servers in addition to IPv4 addresses using the YFSVL.GetEndpoints operation which we should use if it's available. To this end: (1) Make rxrpc_kernel_recv_data() return the call's current service ID so that the caller can detect service upgrade and see what the service was upgraded to. (2) When we see a VL server address we haven't seen before, send a VL.GetCapabilities operation to it with the service upgrade bit set. If we get an upgrade to the YFS VL service, change the service ID in the address list for that address to use the upgraded service and set a flag to note that this appears to be a YFS-compatible server. (3) If, when a server's addresses are being looked up, we note that we previously detected a YFS-compatible server, then send the YFSVL.GetEndpoints operation rather than VL.GetAddrsU. (4) Build a fileserver address list from the reply of YFSVL.GetEndpoints, including both IPv4 and IPv6 addresses. Volume server addresses are discarded. (5) The address list is sorted by address and port now, instead of just address. This allows multiple servers on the same host sitting on different ports. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
The current code assumes that volumes and servers are per-cell and are never shared, but this is not enforced, and, indeed, public cells do exist that are aliases of each other. Further, an organisation can, say, set up a public cell and a private cell with overlapping, but not identical, sets of servers. The difference is purely in the database attached to the VL servers. The current code will malfunction if it sees a server in two cells as it assumes global address -> server record mappings and that each server is in just one cell. Further, each server may have multiple addresses - and may have addresses of different families (IPv4 and IPv6, say). To this end, the following structural changes are made: (1) Server record management is overhauled: (a) Server records are made independent of cell. The namespace keeps track of them, volume records have lists of them and each vnode has a server on which its callback interest currently resides. (b) The cell record no longer keeps a list of servers known to be in that cell. (c) The server records are now kept in a flat list because there's no single address to sort on. (d) Server records are now keyed by their UUID within the namespace. (e) The addresses for a server are obtained with the VL.GetAddrsU rather than with VL.GetEntryByName, using the server's UUID as a parameter. (f) Cached server records are garbage collected after a period of non-use and are counted out of existence before purging is allowed to complete. This protects the work functions against rmmod. (g) The servers list is now in /proc/fs/afs/servers. (2) Volume record management is overhauled: (a) An RCU-replaceable server list is introduced. This tracks both servers and their coresponding callback interests. (b) The superblock is now keyed on cell record and numeric volume ID. (c) The volume record is now tied to the superblock which mounts it, and is activated when mounted and deactivated when unmounted. This makes it easier to handle the cache cookie without causing a double-use in fscache. (d) The volume record is loaded from the VLDB using VL.GetEntryByNameU to get the server UUID list. (e) The volume name is updated if it is seen to have changed when the volume is updated (the update is keyed on the volume ID). (3) The vlocation record is got rid of and VLDB records are no longer cached. Sufficient information is stored in the volume record, though an update to a volume record is now no longer shared between related volumes (volumes come in bundles of three: R/W, R/O and backup). and the following procedural changes are made: (1) The fileserver cursor introduced previously is now fleshed out and used to iterate over fileservers and their addresses. (2) Volume status is checked during iteration, and the server list is replaced if a change is detected. (3) Server status is checked during iteration, and the address list is replaced if a change is detected. (4) The abort code is saved into the address list cursor and -ECONNABORTED returned in afs_make_call() if a remote abort happened rather than translating the abort into an error message. This allows actions to be taken depending on the abort code more easily. (a) If a VMOVED abort is seen then this is handled by rechecking the volume and restarting the iteration. (b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is handled by sleeping for a short period and retrying and/or trying other servers that might serve that volume. A message is also displayed once until the condition has cleared. (c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the moment. (d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to see if it has been deleted; if not, the fileserver is probably indicating that the volume couldn't be attached and needs salvaging. (e) If statfs() sees one of these aborts, it does not sleep, but rather returns an error, so as not to block the umount program. (5) The fileserver iteration functions in vnode.c are now merged into their callers and more heavily macroised around the cursor. vnode.c is removed. (6) Operations on a particular vnode are serialised on that vnode because the server will lock that vnode whilst it operates on it, so a second op sent will just have to wait. (7) Fileservers are probed with FS.GetCapabilities before being used. This is where service upgrade will be done. (8) A callback interest on a fileserver is set up before an FS operation is performed and passed through to afs_make_call() so that it can be set on the vnode if the operation returns a callback. The callback interest is passed through to afs_iget() also so that it can be set there too. In general, record updating is done on an as-needed basis when we try to access servers, volumes or vnodes rather than offloading it to work items and special threads. Notes: (1) Pre AFS-3.4 servers are no longer supported, though this can be added back if necessary (AFS-3.4 was released in 1998). (2) VBUSY is retried forever for the moment at intervals of 1s. (3) /proc/fs/afs/<cell>/servers no longer exists. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Move server rotation code into its own file. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Add an RCU replaceable address list structure to hold a list of server addresses. The list also holds the To this end: (1) A cell's VL server address list can be loaded directly via insmod or echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB or SRV records. (2) Anyone wanting to use a cell's VL server address must wait until the cell record comes online and has tried to obtain some addresses. (3) An FS server's address list, for the moment, has a single entry that is the key to the server list. This will change in the future when a server is instead keyed on its UUID and the VL.GetAddrsU operation is used. (4) An 'address cursor' concept is introduced to handle iteration through the address list. This is passed to the afs_make_call() as, in the future, stuff (such as abort code) that doesn't outlast the call will be returned in it. In the future, we might want to annotate the list with information about how each address fares. We might then want to propagate such annotations over address list replacement. Whilst we're at it, we allow IPv6 addresses to be specified in colon-delimited lists by enclosing them in square brackets. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Overhaul the way that the in-kernel AFS client keeps track of cells in the following manner: (1) Cells are now held in an rbtree to make walking them quicker and RCU managed (though this is probably overkill). (2) Cells now have a manager work item that: (A) Looks after fetching and refreshing the VL server list. (B) Manages cell record lifetime, including initialising and destruction. (B) Manages cell record caching whereby threads are kept around for a certain time after last use and then destroyed. (C) Manages the FS-Cache index cookie for a cell. It is not permitted for a cookie to be in use twice, so we have to be careful to not allow a new cell record to exist at the same time as an old record of the same name. (3) Each AFS network namespace is given a manager work item that manages the cells within it, maintaining a single timer to prod cells into updating their DNS records. This uses the reduce_timer() facility to make the timer expire at the soonest timed event that needs happening. (4) When a module is being unloaded, cells and cell managers are now counted out using dec_after_work() to make sure the module text is pinned until after the data structures have been cleaned up. (5) Each cell's VL server list is now protected by a seqlock rather than a semaphore. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Overhaul permit caching in AFS by making it per-vnode and sharing permit lists where possible. When most of the fileserver operations are called, they return a status structure indicating the (revised) details of the vnode or vnodes involved in the operation. This includes the access mark derived from the ACL (named CallerAccess in the protocol definition file). This is cacheable and if the ACL changes, the server will tell us that it is breaking the callback promise, at which point we can discard the currently cached permits. With this patch, the afs_permits structure has, at the end, an array of { key, CallerAccess } elements, sorted by key pointer. This is then cached in a hash table so that it can be shared between vnodes with the same access permits. Permit lists can only be shared if they contain the exact same set of key->CallerAccess mappings. Note that that table is global rather than being per-net_ns. If the keys in a permit list cross net_ns boundaries, there is no problem sharing the cached permits, since the permits are just integer masks. Since permit lists pin keys, the permit cache also makes it easier for a future patch to find all occurrences of a key and remove them by means of setting the afs_permits::invalidated flag and then clearing the appropriate key pointer. In such an event, memory barriers will need adding. Lastly, the permit caching is skipped if the server has sent either a vnode-specific or an entire-server callback since the start of the operation. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Overhaul the AFS callback handling by the following means: (1) Don't give up callback promises on vnodes that we are no longer using, rather let them just expire on the server or let the server break them. This is actually more efficient for the server as the callback lookup is expensive if there are lots of extant callbacks. (2) Only give up the callback promises we have from a server when the server record is destroyed. Then we can just give up *all* the callback promises on it in one go. (3) Servers can end up being shared between cells if cells are aliased, so don't add all the vnodes being backed by a particular server into a big FID-indexed tree on that server as there may be duplicates. Instead have each volume instance (~= superblock) register an interest in a server as it starts to make use of it and use this to allow the processor for callbacks from the server to find the superblock and thence the inode corresponding to the FID being broken by means of ilookup_nowait(). (4) Rather than iterating over the entire callback list when a mass-break comes in from the server, maintain a counter of mass-breaks in afs_server (cb_seq) and make afs_validate() check it against the copy in afs_vnode. It would be nice not to have to take a read_lock whilst doing this, but that's tricky without using RCU. (5) Save a ref on the fileserver we're using for a call in the afs_call struct so that we can access its cb_s_break during call decoding. (6) Write-lock around callback and status storage in a vnode and read-lock around getattr so that we don't see the status mid-update. This has the following consequences: (1) Data invalidation isn't seen until someone calls afs_validate() on a vnode. Unfortunately, we need to use a key to query the server, but getting one from a background thread is tricky without caching loads of keys all over the place. (2) Mass invalidation isn't seen until someone calls afs_validate(). (3) Callback breaking is going to hit the inode_hash_lock quite a bit. Could this be replaced with rcu_read_lock() since inodes are destroyed under RCU conditions. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Rename the server member of struct afs_call to cm_server as we're only going to be using it for incoming calls for the Cache Manager service. This makes it easier to differentiate from the pointer to the target server for the client, which will point to a different structure to allow for callback handling. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
In AFS's encoding of a UUID, the eight 'char' fields are all signed, so represent them with __s8 rather than __u8. This makes the compiler sign-extend them correctly when XDR-encoding them. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
The handler for the CB.ProbeUuid operation in the cache manager is implemented, but isn't listed in the switch-statement of operation selection, so won't be used. Fix this by adding it. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
If call->ret_reply0 is set, return call->reply[0] on success. Change the return type of afs_make_call() to long so that this can be passed back without bit loss and then cast to a pointer if required. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Condense struct afs_call's reply anchor members - reply{,2,3,4} - into an array. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
The AFS abort code space is shared across all services, so there's no need for separate abort_to_error translators for each service. Consolidate them into a single function and remove the function pointers for them. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Allow VL server specifications to be given IPv6 addresses as well as IPv4 addresses, for example as: echo add foo.org 1111:2222:3333:0:4444:5555:6666:7777 >/proc/fs/afs/cells Note that ':' is the expected separator for separating IPv4 addresses, but if a ',' is detected or no '.' is detected in the string, the delimiter is switched to ','. This also works with DNS AFSDB or SRV record strings fetched by upcall from userspace. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Keep and pass sockaddr_rxrpc addresses around rather than keeping and passing in_addr addresses to allow for the use of IPv6 and non-standard port numbers in future. This also allows the port and service_id fields to be removed from the afs_call struct. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Update the cache index structure in the following ways: (1) Don't use the volume name followed by the volume type as levels in the cache index. Volumes can be renamed. Use the volume ID instead. (2) Don't store the VLDB data for a volume in the tree. If the volume database should be cached locally, then it should be done in a separate tree. (3) Expand the volume ID stored in the cache to 64 bits. (4) Expand the file/vnode ID stored in the cache to 96 bits. (5) Increment the cache structure version number to 1. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Add some protocol definitions, including max field lengths, flag defs, an XDR-encoded UUID def, more VL operation IDs and more fileserver abort codes. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Push the network namespace pointer to more places in AFS, including the afs_server structure (which doesn't hold a ref on the netns). In particular, afs_put_cell() now takes requires a net ns parameter so that it can safely alter the netns after decrementing the cell usage count - the cell will be deallocated by a background thread after being cached for a period, which means that it's not safe to access it after reducing its usage count. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Keep a reference to the cell in the superblock info structure in addition to the volume and net pointers. This will make it easier to clean up in a future patch in which afs_put_volume() will need the cell pointer. Whilst we're at it, make the cell and volume getting functions return a pointer to the object got to make the call sites look neater. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Fix server reaping and make sure it's all done before we start trying to purge cells, given that servers currently pin cells. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Close the rxrpc socket only after we've purged the server records (and also cell and volume records which might refer to servers) so that we can give up the callbacks on each server. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Lay the groundwork for supporting network namespaces (netns) to the AFS filesystem by moving various global features to a network-namespace struct (afs_net) and providing an instance of this as a temporary global variable that everything uses via accessor functions for the moment. The following changes have been made: (1) Store the netns in the superblock info. This will be obtained from the mounter's nsproxy on a manual mount and inherited from the parent superblock on an automount. (2) The cell list is made per-netns. It can be viewed through /proc/net/afs/cells and also be modified by writing commands to that file. (3) The local workstation cell is set per-ns in /proc/net/afs/rootcell. This is unset by default. (4) The 'rootcell' module parameter, which sets a cell and VL server list modifies the init net namespace, thereby allowing an AFS root fs to be theoretically used. (5) The volume location lists and the file lock manager are made per-netns. (6) The AF_RXRPC socket and associated I/O bits are made per-ns. The various workqueues remain global for the moment. Changes still to be made: (1) /proc/fs/afs/ should be moved to /proc/net/afs/ and a symlink emplaced from the old name. (2) A per-netns subsys needs to be registered for AFS into which it can store its per-netns data. (3) Rather than the AF_RXRPC socket being opened on module init, it needs to be opened on the creation of a superblock in that netns. (4) The socket needs to be closed when the last superblock using it is destroyed and all outstanding client calls on it have been completed. This prevents a reference loop on the namespace. (5) It is possible that several namespaces will want to use AFS, in which case each one will need its own UDP port. These can either be set through /proc/net/afs/cm_port or the kernel can pick one at random. The init_ns gets 7001 by default. Other issues that need resolving: (1) The DNS keyring needs net-namespacing. (2) Where do upcalls go (eg. DNS request-key upcall)? (3) Need something like open_socket_in_file_ns() syscall so that AFS command line tools attempting to operate on an AFS file/volume have their RPC calls go to the right place. Signed-off-by:
David Howells <dhowells@redhat.com>
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David Howells authored
Make wait_on_atomic_t() pass the TASK_* mode onto its action function as an extra argument and make it 'unsigned int throughout. Also, consolidate a bunch of identical action functions into a default function that can do the appropriate thing for the mode. Also, change the argument name in the bit_wait*() function declarations to reflect the fact that it's the mode and not the bit number. [Peter Z gives this a grudging ACK, but thinks that the whole atomic_t wait should be done differently, though he's not immediately sure as to how] Signed-off-by:
David Howells <dhowells@redhat.com> Acked-by:
Peter Zijlstra <peterz@infradead.org> cc: Ingo Molnar <mingo@kernel.org>
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David Howells authored
These AFS patches need the timer_reduce() patch from timers/core. Signed-off-by:
David Howells <dhowells@redhat.com>
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David S. Miller authored
Xin Long says: ==================== net: improve the process of redirect and toobig for ipv6 tunnels Now let's say there are 3 kinds of icmp packets to process for tunnels, toobig(needfrag), redirect, others, their process should be: - toobig(needfrag) update the lower dst's pmtu by route cache, also update sk dst's pmtu if possible, or it will be fine if sk dst pmtu will get updated on tx path. - redirect update the lower dst's gw by route cache and return, no need to send this redirect packet to user sk. - others send the packet to user's sk, or it will also be fine to use err_count to count it and report fail link on tx path. All ipv4 tunnels basically follow this while some of ipv6 tunnels are doing in different ways, like ip6gre and ip6_tunnels update tnl dev's mtu instead of updating lower dst pmtu, no redirect process on their err_handlers, which doesn't make any sense and even causes performance problems. This patchset is to improve the process of redirect and toobig for ip6gre ip4ip6, ip6ip6 tunnels, as in ipv4 tunnels. ==================== Signed-off-by:
David S. Miller <davem@davemloft.net>
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Xin Long authored
This patch is to remove some useless codes of redirect and fix some indents on ip4ip6 and ip6ip6's err_handlers. Note that redirect icmp packet is already processed in ip6_tnl_err, the old redirect codes in ip4ip6_err actually never worked even before this patch. Besides, there's no need to send redirect to user's sk, it's for lower dst, so just remove it in this patch. Signed-off-by:
Xin Long <lucien.xin@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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Xin Long authored
The same improvement in "ip6_gre: process toobig in a better way" is needed by ip4ip6 and ip6ip6 as well. Note that ip4ip6 and ip6ip6 will also update sk dst pmtu in their err_handlers. Like I said before, gre6 could not do this as it's inner proto is not certain. But for all of them, sk dst pmtu will be updated in tx path if in need. Signed-off-by:
Xin Long <lucien.xin@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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Xin Long authored
The same process for redirect in "ip6_gre: add the process for redirect in ip6gre_err" is needed by ip4ip6 and ip6ip6 as well. Signed-off-by:
Xin Long <lucien.xin@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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