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* afs: Display manually added cells in dynamic root mountDavid Howells2018-06-151-20/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <dhowells@redhat.com>
* Merge tag 'afs-fixes-20180514' into afs-procAl Viro2018-06-021-2/+2
|\ | | | | | | | | | | | | backmerge AFS fixes that went into mainline and deal with the conflict in fs/afs/fsclient.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * afs: Fix whole-volume callback handlingDavid Howells2018-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | It's possible for an AFS file server to issue a whole-volume notification that callbacks on all the vnodes in the file have been broken. This is done for R/O and backup volumes (which don't have per-file callbacks) and for things like a volume being taken offline. Fix callback handling to detect whole-volume notifications, to track it across operations and to check it during inode validation. Fixes: c435ee34551e ("afs: Overhaul the callback handling") Signed-off-by: David Howells <dhowells@redhat.com>
| * afs: Fix directory page lockingDavid Howells2018-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The afs directory loading code (primarily afs_read_dir()) locks all the pages that hold a directory's content blob to defend against getdents/getdents races and getdents/lookup races where the competitors issue conflicting reads on the same data. As the reads will complete consecutively, they may retrieve different versions of the data and one may overwrite the data that the other is busy parsing. Fix this by not locking the pages at all, but rather by turning the validation lock into an rwsem and getting an exclusive lock on it whilst reading the data or validating the attributes and a shared lock whilst parsing the data. Sharing the attribute validation lock should be fine as the data fetch will retrieve the attributes also. The individual page locks aren't needed at all as the only place they're being used is to serialise data loading. Without this patch, the: if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) { ... } part of afs_read_dir() may be skipped, leaving the pages unlocked when we hit the success: clause - in which case we try to unlock the not-locked pages, leading to the following oops: page:ffffe38b405b4300 count:3 mapcount:0 mapping:ffff98156c83a978 index:0x0 flags: 0xfffe000001004(referenced|private) raw: 000fffe000001004 ffff98156c83a978 0000000000000000 00000003ffffffff raw: dead000000000100 dead000000000200 0000000000000001 ffff98156b27c000 page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) page->mem_cgroup:ffff98156b27c000 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:1205! ... RIP: 0010:unlock_page+0x43/0x50 ... Call Trace: afs_dir_iterate+0x789/0x8f0 [kafs] ? _cond_resched+0x15/0x30 ? kmem_cache_alloc_trace+0x166/0x1d0 ? afs_do_lookup+0x69/0x490 [kafs] ? afs_do_lookup+0x101/0x490 [kafs] ? key_default_cmp+0x20/0x20 ? request_key+0x3c/0x80 ? afs_lookup+0xf1/0x340 [kafs] ? __lookup_slow+0x97/0x150 ? lookup_slow+0x35/0x50 ? walk_component+0x1bf/0x490 ? path_lookupat.isra.52+0x75/0x200 ? filename_lookup.part.66+0xa0/0x170 ? afs_end_vnode_operation+0x41/0x60 [kafs] ? __check_object_size+0x9c/0x171 ? strncpy_from_user+0x4a/0x170 ? vfs_statx+0x73/0xe0 ? __do_sys_newlstat+0x39/0x70 ? __x64_sys_getdents+0xc9/0x140 ? __x64_sys_getdents+0x140/0x140 ? do_syscall_64+0x5b/0x160 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: f3ddee8dc4e2 ("afs: Fix directory handling") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
* | afs: Implement network namespacingDavid Howells2018-05-231-8/+12
|/ | | | | | | | Implement network namespacing within AFS, but don't yet let mounts occur outside the init namespace. An additional patch will be required propagate the network namespace across automounts. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Split the dynroot stuff out and give it its own ops tablesDavid Howells2018-04-091-4/+7
| | | | | | | | | Split the AFS dynamic root stuff out of the main directory handling file and into its own file as they share little in common. The dynamic root code also gets its own dentry and inode ops tables. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Support the AFS dynamic rootDavid Howells2018-02-061-42/+90
| | | | | | | | | | | | | | | | | | | | | | | Support the AFS dynamic root which is a pseudo-volume that doesn't connect to any server resource, but rather is just a root directory that dynamically creates mountpoint directories where the name of such a directory is the name of the cell. Such a mount can be created thus: mount -t afs none /afs -o dyn Dynamic root superblocks aren't shared except by bind mounts and propagation. Cell root volumes can then be mounted by referring to them by name, e.g.: ls /afs/grand.central.org/ ls /afs/.grand.central.org/ The kernel will upcall to consult the DNS if the address wasn't supplied directly. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Properly reset afs_vnode (inode) fieldsDavid Howells2017-12-011-1/+13
| | | | | | | | | | | | | | | | When an AFS inode is allocated by afs_alloc_inode(), the allocated afs_vnode struct isn't necessarily reset from the last time it was used as an inode because the slab constructor is only invoked once when the memory is obtained from the page allocator. This means that information can leak from one inode to the next because we're not calling kmem_cache_zalloc(). Some of the information isn't reset, in particular the permit cache pointer. Bring the clearances up to date. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
* Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds2017-11-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* afs: Get rid of the afs_writeback recordDavid Howells2017-11-131-2/+2
| | | | | | | | | | 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>
* afs: Overhaul volume and server record caching and fileserver rotationDavid Howells2017-11-131-35/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* afs: Overhaul cell database managementDavid Howells2017-11-131-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* afs: Overhaul permit cachingDavid Howells2017-11-131-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* afs: Overhaul the callback handlingDavid Howells2017-11-131-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* afs: Push the net ns pointer to more placesDavid Howells2017-11-131-6/+6
| | | | | | | | | | | | | 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>
* afs: Note the cell in the superblock info alsoDavid Howells2017-11-131-22/+35
| | | | | | | | | | | 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>
* afs: Lay the groundwork for supporting network namespacesDavid Howells2017-11-131-19/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'work.mount' of ↵Linus Torvalds2017-07-151-2/+43
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ->s_options removal from Al Viro: "Preparations for fsmount/fsopen stuff (coming next cycle). Everything gets moved to explicit ->show_options(), killing ->s_options off + some cosmetic bits around fs/namespace.c and friends. Basically, the stuff needed to work with fsmount series with minimum of conflicts with other work. It's not strictly required for this merge window, but it would reduce the PITA during the coming cycle, so it would be nice to have those bits and pieces out of the way" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: isofs: Fix isofs_show_options() VFS: Kill off s_options and helpers orangefs: Implement show_options 9p: Implement show_options isofs: Implement show_options afs: Implement show_options affs: Implement show_options befs: Implement show_options spufs: Implement show_options bpf: Implement show_options ramfs: Implement show_options pstore: Implement show_options omfs: Implement show_options hugetlbfs: Implement show_options VFS: Don't use save/replace_mount_options if not using generic_show_options VFS: Provide empty name qstr VFS: Make get_filesystem() return the affected filesystem VFS: Clean up whitespace in fs/namespace.c and fs/super.c Provide a function to create a NUL-terminated string from unterminated data
| * afs: Implement show_optionsDavid Howells2017-07-111-2/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement the show_options superblock op for afs as part of a bid to get rid of s_options and generic_show_options() to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Also implement the show_devname op to display the correct device name and thus avoid the need to display the cell= and volume= options. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | afs: Add metadata xattrsDavid Howells2017-07-091-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add xattrs to allow the user to get/set metadata in lieu of having pioctl() available. The following xattrs are now available: - "afs.cell" The name of the cell in which the vnode's volume resides. - "afs.fid" The volume ID, vnode ID and vnode uniquifier of the file as three hex numbers separated by colons. - "afs.volume" The name of the volume in which the vnode resides. For example: # getfattr -d -m ".*" /mnt/scratch getfattr: Removing leading '/' from absolute path names # file: mnt/scratch afs.cell="mycell.myorg.org" afs.fid="10000b:1:1" afs.volume="scratch" Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* afs: Convert to separately allocated bdiJan Kara2017-04-201-1/+4
| | | | | | | | | | | Allocate struct backing_dev_info separately instead of embedding it inside the superblock. This unifies handling of bdi among users. CC: David Howells <dhowells@redhat.com> CC: linux-afs@lists.infradead.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
* mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov2016-04-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kmemcg: account certain kmem allocations to memcgVladimir Davydov2016-01-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-151-1/+1
| | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman2013-03-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* afs: Only allow mounting afs in the intial network namespaceEric W. Biederman2013-02-131-0/+6
| | | | | | | | rxrpc sockets only work in the initial network namespace so it isn't possible to support afs in any other network namespace. Cc: David Howells <dhowells@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* fs: push rcu_barrier() from deactivate_locked_super() to filesystemsKirill A. Shutemov2012-10-021-0/+5
| | | | | | | | | | | | | | | There's no reason to call rcu_barrier() on every deactivate_locked_super(). We only need to make sure that all delayed rcu free inodes are flushed before we destroy related cache. Removing rcu_barrier() from deactivate_locked_super() affects some fast paths. E.g. on my machine exit_group() of a last process in IPC namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 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>
* VFS: Pass mount flags to sget()David Howells2012-07-141-2/+1
| | | | | | | | | 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>
* switch open-coded instances of d_make_root() to new helperAl Viro2012-03-201-5/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: fix the stupidity with i_dentry in inode destructorsAl Viro2012-01-031-1/+0
| | | | | | | | | | Seeing that just about every destructor got that INIT_LIST_HEAD() copied into it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once(); the cost of taking it into inode_init_always() will be negligible for pipes and sockets and negative for everything else. Not to mention the removal of boilerplate code from ->destroy_inode() instances... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* AFS: Set s_id in the superblock to the volume nameDavid Howells2011-06-161-0/+1
| | | | | | | | Set s_id in the superblock to the name of the AFS volume that this superblock corresponds to. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* afs: fix sget() races, close leak on umountAl Viro2011-06-121-41/+32
| | | | | | | | | | | * set ->s_fs_info in set() callback passed to sget() * allocate the thing and set it up enough for afs_test_super() before making it visible * have it freed in ->kill_sb() (current tree simply leaks it) * have ->put_super() leave ->s_fs_info->volume alone; it's too early for dropping it; do that from ->kill_sb() after having called kill_anon_super(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch afsAl Viro2011-01-121-0/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: icache RCU free inodesNick Piggin2011-01-071-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* convert afsAl Viro2010-10-291-12/+7
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* BKL: Remove BKL from afsArnd Bergmann2010-10-041-10/+0
| | | | | | | | | | The BKL is only used in put_super and fill_super, which are both protected by the superblocks s_umount rw_semaphore. Therefore it is safe to remove the BKL entirely. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: linux-afs@lists.infradead.org Cc: David Howells <dhowells@redhat.com>
* BKL: Explicitly add BKL around get_sb/fill_superJan Blunck2010-10-041-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* AFS: Implement an autocell mount capability [ver #2]wanglei2010-08-111-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement the ability for the root directory of a mounted AFS filesystem to accept lookups of arbitrary directory names, to interpet the names as the names of cells, to look the cell names up in the DNS for AFSDB records and to mount the root.cell volume of the nominated cell on the pseudo-directory created by lookup. This facility is requested by passing: -o autocell to the mountpoint for which this is desired, usually the /afs mount. To use this facility, a DNS upcall program is required for AFSDB records. This can be obtained from: http://people.redhat.com/~dhowells/afs/dns.afsdb.c It should be compiled with -lresolv and -lkeyutils and installed as, say: /usr/sbin/dns.afsdb Then the following line needs to be added to /sbin/request-key.conf: create dns_resolver afsdb:* * /usr/sbin/dns.afsdb %k This can be tested by mounting AFS, say: insmod dns_resolver.ko insmod af-rxrpc.ko insmod kafs.ko rootcell=grand.central.org mount -t afs "#grand.central.org:root.cell." /afs -o autocell and doing: ls /afs/grand.central.org/ which should show: archive/ cvs/ doc/ local/ project/ service/ software/ user/ www/ if it works. Signed-off-by: Wang Lei <wang840925@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
* convert remaining ->clear_inode() to ->evict_inode()Al Viro2010-08-091-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* afs: add bdi backing to mount session.Jens Axboe2010-04-221-0/+1
| | | | | | This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* make sure data is on disk before calling ->write_inodeChristoph Hellwig2010-03-051-1/+0
| | | | | | | | | | | | | | | | | Similar to the fsync issue fixed a while ago in commit 2daea67e966dc0c42067ebea015ddac6834cef88 we need to write for data to actually hit the disk before writing out the metadata to guarantee data integrity for filesystems that modify the inode in the data I/O completion path. Currently XFS and NFS handle this manually, and AFS has a write_inode method that does nothing but waiting for data, while others are possibly missing out on this. Fortunately this change has a lot less impact than the fsync change as none of the write_inode methods starts data writeout of any form by itself. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* headers: smp_lock.h reduxAlexey Dobriyan2009-07-121-0/+1
| | | | | | | | | | | | | * Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* push BKL down into ->put_superChristoph Hellwig2009-06-111-0/+4
| | | | | | | | | | | | | | | | | Move BKL into ->put_super from the only caller. A couple of filesystems had trivial enough ->put_super (only kfree and NULLing of s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs, hugetlbfs, omfs, qnx4, shmem, all others got the full treatment. Most of them probably don't need it, but I'd rather sort that out individually. Preferably after all the other BKL pushdowns in that area. [AV: original used to move lock_super() down as well; these changes are removed since we don't do lock_super() at all in generic_shutdown_super() now] [AV: fuse, btrfs and xfs are known to need no damn BKL, exempt] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Fix races around the access to ->s_optionsAl Viro2009-05-091-2/+2
| | | | | | | | | Put generic_show_options read access to s_options under rcu_read_lock, split save_mount_options() into "we are setting it the first time" (uses in foo_fill_super()) and "we are relacing and freeing the old one", synchronize_rcu() before kfree() in the latter. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Convert obvious places to deactivate_locked_super()Al Viro2009-05-091-2/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Use const for kernel parser tableSteven Whitehouse2008-10-131-1/+1
| | | | | | | | | | | | | | This is a much better version of a previous patch to make the parser tables constant. Rather than changing the typedef, we put the "const" in all the various places where its required, allowing the __initconst exception for nfsroot which was the cause of the previous trouble. This was posted for review some time ago and I believe its been in -mm since then. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Alexander Viro <aviro@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix various old email addresses for dwmw2David Woodhouse2008-06-061-1/+1
| | | | | | | | | Although if people have questions about ARCnet, perhaps it's _better_ for them to be mailing dwmw2@cam.ac.uk about it... Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] do shrink_submounts() for all fs typesAl Viro2008-03-271-1/+0
| | | | | | | | | ... and take it out of ->umount_begin() instances. Call with all locks already taken (by do_umount()) and leave calling release_mounts() to caller (it will do release_mounts() anyway, so we can just put into the same list). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mount options: fix afsMiklos Szeredi2008-02-081-0/+5
| | | | | | | | | | | | Add a .show_options super operation to afs. Use generic_show_options() and save the complete option string in afs_get_sb(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 23:15:09 +0000