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2015-10-27overlayfs: Make f_path always point to the overlay and f_inode to the underlayDavid Howells
[ Upstream commit 4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01 ] Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:38 5 -> /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:22 5 -> /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2014-10-24vfs: export __inode_permission() to modulesMiklos Szeredi
We need to be able to check inode permissions (but not filesystem implied permissions) for stackable filesystems. Expose this interface for overlayfs. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24vfs: export do_splice_direct() to modulesMiklos Szeredi
Export do_splice_direct() to modules. Needed by overlay filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...
2014-10-09vfs: guard end of device for mpage interfaceAkinobu Mita
Add guard_bio_eod() check for mpage code in order to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. Using mpage_readpages() for block device requires this guard check. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09fs: namespace: suppress 'may be used uninitialized' warningsTim Gardner
The gcc version 4.9.1 compiler complains Even though it isn't possible for these variables to not get initialized before they are used. fs/namespace.c: In function ‘SyS_mount’: fs/namespace.c:2720:8: warning: ‘kernel_dev’ may be used uninitialized in this function [-Wmaybe-uninitialized] ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags, ^ fs/namespace.c:2699:8: note: ‘kernel_dev’ was declared here char *kernel_dev; ^ fs/namespace.c:2720:8: warning: ‘kernel_type’ may be used uninitialized in this function [-Wmaybe-uninitialized] ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags, ^ fs/namespace.c:2697:8: note: ‘kernel_type’ was declared here char *kernel_type; ^ Fix the warnings by simplifying copy_mount_string() as suggested by Al Viro. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07make fs/{namespace,super}.c forget about acct.hAl Viro
These externs belong in fs/internal.h. Rename (they are not acct-specific anymore) and move them over there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: switch to __kernel_write()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09get rid of s_files and files_lockAl Viro
The only thing we need it for is alt-sysrq-r (emergency remount r/o) and these days we can do just as well without going through the list of files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24new helpers: lock_mount_hash/unlock_mount_hashAl Viro
aka br_write_{lock,unlock} of vfsmount_lock. Inlines in fs/mount.h, vfsmount_lock extern moved over there as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10fs: convert inode and dentry shrinking to be node awareDave Chinner
Now that the shrinker is passing a node in the scan control structure, we can pass this to the the generic LRU list code to isolate reclaim to the lists on matching nodes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Glauber Costa <glommer@parallels.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10shrinker: convert superblock shrinkers to new APIDave Chinner
Convert superblock shrinker to use the new count/scan API, and propagate the API changes through to the filesystem callouts. The filesystem callouts already use a count/scan API, so it's just changing counters to longs to match the VM API. This requires the dentry and inode shrinker callouts to be converted to the count/scan API. This is mainly a mechanical change. [glommer@openvz.org: use mult_frac for fractional proportions, build fixes] Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Glauber Costa <glommer@openvz.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10fs: bump inode and dentry counters to longGlauber Costa
This series reworks our current object cache shrinking infrastructure in two main ways: * Noticing that a lot of users copy and paste their own version of LRU lists for objects, we put some effort in providing a generic version. It is modeled after the filesystem users: dentries, inodes, and xfs (for various tasks), but we expect that other users could benefit in the near future with little or no modification. Let us know if you have any issues. * The underlying list_lru being proposed automatically and transparently keeps the elements in per-node lists, and is able to manipulate the node lists individually. Given this infrastructure, we are able to modify the up-to-now hammer called shrink_slab to proceed with node-reclaim instead of always searching memory from all over like it has been doing. Per-node lru lists are also expected to lead to less contention in the lru locks on multi-node scans, since we are now no longer fighting for a global lock. The locks usually disappear from the profilers with this change. Although we have no official benchmarks for this version - be our guest to independently evaluate this - earlier versions of this series were performance tested (details at http://permalink.gmane.org/gmane.linux.kernel.mm/100537) yielding no visible performance regressions while yielding a better qualitative behavior in NUMA machines. With this infrastructure in place, we can use the list_lru entry point to provide memcg isolation and per-memcg targeted reclaim. Historically, those two pieces of work have been posted together. This version presents only the infrastructure work, deferring the memcg work for a later time, so we can focus on getting this part tested. You can see more about the history of such work at http://lwn.net/Articles/552769/ Dave Chinner (18): dcache: convert dentry_stat.nr_unused to per-cpu counters dentry: move to per-sb LRU locks dcache: remove dentries from LRU before putting on dispose list mm: new shrinker API shrinker: convert superblock shrinkers to new API list: add a new LRU list type inode: convert inode lru list to generic lru list code. dcache: convert to use new lru list infrastructure list_lru: per-node list infrastructure shrinker: add node awareness fs: convert inode and dentry shrinking to be node aware xfs: convert buftarg LRU to generic code xfs: rework buffer dispose list tracking xfs: convert dquot cache lru to list_lru fs: convert fs shrinkers to new scan/count API drivers: convert shrinkers to new count/scan API shrinker: convert remaining shrinkers to count/scan API shrinker: Kill old ->shrink API. Glauber Costa (7): fs: bump inode and dentry counters to long super: fix calculation of shrinkable objects for small numbers list_lru: per-node API vmscan: per-node deferred work i915: bail out earlier when shrinker cannot acquire mutex hugepage: convert huge zero page shrinker to new shrinker API list_lru: dynamically adjust node arrays This patch: There are situations in very large machines in which we can have a large quantity of dirty inodes, unused dentries, etc. This is particularly true when umounting a filesystem, where eventually since every live object will eventually be discarded. Dave Chinner reported a problem with this while experimenting with the shrinker revamp patchset. So we believe it is time for a change. This patch just moves int to longs. Machines where it matters should have a big long anyway. Signed-off-by: Glauber Costa <glommer@openvz.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Chinner <dchinner@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-08rename user_path_umountat() to user_path_mountpoint_at()Al Viro
... and move the extern from linux/namei.h to fs/internal.h, along with that of vfs_path_lookup(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-05vfs: check unlinked ancestors before mountMiklos Szeredi
We check submounts before doing d_drop() on a non-empty directory dentry in NFS (have_submounts()), but we do not exclude a racing mount. Nor do we prevent mounts to be added to the disconnected subtree using relative paths after the d_drop(). This patch fixes these issues by checking for unlinked (unhashed, non-root) ancestors before proceeding with the mount. This is done with rename seqlock taken for write and with ->d_lock grabbed on each ancestor in turn, including our dentry itself. This ensures that the only one of check_submounts_and_drop() or has_unlinked_ancestor() can succeed. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29constify rw_verify_area()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29allow build_open_flags() to return an errorAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-20splice: don't pass the address of ->f_pos to methodsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09pipe: fold file_operations instances in oneAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-21Don't bother with redoing rw_verify_area() from default_file_splice_from()Al Viro
default_file_splice_from() ends up calling vfs_write() (via very convoluted callchain). It's an overkill, since we already have done rw_verify_area() in the caller by the time we call vfs_write() we are under set_fs(KERNEL_DS), so access_ok() is also pointless. Add a new helper (__kernel_write()), use it instead of kernel_write() in there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-01constify path_get/path_put and fs_struct.c stuffAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-26writeback: put unused inodes to LRU after writeback completionJan Kara
Commit 169ebd90131b ("writeback: Avoid iput() from flusher thread") removed iget-iput pair from inode writeback. As a side effect, inodes that are dirty during iput_final() call won't be ever added to inode LRU (iput_final() doesn't add dirty inodes to LRU and later when the inode is cleaned there's noone to add the inode there). Thus inodes are effectively unreclaimable until someone looks them up again. The practical effect of this bug is limited by the fact that inodes are pinned by a dentry for long enough that the inode gets cleaned. But still the bug can have nasty consequences leading up to OOM conditions under certain circumstances. Following can easily reproduce the problem: for (( i = 0; i < 1000; i++ )); do mkdir $i for (( j = 0; j < 1000; j++ )); do touch $i/$j echo 2 > /proc/sys/vm/drop_caches done done then one needs to run 'sync; ls -lR' to make inodes reclaimable again. We fix the issue by inserting unused clean inodes into the LRU after writeback finishes in inode_sync_complete(). Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-12vfs: make path_openat take a struct filename pointerJeff Layton
...and fix up the callers. For do_file_open_root, just declare a struct filename on the stack and fill out the .name field. For do_filp_open, make it also take a struct filename pointer, and fix up its callers to call it appropriately. For filp_open, add a variant that takes a struct filename pointer and turn filp_open into a wrapper around it. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31fs: Add freezing handling to mnt_want_write() / mnt_drop_write()Jan Kara
Most of places where we want freeze protection coincides with the places where we also have remount-ro protection. So make mnt_want_write() and mnt_drop_write() (and their _file alternative) prevent freezing as well. For the few cases that are really interested only in remount-ro protection provide new function variants. BugLink: https://bugs.launchpad.net/bugs/897421 Tested-by: Kamal Mostafa <kamal@canonical.com> Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com> Tested-by: Dann Frazier <dann.frazier@canonical.com> Tested-by: Massimo Morana <massimo.morana@canonical.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
2012-07-14kill struct opendataAl Viro
Just pass struct file *. Methods are happier that way... There's no need to return struct file * from finish_open() now, so let it return int. Next: saner prototypes for parts in namei.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14kill opendata->{mnt,dentry}Al Viro
->filp->f_path is there for purpose... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14vfs: remove open intents from nameidataMiklos Szeredi
All users of open intents have been converted to use ->atomic_{open,create}. This patch gets rid of nd->intent.open and related infrastructure. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14vfs: add i_op->atomic_open()Miklos Szeredi
Add a new inode operation which is called on the last component of an open. Using this the filesystem can look up, possibly create and open the file in one atomic operation. If it cannot perform this (e.g. the file type turned out to be wrong) it may signal this by returning NULL instead of an open struct file pointer. i_op->atomic_open() is only called if the last component is negative or needs lookup. Handling cached positive dentries here doesn't add much value: these can be opened using f_op->open(). If the cached file turns out to be invalid, the open can be retried, this time using ->atomic_open() with a fresh dentry. For now leave the old way of using open intents in lookup and revalidate in place. This will be removed once all the users are converted. David Howells noticed that if ->atomic_open() opens the file but does not create it, handle_truncate() will be called on it even if it is not a regular file. Fix this by checking the file type in this case too. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14get rid of ->mnt_longtermAl Viro
it's enough to set ->mnt_ns of internal vfsmounts to something distinct from all struct mnt_namespace out there; then we can just use the check for ->mnt_ns != NULL in the fast path of mntput_no_expire() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01vfs: split __dentry_open()Miklos Szeredi
Split __dentry_open() into two functions: do_dentry_open() - does most of the actual work, doesn't put file on failure open_check_o_direct() - after a successful open, checks direct_IO method This will allow i_op->atomic_open to do just the file initialization and leave the direct_IO checking to the VFS. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29brlocks/lglocks: turn into functionsAndi Kleen
lglocks and brlocks are currently generated with some complicated macros in lglock.h. But there's no reason to not just use common utility functions and put all the data into a common data structure. Since there are at least two users it makes sense to share this code in a library. This is also easier maintainable than a macro forest. This will also make it later possible to dynamically allocate lglocks and also use them in modules (this would both still need some additional, but now straightforward, code) [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06vfs: protect remounting superblock read-onlyMiklos Szeredi
Currently remouting superblock read-only is racy in a major way. With the per mount read-only infrastructure it is now possible to prevent most races, which this patch attempts. Before starting the remount read-only, iterate through all mounts belonging to the superblock and if none of them have any pending writes, set sb->s_readonly_remount. This indicates that remount is in progress and no further write requests are allowed. If the remount succeeds set MS_RDONLY and reset s_readonly_remount. If the remounting is unsuccessful just reset s_readonly_remount. This can result in transient EROFS errors, despite the fact the remount failed. Unfortunately hodling off writes is difficult as remount itself may touch the filesystem (e.g. through load_nls()) which would deadlock. A later patch deals with delayed writes due to nlink going to zero. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06Merge branches 'vfsmount-guts', 'umode_t' and 'partitions' into ZAl Viro
2012-01-03vfs: spread struct mount - __lookup_mnt() resultAl Viro
switch __lookup_mnt() to returning struct mount *; callers adjusted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch open and mkdir syscalls to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03vfs: new helper - vfs_ustat()Al Viro
... and bury user_get_super()/statfs_by_dentry() - they are purely internal now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03trim fs/internal.hAl Viro
some stuff in there can actually become static; some belongs to pnode.h as it's a private interface between namespace.c and pnode.c... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20superblock: move pin_sb_for_writeback() to fs/super.cDave Chinner
The per-sb shrinker has the same requirement as the writeback threads of ensuring that the superblock is usable and pinned for the time it takes to run the work. Both need to take a passive reference to the sb, take a read lock on the s_umount lock and then only continue if an unmount is not in progress. pin_sb_for_writeback() does this exactly, so move it to fs/super.c and rename it to grab_super_passive() and exporting it via fs/internal.h for all the VFS code to be able to use. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20Make ->d_sb assign-once and always non-NULLAl Viro
New helper (non-exported, fs/internal.h-only): __d_alloc(sb, name). Allocates dentry, sets its ->d_sb to given superblock and sets ->d_op accordingly. Old d_alloc(NULL, name) callers are converted to that (all of them know what superblock they want). d_alloc() itself is left only for parent != NULl case; uses __d_alloc(), inserts result into the list of parent's children. Note that now ->d_sb is assign-once and never NULL *and* ->d_parent is never NULL either. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24fs: move i_wb_list out from under inode_lockDave Chinner
Protect the inode writeback list with a new global lock inode_wb_list_lock and use it to protect the list manipulations and traversals. This lock replaces the inode_lock as the inodes on the list can be validity checked while holding the inode->i_lock and hence the inode_lock is no longer needed to protect the list. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24fs: move i_sb_list out from under inode_lockDave Chinner
Protect the per-sb inode list with a new global lock inode_sb_list_lock and use it to protect the list manipulations and traversals. This lock replaces the inode_lock as the inodes on the list can be validity checked while holding the inode->i_lock and hence the inode_lock is no longer needed to protect the list. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-21FS: lookup_mnt() is only used in the core fs routines nowDavid Howells
lookup_mnt() is only used in the core fs routines now, so it doesn't need to be globally declared anymore. It isn't exported to modules at the moment, so nothing that can be modularised seems to be using it. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-17vfs: split off vfsmount-related parts of vfs_kern_mount()Al Viro
new function: mount_fs(). Does all work done by vfs_kern_mount() except the allocation and filling of vfsmount; returns root dentry or ERR_PTR(). vfs_kern_mount() switched to using it and taken to fs/namespace.c, along with its wrappers. alloc_vfsmnt()/free_vfsmnt() made static. functions in namespace.c slightly reordered. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15vfs: Add open by file handle supportAneesh Kumar K.V
[AV: duplicate of open() guts removed; file_open_root() used instead] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-14open-style analog of vfs_path_lookup()Al Viro
new function: file_open_root(dentry, mnt, name, flags) opens the file vfs_path_lookup would arrive to. Note that name can be empty; in that case the usual requirement that dentry should be a directory is lifted. open-coded equivalents switched to it, may_open() got down exactly one caller and became static. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-14switch do_filp_open() to struct open_flagsAl Viro
take calculation of open_flags by open(2) arguments into new helper in fs/open.c, move filp_open() over there, have it and do_sys_open() use that helper, switch exec.c callers of do_filp_open() to explicit (and constant) struct open_flags. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-02-24Fix over-zealous flush_disk when changing device size.NeilBrown
There are two cases when we call flush_disk. In one, the device has disappeared (check_disk_change) so any data will hold becomes irrelevant. In the oter, the device has changed size (check_disk_size_change) so data we hold may be irrelevant. In both cases it makes sense to discard any 'clean' buffers, so they will be read back from the device if needed. In the former case it makes sense to discard 'dirty' buffers as there will never be anywhere safe to write the data. In the second case it *does*not* make sense to discard dirty buffers as that will lead to file system corruption when you simply enlarge the containing devices. flush_disk calls __invalidate_devices. __invalidate_device calls both invalidate_inodes and invalidate_bdev. invalidate_inodes *does* discard I_DIRTY inodes and this does lead to fs corruption. invalidate_bev *does*not* discard dirty pages, but I don't really care about that at present. So this patch adds a flag to __invalidate_device (calling it __invalidate_device2) to indicate whether dirty buffers should be killed, and this is passed to invalidate_inodes which can choose to skip dirty inodes. flusk_disk then passes true from check_disk_change and false from check_disk_size_change. dm avoids tripping over this problem by calling i_size_write directly rathher than using check_disk_size_change. md does use check_disk_size_change and so is affected. This regression was introduced by commit 608aeef17a which causes check_disk_size_change to call flush_disk, so it is suitable for any kernel since 2.6.27. Cc: stable@kernel.org Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-17tidy up around finish_automount()Al Viro
do_add_mount() and mnt_clear_expiry() are not needed outside of namespace.c anymore, now that namei has finish_automount() to use. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-17Take the completion of automount into new helperAl Viro
... and shift it from namei.c to namespace.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>