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2016-01-04configfs: implement binary attributesPantelis Antoniou
ConfigFS lacked binary attributes up until now. This patch introduces support for binary attributes in a somewhat similar manner of sysfs binary attributes albeit with changes that fit the configfs usage model. Problems that configfs binary attributes fix are everything that requires a binary blob as part of the configuration of a resource, such as bitstream loading for FPGAs, DTBs for dynamically created devices etc. Look at Documentation/filesystems/configfs/configfs.txt for internals and howto use them. This patch is against linux-next as of today that contains Christoph's configfs rework. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [hch: folded a fix from Geert Uytterhoeven <geert+renesas@glider.be>] [hch: a few tiny updates based on review feedback] Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-12-30switch ->get_link() to delayed_call, kill ->put_link()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-29kill free_page_put_link()Al Viro
all callers are better off with kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-20fs: configfs: Add unlocked version of configfs_depend_item()Krzysztof Opasiak
This change is necessary for the SCSI target usb gadget composed with configfs. In this case configfs will be used for two different purposes: to compose a usb gadget and to configure the target part. If an instance of tcm function is created in $CONFIGFS_ROOT/usb_gadget/<gadget>/functions a tpg can be created in $CONFIGFS_ROOT/target/usb_gadget/<wwn>/, but after a tpg is created the tcm function must not be removed until its corresponding tpg is gone. While the configfs_depend/undepend_item() are meant exactly for creating this kind of dependencies, they are not suitable if the other kernel subsystem happens to be another subsystem in configfs, so this patch adds unlocked versions meant for configfs callbacks. Above description has been provided by: Andrzej Pietrasiewicz <andrzej.p@samsung.com> In configfs_depend_item() we have to consider two possible cases: 1) When we are called to depend another item in the same subsystem as caller In this case we should skip locking configfs root as we know that configfs is in valid state and our subsystem will not be unregistered during this call. 2) When we are called to depend item in different subsystem than our caller In this case we are also sure that configfs is in valid state but we have to lock root of configfs to avoid unregistration of target's subsystem. As it is other than caller's subsystem, there may be nothing what protects us against unregistration of that subsystem. Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20fs: configfs: Factor out configfs_find_subsys_dentry()Krzysztof Opasiak
configfs_depend_item() is quite complicated and should be split up into smaller functions. This also allow to share this code with other functions. Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20fs: configfs: Factor out configfs_do_depend_item()Krzysztof Opasiak
configfs_depend_item() is quite complicated and should be split up into smaller functions. This also allow to share this code with other functions. Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20fs: configfs: Drop unused parameter from configfs_undepend_item()Krzysztof Opasiak
subsys parameter is never used by configfs_undepend_item() so there is no point in passing it to this function. Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-08replace ->follow_link() with new method that could stay in RCU modeAl Viro
new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-20configfs: allow dynamic group creationDaniel Baluta
This patchset introduces IIO software triggers, offers a way of configuring them via configfs and adds the IIO hrtimer based interrupt source to be used with software triggers. The architecture is now split in 3 parts, to remove all IIO trigger specific parts from IIO configfs core: (1) IIO configfs - creates the root of the IIO configfs subsys. (2) IIO software triggers - software trigger implementation, dynamically creating /config/iio/triggers group. (3) IIO hrtimer trigger - is the first interrupt source for software triggers (with syfs to follow). Each trigger type can implement its own set of attributes. Lockdep seems to be happy with the locking in configfs patch. This patch (of 5): We don't want to hardcode default groups at subsystem creation time. We export: * configfs_register_group * configfs_unregister_group to allow drivers to programatically create/destroy groups later, after module init time. This is needed for IIO configfs support. (akpm: the other 4 patches to be merged via the IIO tree) Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Joel Becker <jlbec@evilplan.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Adriana Reus <adriana.reus@intel.com> Cc: Cristina Opriceana <cristina.opriceana@gmail.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-13configfs: remove old APIChristoph Hellwig
Remove the old show_attribute and store_attribute methods and update the documentation. Also replace the two C samples with a single new one in the proper samples directory where people expect to find it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-10-13configfs: add show and store methods to struct configfs_attributeChristoph Hellwig
Add methods to struct configfs_attribute to directly show and store attributes without adding boilerplate code to every user. In addition to the methods this also adds 3 helper macros to define read/write, read-only and write-only attributes with a single line of code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-07-17configfs: fix kernel infoleak through user-controlled format stringNicolas Iooss
Some modules call config_item_init_type_name() and config_group_init_type_name() with parameter "name" directly controlled by userspace. These two functions call config_item_set_name() with this name used as a format string, which can be used to leak information such as content of the stack to userspace. For example, make_netconsole_target() in netconsole module calls config_item_init_type_name() with the name of a newly-created directory. This means that the following commands give some unexpected output, with configfs mounted in /sys/kernel/config/ and on a system with a configured eth0 ethernet interface: # modprobe netconsole # mkdir /sys/kernel/config/netconsole/target_%lx # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name # echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name # dmesg |tail -n1 [ 142.697668] netconsole: target (target_ffffffffc0ae8080) is enabled, disable to update parameters The directory name is correct but %lx has been interpreted in the internal item name, displayed here in the error message used by store_dev_name() in drivers/net/netconsole.c. To fix this, update every caller of config_item_set_name to use "%s" when operating on untrusted input. This issue was found using -Wformat-security gcc flag, once a __printf attribute has been added to config_item_set_name(). Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Felipe Balbi <balbi@ti.com> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
2015-07-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace updates from Eric Biederman: "Long ago and far away when user namespaces where young it was realized that allowing fresh mounts of proc and sysfs with only user namespace permissions could violate the basic rule that only root gets to decide if proc or sysfs should be mounted at all. Some hacks were put in place to reduce the worst of the damage could be done, and the common sense rule was adopted that fresh mounts of proc and sysfs should allow no more than bind mounts of proc and sysfs. Unfortunately that rule has not been fully enforced. There are two kinds of gaps in that enforcement. Only filesystems mounted on empty directories of proc and sysfs should be ignored but the test for empty directories was insufficient. So in my tree directories on proc, sysctl and sysfs that will always be empty are created specially. Every other technique is imperfect as an ordinary directory can have entries added even after a readdir returns and shows that the directory is empty. Special creation of directories for mount points makes the code in the kernel a smidge clearer about it's purpose. I asked container developers from the various container projects to help test this and no holes were found in the set of mount points on proc and sysfs that are created specially. This set of changes also starts enforcing the mount flags of fresh mounts of proc and sysfs are consistent with the existing mount of proc and sysfs. I expected this to be the boring part of the work but unfortunately unprivileged userspace winds up mounting fresh copies of proc and sysfs with noexec and nosuid clear when root set those flags on the previous mount of proc and sysfs. So for now only the atime, read-only and nodev attributes which userspace happens to keep consistent are enforced. Dealing with the noexec and nosuid attributes remains for another time. This set of changes also addresses an issue with how open file descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of /proc/<pid>/fd has been triggering a WARN_ON that has not been meaningful since it was added (as all of the code in the kernel was converted) and is not now actively wrong. There is also a short list of issues that have not been fixed yet that I will mention briefly. It is possible to rename a directory from below to above a bind mount. At which point any directory pointers below the renamed directory can be walked up to the root directory of the filesystem. With user namespaces enabled a bind mount of the bind mount can be created allowing the user to pick a directory whose children they can rename to outside of the bind mount. This is challenging to fix and doubly so because all obvious solutions must touch code that is in the performance part of pathname resolution. As mentioned above there is also a question of how to ensure that developers by accident or with purpose do not introduce exectuable files on sysfs and proc and in doing so introduce security regressions in the current userspace that will not be immediately obvious and as such are likely to require breaking userspace in painful ways once they are recognized" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Remove incorrect debugging WARN in prepend_path mnt: Update fs_fully_visible to test for permanently empty directories sysfs: Create mountpoints with sysfs_create_mount_point sysfs: Add support for permanently empty directories to serve as mount points. kernfs: Add support for always empty directories. proc: Allow creating permanently empty directories that serve as mount points sysctl: Allow creating permanently empty directories that serve as mountpoints. fs: Add helper functions for permanently empty directories. vfs: Ignore unlocked mounts in fs_fully_visible mnt: Modify fs_fully_visible to deal with locked ro nodev and atime mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-01sysfs: Create mountpoints with sysfs_create_mount_pointEric W. Biederman
This allows for better documentation in the code and it allows for a simpler and fully correct version of fs_fully_visible to be written. The mount points converted and their filesystems are: /sys/hypervisor/s390/ s390_hypfs /sys/kernel/config/ configfs /sys/kernel/debug/ debugfs /sys/firmware/efi/efivars/ efivarfs /sys/fs/fuse/connections/ fusectl /sys/fs/pstore/ pstore /sys/kernel/tracing/ tracefs /sys/fs/cgroup/ cgroup /sys/kernel/security/ securityfs /sys/fs/selinux/ selinuxfs /sys/fs/smackfs/ smackfs Cc: stable@vger.kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-06-24configfs: unexport/make static config_item_init()Fabian Frederick
config_item_init() is only used in item.c Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-23make simple_positive() publicAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new helper: free_page_put_link()Al Viro
similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11switch ->put_link() from dentry to inodeAl Viro
only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10don't pass nameidata to ->follow_link()Al Viro
its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10new ->follow_link() and ->put_link() calling conventionsAl Viro
a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-05configfs: init configfs module earlier at boot timeDaniel Baluta
We need this earlier in the boot process to allow various subsystems to use configfs (e.g Industrial IIO). Also, debugfs is at core_initcall level and configfs should be on the same level from infrastructure point of view. Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells
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>
2015-04-15configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inodeDavid Howells
Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-20configfs: Fix potential NULL d_inode dereferenceDavid Howells
Code that does this: if (!(d_unhashed(dentry) && dentry->d_inode)) { ... simple_unlink(parent->d_inode, dentry); } is broken because: !(d_unhashed(dentry) && dentry->d_inode) is equivalent to: !d_unhashed(dentry) || !dentry->d_inode so it is possible to get into simple_unlink() with dentry->d_inode == NULL. simple_unlink(), however, assumes dentry->d_inode cannot be NULL. I think that what was meant is this: !d_unhashed(dentry) && dentry->d_inode and that the logical-not operator or the final close-bracket was misplaced. Signed-off-by: David Howells <dhowells@redhat.com> cc: Joel Becker <joel.becker@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17configfs_add_file: fold into its sole callerAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17configfs: fold create_dir() into its only callerAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17configfs: configfs_create() init callback is never NULL and it never failsAl Viro
... so make it return void and drop the check for it being non-NULL Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-20fs: remove mapping->backing_dev_infoChristoph Hellwig
Now that we never use the backing_dev_info pointer in struct address_space we can simply remove it and save 4 to 8 bytes in every inode. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20fs: introduce f_op->mmap_capabilities for nommu mmap supportChristoph Hellwig
Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-19assorted conversions to %p[dD]Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-04fs/configfs: use pr_fmtFabian Frederick
Add pr_fmt based on module name. Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/configfs: convert printk to pr_foo()Fabian Frederick
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/configs/item.c: kernel-doc fixes + clean-upFabian Frederick
Fix function parameter documentation EXPORT_SYMBOLS moved after corresponding functions Small coding style and checkpatch warning fixes Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-21configfs: fix race between dentry put and lookupJunxiao Bi
A race window in configfs, it starts from one dentry is UNHASHED and end before configfs_d_iput is called. In this window, if a lookup happen, since the original dentry was UNHASHED, so a new dentry will be allocated, and then in configfs_attach_attr(), sd->s_dentry will be updated to the new dentry. Then in configfs_d_iput(), BUG_ON(sd->s_dentry != dentry) will be triggered and system panic. sys_open: sys_close: ... fput dput dentry_kill __d_drop <--- dentry unhashed here, but sd->dentry still point to this dentry. lookup_real configfs_lookup configfs_attach_attr---> update sd->s_dentry to new allocated dentry here. d_kill configfs_d_iput <--- BUG_ON(sd->s_dentry != dentry) triggered here. To fix it, change configfs_d_iput to not update sd->s_dentry if sd->s_count > 2, that means there are another dentry is using the sd beside the one that is going to be put. Use configfs_dirent_lock in configfs_attach_attr to sync with configfs_d_iput. With the following steps, you can reproduce the bug. 1. enable ocfs2, this will mount configfs at /sys/kernel/config and fill configure in it. 2. run the following script. while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done & while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done & Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15consolidate simple ->d_delete() instancesAl Viro
Rename simple_delete_dentry() to always_delete_dentry() and export it. Export simple_dentry_operations, while we are at it, and get rid of their duplicates Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs stuff from Al Viro: "O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including making simple_lookup() usable for filesystems with non-NULL s_d_op, which allows us to get rid of quite a bit of ugliness" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: sunrpc: now we can just set ->s_d_op cgroup: we can use simple_lookup() now efivarfs: we can use simple_lookup() now make simple_lookup() usable for filesystems that set ->s_d_op configfs: don't open-code d_alloc_name() __rpc_lookup_create_exclusive: pass string instead of qstr rpc_create_*_dir: don't bother with qstr llist: llist_add() can use llist_add_batch() llist: fix/simplify llist_add() and llist_add_batch() fput: turn "list_head delayed_fput_list" into llist_head fs/file_table.c:fput(): add comment Safer ABI for O_TMPFILE
2013-07-14configfs: don't open-code d_alloc_name()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull third set of VFS updates from Al Viro: "Misc stuff all over the place. There will be one more pile in a couple of days" This is an "evil merge" that also uses the new d_count helper in fs/configfs/dir.c, missed by commit 84d08fa888e7 ("helper for reading ->d_count") * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ncpfs: fix error return code in ncp_parse_options() locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock seq_file: add seq_list_*_percpu helpers f2fs: fix readdir incorrectness mode_t whack-a-mole... lustre: kill the pointless wrapper helper for reading ->d_count
2013-07-03configfs: use capped length for ->store_attribute()Dan Carpenter
The difference between "count" and "len" is that "len" is capped at 4095. Changing it like this makes it match how sysfs_write_file() is implemented. This is a static analysis patch. I haven't found any store_attribute() functions where this change makes a difference. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-29[readdir] convert configfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-03fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman
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>
2013-02-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-21configfs: move the dereference below the NULL testWei Yongjun
The dereference should be moved below the NULL test. spatch with a semantic match is used to found this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17lseek: the "whence" argument is called "whence"Andrew Morton
But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-18userns: Convert configfs to use kuid and kgid where appropriateEric W. Biederman
Cc: Joel Becker <jlbec@evilplan.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-07-14stop passing nameidata to ->lookup()Al Viro
Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20make configfs_pin_fs() return root dentry on successAl Viro
... and make configfs_mnt static Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20configfs: configfs_create_dir() has parent dentry in dentry->d_parentAl Viro
no need to play sick games with parent item, internal mount, etc. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>