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* 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-03-192-9/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: - Preparations of parallel lookups (the remaining main obstacle is the need to move security_d_instantiate(); once that becomes safe, the rest will be a matter of rather short series local to fs/*.c - preadv2/pwritev2 series from Christoph - assorted fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) splice: handle zero nr_pages in splice_to_pipe() vfs: show_vfsstat: do not ignore errors from show_devname method dcache.c: new helper: __d_add() don't bother with __d_instantiate(dentry, NULL) untangle fsnotify_d_instantiate() a bit uninline d_add() replace d_add_unique() with saner primitive quota: use lookup_one_len_unlocked() cifs_get_root(): use lookup_one_len_unlocked() nfs_lookup: don't bother with d_instantiate(dentry, NULL) kill dentry_unhash() ceph_fill_trace(): don't bother with d_instantiate(dn, NULL) autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup() configfs: move d_rehash() into configfs_create() for regular files ceph: don't bother with d_rehash() in splice_dentry() namei: teach lookup_slow() to skip revalidate namei: massage lookup_slow() to be usable by lookup_one_len_unlocked() lookup_one_len_unlocked(): use lookup_dcache() namei: simplify invalidation logics in lookup_dcache() namei: change calling conventions for lookup_{fast,slow} and follow_managed() ...
| * configfs: move d_rehash() into configfs_create() for regular filesAl Viro2016-03-142-9/+12
| | | | | | | | | | | | ... and turn it into d_add in there Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | configfs: switch ->default groups to a linked listChristoph Hellwig2016-03-062-24/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the current NULL-terminated array of default groups with a linked list. This gets rid of lots of nasty code to size and/or dynamically allocate the array. While we're at it also provide a conveniant helper to remove the default groups. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Felipe Balbi <balbi@kernel.org> [drivers/usb/gadget] Acked-by: Joel Becker <jlbec@evilplan.org> Acked-by: Nicholas Bellinger <nab@linux-iscsi.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
* | configfs: Replace CURRENT_TIME by current_fs_time()Deepa Dinamani2016-02-261-3/+5
|/ | | | | | | | | | CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_fs_time() instead. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
* wrappers for ->i_mutex accessAl Viro2016-01-223-35/+35
| | | | | | | | | | | parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-next' of ↵Linus Torvalds2016-01-201-29/+121
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "The highlights this round include: - Introduce configfs support for unlocked configfs_depend_item() (krzysztof + andrezej) - Conversion of usb-gadget target driver to new function registration interface (andrzej + sebastian) - Enable qla2xxx FC target mode support for Extended Logins (himansu + giridhar) - Enable qla2xxx FC target mode support for Exchange Offload (himansu + giridhar) - Add qla2xxx FC target mode irq affinity notification + selective command queuing. (quinn + himanshu) - Fix iscsi-target deadlock in se_node_acl configfs deletion (sagi + nab) - Convert se_node_acl configfs deletion + se_node_acl->queue_depth to proper se_session->sess_kref + target_get_session() usage. (hch + sagi + nab) - Fix long-standing race between se_node_acl->acl_kref get and get_initiator_node_acl() lookup. (hch + nab) - Fix target/user block-size handling, and make sure netlink reaches all network namespaces (sheng + andy) Note there is an outstanding bug-fix series for remote I_T nexus port TMR LUN_RESET has been posted and still being tested, and will likely become post -rc1 material at this point" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (56 commits) scsi: qla2xxxx: avoid type mismatch in comparison target/user: Make sure netlink would reach all network namespaces target: Obtain se_node_acl->acl_kref during get_initiator_node_acl target: Convert ACL change queue_depth se_session reference usage iscsi-target: Fix potential dead-lock during node acl delete ib_srpt: Convert acl lookup to modern get_initiator_node_acl usage tcm_fc: Convert acl lookup to modern get_initiator_node_acl usage tcm_fc: Wait for command completion before freeing a session target: Fix a memory leak in target_dev_lba_map_store() target: Support aborting tasks with a 64-bit tag usb/gadget: Remove set-but-not-used variables target: Remove an unused variable target: Fix indentation in target_core_configfs.c target/user: Allow user to set block size before enabling device iser-target: Fix non negative ERR_PTR isert_device_get usage target/fcoe: Add tag support to tcm_fc qla2xxx: Check for online flag instead of active reset when transmitting responses qla2xxx: Set all queues to 4k qla2xxx: Disable ZIO at start time. qla2xxx: Move atioq to a different lock to reduce lock contention ...
| * fs: configfs: Add unlocked version of configfs_depend_item()Krzysztof Opasiak2015-12-201-0/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * fs: configfs: Factor out configfs_find_subsys_dentry()Krzysztof Opasiak2015-12-201-12/+21
| | | | | | | | | | | | | | | | | | | | | | 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>
| * fs: configfs: Factor out configfs_do_depend_item()Krzysztof Opasiak2015-12-201-15/+26
| | | | | | | | | | | | | | | | | | | | | | 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>
| * fs: configfs: Drop unused parameter from configfs_undepend_item()Krzysztof Opasiak2015-12-201-2/+1
| | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'configfs-for-linus' of git://git.infradead.org/users/hch/configfsLinus Torvalds2016-01-124-13/+276
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull configfs updates from Christoph Hellwig: "I'm assisting Joel as co-maintainer and patch monkey now, and you will see pull reuquests from me for a while. Besides the MAINTAINERS update there is just a single change, which adds support for binary attributes to configfs, which are very similar to the sysfs binary attributes. Thanks to Pantelis Antoniou! You will see another actually bigger set of configfs changes in the SCSI target pull from Nic - those were merged before this new tree even existed" * tag 'configfs-for-linus' of git://git.infradead.org/users/hch/configfs: configfs: add myself as co-maintainer, updated git tree configfs: implement binary attributes
| * | configfs: implement binary attributesPantelis Antoniou2016-01-044-13/+276
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | switch ->get_link() to delayed_call, kill ->put_link()Al Viro2015-12-301-8/+9
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | kill free_page_put_link()Al Viro2015-12-291-6/+6
| | | | | | | | | | | | all callers are better off with kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | replace ->follow_link() with new method that could stay in RCU modeAl Viro2015-12-081-3/+8
|/ | | | | | | | | | | | | | | | | | 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>
* configfs: allow dynamic group creationDaniel Baluta2015-11-201-0/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* configfs: remove old APIChristoph Hellwig2015-10-131-12/+3
| | | | | | | | | 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>
* configfs: add show and store methods to struct configfs_attributeChristoph Hellwig2015-10-131-5/+12
| | | | | | | | | | | | 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>
* configfs: fix kernel infoleak through user-controlled format stringNicolas Iooss2015-07-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-07-041-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * make simple_positive() publicAl Viro2015-06-231-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2015-07-031-6/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | sysfs: Create mountpoints with sysfs_create_mount_pointEric W. Biederman2015-07-011-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | configfs: unexport/make static config_item_init()Fabian Frederick2015-06-241-2/+1
| |/ |/| | | | | | | | | | | | | | | 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>
* | new helper: free_page_put_link()Al Viro2015-05-111-6/+1
| | | | | | | | | | | | similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | switch ->put_link() from dentry to inodeAl Viro2015-05-111-1/+1
| | | | | | | | | | | | | | 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>
* | don't pass nameidata to ->follow_link()Al Viro2015-05-101-1/+1
| | | | | | | | | | | | | | 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>
* | new ->follow_link() and ->put_link() calling conventionsAl Viro2015-05-101-16/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | configfs: init configfs module earlier at boot timeDaniel Baluta2015-05-051-1/+1
|/ | | | | | | | | | | | | | | | 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>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-153-45/+45
| | | | | | | 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>
* configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inodeDavid Howells2015-04-151-1/+1
| | | | | | | | 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>
* configfs: Fix potential NULL d_inode dereferenceDavid Howells2015-02-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* configfs_add_file: fold into its sole callerAl Viro2015-02-172-19/+10
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* configfs: fold create_dir() into its only callerAl Viro2015-02-171-34/+29
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* configfs: configfs_create() init callback is never NULL and it never failsAl Viro2015-02-173-15/+6
| | | | | | ... so make it return void and drop the check for it being non-NULL Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: remove mapping->backing_dev_infoChristoph Hellwig2015-01-201-1/+0
| | | | | | | | | | | 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>
* fs: introduce f_op->mmap_capabilities for nommu mmap supportChristoph Hellwig2015-01-203-28/+3
| | | | | | | | | | | | | | | | | | | 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>
* assorted conversions to %p[dD]Al Viro2014-11-191-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/configfs: use pr_fmtFabian Frederick2014-06-044-5/+11
| | | | | | | | | 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>
* fs/configfs: convert printk to pr_foo()Fabian Frederick2014-06-043-8/+7
| | | | | | | 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>
* fs/configs/item.c: kernel-doc fixes + clean-upFabian Frederick2014-06-041-30/+28
| | | | | | | | | | | | | 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>
* configfs: fix race between dentry put and lookupJunxiao Bi2013-11-211-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* consolidate simple ->d_delete() instancesAl Viro2013-11-151-11/+1
| | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-07-141-11/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * configfs: don't open-code d_alloc_name()Al Viro2013-07-141-11/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2013-07-091-1/+1
|/ | | | | | | | | | | | | | | | | | | | | 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
* configfs: use capped length for ->store_attribute()Dan Carpenter2013-07-031-1/+1
| | | | | | | | | | | | | | 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>
* [readdir] convert configfsAl Viro2013-06-291-70/+52
| | | | 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>
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