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2012-09-21userns: Convert loop to use kuid_t instead of uid_tEric W. Biederman1-1/+1
Cc: Jens Axboe <jaxboe@fusionio.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18userns: Convert struct dquot dq_id to be a struct kqidEric W. Biederman1-2/+1
Change struct dquot dq_id to a struct kqid and remove the now unecessary dq_type. Make minimal changes to dquot, quota_tree, quota_v1, quota_v2, ext3, ext4, and ocfs2 to deal with the change in quota structures and signatures. The ocfs2 changes are larger than most because of the extensive tracing throughout the ocfs2 quota code that prints out dq_id. quota_tree.c:get_index is modified to take a struct kqid instead of a qid_t because all of it's callers pass in dquot->dq_id and it allows me to introduce only a single conversion. The rest of the changes are either just replacing dq_type with dq_id.type, adding conversions to deal with the change in type and occassionally adding qid_eq to allow quota id comparisons in a user namespace safe way. Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Theodore Tso <tytso@mit.edu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Modify dqget to take struct kqidEric W. Biederman1-1/+1
Modify dqget to take struct kqid instead of a type and an identifier pair. Modify the callers of dqget in ocfs2 and dquot to take generate a struct kqid so they can continue to call dqget. The conversion to create struct kqid should all be the final conversions that are needed in those code paths. Cc: Jan Kara <jack@suse.cz> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Convert quota netlink aka quota_send_warningEric W. Biederman1-2/+2
Modify quota_send_warning to take struct kqid instead a type and identifier pair. When sending netlink broadcasts always convert uids and quota identifiers into the intial user namespace. There is as yet no way to send a netlink broadcast message with different contents to receivers in different namespaces, so for the time being just map all of the identifiers into the initial user namespace which preserves the current behavior. Change the callers of quota_send_warning in gfs2, xfs and dquot to generate a struct kqid to pass to quota send warning. When all of the user namespaces convesions are complete a struct kqid values will be availbe without need for conversion, but a conversion is needed now to avoid needing to convert everything at once. Cc: Ben Myers <bpm@sgi.com> Cc: Alex Elder <elder@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Convert qutoactlEric W. Biederman2-4/+4
Update the quotactl user space interface to successfull compile with user namespaces support enabled and to hand off quota identifiers to lower layers of the kernel in struct kqid instead of type and qid pairs. The quota on function is not converted because while it takes a quota type and an id. The id is the on disk quota format to use, which is something completely different. The signature of two struct quotactl_ops methods were changed to take struct kqid argumetns get_dqblk and set_dqblk. The dquot, xfs, and ocfs2 implementations of get_dqblk and set_dqblk are minimally changed so that the code continues to work with the change in parameter type. This is the first in a series of changes to always store quota identifiers in the kernel in struct kqid and only use raw type and qid values when interacting with on disk structures or userspace. Always using struct kqid internally makes it hard to miss places that need conversion to or from the kernel internal values. Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: Alex Elder <elder@kernel.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Implement struct kqidEric W. Biederman1-0/+125
Add the data type struct kqid which holds the kernel internal form of the owning identifier of a quota. struct kqid is a replacement for the implicit union of uid, gid and project id stored in an unsigned int and the quota type field that is was used in the quota data structures. Making the data type explicit allows the kuid_t and kgid_t type safety to propogate more thoroughly through the code, revealing more places where uid/gid conversions need be made. Along with the data type struct kqid comes the helper functions qid_eq, qid_lt, from_kqid, from_kqid_munged, qid_valid, make_kqid, make_kqid_invalid, make_kqid_uid, make_kqid_gid. Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Add kprojid_t and associated infrastructure in projid.hEric W. Biederman2-0/+107
Implement kprojid_t a cousin of the kuid_t and kgid_t. The per user namespace mapping of project id values can be set with /proc/<pid>/projid_map. A full compliment of helpers is provided: make_kprojid, from_kprojid, from_kprojid_munged, kporjid_has_mapping, projid_valid, projid_eq, projid_eq, projid_lt. Project identifiers are part of the generic disk quota interface, although it appears only xfs implements project identifiers currently. The xfs code allows anyone who has permission to set the project identifier on a file to use any project identifier so when setting up the user namespace project identifier mappings I do not require a capability. Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattrEric W. Biederman1-2/+4
- Pass the user namespace the uid and gid values in the xattr are stored in into posix_acl_from_xattr. - Pass the user namespace kuid and kgid values should be converted into when storing uid and gid values in an xattr in posix_acl_to_xattr. - Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to pass in &init_user_ns. In the short term this change is not strictly needed but it makes the code clearer. In the longer term this change is necessary to be able to mount filesystems outside of the initial user namespace that natively store posix acls in the linux xattr format. Cc: Theodore Tso <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18userns: Convert vfs posix_acl support to use kuids and kgidsEric W. Biederman2-1/+19
- In setxattr if we are setting a posix acl convert uids and gids from the current user namespace into the initial user namespace, before the xattrs are passed to the underlying filesystem. Untranslatable uids and gids are represented as -1 which posix_acl_from_xattr will represent as INVALID_UID or INVALID_GID. posix_acl_valid will fail if an acl from userspace has any INVALID_UID or INVALID_GID values. In net this guarantees that untranslatable posix acls will not be stored by filesystems. - In getxattr if we are reading a posix acl convert uids and gids from the initial user namespace into the current user namespace. Uids and gids that can not be tranlsated into the current user namespace will be represented as -1. - Replace e_id in struct posix_acl_entry with an anymouns union of e_uid and e_gid. For the short term retain the e_id field until all of the users are converted. - Don't set struct posix_acl.e_id in the cases where the acl type does not use e_id. Greatly reducing the use of ACL_UNDEFINED_ID. - Rework the ordering checks in posix_acl_valid so that I use kuid_t and kgid_t types throughout the code, and so that I don't need arithmetic on uid and gid types. Cc: Theodore Tso <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18userns: Convert taskstats to handle the user and pid namespaces.Eric W. Biederman1-2/+6
- Explicitly limit exit task stat broadcast to the initial user and pid namespaces, as it is already limited to the initial network namespace. - For broadcast task stats explicitly generate all of the idenitiers in terms of the initial user namespace and the initial pid namespace. - For request stats report them in terms of the current user namespace and the current pid namespace. Netlink messages are delivered syncrhonously to the kernel allowing us to get the user namespace and the pid namespace from the current task. - Pass the namespaces for representing pids and uids and gids into bacct_add_task. Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-17userns: Convert the audit loginuid to be a kuidEric W. Biederman4-7/+7
Always store audit loginuids in type kuid_t. Print loginuids by converting them into uids in the appropriate user namespace, and then printing the resulting uid. Modify audit_get_loginuid to return a kuid_t. Modify audit_set_loginuid to take a kuid_t. Modify /proc/<pid>/loginuid on read to convert the loginuid into the user namespace of the opener of the file. Modify /proc/<pid>/loginud on write to convert the loginuid rom the user namespace of the opener of the file. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Paul Moore <paul@paul-moore.com> ? Cc: David Miller <davem@davemloft.net> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-17audit: Add typespecific uid and gid comparatorsEric W. Biederman1-0/+2
The audit filter code guarantees that uid are always compared with uids and gids are always compared with gids, as the comparason operations are type specific. Take advantage of this proper to define audit_uid_comparator and audit_gid_comparator which use the type safe comparasons from uidgid.h. Build on audit_uid_comparator and audit_gid_comparator and replace audit_compare_id with audit_compare_uid and audit_compare_gid. This is one of those odd cases where being type safe and duplicating code leads to simpler shorter and more concise code. Don't allow bitmask operations in uid and gid comparisons in audit_data_to_entry. Bitmask operations are already denined in audit_rule_to_entry. Convert constants in audit_rule_to_entry and audit_data_to_entry into kuids and kgids when appropriate. Convert the uid and gid field in struct audit_names to be of type kuid_t and kgid_t respectively, so that the new uid and gid comparators can be applied in a type safe manner. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-17audit: Remove the unused uid parameter from audit_receive_filterEric W. Biederman1-1/+1
Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-17audit: Use current instead of NETLINK_CREDS() in audit_filterEric W. Biederman1-1/+1
Get caller process uid and gid and pid values from the current task instead of the NETLINK_CB. This is simpler than passing NETLINK_CREDS from from audit_receive_msg to audit_filter_user_rules and avoid the chance of being hit by the occassional bugs in netlink uid/gid credential passing. This is a safe changes because all netlink requests are processed in the task of the sending process. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-13userns: Convert security/keys to the new userns infrastructureEric W. Biederman1-4/+5
- Replace key_user ->user_ns equality checks with kuid_has_mapping checks. - Use from_kuid to generate key descriptions - Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t - Avoid potential problems with file descriptor passing by displaying keys in the user namespace of the opener of key status proc files. Cc: linux-security-module@vger.kernel.org Cc: keyrings@linux-nfs.org Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-06userns: Convert ipc to use kuid and kgid where appropriateEric W. Biederman1-4/+5
- Store the ipc owner and creator with a kuid - Store the ipc group and the crators group with a kgid. - Add error handling to ipc_update_perms, allowing it to fail if the uids and gids can not be converted to kuids or kgids. - Modify the proc files to display the ipc creator and owner in the user namespace of the opener of the proc file. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14userns: Teach inet_diag to work with user namespacesEric W. Biederman1-0/+1
Compute the user namespace of the socket that we are replying to and translate the kuids of reported sockets into that user namespace. Cc: Andrew Vagin <avagin@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14netlink: Make the sending netlink socket availabe in NETLINK_CBEric W. Biederman1-0/+1
The sending socket of an skb is already available by it's port id in the NETLINK_CB. If you want to know more like to examine the credentials on the sending socket you have to look up the sending socket by it's port id and all of the needed functions and data structures are static inside of af_netlink.c. So do the simple thing and pass the sending socket to the receivers in the NETLINK_CB. I intend to use this to get the user namespace of the sending socket in inet_diag so that I can report uids in the context of the process who opened the socket, the same way I report uids in the contect of the process who opens files. Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14userns: Make seq_file's user namespace accessibleEric W. Biederman1-0/+14
struct file already has a user namespace associated with it in file->f_cred->user_ns, unfortunately because struct seq_file has no struct file backpointer associated with it, it is difficult to get at the user namespace in seq_file context. Therefore add a helper function seq_user_ns to return the associated user namespace and a user_ns field to struct seq_file to be used in implementing seq_user_ns. Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-02Merge branch 'for-linus-3.6' of git://dev.laptop.org/users/dilinger/linux-olpcLinus Torvalds1-0/+41
Pull OLPC platform updates from Andres Salomon: "These move the OLPC Embedded Controller driver out of arch/x86/platform and into drivers/platform/olpc. OLPC machines are now ARM-based (which means lots of x86 and ARM changes), but are typically pretty self-contained.. so it makes more sense to go through a separate OLPC tree after getting the appropriate review/ACKs." * 'for-linus-3.6' of git://dev.laptop.org/users/dilinger/linux-olpc: x86: OLPC: move s/r-related EC cmds to EC driver Platform: OLPC: move global variables into priv struct Platform: OLPC: move debugfs support from x86 EC driver x86: OLPC: switch over to using new EC driver on x86 Platform: OLPC: add a suspended flag to the EC driver Platform: OLPC: turn EC driver into a platform_driver Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call it drivers: OLPC: update various drivers to include olpc-ec.h Platform: OLPC: add a stub to drivers/platform/ for the OLPC EC driver
2012-08-02Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-shLinus Torvalds1-0/+2
Pull SuperH fixes from Paul Mundt. * tag 'sh-for-linus' of git://github.com/pmundt/linux-sh: (24 commits) sh: explicitly include sh_dma.h in setup-sh7722.c sh: ecovec: care CN5 VBUS if USB host mode sh: sh7724: fixup renesas_usbhs clock settings sh: intc: initial irqdomain support. sh: pfc: Fix up init ordering mess. serial: sh-sci: fix compilation breakage, when DMA is enabled dmaengine: shdma: restore partial transfer calculation sh: modify the sh_dmae_slave_config for RSPI in setup-sh7757 sh: Fix up recursive fault in oops with unset TTB. sh: pfc: Build fix for pinctrl_remove_gpio_range() changes. sh: select the fixed regulator driver on several boards sh: ecovec: switch MMC power control to regulators sh: add fixed voltage regulators to se7724 sh: add fixed voltage regulators to sdk7786 sh: add fixed voltage regulators to rsk sh: add fixed voltage regulators to migor sh: add fixed voltage regulators to kfr2r09 sh: add fixed voltage regulators to ap325rxa sh: add fixed voltage regulators to sh7757lcr sh: add fixed voltage regulators to sh2007 ...
2012-08-01Merge branch 'dmaengine' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds2-148/+30
Pull ARM DMA engine updates from Russell King: "This looks scary at first glance, but what it is is: - a rework of the sa11x0 DMA engine driver merged during the previous cycle, to extract a common set of helper functions for DMA engine implementations. - conversion of amba-pl08x.c to use these helper functions. - addition of OMAP DMA engine driver (using these helper functions), and conversion of some of the OMAP DMA users to use DMA engine. Nothing in the helper functions is ARM specific, so I hope that other implementations can consolidate some of their code by making use of these helpers. This has been sitting in linux-next most of the merge cycle, and has been tested by several OMAP folk. I've tested it on sa11x0 platforms, and given it my best shot on my broken platforms which have the amba-pl08x controller. The last point is the addition to feature-removal-schedule.txt, which will have a merge conflict. Between myself and TI, we're planning to remove the old TI DMA implementation next year." Fix up trivial add/add conflicts in Documentation/feature-removal-schedule.txt and drivers/dma/{Kconfig,Makefile} * 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm: (53 commits) ARM: 7481/1: OMAP2+: omap2plus_defconfig: enable OMAP DMA engine ARM: 7464/1: mmc: omap_hsmmc: ensure probe returns error if DMA channel request fails Add feature removal of old OMAP private DMA implementation mtd: omap2: remove private DMA API implementation mtd: omap2: add DMA engine support spi: omap2-mcspi: remove private DMA API implementation spi: omap2-mcspi: add DMA engine support ARM: omap: remove mmc platform data dma_mask and initialization mmc: omap: remove private DMA API implementation mmc: omap: add DMA engine support mmc: omap_hsmmc: remove private DMA API implementation mmc: omap_hsmmc: add DMA engine support dmaengine: omap: add support for cyclic DMA dmaengine: omap: add support for setting fi dmaengine: omap: add support for returning residue in tx_state method dmaengine: add OMAP DMA engine driver dmaengine: sa11x0-dma: add cyclic DMA support dmaengine: sa11x0-dma: fix DMA residue support dmaengine: PL08x: ensure all descriptors are freed when channel is released dmaengine: PL08x: get rid of write only pool_ctr and free_txd locking ...
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds6-12/+151
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-08-01Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds1-2/+6
Pull block driver changes from Jens Axboe: - Making the plugging support for drivers a bit more sane from Neil. This supersedes the plugging change from Shaohua as well. - The usual round of drbd updates. - Using a tail add instead of a head add in the request completion for ndb, making us find the most completed request more quickly. - A few floppy changes, getting rid of a duplicated flag and also running the floppy init async (since it takes forever in boot terms) from Andi. * 'for-3.6/drivers' of git://git.kernel.dk/linux-block: floppy: remove duplicated flag FD_RAW_NEED_DISK blk: pass from_schedule to non-request unplug functions. block: stack unplug blk: centralize non-request unplug handling. md: remove plug_cnt feature of plugging. block/nbd: micro-optimization in nbd request completion drbd: announce FLUSH/FUA capability to upper layers drbd: fix max_bio_size to be unsigned drbd: flush drbd work queue before invalidate/invalidate remote drbd: fix potential access after free drbd: call local-io-error handler early drbd: do not reset rs_pending_cnt too early drbd: reset congestion information before reporting it in /proc/drbd drbd: report congestion if we are waiting for some userland callback drbd: differentiate between normal and forced detach drbd: cleanup, remove two unused global flags floppy: Run floppy initialization asynchronous
2012-08-01Merge branch 'for-3.6/core' of git://git.kernel.dk/linux-blockLinus Torvalds5-23/+92
Pull core block IO bits from Jens Axboe: "The most complicated part if this is the request allocation rework by Tejun, which has been queued up for a long time and has been in for-next ditto as well. There are a few commits from yesterday and today, mostly trivial and obvious fixes. So I'm pretty confident that it is sound. It's also smaller than usual." * 'for-3.6/core' of git://git.kernel.dk/linux-block: block: remove dead func declaration block: add partition resize function to blkpg ioctl block: uninitialized ioc->nr_tasks triggers WARN_ON block: do not artificially constrain max_sectors for stacking drivers blkcg: implement per-blkg request allocation block: prepare for multiple request_lists block: add q->nr_rqs[] and move q->rq.elvpriv to q->nr_rqs_elvpriv blkcg: inline bio_blkcg() and friends block: allocate io_context upfront block: refactor get_request[_wait]() block: drop custom queue draining used by scsi_transport_{iscsi|fc} mempool: add @gfp_mask to mempool_create_node() blkcg: make root blkcg allocation use %GFP_KERNEL blkcg: __blkg_lookup_create() doesn't need radix preload
2012-08-01locks: remove unused lm_release_privateJ. Bruce Fields1-1/+0
In commit 3b6e2723f32d ("locks: prevent side-effects of locks_release_private before file_lock is initialized") we removed the last user of lm_release_private without removing the field itself. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01block: add partition resize function to blkpg ioctlVivek Goyal2-0/+58
Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. This patch converts hd_struct->nr_sects into sequence counter because One might extend a partition while IO is happening to it and update of nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This can lead to issues like reading inconsistent size of a partition. Sequence counter have been used so that readers don't have to take bdev mutex lock as we call sector_in_part() very frequently. Now all the access to hd_struct->nr_sects should happen using sequence counter read/update helper functions part_nr_sects_read/part_nr_sects_write. There is one exception though, set_capacity()/get_capacity(). I think theoritically race should exist there too but this patch does not modify set_capacity()/get_capacity() due to sheer number of call sites and I am afraid that change might break something. I have left that as a TODO item. We can handle it later if need be. This patch does not introduce any new races as such w.r.t set_capacity()/get_capacity(). v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Phillip Susi <psusi@ubuntu.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-01Merge branch 'common/irqdomain' into sh-latestPaul Mundt2-9/+34
2012-08-01dmaengine: shdma: restore partial transfer calculationGuennadi Liakhovetski1-0/+2
The recent shdma driver split has mistakenly removed support for partial DMA transfer size calculation on forced termination. This patch restores it. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Acked-by: Vinod Koul <vinod.koul@linux.intel.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-07-31Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds2-9/+34
Pull irqdomain changes from Grant Likely: "Round of refactoring and enhancements to irq_domain infrastructure. This series starts the process of simplifying irqdomain. The ultimate goal is to merge LEGACY, LINEAR and TREE mappings into a single system, but had to back off from that after some last minute bugs. Instead it mainly reorganizes the code and ensures that the reverse map gets populated when the irq is mapped instead of the first time it is looked up. Merging of the irq_domain types is deferred to v3.7 In other news, this series adds helpers for creating static mappings on a linear or tree mapping." * tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6: irqdomain: Improve diagnostics when a domain mapping fails irqdomain: eliminate slow-path revmap lookups irqdomain: Fix irq_create_direct_mapping() to test irq_domain type. irqdomain: Eliminate dedicated radix lookup functions irqdomain: Support for static IRQ mapping and association. irqdomain: Always update revmap when setting up a virq irqdomain: Split disassociating code into separate function irq_domain: correct a minor wrong comment for linear revmap irq_domain: Standardise legacy/linear domain selection irqdomain: Make ops->map hook optional irqdomain: Remove unnecessary test for IRQ_DOMAIN_MAP_LEGACY irqdomain: Simple NUMA awareness. devicetree: add helper inline for retrieving a node's full name
2012-07-31Platform: OLPC: turn EC driver into a platform_driverAndres Salomon1-0/+6
The 1.75-based OLPC EC driver already does this; let's do it for all EC drivers. This gives us nice suspend/resume hooks, amongst other things. We want to run the EC's suspend hooks later than other drivers (which may be setting wakeup masks or be running EC commands). We also want to run the EC's resume hooks earlier than other drivers (which may want to run EC commands). Signed-off-by: Andres Salomon <dilinger@queued.net> Acked-by: Paul Fox <pgf@laptop.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call itAndres Salomon1-0/+6
This provides a new API allows different OLPC architectures to override the EC driver. x86 and ARM OLPC machines use completely different EC backends. The olpc_ec_cmd is synchronous, and waits for the workqueue to send the command to the EC. Multiple callers can run olpc_ec_cmd() at once, and they will by serialized and sleep while only one executes on the EC at a time. We don't provide an unregister function, as that doesn't make sense within the context of OLPC machines - there's only ever 1 EC, it's critical to functionality, and it certainly not hotpluggable. Signed-off-by: Andres Salomon <dilinger@queued.net> Acked-by: Paul Fox <pgf@laptop.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31Platform: OLPC: add a stub to drivers/platform/ for the OLPC EC driverAndres Salomon1-0/+29
The OLPC EC driver has outgrown arch/x86/platform/. It's time to both share common code amongst different architectures, as well as move it out of arch/x86/. The XO-1.75 is ARM-based, and the EC driver shares a lot of code with the x86 code. Signed-off-by: Andres Salomon <dilinger@queued.net> Acked-by: Paul Fox <pgf@laptop.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds28-69/+456
Merge Andrew's second set of patches: - MM - a few random fixes - a couple of RTC leftovers * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits) rtc/rtc-88pm80x: remove unneed devm_kfree rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables tmpfs: distribute interleave better across nodes mm: remove redundant initialization mm: warn if pg_data_t isn't initialized with zero mips: zero out pg_data_t when it's allocated memcg: gix memory accounting scalability in shrink_page_list mm/sparse: remove index_init_lock mm/sparse: more checks on mem_section number mm/sparse: optimize sparse_index_alloc memcg: add mem_cgroup_from_css() helper memcg: further prevent OOM with too many dirty pages memcg: prevent OOM with too many dirty pages mm: mmu_notifier: fix freed page still mapped in secondary MMU mm: memcg: only check anon swapin page charges for swap cache mm: memcg: only check swap cache pages for repeated charging mm: memcg: split swapin charge function into private and public part mm: memcg: remove needless !mm fixup to init_mm when charging mm: memcg: remove unneeded shmem charge type ...
2012-07-31Merge tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfioLinus Torvalds1-0/+445
Pull VFIO core from Alex Williamson: "This series includes the VFIO userspace driver interface for the 3.6 kernel merge window. This driver is intended to provide a secure interface for device access using IOMMU protection for applications like assignment of physical devices to virtual machines. Qemu will be the first user of this interface, enabling assignment of PCI devices to Qemu guests. This interface is intended to eventually replace the x86-specific assignment mechanism currently available in KVM. This interface has the advantage of being more secure, by working with IOMMU groups to ensure device isolation and providing it's own filtered resource access mechanism, and also more flexible, in not being x86 or KVM specific (extensions to enable POWER are already working). This driver is originally the work of Tom Lyon, but has since been handed over to me and gone through a complete overhaul thanks to the input from David Gibson, Ben Herrenschmidt, Chris Wright, Joerg Roedel, and others. This driver has been available in linux-next for the last month." Paul Mackerras says: "I would be glad to see it go in since we want to use it with KVM on PowerPC. If possible we'd like the PowerPC bits for it to go in as well." * tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfio: vfio: Add PCI device driver vfio: Type1 IOMMU implementation vfio: Add documentation vfio: VFIO core
2012-07-31Merge tag 'random_for_linus' of ↵Linus Torvalds3-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random subsystem patches from Ted Ts'o: "This patch series contains a major revamp of how we collect entropy from interrupts for /dev/random and /dev/urandom. The goal is to addresses weaknesses discussed in the paper "Mining your Ps and Qs: Detection of Widespread Weak Keys in Network Devices", by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will be published in the Proceedings of the 21st Usenix Security Symposium, August 2012. (See https://factorable.net for more information and an extended version of the paper.)" Fix up trivial conflicts due to nearby changes in drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c} * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits) random: mix in architectural randomness in extract_buf() dmi: Feed DMI table to /dev/random driver random: Add comment to random_initialize() random: final removal of IRQF_SAMPLE_RANDOM um: remove IRQF_SAMPLE_RANDOM which is now a no-op sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op [ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op ...
2012-07-31Merge branch 'v4l_for_linus' of ↵Linus Torvalds1-10/+37
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull second set of media updates from Mauro Carvalho Chehab: - radio API: add support to work with radio frequency bands - new AM/FM radio drivers: radio-shark, radio-shark2 - new Remote Controller USB driver: iguanair - conversion of several drivers to the v4l2 core control framework - new board additions at existing drivers - the remaining (and vast majority of the patches) are due to drivers/DocBook fixes/cleanups. * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (154 commits) [media] radio-tea5777: use library for 64bits div [media] tlg2300: Declare MODULE_FIRMWARE usage [media] lgs8gxx: Declare MODULE_FIRMWARE usage [media] xc5000: Add MODULE_FIRMWARE statements [media] s2255drv: Add MODULE_FIRMWARE statement [media] dib8000: move dereference after check for NULL [media] Documentation: Update cardlists [media] bttv: add support for Aposonic W-DVR [media] cx25821: Remove bad strcpy to read-only char* [media] pms.c: remove duplicated include [media] smiapp-core.c: remove duplicated include [media] via-camera: pass correct format settings to sensor [media] rtl2832.c: minor cleanup [media] Add support for the IguanaWorks USB IR Transceiver [media] Minor cleanups for MCE USB [media] drivers/media/dvb/siano/smscoreapi.c: use list_for_each_entry [media] Use a named union in struct v4l2_ioctl_info [media] mceusb: Add Twisted Melon USB IDs [media] staging/media/solo6x10: use module_pci_driver macro [media] staging/media/dt3155v4l: use module_pci_driver macro ... Conflicts: Documentation/feature-removal-schedule.txt
2012-07-31Merge tag 'nfs-for-3.6-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds4-8/+16
Pull second wave of NFS client updates from Trond Myklebust: - Patches from Bryan to allow splitting of the NFSv2/v3/v4 code into separate modules. - Fix Oopses in the NFSv4 idmapper - Fix a deadlock whereby rpciod tries to allocate a new socket and ends up recursing into the NFS code due to memory reclaim. - Increase the number of permitted callback connections. * tag 'nfs-for-3.6-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: explicitly reject LOCK_MAND flock() requests nfs: increase number of permitted callback connections. SUNRPC: return negative value in case rpcbind client creation error NFS: Convert v4 into a module NFS: Convert v3 into a module NFS: Convert v2 into a module NFS: Keep module parameters in the generic NFS client NFS: Split out remaining NFS v4 inode functions NFS: Pass super operations and xattr handlers in the nfs_subversion NFS: Only initialize the ACL client in the v3 case NFS: Create a try_mount rpc op NFS: Remove the NFS v4 xdev mount function NFS: Add version registering framework NFS: Fix a number of bugs in the idmapper nfs: skip commit in releasepage if we're freeing memory for fs-related reasons sunrpc: clarify comments on rpc_make_runnable pnfsblock: bail out partial page IO
2012-07-31mm: hugetlbfs: close race during teardown of hugetlbfs shared page tablesMel Gorman1-0/+11
If a process creates a large hugetlbfs mapping that is eligible for page table sharing and forks heavily with children some of whom fault and others which destroy the mapping then it is possible for page tables to get corrupted. Some teardowns of the mapping encounter a "bad pmd" and output a message to the kernel log. The final teardown will trigger a BUG_ON in mm/filemap.c. This was reproduced in 3.4 but is known to have existed for a long time and goes back at least as far as 2.6.37. It was probably was introduced in 2.6.20 by [39dde65c: shared page table for hugetlb page]. The messages look like this; [ ..........] Lots of bad pmd messages followed by this [ 127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7). [ 127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7). [ 127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7). [ 127.186778] ------------[ cut here ]------------ [ 127.186781] kernel BUG at mm/filemap.c:134! [ 127.186782] invalid opcode: 0000 [#1] SMP [ 127.186783] CPU 7 [ 127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod [ 127.186801] [ 127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR [ 127.186804] RIP: 0010:[<ffffffff810ed6ce>] [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186809] RSP: 0000:ffff8804144b5c08 EFLAGS: 00010002 [ 127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0 [ 127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00 [ 127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003 [ 127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8 [ 127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8 [ 127.186815] FS: 00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000 [ 127.186816] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0 [ 127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0) [ 127.186821] Stack: [ 127.186822] ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b [ 127.186824] ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98 [ 127.186825] ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000 [ 127.186827] Call Trace: [ 127.186829] [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80 [ 127.186832] [<ffffffff811bc925>] truncate_hugepages+0x115/0x220 [ 127.186834] [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30 [ 127.186837] [<ffffffff811655c7>] evict+0xa7/0x1b0 [ 127.186839] [<ffffffff811657a3>] iput_final+0xd3/0x1f0 [ 127.186840] [<ffffffff811658f9>] iput+0x39/0x50 [ 127.186842] [<ffffffff81162708>] d_kill+0xf8/0x130 [ 127.186843] [<ffffffff81162812>] dput+0xd2/0x1a0 [ 127.186845] [<ffffffff8114e2d0>] __fput+0x170/0x230 [ 127.186848] [<ffffffff81236e0e>] ? rb_erase+0xce/0x150 [ 127.186849] [<ffffffff8114e3ad>] fput+0x1d/0x30 [ 127.186851] [<ffffffff81117db7>] remove_vma+0x37/0x80 [ 127.186853] [<ffffffff81119182>] do_munmap+0x2d2/0x360 [ 127.186855] [<ffffffff811cc639>] sys_shmdt+0xc9/0x170 [ 127.186857] [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b [ 127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0 [ 127.186868] RIP [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186870] RSP <ffff8804144b5c08> [ 127.186871] ---[ end trace 7cbac5d1db69f426 ]--- The bug is a race and not always easy to reproduce. To reproduce it I was doing the following on a single socket I7-based machine with 16G of RAM. $ hugeadm --pool-pages-max DEFAULT:13G $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall $ for i in `seq 1 9000`; do ./hugetlbfs-test; done On my particular machine, it usually triggers within 10 minutes but enabling debug options can change the timing such that it never hits. Once the bug is triggered, the machine is in trouble and needs to be rebooted. The machine will respond but processes accessing proc like "ps aux" will hang due to the BUG_ON. shutdown will also hang and needs a hard reset or a sysrq-b. The basic problem is a race between page table sharing and teardown. For the most part page table sharing depends on i_mmap_mutex. In some cases, it is also taking the mm->page_table_lock for the PTE updates but with shared page tables, it is the i_mmap_mutex that is more important. Unfortunately it appears to be also insufficient. Consider the following situation Process A Process B --------- --------- hugetlb_fault shmdt LockWrite(mmap_sem) do_munmap unmap_region unmap_vmas unmap_single_vma unmap_hugepage_range Lock(i_mmap_mutex) Lock(mm->page_table_lock) huge_pmd_unshare/unmap tables <--- (1) Unlock(mm->page_table_lock) Unlock(i_mmap_mutex) huge_pte_alloc ... Lock(i_mmap_mutex) ... vma_prio_walk, find svma, spte ... Lock(mm->page_table_lock) ... share spte ... Unlock(mm->page_table_lock) ... Unlock(i_mmap_mutex) ... hugetlb_no_page <--- (2) free_pgtables unlink_file_vma hugetlb_free_pgd_range remove_vma_list In this scenario, it is possible for Process A to share page tables with Process B that is trying to tear them down. The i_mmap_mutex on its own does not prevent Process A walking Process B's page tables. At (1) above, the page tables are not shared yet so it unmaps the PMDs. Process A sets up page table sharing and at (2) faults a new entry. Process B then trips up on it in free_pgtables. This patch fixes the problem by adding a new function __unmap_hugepage_range_final that is only called when the VMA is about to be destroyed. This function clears VM_MAYSHARE during unmap_hugepage_range() under the i_mmap_mutex. This makes the VMA ineligible for sharing and avoids the race. Superficially this looks like it would then be vunerable to truncate and madvise issues but hugetlbfs has its own truncate handlers so does not use unmap_mapping_range() and does not support madvise(DONTNEED). This should be treated as a -stable candidate if it is merged. Test program is as follows. The test case was mostly written by Michal Hocko with a few minor changes to reproduce this bug. ==== CUT HERE ==== static size_t huge_page_size = (2UL << 20); static size_t nr_huge_page_A = 512; static size_t nr_huge_page_B = 5632; unsigned int get_random(unsigned int max) { struct timeval tv; gettimeofday(&tv, NULL); srandom(tv.tv_usec); return random() % max; } static void play(void *addr, size_t size) { unsigned char *start = addr, *end = start + size, *a; start += get_random(size/2); /* we could itterate on huge pages but let's give it more time. */ for (a = start; a < end; a += 4096) *a = 0; } int main(int argc, char **argv) { key_t key = IPC_PRIVATE; size_t sizeA = nr_huge_page_A * huge_page_size; size_t sizeB = nr_huge_page_B * huge_page_size; int shmidA, shmidB; void *addrA = NULL, *addrB = NULL; int nr_children = 300, n = 0; if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } fork_child: switch(fork()) { case 0: switch (n%3) { case 0: play(addrA, sizeA); break; case 1: play(addrB, sizeB); break; case 2: break; } break; case -1: perror("fork:"); break; default: if (++n < nr_children) goto fork_child; play(addrA, sizeA); break; } shmdt(addrA); shmdt(addrB); do { wait(NULL); } while (--n > 0); shmctl(shmidA, IPC_RMID, NULL); shmctl(shmidB, IPC_RMID, NULL); return 0; } [akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build] Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: remove redundant initializationMinchan Kim1-5/+0
pg_data_t is zeroed before reaching free_area_init_core(), so remove the now unnecessary initializations. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: memcg: fix compaction/migration failing due to memcg limitsJohannes Weiner1-6/+5
Compaction (and page migration in general) can currently be hindered through pages being owned by memory cgroups that are at their limits and unreclaimable. The reason is that the replacement page is being charged against the limit while the page being replaced is also still charged. But this seems unnecessary, given that only one of the two pages will still be in use after migration finishes. This patch changes the memcg migration sequence so that the replacement page is not charged. Whatever page is still in use after successful or failed migration gets to keep the charge of the page that was going to be replaced. The replacement page will still show up temporarily in the rss/cache statistics, this can be fixed in a later patch as it's less urgent. Reported-by: David Rientjes <rientjes@google.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31nfs: enable swap on NFSMel Gorman2-2/+5
Implement the new swapfile a_ops for NFS and hook up ->direct_IO. This will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol ->connect() method. PF_MEMALLOC should allow the allocation of struct socket and related objects and the early (re)setting of SOCK_MEMALLOC should allow us to receive the packets required for the TCP connection buildup. [jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases] [dfeng@redhat.com: Fix handling of multiple swap files] [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: add support for direct_IO to highmem pagesMel Gorman1-0/+7
The patch "mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages" added support for using direct_IO to write swap pages but it is insufficient for highmem pages. To support highmem pages, this patch kmaps() the page before calling the direct_IO() handler. As direct_IO deals with virtual addresses an additional helper is necessary for get_kernel_pages() to lookup the struct page for a kmap virtual address. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: swap: implement generic handler for swap_activateMel Gorman2-2/+9
The version of swap_activate introduced is sufficient for swap-over-NFS but would not provide enough information to implement a generic handler. This patch shuffles things slightly to ensure the same information is available for aops->swap_activate() as is available to the core. No functionality change. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: add support for a filesystem to activate swap files and use direct_IO ↵Mel Gorman2-0/+6
for writing swap pages Currently swapfiles are managed entirely by the core VM by using ->bmap to allocate space and write to the blocks directly. This effectively ensures that the underlying blocks are allocated and avoids the need for the swap subsystem to locate what physical blocks store offsets within a file. If the swap subsystem is to use the filesystem information to locate the blocks, it is critical that information such as block groups, block bitmaps and the block descriptor table that map the swap file were resident in memory. This patch adds address_space_operations that the VM can call when activating or deactivating swap backed by a file. int swap_activate(struct file *); int swap_deactivate(struct file *); The ->swap_activate() method is used to communicate to the file that the VM relies on it, and the address_space should take adequate measures such as reserving space in the underlying device, reserving memory for mempools and pinning information such as the block descriptor table in memory. The ->swap_deactivate() method is called on sys_swapoff() if ->swap_activate() returned success. After a successful swapfile ->swap_activate, the swapfile is marked SWP_FILE and swapper_space.a_ops will proxy to sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache pages and ->readpage to read. It is perfectly possible that direct_IO be used to read the swap pages but it is an unnecessary complication. Similarly, it is possible that ->writepage be used instead of direct_io to write the pages but filesystem developers have stated that calling writepage from the VM is undesirable for a variety of reasons and using direct_IO opens up the possibility of writing back batches of swap pages in the future. [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: add get_kernel_page[s] for pinning of kernel addresses for I/OMel Gorman3-0/+8
This patch adds two new APIs get_kernel_pages() and get_kernel_page() that may be used to pin a vector of kernel addresses for IO. The initial user is expected to be NFS for allowing pages to be written to swap using aops->direct_IO(). Strictly speaking, swap-over-NFS only needs to pin one page for IO but it makes sense to express the API in terms of a vector and add a helper for pinning single pages. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: methods for teaching filesystems about PG_swapcache pagesMel Gorman3-0/+31
In order to teach filesystems to handle swap cache pages, three new page functions are introduced: pgoff_t page_file_index(struct page *); loff_t page_file_offset(struct page *); struct address_space *page_file_mapping(struct page *); page_file_index() - gives the offset of this page in the file in PAGE_CACHE_SIZE blocks. Like page->index is for mapped pages, this function also gives the correct index for PG_swapcache pages. page_file_offset() - uses page_file_index(), so that it will give the expected result, even for PG_swapcache pages. page_file_mapping() - gives the mapping backing the actual page; that is for swap cache pages it will give swap_file->f_mapping. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: account for the number of times direct reclaimers get throttledMel Gorman1-0/+1
Under significant pressure when writing back to network-backed storage, direct reclaimers may get throttled. This is expected to be a short-lived event and the processes get woken up again but processes do get stalled. This patch counts how many times such stalling occurs. It's up to the administrator whether to reduce these stalls by increasing min_free_kbytes. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Mel Gorman <mgorman@suse.de> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is ↵Mel Gorman1-0/+1
backed by network storage If swap is backed by network storage such as NBD, there is a risk that a large number of reclaimers can hang the system by consuming all PF_MEMALLOC reserves. To avoid these hangs, the administrator must tune min_free_kbytes in advance which is a bit fragile. This patch throttles direct reclaimers if half the PF_MEMALLOC reserves are in use. If the system is routinely getting throttled the system administrator can increase min_free_kbytes so degradation is smoother but the system will keep running. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Mel Gorman <mgorman@suse.de> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31netvm: propagate page->pfmemalloc from skb_alloc_page to skbMel Gorman1-0/+55
The skb->pfmemalloc flag gets set to true iff during the slab allocation of data in __alloc_skb that the the PFMEMALLOC reserves were used. If page splitting is used, it is possible that pages will be allocated from the PFMEMALLOC reserve without propagating this information to the skb. This patch propagates page->pfmemalloc from pages allocated for fragments to the skb. It works by reintroducing and expanding the skb_alloc_page() API to take an skb. If the page was allocated from pfmemalloc reserves, it is automatically copied. If the driver allocates the page before the skb, it should call skb_propagate_pfmemalloc() after the skb is allocated to ensure the flag is copied properly. Failure to do so is not critical. The resulting driver may perform slower if it is used for swap-over-NBD or swap-over-NFS but it should not result in failure. [davem@davemloft.net: API rename and consistency] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: David S. Miller <davem@davemloft.net> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Mel Gorman <mgorman@suse.de> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>