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2010-05-21Merge branch 'master' into for-2.6.35Jens Axboe295-7248/+9784
Conflicts: fs/ext3/fsync.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21pipe: set lower and upper limit on max pages in the pipe page arrayJens Axboe1-0/+15
We need at least two to guarantee proper POSIX behaviour, so never allow a smaller limit than that. Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows root to define a sane upper limit. Make it default to 16 times the default size, which is 16 pages. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21pipe: add support for shrinking and growing pipesJens Axboe3-58/+205
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for growing and shrinking the size of a pipe and adjusts pipe.c and splice.c (and relay and network splice) usage to work with these larger (or smaller) pipes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21Merge branch 'for_linus' of ↵Linus Torvalds3-19/+29
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6: udf: BKL ioctl pushdown
2010-05-21writeback: fix problem with !CONFIG_BLOCK compilationJens Axboe1-0/+1
When CONFIG_BLOCK isn't enabled: mm/page-writeback.c: In function 'laptop_mode_timer_fn': mm/page-writeback.c:708: error: dereferencing pointer to incomplete type mm/page-writeback.c:709: error: dereferencing pointer to incomplete type Fix this by essentially eliminating the laptop sync handlers when CONFIG_BLOCK isn't set, as most are only used from the block layer code. The exception is laptop_sync_completion() which is used from sys_sync(), make that an empty declaration in that case. Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21block: improve automatic native capacity unlockingTejun Heo2-14/+60
Currently, native capacity unlocking is initiated only when a recognized partition extends beyond the end of the disk. However, there are several other unhandled cases where truncated capacity can lead to misdetection of partitions. * Partition table is fully beyond EOD. * Partition table is partially beyond EOD (daisy chained ones). * Recognized partition starts beyond EOD. This patch updates generic partition check code such that all the above three cases are handled too. For the first two, @state tracks whether low level partition check code tried to read beyond EOD during partition scan and triggers native capacity unlocking accordingly. The third is now handled similarly to the original unlocking case. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21block: use struct parsed_partitions *state universally in partition check codeTejun Heo30-239/+225
Make the following changes to partition check code. * Add ->bdev to struct parsed_partitions. * Introduce read_part_sector() which is a simple wrapper around read_dev_sector() which takes struct parsed_partitions *state instead of @bdev. * For functions which used to take @state and @bdev, drop @bdev. For functions which used to take @bdev, replace it with @state. * While updating, drop superflous checks on NULL state/bdev in ldm.c. This cleans up the API a bit and enables better handling of IO errors during partition check as the generic partition check code now has much better visibility into what went wrong in the low level code paths. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()Tejun Heo1-2/+2
bdops->set_capacity() is unnecessarily generic. All that's required is a simple one way notification to lower level driver telling it to try to unlock native capacity. There's no reason to pass in target capacity or return the new capacity. The former is always the inherent native capacity and the latter can be handled via the usual device resize / revalidation path. In fact, the current API is always used that way. Replace ->set_capacity() with ->unlock_native_capacity() which take only @disk and doesn't return anything. IDE which is the only current user of the API is converted accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21block: restart partition scan after resizing a deviceTejun Heo1-10/+6
Device resize via ->set_capacity() can reveal new partitions (e.g. in chained partition table formats such as dos extended parts). Restart partition scan from the beginning after resizing a device. This change also makes libata always revalidate the disk after resize which makes lower layer native capacity unlocking implementation simpler and more robust as resize can be handled in the usual path. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21buffer: make invalidate_bdev() drain all percpu LRU add cachesTejun Heo1-0/+1
invalidate_bdev() should release all page cache pages which are clean and not being used; however, if some pages are still in the percpu LRU add caches on other cpus, those pages are considered in used and don't get released. Fix it by calling lru_add_drain_all() before trying to invalidate pages. This problem was discovered while testing block automatic native capacity unlocking. Null pages which were read before automatic unlocking didn't get released by invalidate_bdev() and ended up interfering with partition scan after unlocking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21writeback: bdi_writeback_task() must set task state before calling schedule()Jens Axboe1-2/+7
Calling schedule without setting the task state to non-running will return immediately, so ensure that we set it properly and check our sleep conditions after doing so. This is a fixup for commit 69b62d01. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21writeback: ensure that WB_SYNC_NONE writeback with sb pinned is syncJens Axboe1-5/+11
Even if the writeout itself isn't a data integrity operation, we need to ensure that the caller doesn't drop the sb umount sem before we have actually done the writeback. This is a fixup for commit e913fc82. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21Merge branch 'for_linus' of ↵Linus Torvalds35-509/+747
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (31 commits) dquot: Detect partial write error to quota file in write_blk() and add printk_ratelimit for quota error messages ocfs2: Fix lock inversion in quotas during umount ocfs2: Use __dquot_transfer to avoid lock inversion ocfs2: Fix NULL pointer deref when writing local dquot ocfs2: Fix estimate of credits needed for quota allocation ocfs2: Fix quota locking ocfs2: Avoid unnecessary block mapping when refreshing quota info ocfs2: Do not map blocks from local quota file on each write quota: Refactor dquot_transfer code so that OCFS2 can pass in its references quota: unify quota init condition in setattr quota: remove sb_has_quota_active in get/set_info quota: unify ->set_dqblk quota: unify ->get_dqblk ext3: make barrier options consistent with ext4 quota: Make quota stat accounting lockless. suppress warning: "quotatypes" defined but not used ext3: Fix waiting on transaction during fsync jbd: Provide function to check whether transaction will issue data barrier ufs: add ufs speciffic ->setattr call BKL: Remove BKL from ext2 filesystem ...
2010-05-21dquot: Detect partial write error to quota file in write_blk() and add ↵Jiaying Zhang3-22/+36
printk_ratelimit for quota error messages This patch changes quota_tree.c:write_blk() to detect error caused by partial write to quota file and add a macro to limit control printed quota error messages so we won't fill up dmesg with a corrupted quota file. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Fix lock inversion in quotas during umountJan Kara2-4/+4
We cannot cancel delayed work from ocfs2_local_free_info because that is called with dqonoff_mutex held and the work it cancels requires dqonoff_mutex to finish. Cancel the work before acquiring dqonoff_mutex. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Use __dquot_transfer to avoid lock inversionJan Kara1-12/+5
dquot_transfer() acquires own references to dquots via dqget(). Thus it waits for dq_lock which creates a lock inversion because dq_lock ranks above transaction start but transaction is already started in ocfs2_setattr(). Fix the problem by passing own references directly to __dquot_transfer. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Fix NULL pointer deref when writing local dquotJan Kara3-12/+12
commit_dqblk() can write quota info to global file. That is actually a bad thing to do because if we are just modifying local quota file, we are not prepared (do not hold proper locks, do not have transaction credits) to do a modification of the global quota file. So do not use commit_dqblk() and instead call our writing function directly. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Fix estimate of credits needed for quota allocationJan Kara1-2/+3
We were missing reservation of a journal credit for modification of quota file inode when creating new dquot structure in the global quota file. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Fix quota lockingJan Kara3-186/+214
OCFS2 had three issues with quota locking: a) When reading dquot from global quota file, we started a transaction while holding dqio_mutex which is prone to deadlocks because other paths do it the other way around b) During ocfs2_sync_dquot we were not protected against concurrent writers on the same node. Because we first copy data to local buffer, a race could happen resulting in old data being written to global quota file and thus causing quota inconsistency after a crash. c) ip_alloc_sem of quota files was acquired while a transaction is started in ocfs2_quota_write which can deadlock because we first get ip_alloc_sem and then start a transaction when extending quota files. We fix the problem a) by pulling all necessary code to ocfs2_acquire_dquot and ocfs2_release_dquot. Thus we no longer depend on generic dquot_acquire to do the locking and can force proper lock ordering. Problems b) and c) are fixed by locking i_mutex and ip_alloc_sem of global quota file in ocfs2_lock_global_qf and removing ip_alloc_sem from ocfs2_quota_read and ocfs2_quota_write. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Avoid unnecessary block mapping when refreshing quota infoJan Kara4-7/+24
The position of global quota file info does not change. So we do not have to do logical -> physical block translation every time we reread it from disk. Thus we can also avoid taking ip_alloc_sem. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Do not map blocks from local quota file on each writeJan Kara3-9/+36
There is no need to map offset of local dquot structure to on disk block in each quota write. It is enough to map it just once and store the physical block number in quota structure in memory. Moreover this simplifies locking as we do not have to take ip_alloc_sem from quota write path. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: Refactor dquot_transfer code so that OCFS2 can pass in its referencesJan Kara1-35/+26
Currently, __dquot_transfer() acquires its own references of dquot structures that will be put into inode. But for OCFS2, this creates a lock inversion between dq_lock (waited on in dqget) and transaction start (started in ocfs2_setattr). Currently, deadlock is impossible because dq_lock is acquired only during dquot_acquire and dquot_release and we already hold a reference to dquot structures in ocfs2_setattr so neither of these functions can be called while we call dquot_transfer. But this is rather subtle and it is hard to teach lockdep about it. So provide __dquot_transfer function that can be passed dquot references directly. OCFS2 can then pass acquired dquot references directly to __dquot_transfer with proper locking. Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: unify quota init condition in setattrDmitry Monakhov9-15/+15
Quota must being initialized if size or uid/git changes requested. But initialization performed in two different places: in case of i_size file system is responsible for dquot init , but in case of uid/gid init will be called internally in dquot_transfer(). This ambiguity makes code harder to understand. Let's move this logic to one common helper function. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: remove sb_has_quota_active in get/set_infoChristoph Hellwig1-4/+0
The methods already do these checks, so remove them in the quotactl implementation to allow non-VFS quota implementations to also support these calls. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: unify ->set_dqblkChristoph Hellwig5-37/+86
Pass the larger struct fs_disk_quota to the ->set_dqblk operation so that the Q_SETQUOTA and Q_XSETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->set_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Add new fieldmask values for setting the numer of blocks and inodes values which is required for the VFS quota, but wasn't for XFS. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: unify ->get_dqblkChristoph Hellwig4-21/+39
Pass the larger struct fs_disk_quota to the ->get_dqblk operation so that the Q_GETQUOTA and Q_XGETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->get_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext3: make barrier options consistent with ext4Eric Sandeen1-7/+26
ext4 was updated to accept barrier/nobarrier mount options in addition to the older barrier=0/1. The barrier story is complex enough, we should help people by making the options the same at least, even if the defaults are different. This patch allows the barrier/nobarrier mount options for ext3, while keeping nobarrier the default. It also unconditionally displays barrier status in show_options, and prints a message at mount time if barriers are not enabled, just as ext4 does. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: Make quota stat accounting lockless.Dmitry Monakhov3-38/+72
Quota stats is mostly writable data structure. Let's alloc percpu bucket for each value. NOTE: dqstats_read() function is racy against dqstats_{inc,dec} and may return inconsistent value. But this is ok since absolute accuracy is not required. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21suppress warning: "quotatypes" defined but not usedSergey Senozhatsky1-0/+2
Suppress compilation warning: "quotatypes" defined but not used. quotatypes is used only when CONFIG_QUOTA_DEBUG or CONFIG_PRINT_QUOTA_WARNING is/are defined. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext3: Fix waiting on transaction during fsyncJan Kara2-12/+10
log_start_commit() returns 1 only when it started a transaction commit. Thus in case transaction commit is already running, we fail to wait for the commit to finish. Fix the issue by always waiting for the commit regardless of the log_start_commit return value. Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21jbd: Provide function to check whether transaction will issue data barrierJan Kara2-1/+40
Provide a function which returns whether a transaction with given tid will send a barrier to the filesystem device. The function will be used by ext3 to detect whether fsync needs to send a separate barrier or not. Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ufs: add ufs speciffic ->setattr callDmitry Monakhov5-3/+13
generic setattr not longer responsible for quota transfer. use ufs_setattr for all ufs's inodes. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21BKL: Remove BKL from ext2 filesystemJan Blunck2-16/+0
The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs() ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(), ext2_fill_super() and ext2_remount() are protected against each other by the struct super_block s_umount rw semaphore. The call in ext2_write_inode() could only protect the modification of the ext2_sb_info through ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount(). ext2_fill_super() and ext2_put_super() can be left out because you need a valid filesystem reference in all three cases, which you do not have when you are one of these functions. If the BKL is only protecting the modification of the ext2_sb_info it can safely be removed since this is protected by the struct ext2_sb_info s_lock. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Add ext2_sb_info s_lock spinlockJan Blunck3-1/+30
Add a spinlock that protects against concurrent modifications of s_mount_state, s_blocks_last, s_overhead_last and the content of the superblock's buffer pointed to by sbi->s_es. The spinlock is now used in ext2_xattr_update_super_block() which was setting the EXT2_FEATURE_COMPAT_EXT_ATTR flag on the superblock without protection before. Likewise the spinlock is used in ext2_show_options() to have a consistent view of the mount options. This is a preparation patch for removing the BKL from ext2 in the next patch. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jan Kara <jack@suse.cz> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Move ext2_write_super() out of ext2_setup_super()Jan Blunck1-3/+5
Move ext2_write_super() out of ext2_setup_super() as a preparation for the next patch that adds a new lock for superblock fields. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Fold ext2_commit_super() into ext2_sync_super()Jan Blunck1-19/+9
Both function originally did similar things except that ext2_sync_super() is returning after the call to sync_dirty_buffer(sbh). Therefore this patch adds a wait flag to tell ext2_sync_super() if it has to call sync_dirty_buffer() to wait for in-progress I/O to finish. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Remove duplicate code from ext2_sync_fs()Jan Blunck1-7/+0
Depending in the state (valid or unchecked) of the filesystem either ext2_sync_super() or ext2_commit_super() is called. If the filesystem is currently valid (it is checked), we first mark it unchecked and afterwards duplicate the work that ext2_sync_super() is doing later. Therefore this patch removes the duplicate code and calls ext2_sync_super() directly after marking the filesystem unchecked. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Set the write time in ext2_sync_fs()Jan Blunck1-1/+1
This is probably a typo since the write time should actually be updated by ext2_sync_fs() instead of the mount time. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Use ext2_clear_super_error() in ext2_sync_fs()Jan Blunck1-17/+3
ext2_sync_fs() used to duplicate the code from ext2_clear_super_error(). Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext3: init statistics after journal recovery v2Dmitry Monakhov1-23/+21
Currently block/inode/dir counters are initialized before journal was recovered. In fact after journal recovery this info will probably change which results in incorrect numbers returned from statfs(2). BUG:#15768 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: remove useless call to brelse() in ext2_free_inode()Francis Moreau1-5/+4
This patch removes a useless call to brelse(bitmap_bh) since at that point bitmap_bh is NULL and slightly cleans up bitmap_bh handling. Signed-off-by: Francis Moreau <francis.moro@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21quota: optimize mark_dirty logicDmitry Monakhov1-2/+11
- Skip locking if quota is dirty already. - Return old quota state to help fs-specciffic implementation to optimize case where quota was dirty already. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext2: Avoid loading bitmaps for full groups during block allocationJan Kara1-0/+6
There is no point in loading bitmap for groups which are completely full. This causes noticeable performance problems (and memory pressure) on small systems with large full filesystem (http://marc.info/?l=linux-ext4&m=126843108314310&w=2). Port of the same ext3 patch. Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ext3: Avoid loading bitmaps for full groups during block allocationFrans van de Wiel1-0/+6
There is no point in loading bitmap for groups which are completely full. This causes noticeable performance problems (and memory pressure) on small systems with large full filesystem (http://marc.info/?l=linux-ext4&m=126843108314310&w=2). Jan Kara: Added a comment and changed check to use cpu-endian value. Signed-off-by: "Frans van de Wiel" <fvdw@fvdw.eu> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright1-13/+11
This allows bin_attr->read,write,mmap callbacks to check file specific data (such as inode owner) as part of any privilege validation. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Remove usage of S_BIAS to avoid merge conflict with the vfs treeEric W. Biederman1-3/+8
In Al's latest vfs tree the code is reworked and S_BIAS has been removed. It turns out that checking to see if a super block is in the middle of an unmount in sysfs_exit_ns is unnecessary because we remove the super_block from the s_supers/s_instances list before struct sysfs_super_info pointed to by sb->s_fs_info is freed. For now just delete the unnecessary check to see if a superblock is in the middle of an unmount, it isn't necessary with or without Al's changes and it just causes a needless conflict. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Comment sysfs directory tagging logicSerge E. Hallyn2-1/+20
Add some in-line comments to explain the new infrastructure, which was introduced to support sysfs directory tagging with namespaces. I think an overall description someplace might be good too, but it didn't really seem to fit into Documentation/filesystems/sysfs.txt, which appears more geared toward users, rather than maintainers, of sysfs. (Tejun, please let me know if I can make anything clearer or failed altogether to comment something that should be commented.) Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Implement sysfs_delete_linkEric W. Biederman1-0/+20
When removing a symlink sysfs_remove_link does not provide enough information to figure out which tagged directory the symlink falls in. So I need sysfs_delete_link which is passed the target of the symlink to delete. sysfs_rename_link is updated to call sysfs_delete_link instead of sysfs_remove_link as we have all of the information necessary and the callers are interesting. Both of these functions now have enough information to find a symlink in a tagged directory. The only restriction is that they must be called before the target kobject is renamed or deleted. If they are called later I loose track of which tag the target kobject was marked with and can no longer find the old symlink to remove it. This patch was split from an earlier patch. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Add support for tagged directories with untagged members.Eric W. Biederman2-9/+5
I had hopped to avoid this but the bonding driver adds a file to /sys/class/net/ and the easiest way to handle that file is to make it untagged and to register it only once. So relax the rules on tagged directories, and make bonding work. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman8-45/+164
The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>