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path: root/fs/nilfs2/the_nilfs.h
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2011-03-09nilfs2: get rid of nilfs_sb_info structureRyusuke Konishi
This directly uses sb->s_fs_info to keep a nilfs filesystem object and fully removes the intermediate nilfs_sb_info structure. With this change, the hierarchy of on-memory structures of nilfs will be simplified as follows: Before: super_block -> nilfs_sb_info -> the_nilfs -> cptree --+-> nilfs_root (current file system) +-> nilfs_root (snapshot A) +-> nilfs_root (snapshot B) : -> nilfs_sc_info (log writer structure) After: super_block -> the_nilfs -> cptree --+-> nilfs_root (current file system) +-> nilfs_root (snapshot A) +-> nilfs_root (snapshot B) : -> nilfs_sc_info (log writer structure) The reason why we didn't design so from the beginning is because the initial shape also differed from the above. The early hierachy was composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a shared nilfs object. On the kernel 2.6.37, it was changed to the current shape in order to unify super block instances into one per device, and this cleanup became applicable as the result. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: use sb instance instead of nilfs_sb_info structRyusuke Konishi
This replaces sbi uses with direct reference to sb instance. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: move log writer onto nilfs objectRyusuke Konishi
Log writer is held by the nilfs_sb_info structure. This moves it into nilfs object and replaces all uses of NILFS_SC() accessor. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: move next generation counter into nilfs objectRyusuke Konishi
Moves s_next_generation counter and a spinlock protecting it to nilfs object from nilfs_sb_info structure. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: move s_inode_lock and s_dirty_files into nilfs objectRyusuke Konishi
Moves s_inode_lock spinlock and s_dirty_files list to nilfs object from nilfs_sb_info structure. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: move parameters on nilfs_sb_info into nilfs objectRyusuke Konishi
This moves four parameter variables on nilfs_sb_info s_resuid, s_resgid, s_interval and s_watermark to the nilfs object. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-09nilfs2: move mount options to nilfs objectRyusuke Konishi
This moves mount_opt local variable to nilfs object from nilfs_sb_info struct. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-01-10nilfs2: get rid of loaded flag from nilfs objectRyusuke Konishi
NILFS_LOADED flag of the nilfs object is not used now, so this will remove it. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: get rid of bdi from nilfs objectRyusuke Konishi
Nilfs now can use sb->s_bdi to get backing_dev_info, so we use it instead of ns_bdi on the nilfs object and remove ns_bdi. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: get rid of back pointer to writable sb instanceRyusuke Konishi
Nilfs object holds a back pointer to a writable super block instance in nilfs->ns_writer, and this became eliminable since sb is now made per device and all inodes have a valid pointer to it. This deletes the ns_writer pointer and a reader/writer semaphore protecting it. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: see state of root dentry for mount check of snapshotsRyusuke Konishi
After applied the patch that unified sb instances, root dentry of snapshots can be left in dcache even after their trees are unmounted. The orphan root dentry/inode keeps a root object, and this causes false positive of nilfs_checkpoint_is_mounted function. This resolves the issue by having nilfs_checkpoint_is_mounted test whether the root dentry is busy or not. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: get rid of GCDAT inodeRyusuke Konishi
This applies prepared rollback function and redirect function of metadata file to DAT file, and eliminates GCDAT inode. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: simplify life cycle management of nilfs objectRyusuke Konishi
This stops pre-allocating nilfs object in nilfs_get_sb routine, and stops managing its life cycle by reference counting. nilfs_find_or_create_nilfs() function, nilfs->ns_mount_mutex, nilfs_objects list, and the reference counter will be removed through the simplification. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: do not allocate multiple super block instances for a deviceRyusuke Konishi
This stops allocating multiple super block instances for a device. All snapshots and a current mode mount (i.e. latest tree) will be controlled with nilfs_root objects that are kept within an sb instance. nilfs_get_sb() is rewritten so that it always has a root object for the latest tree and snapshots make additional root objects. The root dentry of the latest tree is binded to sb->s_root even if it isn't attached on a directory. Root dentries of snapshots or the latest tree are binded to mnt->mnt_root on which they are mounted. With this patch, nilfs_find_sbinfo() function, nilfs->ns_supers list, and nilfs->ns_current back pointer, are deleted. In addition, init_nilfs() and load_nilfs() are simplified since they will be called once for a device, not repeatedly called for mount points. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: add checkpoint tree to nilfs objectRyusuke Konishi
To hold multiple versions of a filesystem in one sb instance, a new on-memory structure is necessary to handle one or more checkpoints. This adds a red-black tree of checkpoints to nilfs object, and adds lookup and create functions for them. Each checkpoint is represented by "nilfs_root" structure, and this structure has rb_node to configure the rb-tree. The nilfs_root object is identified with a checkpoint number. For each snapshot, a nilfs_root object is allocated and the checkpoint number of snapshot is assigned to it. For a regular mount (i.e. current mode mount), NILFS_CPTREE_CURRENT_CNO constant is assigned to the corresponding nilfs_root object. Each nilfs_root object has an ifile inode and some counters. These items will displace those of nilfs_sb_info structure in successive patches. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: remove own inode hash used for GCRyusuke Konishi
This uses inode hash function that vfs provides instead of the own hash table for caching gc inodes. This finally removes the own inode hash from nilfs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-07-23nilfs2: do not update log cursor for small changeRyusuke Konishi
Super blocks of nilfs are periodically overwritten in order to record the recent log position. This shortens recovery time after unclean unmount, but the current implementation performs the update even for a few blocks of change. If the filesystem gets small changes slowly and continually, super blocks may be updated excessively. This moderates the issue by skipping update of log cursor if it does not cross a segment boundary. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-07-23nilfs2: sync super blocks in turnsJiro SEKIBA
This will sync super blocks in turns instead of syncing duplicate super blocks at the time. This will help searching valid super root when super block is written into disk before log is written, which is happen when barrier-less block devices are unmounted uncleanly. In the situation, old super block likely points to valid log. This patch introduces ns_sbwcount member to the nilfs object and adds nilfs_sb_will_flip() function; ns_sbwcount counts how many times super blocks write back to the disk. And, nilfs_sb_will_flip() decides whether flipping required or not based on the count of ns_sbwcount to sync super blocks asymmetrically. The following functions are also changed: - nilfs_prepare_super(): flips super blocks according to the argument. The argument is calculated by nilfs_sb_will_flip() function. - nilfs_cleanup_super(): sets "clean" flag to both super blocks if they point to the same checkpoint. To update both of super block information, caller of nilfs_commit_super must set the information on both super blocks. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-07-23nilfs2: get rid of ns_free_segments_countRyusuke Konishi
This counter is unused. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-07-23nilfs2: add blocksize member to nilfs objectRyusuke Konishi
This stores blocksize in nilfs objects for the successive refactoring of recovery logic. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-13nilfs2: get rid of s_dirt flag useRyusuke Konishi
This replaces s_dirt flag use in nilfs with a new flag added on the nilfs object. The s_dirt flag was used to indicate if sop->write_super() should be called, however the current version of nilfs does not use the callback. Thus, it can be replaced with the own flag. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Jiro SEKIBA <jir@unicus.jp>
2010-02-13nilfs2: issue discard request after cleaning segmentsJiro SEKIBA
This adds a function to send discard requests for given array of segment numbers, and calls the function when garbage collection succeeded. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: add helper to get if volume is in a valid stateRyusuke Konishi
This adds a helper function, nilfs_valid_fs() which returns if nilfs is in a valid state or not. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-09-14nilfs2: shorten freeze period due to GC in write operation v3Jiro SEKIBA
This is a re-revised patch to shorten freeze period. This version include a fix of the bug Konishi-san mentioned last time. When GC is runnning, GC moves live block to difference segments. Copying live blocks into memory is done in a transaction, however it is not necessarily to be in the transaction. This patch will get the nilfs_ioctl_move_blocks() out from transaction lock and put it before the transaction. I ran sysbench fileio test against nilfs partition. I copied some DVD/CD images and created snapshot to create live blocks before starting the benchmark. Followings are summary of rc8 and rc8 w/ the patch of per-request statistics, which is min/max and avg. I ran each test three times and bellow is average of those numers. According to this benchmark result, average time is slightly degrated. However, worstcase (max) result is significantly improved. This can address a few seconds write freeze. - random write per-request performance of rc8 min 0.843ms max 680.406ms avg 3.050ms - random write per-request performance of rc8 w/ this patch min 0.843ms -> 100.00% max 380.490ms -> 55.90% avg 3.233ms -> 106.00% - sequential write per-request performance of rc8 min 0.736ms max 774.343ms avg 2.883ms - sequential write per-request performance of rc8 w/ this patch min 0.720ms -> 97.80% max 644.280ms-> 83.20% avg 3.130ms -> 108.50% -----8<-----8<-----nilfs_cleanerd.conf-----8<-----8<----- protection_period 150 selection_policy timestamp # timestamp in ascend order nsegments_per_clean 2 cleaning_interval 2 retry_interval 60 use_mmap log_priority info -----8<-----8<-----nilfs_cleanerd.conf-----8<-----8<----- Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-09-14nilfs2: clean up nilfs_write_superJiro SEKIBA
Separate conditions that check if syncing super block and alternative super block are required as inline functions to reuse the conditions. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-09-14nilfs2: use semaphore to protect pointer to a writable FS-instanceRyusuke Konishi
will get rid of nilfs_get_writer() and nilfs_put_writer() pair used to retain a writable FS-instance for a period. The pair functions were making up some kind of recursive lock with a mutex, but they became overkill since the commit 201913ed746c7724a40d33ee5a0b6a1fd2ef3193. Furthermore, they caused the following lockdep warning because the mutex can be released by a task which didn't lock it: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- kswapd0/422 is trying to release lock (&nilfs->ns_writer_mutex) at: [<c1359ff5>] mutex_unlock+0x8/0xa but there are no more locks to release! other info that might help us debug this: no locks held by kswapd0/422. stack backtrace: Pid: 422, comm: kswapd0 Not tainted 2.6.31-rc4-nilfs #51 Call Trace: [<c1358f97>] ? printk+0xf/0x18 [<c104fea7>] print_unlock_inbalance_bug+0xcc/0xd7 [<c11578de>] ? prop_put_global+0x3/0x35 [<c1050195>] lock_release+0xed/0x1dc [<c1359ff5>] ? mutex_unlock+0x8/0xa [<c1359f83>] __mutex_unlock_slowpath+0xaf/0x119 [<c1359ff5>] mutex_unlock+0x8/0xa [<d1284add>] nilfs_mdt_write_page+0xd8/0xe1 [nilfs2] [<c1092653>] shrink_page_list+0x379/0x68d [<c109171b>] ? isolate_pages_global+0xb4/0x18c [<c1092bd2>] shrink_list+0x26b/0x54b [<c10930be>] shrink_zone+0x20c/0x2a2 [<c10936b7>] kswapd+0x407/0x591 [<c1091667>] ? isolate_pages_global+0x0/0x18c [<c1040603>] ? autoremove_wake_function+0x0/0x33 [<c10932b0>] ? kswapd+0x0/0x591 [<c104033b>] kthread+0x69/0x6e [<c10402d2>] ? kthread+0x0/0x6e [<c1003e33>] kernel_thread_helper+0x7/0x1a This patch uses a reader/writer semaphore instead of the own lock and kills this warning. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-08-19nilfs2: fix oopses with doubly mounted snapshotsRyusuke Konishi
will fix kernel oopses like the following: # mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test1 # mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test2 # umount /test1 # umount /test2 BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:1069 in_atomic(): 0, irqs_disabled(): 1, pid: 3886, name: umount.nilfs2 1 lock held by umount.nilfs2/3886: #0: (&type->s_umount_key#31){+.+...}, at: [<c10b398a>] deactivate_super+0x52/0x6c irq event stamp: 1219 hardirqs last enabled at (1219): [<c135c774>] __mutex_unlock_slowpath+0xf8/0x119 hardirqs last disabled at (1218): [<c135c6d5>] __mutex_unlock_slowpath+0x59/0x119 softirqs last enabled at (1214): [<c1033316>] __do_softirq+0x1a5/0x1ad softirqs last disabled at (1205): [<c1033354>] do_softirq+0x36/0x5a Pid: 3886, comm: umount.nilfs2 Not tainted 2.6.31-rc6 #55 Call Trace: [<c1023549>] __might_sleep+0x107/0x10e [<c13603c0>] do_page_fault+0x246/0x397 [<c136017a>] ? do_page_fault+0x0/0x397 [<c135e753>] error_code+0x6b/0x70 [<c136017a>] ? do_page_fault+0x0/0x397 [<c104f805>] ? __lock_acquire+0x91/0x12fd [<c1050a62>] ? __lock_acquire+0x12ee/0x12fd [<c1050a62>] ? __lock_acquire+0x12ee/0x12fd [<c1050b2b>] lock_acquire+0xba/0xdd [<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<c135d4fe>] down_write+0x2a/0x46 [<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<d0d17d3f>] nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2] [<c104ea2c>] ? mark_held_locks+0x43/0x5b [<c104ecb1>] ? trace_hardirqs_on_caller+0x10b/0x133 [<c104ece4>] ? trace_hardirqs_on+0xb/0xd [<d0d09ac1>] nilfs_put_super+0x2f/0xca [nilfs2] [<c10b3352>] generic_shutdown_super+0x49/0xb8 [<c10b33de>] kill_block_super+0x1d/0x31 [<c10e6599>] ? vfs_quota_off+0x0/0x12 [<c10b398f>] deactivate_super+0x57/0x6c [<c10c4bc3>] mntput_no_expire+0x8c/0xb4 [<c10c5094>] sys_umount+0x27f/0x2a4 [<c10c50c6>] sys_oldumount+0xd/0xf [<c10031a4>] sysenter_do_call+0x12/0x38 ... This turns out to be a bug brought by an -rc1 patch ("nilfs2: simplify remaining sget() use"). In the patch, a new "put resource" function, nilfs_put_sbinfo() was introduced to delay freeing nilfs_sb_info struct. But the nilfs_put_sbinfo() mistakenly used atomic_dec_and_test() function to check the reference count, and it caused the nilfs_sb_info was freed when user mounted a snapshot twice. This bug also suggests there was unseen memory leak in usual mount /umount operations for nilfs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-06-11nilfs2: get rid of bd_mount_sem use from nilfsRyusuke Konishi
This will remove every bd_mount_sem use in nilfs. The intended exclusion control was replaced by the previous patch ("nilfs2: correct exclusion control in nilfs_remount function") for nilfs_remount(), and this patch will replace remains with a new mutex that this inserts in nilfs object. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11nilfs2: correct exclusion control in nilfs_remount functionRyusuke Konishi
nilfs_remount() changes mount state of a superblock instance. Even though nilfs accesses other superblock instances during mount or remount, the mount state was not properly protected in nilfs_remount(). Moreover, nilfs_remount() has a lock order reversal problem; nilfs_get_sb() holds: 1. bdev->bd_mount_sem 2. sb->s_umount (sget acquires) and nilfs_remount() holds: 1. sb->s_umount (locked by the caller in vfs) 2. bdev->bd_mount_sem To avoid these problems, this patch divides a semaphore protecting super block instances from nilfs->ns_sem, and applies it to the mount state protection in nilfs_remount(). With this change, bd_mount_sem use is removed from nilfs_remount() and the lock order reversal will be resolved. And the new rw-semaphore, nilfs->ns_super_sem will properly protect the mount state except the modification from nilfs_error function. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11nilfs2: simplify remaining sget() useRyusuke Konishi
This simplifies the test function passed on the remaining sget() callsite in nilfs. Instead of checking mount type (i.e. ro-mount/rw-mount/snapshot mount) in the test function passed to sget(), this patch first looks up the nilfs_sb_info struct which the given mount type matches, and then acquires the super block instance holding the nilfs_sb_info. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11nilfs2: get rid of sget use for checking if current mount is presentRyusuke Konishi
This stops using sget() for checking if an r/w-mount or an r/o-mount exists on the device. This elimination uses a back pointer to the current mount added to nilfs object. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11nilfs2: get rid of sget use for acquiring nilfs objectRyusuke Konishi
This will change the way to obtain nilfs object in nilfs_get_sb() function. Previously, a preliminary sget() call was performed, and the nilfs object was acquired from a super block instance found by the sget() call. This patch, instead, instroduces a new dedicated function find_or_create_nilfs(); as the name implies, the function finds an existent nilfs object from a global list or creates a new one if no object is found on the device. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-07nilfs2: introduce secondary super blockRyusuke Konishi
The former versions didn't have extra super blocks. This improves the weak point by introducing another super block at unused region in tail of the partition. This doesn't break disk format compatibility; older versions just ingore the secondary super block, and new versions just recover it if it doesn't exist. The partition created by an old mkfs may not have unused region, but in that case, the secondary super block will not be added. This doesn't make more redundant copies of the super block; it is a future work. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: simplify handling of active state of segmentsRyusuke Konishi
will reduce some lines of segment constructor. Previously, the state was complexly controlled through a list of segments in order to keep consistency in meta data of usage state of segments. Instead, this presents ``calculated'' active flags to userland cleaner program and stop maintaining its real flag on disk. Only by this fake flag, the cleaner cannot exactly know if each segment is reclaimable or not. However, the recent extension of nilfs_sustat ioctl struct (nilfs2-extend-nilfs_sustat-ioctl-struct.patch) can prevent the cleaner from reclaiming in-use segment wrongly. So, now I can apply this for simplification. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: extend nilfs_sustat ioctl structRyusuke Konishi
This adds a new argument to the nilfs_sustat structure. The extended field allows to delete volatile active state of segments, which was needed to protect freshly-created segments from garbage collection but has confused code dealing with segments. This extension alleviates the mess and gives room for further simplifications. The volatile active flag is not persistent, so it's eliminable on this occasion without affecting compatibility other than the ioctl change. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: remove timedwait ioctl commandRyusuke Konishi
This removes NILFS_IOCTL_TIMEDWAIT command from ioctl interface along with the related flags and wait queue. The command is terrible because it just sleeps in the ioctl. I prefer to avoid this by devising means of event polling in userland program. By reconsidering the userland GC daemon, I found this is possible without changing behaviour of the daemon and sacrificing efficiency. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: avoid double error caused by nilfs_transaction_endRyusuke Konishi
Pekka Enberg pointed out that double error handlings found after nilfs_transaction_end() can be avoided by separating abort operation: OK, I don't understand this. The only way nilfs_transaction_end() can fail is if we have NILFS_TI_SYNC set and we fail to construct the segment. But why do we want to construct a segment if we don't commit? I guess what I'm asking is why don't we have a separate nilfs_transaction_abort() function that can't fail for the erroneous case to avoid this double error value tracking thing? This does the separation and renames nilfs_transaction_end() to nilfs_transaction_commit() for clarification. Since, some calls of these functions were used just for exclusion control against the segment constructor, they are replaced with semaphore operations. Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: add inode and other major structuresRyusuke Konishi
This adds the following common structures of the NILFS2 file system. * nilfs_inode_info structure: gives on-memory inode. * nilfs_sb_info structure: keeps per-mount state and a special inode for the ifile. This structure is attached to the super_block structure. * the_nilfs structure: keeps shared state and locks among a read/write mount and snapshot mounts. This keeps special inodes for the sufile, cpfile, dat, and another dat inode used during GC (gcdat). This also has a hash table of dummy inodes to cache disk blocks during GC (gcinodes). * nilfs_transaction_info structure: keeps per task state while nilfs is writing logs or doing indivisible inode or namespace operations. This structure is used to identify context during log making and store nest level of the lock which ensures atomicity of file system operations. Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>