kernel.git/fs/nilfs2/segment.h, branch linux-2.6.34.y

nilfs2: remove spaces before tabs

2010-03-14T01:29:51Z

This kills the following checkpatch warnings: WARNING: please, no space before tabs #74: FILE: segment.h:74: +^Iunsigned ^I^Iflags;$ WARNING: please, no space before tabs #35: FILE: segbuf.c:35: +^Iint ^I^I^Istart, end; /* The region to be submitted */$ Signed-off-by: Ryusuke Konishi

nilfs2: fix various typos in comments

2010-03-14T01:29:51Z

This fixes various typos I found in comments of nilfs2. Signed-off-by: Ryusuke Konishi

nilfs2: get rid of nilfs_segctor_req struct

2010-02-13T03:26:03Z

This will clean up nilfs_segctor_req struct and the obscure request argument passed among private methods of segment constructor. Signed-off-by: Ryusuke Konishi

nilfs2: separate wait function from nilfs_segctor_write

2009-11-30T12:17:52Z

This separates wait function for submitted logs from the write function nilfs_segctor_write(). A new list of segment buffers "sc_write_logs" is added to hold logs under writing, and double buffering is partially applied to hide io latency. At this point, the double buffering is disabled for blocksize < pagesize because page dirty flag is turned off during write and dirty buffers are not properly collected for pages crossing over segments. To receive full benefit of the double buffering, further refinement is needed to move the io wait outside the lock section of log writer. Signed-off-by: Ryusuke Konishi

nilfs2: remove header file for segment list operations

2009-06-10T14:41:09Z

This will eliminate obsolete list operations of nilfs_segment_entry structure which has been used to handle mutiple segment numbers. The patch ("nilfs2: remove list of freeing segments") removed use of the structure from the segment constructor code, and this patch simplifies the remaining code by integrating it into recovery.c. Signed-off-by: Ryusuke Konishi

nilfs2: eliminate removal list of segments

2009-06-10T14:41:09Z

This will clean up the removal list of segments and the related functions from segment.c and ioctl.c, which have hurt code readability. This elimination is applied by using nilfs_sufile_updatev() previously introduced in the patch ("nilfs2: add sufile function that can modify multiple segment usages"). Signed-off-by: Ryusuke Konishi

nilfs2: fix lock order reversal in nilfs_clean_segments ioctl

2009-05-11T05:54:41Z

This is a companion patch to ("nilfs2: fix possible circular locking for get information ioctls"). This corrects lock order reversal between mm->mmap_sem and nilfs->ns_segctor_sem in nilfs_clean_segments() which was detected by lockdep check: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.30-rc3-nilfs-00003-g360bdc1 #7 ------------------------------------------------------- mmap/5294 is trying to acquire lock: (&nilfs->ns_segctor_sem){++++.+}, at: [] nilfs_transaction_begin+0xb6/0x10c [nilfs2] but task is already holding lock: (&mm->mmap_sem){++++++}, at: [] do_page_fault+0x1d8/0x30a which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem){++++++}: [] __lock_acquire+0x1066/0x13b0 [] lock_acquire+0xba/0xdd [] might_fault+0x68/0x88 [] copy_from_user+0x2a/0x111 [] nilfs_ioctl_prepare_clean_segments+0x1d/0xf1 [nilfs2] [] nilfs_clean_segments+0x6d/0x1b9 [nilfs2] [] nilfs_ioctl+0x2ad/0x318 [nilfs2] [] vfs_ioctl+0x22/0x69 [] do_vfs_ioctl+0x460/0x499 [] sys_ioctl+0x40/0x5a [] sysenter_do_call+0x12/0x38 [] 0xffffffff -> #0 (&nilfs->ns_segctor_sem){++++.+}: [] __lock_acquire+0xdcc/0x13b0 [] lock_acquire+0xba/0xdd [] down_read+0x2a/0x3e [] nilfs_transaction_begin+0xb6/0x10c [nilfs2] [] nilfs_page_mkwrite+0xe7/0x154 [nilfs2] [] __do_fault+0x165/0x376 [] handle_mm_fault+0x287/0x5d1 [] do_page_fault+0x2fb/0x30a [] error_code+0x72/0x78 [] 0xffffffff where nilfs_clean_segments() holds: nilfs->ns_segctor_sem -> copy_from_user() --> page fault -> mm->mmap_sem And, page fault path may hold: page fault -> mm->mmap_sem --> nilfs_page_mkwrite() -> nilfs->ns_segctor_sem Even though nilfs_clean_segments() does not perform write access on given user pages, it may cause deadlock because nilfs->ns_segctor_sem is shared per device and mm->mmap_sem can be shared with other tasks. To avoid this problem, this patch moves all calls of copy_from_user() outside the nilfs->ns_segctor_sem lock in the ioctl. Signed-off-by: Ryusuke Konishi

nilfs2: introduce secondary super block

2009-04-07T15:31:20Z

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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: simplify handling of active state of segments

2009-04-07T15:31:20Z

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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: mark minor flag for checkpoint created by internal operation

2009-04-07T15:31:19Z

Nilfs creates checkpoints even for garbage collection or metadata updates such as checkpoint mode change. So, user often sees checkpoints created only by such internal operations. This is inconvenient in some situations. For example, application that monitors checkpoints and changes them to snapshots, will fall into an infinite loop because it cannot distinguish internally created checkpoints. This patch solves this sort of problem by adding a flag to checkpoint for identification. Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds