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path: root/fs/nilfs2/page.h
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2013-04-30nilfs2: fix issue with flush kernel thread after remount in RO mode because ↵Vyacheslav Dubeyko
of driver's internal error or metadata corruption The NILFS2 driver remounts itself in RO mode in the case of discovering metadata corruption (for example, discovering a broken bmap). But usually, this takes place when there have been file system operations before remounting in RO mode. Thereby, NILFS2 driver can be in RO mode with presence of dirty pages in modified inodes' address spaces. It results in flush kernel thread's infinite trying to flush dirty pages in RO mode. As a result, it is possible to see such side effects as: (1) flush kernel thread occupies 50% - 99% of CPU time; (2) system can't be shutdowned without manual power switch off. SYMPTOMS: (1) System log contains error message: "Remounting filesystem read-only". (2) The flush kernel thread occupies 50% - 99% of CPU time. (3) The system can't be shutdowned without manual power switch off. REPRODUCTION PATH: (1) Create volume group with name "unencrypted" by means of vgcreate utility. (2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>): ----------------[BEGIN SCRIPT]-------------------- #!/bin/bash VG=unencrypted #apt-get install nilfs-tools darcs lvcreate --size 2G --name ntest $VG mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest mkdir /var/tmp/n mkdir /var/tmp/n/ntest mount /dev/mapper/$VG-ntest /var/tmp/n/ntest mkdir /var/tmp/n/ntest/thedir cd /var/tmp/n/ntest/thedir sleep 2 date darcs init sleep 2 dmesg|tail -n 5 date darcs whatsnew || true date sleep 2 dmesg|tail -n 5 ----------------[END SCRIPT]-------------------- (3) Try to shutdown the system. REPRODUCIBILITY: 100% FIX: This patch implements checking mount state of NILFS2 driver in nilfs_writepage(), nilfs_writepages() and nilfs_mdt_write_page() methods. If it is detected the RO mount state then all dirty pages are simply discarded with warning messages is written in system log. [akpm@linux-foundation.org: fix printk warning] Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Anthony Doggett <Anthony2486@interfaces.org.uk> Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp> Cc: Piotr Szymaniak <szarpaj@grubelek.pl> Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com> Cc: Elmer Zhang <freeboy6716@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-10nilfs2: use mark_buffer_dirty to mark btnode or meta data dirtyRyusuke Konishi
This replaces nilfs_mdt_mark_buffer_dirty and nilfs_btnode_mark_dirty macros with mark_buffer_dirty and gets rid of nilfs_mark_buffer_dirty, an own mark buffer dirty function. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-05-10nilfs2: always set back pointer to host inode in mapping->hostRyusuke Konishi
In the current nilfs, page cache for btree nodes and meta data files do not set a valid back pointer to the host inode in mapping->host. This will change it so that every address space in nilfs uses mapping->host to hold its host inode. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-05-10nilfs2: get rid of private page allocatorRyusuke Konishi
Previously, nilfs was cloning pages for mmapped region to freeze their data and ensure consistency of checksum during writeback cycles. A private page allocator was used for this page cloning. But, we no longer need to do that since clear_page_dirty_for_io function sets up pte so that vm_ops->page_mkwrite function is called right before the mmapped pages are modified and nilfs_page_mkwrite function can safely wait for the pages to be written back to disk. So, this stops making a copy of mmapped pages during writeback, and eliminates the private page allocation and deallocation functions from nilfs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2011-03-10Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe
Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-02-23mm: prevent concurrent unmap_mapping_range() on the same inodeMiklos Szeredi
Michael Leun reported that running parallel opens on a fuse filesystem can trigger a "kernel BUG at mm/truncate.c:475" Gurudas Pai reported the same bug on NFS. The reason is, unmap_mapping_range() is not prepared for more than one concurrent invocation per inode. For example: thread1: going through a big range, stops in the middle of a vma and stores the restart address in vm_truncate_count. thread2: comes in with a small (e.g. single page) unmap request on the same vma, somewhere before restart_address, finds that the vma was already unmapped up to the restart address and happily returns without doing anything. Another scenario would be two big unmap requests, both having to restart the unmapping and each one setting vm_truncate_count to its own value. This could go on forever without any of them being able to finish. Truncate and hole punching already serialize with i_mutex. Other callers of unmap_mapping_range() do not, and it's difficult to get i_mutex protection for all callers. In particular ->d_revalidate(), which calls invalidate_inode_pages2_range() in fuse, may be called with or without i_mutex. This patch adds a new mutex to 'struct address_space' to prevent running multiple concurrent unmap_mapping_range() on the same mapping. [ We'll hopefully get rid of all this with the upcoming mm preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex lockbreak" patch in particular. But that is for 2.6.39 ] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reported-by: Michael Leun <lkml20101129@newton.leun.net> Reported-by: Gurudas Pai <gurudas.pai@oracle.com> Tested-by: Gurudas Pai <gurudas.pai@oracle.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10nilfs2: fiemap supportRyusuke Konishi
This adds fiemap to nilfs. Two new functions, nilfs_fiemap and nilfs_find_uncommitted_extent are added. nilfs_fiemap() implements the fiemap inode operation, and nilfs_find_uncommitted_extent() helps to get a range of data blocks whose physical location has not been determined. nilfs_fiemap() collects extent information by looping through nilfs_bmap_lookup_contig and nilfs_find_uncommitted_extent routines. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: add routines to redirect access to buffers of DAT fileRyusuke Konishi
During garbage collection (GC), DAT file, which converts virtual block number to real block number, may return disk block number that is not yet written to the device. To avoid access to unwritten blocks, the current implementation stores changes to the caches of GCDAT during GC and atomically commit the changes into the DAT file after they are written to the device. This patch, instead, adds a function that makes a copy of specified buffer and stores it in nilfs_shadow_map, and a function to get the backup copy as needed (nilfs_mdt_freeze_buffer and nilfs_mdt_get_frozen_buffer respectively). Before DAT changes block number in an entry block, it makes a copy and redirect access to the buffer so that address conversion function (i.e. nilfs_dat_translate) refers to the old address saved in the copy. This patch gives requisites for such redirection. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-10-23nilfs2: add routines to roll back state of DAT fileRyusuke Konishi
This adds optional function to metadata files which makes a copy of bmap, page caches, and b-tree node cache, and rolls back to the copy as needed. This enhancement is intended to displace gcdat inode that provides a similar function in a different way. In this patch, nilfs_shadow_map structure is added to store a copy of the foregoing states. nilfs_mdt_setup_shadow_map relates this structure to a metadata file. And, nilfs_mdt_save_to_shadow_map() and nilfs_mdt_restore_from_shadow_map() provides save and restore functions respectively. Finally, nilfs_mdt_clear_shadow_map() clears states of nilfs_shadow_map. The copy of b-tree node cache and page cache is made by duplicating only dirty pages into corresponding caches in nilfs_shadow_map. Their restoration is done by clearing dirty pages from original caches and by copying dirty pages back from nilfs_shadow_map. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-07-23nilfs2: introduce check flag to btree node bufferRyusuke Konishi
nilfs_btree_get_block() now may return untested buffer due to read-ahead. This adds a new flag for buffer heads so that the btree code can check whether the buffer is already verified or not. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-04-07nilfs2: buffer and page operationsRyusuke Konishi
This adds common routines for buffer/page operations used in B-tree node caches, meta data files, or segment constructor (log writer). NILFS uses copy functions for buffers and pages due to the following reasons: 1) Relocation required for COW Since NILFS changes address of on-disk blocks, moving buffers in page cache is needed for the buffers which are not addressed by a file offset. If buffer size is smaller than page size, this involves partial copy of pages. 2) Freezing mmapped pages NILFS calculates checksums for each log to ensure its validity. If page data changes after the checksum calculation, this validity check will not work correctly. To avoid this failure for mmaped pages, NILFS freezes their data by copying. 3) Copy-on-write for DAT pages NILFS makes clones of DAT page caches in a copy-on-write manner during GC processes, and this ensures atomicity and consistency of the DAT in the transient state. In addition, NILFS uses two obsolete functions, nilfs_mark_buffer_dirty() and nilfs_clear_page_dirty() respectively. * nilfs_mark_buffer_dirty() was required to avoid NULL pointer dereference faults: Since the page cache of B-tree node pages or data page cache of pseudo inodes does not have a valid mapping->host, calling mark_buffer_dirty() for their buffers causes the fault; it calls __mark_inode_dirty(NULL) through __set_page_dirty(). * nilfs_clear_page_dirty() was needed in the two cases: 1) For B-tree node pages and data pages of the dat/gcdat, NILFS2 clears page dirty flags when it copies back pages from the cloned cache (gcdat->{i_mapping,i_btnode_cache}) to its original cache (dat->{i_mapping,i_btnode_cache}). 2) Some B-tree operations like insertion or deletion may dispose buffers in dirty state, and this needs to cancel the dirty state of their pages. clear_page_dirty_for_io() caused faults because it does not clear the dirty tag on the page cache. Signed-off-by: Seiji Kihara <kihara.seiji@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>