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2010-11-20ext4: Add EXT4_IOC_TRIM ioctl to handle batched discardLukas Czerner
Filesystem independent ioctl was rejected as not common enough to be in core vfs ioctl. Since we still need to access to this functionality this commit adds ext4 specific ioctl EXT4_IOC_TRIM to dispatch ext4_trim_fs(). It takes fstrim_range structure as an argument. fstrim_range is definec in the include/linux/fs.h and its definition is as follows. struct fstrim_range { __u64 start; __u64 len; __u64 minlen; } start - first Byte to trim len - number of Bytes to trim from start minlen - minimum extent length to trim, free extents shorter than this number of Bytes will be ignored. This will be rounded up to fs block size. After the FITRIM is done, the number of actually discarded Bytes is stored in fstrim_range.len to give the user better insight on how much storage space has been really released for wear-leveling. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-20fs: Do not dispatch FITRIM through separate super_operationLukas Czerner
There was concern that FITRIM ioctl is not common enough to be included in core vfs ioctl, as Christoph Hellwig pointed out there's no real point in dispatching this out to a separate vector instead of just through ->ioctl. So this commit removes ioctl_fstrim() from vfs ioctl and trim_fs from super_operation structure. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-19ext4: ext4_fill_super shouldn't return 0 on corruptionDarrick J. Wong
At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path out of that function returns ret. However, the generic_check_addressable clause sets ret = 0 (if it passes), which means that a subsequent failure (e.g. a group checksum error) returns 0 even though the mount should fail. This causes vfs_kern_mount in turn to think that the mount succeeded, leading to an oops. A simple fix is to avoid using ret for the generic_check_addressable check, which was last changed in commit 30ca22c70e3ef0a96ff84de69cd7e8561b416cb2. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-18ext4: missing unlock in ext4_clear_request_list()Dan Carpenter
If the the li_request_list was empty then it returned with the lock held. Instead of adding a "goto unlock" I just removed that special case and let it go past the empty list_for_each_safe(). Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-18ext4: fix setting random pages PageUptodateMarkus Trippelsdorf
ext4_end_bio calls put_page and kmem_cache_free before calling SetPageUpdate(). This can result in setting the PageUptodate bit on random pages and causes the following BUG: BUG: Bad page state in process rm pfn:52e54 page:ffffea0001222260 count:0 mapcount:0 mapping: (null) index:0x0 arch kernel: page flags: 0x4000000000000008(uptodate) Fix the problem by moving put_io_page() after the SetPageUpdate() call. Thanks to Hugh Dickins for analyzing this problem. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-08Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: Add new ext4 inode tracepoints ext4: Don't call sb_issue_discard() in ext4_free_blocks() ext4: do not try to grab the s_umount semaphore in ext4_quota_off ext4: fix potential race when freeing ext4_io_page structures ext4: handle writeback of inodes which are being freed ext4: initialize the percpu counters before replaying the journal ext4: "ret" may be used uninitialized in ext4_lazyinit_thread() ext4: fix lazyinit hang after removing request
2010-11-08ext4: Add new ext4 inode tracepointsTheodore Ts'o
Add ext4_evict_inode, ext4_drop_inode, ext4_mark_inode_dirty, and ext4_begin_ordered_truncate() Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-08ext4: Don't call sb_issue_discard() in ext4_free_blocks()Theodore Ts'o
Commit 5c521830cf (ext4: Support discard requests when running in no-journal mode) attempts to add sb_issue_discard() for data blocks (in data=writeback mode) and in no-journal mode. Unfortunately, this no longer works, because in commit dd3932eddf (block: remove BLKDEV_IFL_WAIT), sb_issue_discard() only presents a synchronous interface, and there are times when we call ext4_free_blocks() when we are are holding a spinlock, or are otherwise in an atomic context. For now, I've removed the call to sb_issue_discard() to prevent a deadlock or (if spinlock debugging is enabled) failures like this: BUG: scheduling while atomic: rc.sysinit/1376/0x00000002 Pid: 1376, comm: rc.sysinit Not tainted 2.6.36-ARCH #1 Call Trace: [<ffffffff810397ce>] __schedule_bug+0x5e/0x70 [<ffffffff81403110>] schedule+0x950/0xa70 [<ffffffff81060bad>] ? insert_work+0x7d/0x90 [<ffffffff81060fbd>] ? queue_work_on+0x1d/0x30 [<ffffffff81061127>] ? queue_work+0x37/0x60 [<ffffffff8140377d>] schedule_timeout+0x21d/0x360 [<ffffffff812031c3>] ? generic_make_request+0x2c3/0x540 [<ffffffff81402680>] wait_for_common+0xc0/0x150 [<ffffffff81041490>] ? default_wake_function+0x0/0x10 [<ffffffff812034bc>] ? submit_bio+0x7c/0x100 [<ffffffff810680a0>] ? wake_bit_function+0x0/0x40 [<ffffffff814027b8>] wait_for_completion+0x18/0x20 [<ffffffff8120a969>] blkdev_issue_discard+0x1b9/0x210 [<ffffffff811ba03e>] ext4_free_blocks+0x68e/0xb60 [<ffffffff811b1650>] ? __ext4_handle_dirty_metadata+0x110/0x120 [<ffffffff811b098c>] ext4_ext_truncate+0x8cc/0xa70 [<ffffffff810d713e>] ? pagevec_lookup+0x1e/0x30 [<ffffffff81191618>] ext4_truncate+0x178/0x5d0 [<ffffffff810eacbb>] ? unmap_mapping_range+0xab/0x280 [<ffffffff810d8976>] vmtruncate+0x56/0x70 [<ffffffff811925cb>] ext4_setattr+0x14b/0x460 [<ffffffff811319e4>] notify_change+0x194/0x380 [<ffffffff81117f80>] do_truncate+0x60/0x90 [<ffffffff811e08fa>] ? security_inode_permission+0x1a/0x20 [<ffffffff811eaec1>] ? tomoyo_path_truncate+0x11/0x20 [<ffffffff81127539>] do_last+0x5d9/0x770 [<ffffffff811278bd>] do_filp_open+0x1ed/0x680 [<ffffffff8140644f>] ? page_fault+0x1f/0x30 [<ffffffff81132bfc>] ? alloc_fd+0xec/0x140 [<ffffffff81118db1>] do_sys_open+0x61/0x120 [<ffffffff81118e8b>] sys_open+0x1b/0x20 [<ffffffff81002e6b>] system_call_fastpath+0x16/0x1b https://bugzilla.kernel.org/show_bug.cgi?id=22302 Reported-by: Mathias Burén <mathias.buren@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: jiayingz@google.com
2010-11-08ext4: do not try to grab the s_umount semaphore in ext4_quota_offDmitry Monakhov
It's not needed to sync the filesystem, and it fixes a lock_dep complaint. Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2010-11-08ext4: fix potential race when freeing ext4_io_page structuresTheodore Ts'o
Use an atomic_t and make sure we don't free the structure while we might still be submitting I/O for that page. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-08ext4: handle writeback of inodes which are being freedTheodore Ts'o
The following BUG can occur when an inode which is getting freed when it still has dirty pages outstanding, and it gets deleted (in this because it was the target of a rename). In ordered mode, we need to make sure the data pages are written just in case we crash before the rename (or unlink) is committed. If the inode is being freed then when we try to igrab the inode, we end up tripping the BUG_ON at fs/ext4/page-io.c:146. To solve this problem, we need to keep track of the number of io callbacks which are pending, and avoid destroying the inode until they have all been completed. That way we don't have to bump the inode count to keep the inode from being destroyed; an approach which doesn't work because the count could have already been dropped down to zero before the inode writeback has started (at which point we're not allowed to bump the count back up to 1, since it's already started getting freed). Thanks to Dave Chinner for suggesting this approach, which is also used by XFS. kernel BUG at /scratch_space/linux-2.6/fs/ext4/page-io.c:146! Call Trace: [<ffffffff811075b1>] ext4_bio_write_page+0x172/0x307 [<ffffffff811033a7>] mpage_da_submit_io+0x2f9/0x37b [<ffffffff811068d7>] mpage_da_map_and_submit+0x2cc/0x2e2 [<ffffffff811069b3>] mpage_add_bh_to_extent+0xc6/0xd5 [<ffffffff81106c66>] write_cache_pages_da+0x2a4/0x3ac [<ffffffff81107044>] ext4_da_writepages+0x2d6/0x44d [<ffffffff81087910>] do_writepages+0x1c/0x25 [<ffffffff810810a4>] __filemap_fdatawrite_range+0x4b/0x4d [<ffffffff810815f5>] filemap_fdatawrite_range+0xe/0x10 [<ffffffff81122a2e>] jbd2_journal_begin_ordered_truncate+0x7b/0xa2 [<ffffffff8110615d>] ext4_evict_inode+0x57/0x24c [<ffffffff810c14a3>] evict+0x22/0x92 [<ffffffff810c1a3d>] iput+0x212/0x249 [<ffffffff810bdf16>] dentry_iput+0xa1/0xb9 [<ffffffff810bdf6b>] d_kill+0x3d/0x5d [<ffffffff810be613>] dput+0x13a/0x147 [<ffffffff810b990d>] sys_renameat+0x1b5/0x258 [<ffffffff81145f71>] ? _atomic_dec_and_lock+0x2d/0x4c [<ffffffff810b2950>] ? cp_new_stat+0xde/0xea [<ffffffff810b29c1>] ? sys_newlstat+0x2d/0x38 [<ffffffff810b99c6>] sys_rename+0x16/0x18 [<ffffffff81002a2b>] system_call_fastpath+0x16/0x1b Reported-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Tested-by: Nick Bowler <nbowler@elliptictech.com>
2010-11-03ext4: initialize the percpu counters before replaying the journalTheodore Ts'o
We now initialize the percpu counters before replaying the journal, but after the journal, we recalculate the global counters, to deal with the possibility of the per-blockgroup counts getting updated by the journal replay. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-02ext4: "ret" may be used uninitialized in ext4_lazyinit_thread()Theodore Ts'o
Newer GCC's reported the following build warning: fs/ext4/super.c: In function 'ext4_lazyinit_thread': fs/ext4/super.c:2702: warning: 'ret' may be used uninitialized in this function Fix it by removing the need for the ret variable in the first place. Signed-off-by: "Lukas Czerner" <lczerner@redhat.com> Reported-by: "Stefan Richter" <stefanr@s5r6.in-berlin.de> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-02ext4: fix lazyinit hang after removing requestLukas Czerner
When the request has been removed from the list and no other request has been issued, we will end up with next wakeup scheduled to MAX_JIFFY_OFFSET which is bad. So check for that. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-11-02ext4: Remove useless spinlock in ext4_getattr()Theodore Ts'o
Linus noted, and complained to me, that doing while lots of "git diff"'s of kernel sources, these spinlocks were responsible for 27% of the spinlock cost on his two-processor system as reported by perf. Git was doing lots of parallel stats, and this was putting a lot of pressure on ext4_getattr(). A spinlock to protect a single memory-to-memory copy is pointless, so remove it. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-29new helper: mount_bdev()Al Viro
... and switch of the obvious get_sb_bdev() users to ->mount() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-28Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: BUG_ON fix: check if page has buffers before calling page_buffers()
2010-10-28ext4: BUG_ON fix: check if page has buffers before calling page_buffers() Theodore Ts'o
We need to make check if a page does not have buffes by checking page_has_buffers(page) before calling page_buffers(page) in ext4_writepage(). Otherwise page_buffers() could throw a BUG_ON. Thanks also to Markus Trippelsdorf and Avinash Kurup who also reported the problem. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Sedat Dilek <sedat.dilek@googlemail.com> Tested-by: Sedat Dilek <sedat.dilek@googlemail.com>
2010-10-28ext4: fix compile with CONFIG_EXT4_FS_XATTR disabledIngo Molnar
Commit 5dabfc78dced ("ext4: rename {exit,init}_ext4_*() to ext4_{exit,init}_*()") causes fs/ext4/super.c:4776: error: implicit declaration of function ‘ext4_init_xattr’ when CONFIG_EXT4_FS_XATTR is disabled. It renamed init_ext4_xattr to ext4_init_xattr but forgot to update the dummy definition in fs/ext4/xattr.h. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28Merge branch 'next' into upstream-mergeTheodore Ts'o
Conflicts: fs/ext4/inode.c fs/ext4/mballoc.c include/trace/events/ext4.h
2010-10-28ext4: optimize orphan_list handling for ext4_setattrDmitry Monakhov
Surprisingly chown() on ext4 is not SMP scalable operation. Due to unconditional orphan_del(NULL, inode) in ext4_setattr() result in significant performance overhead because of global orphan mutex, especially in no-journal mode (where orphan_add() is noop). It is possible to skip explicit orphan_del if possible. Results of fchown() micro-benchmark in no-journal mode while (1) { iteration++; fchown(fd, uid, gid); fchown(fd, uid + 1, gid + 1) } measured: iterations per millisecond | nr_tasks | w/o patch | with patch | | 1 | 142 | 185 | | 4 | 109 | 642 | Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: fix unbalanced mutex unlock in error path of ext4_li_request_newNicolas Kaiser
Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: fix compile error in ext4_fallocate()Kazuya Mio
When I compiled 2.6.36-rc3 kernel with EXT4FS_DEBUG definition, I got the following compile error. CC [M] fs/ext4/extents.o fs/ext4/extents.c: In function 'ext4_fallocate': fs/ext4/extents.c:3772: error: 'block' undeclared (first use in this function) fs/ext4/extents.c:3772: error: (Each undeclared identifier is reported only once fs/ext4/extents.c:3772: error: for each function it appears in.) make[2]: *** [fs/ext4/extents.o] Error 1 The patch fixes this problem. Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: move ext4_mb_{get,put}_buddy_cache_lock and make them staticEric Sandeen
These functions are only used within fs/ext4/mballoc.c, so move them so they are used after they are defined, and then make them be static. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: rename mark_bitmap_end() to ext4_mark_bitmap_end()Theodore Ts'o
Fix a namespace leak from fs/ext4 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: move flush_completed_IO to fs/ext4/fsync.c and make it staticTheodore Ts'o
Fix a namespace leak by moving the function to the file where it is used and making it static. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: rename {ext,idx}_pblock and inline small extent functionsTheodore Ts'o
Cleanup namespace leaks from fs/ext4 and the inline trivial functions ext4_{ext,idx}_pblock() and ext4_{ext,idx}_store_pblock() since the code size actually shrinks when we make these functions inline, they're so trivial. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: make various ext4 functions be staticTheodore Ts'o
These functions have no need to be exported beyond file context. No functions needed to be moved for this commit; just some function declarations changed to be static and removed from header files. (A similar patch was submitted by Eric Sandeen, but I wanted to handle code movement in separate patches to make sure code changes didn't accidentally get dropped.) Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: rename {exit,init}_ext4_*() to ext4_{exit,init}_*()Theodore Ts'o
This is a cleanup to avoid namespace leaks out of fs/ext4 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: fix kernel oops if the journal superblock has a non-zero j_errnoTheodore Ts'o
Commit 84061e0 fixed an accounting bug only to introduce the possibility of a kernel OOPS if the journal has a non-zero j_errno field indicating that the file system had detected a fs inconsistency. After the journal replay, if the journal superblock indicates that the file system has an error, this indication is transfered to the file system and then ext4_commit_super() is called to write this to the disk. But since the percpu counters are now initialized after the journal replay, the call to ext4_commit_super() will cause a kernel oops since it needs to use the percpu counters the ext4 superblock structure. The fix is to skip setting the ext4 free block and free inode fields if the percpu counter has not been set. Thanks to Ken Sumrall for reporting and analyzing the root causes of this bug. Addresses-Google-Bug: #3054080 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: update writeback_index based on last page scannedEric Sandeen
As pointed out in a prior patch, updating the mapping's writeback_index based on pages written isn't quite right; what the writeback index is really supposed to reflect is the next page which should be scanned for writeback during periodic flush. As in write_cache_pages(), write_cache_pages_da() does this scanning for us as we assemble the mpd for later writeout. If we keep track of the next page after the current scan, we can easily update writeback_index without worrying about pages written vs. pages skipped, etc. Without this, an fsync will reset writeback_index to 0 (its starting index) + however many pages it wrote, which can mess up the progress of periodic flush. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: implement writeback livelock avoidance using page taggingEric Sandeen
This is analogous to Jan Kara's commit, f446daaea9d4a420d16c606f755f3689dcb2d0ce mm: implement writeback livelock avoidance using page tagging but since we forked write_cache_pages, we need to reimplement it there (and in ext4_da_writepages, since range_cyclic handling was moved to there) If you start a large buffered IO to a file, and then set fsync after it, you'll find that fsync does not complete until the other IO stops. If you continue re-dirtying the file (say, putting dd with conv=notrunc in a loop), when fsync finally completes (after all IO is done), it reports via tracing that it has written many more pages than the file contains; in other words it has synced and re-synced pages in the file multiple times. This then leads to problems with our writeback_index update, since it advances it by pages written, and essentially sets writeback_index off the end of the file... With the following patch, we only sync as much as was dirty at the time of the sync. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: tidy up a void argument in inode.cEric Sandeen
This doesn't fix anything at all, it just removes a vestige of prior use from __mpage_da_writepage() __mpage_da_writepage() had a *void argument leftover from its previous life as a callback; make it reflect the actual type. Fixing this up makes it slightly more obvious to read, and enables proper typechecking. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: add batched_discard into ext4 feature listLukas Czerner
Should be applied on the top of "lazy inode table initialization" and "batched discard support" patch-sets. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: Add batched discard support for ext4Lukas Czerner
Walk through allocation groups and trim all free extents. It can be invoked through FITRIM ioctl on the file system. The main idea is to provide a way to trim the whole file system if needed, since some SSD's may suffer from performance loss after the whole device was filled (it does not mean that fs is full!). It search for free extents in allocation groups specified by Byte range start -> start+len. When the free extent is within this range, blocks are marked as used and then trimmed. Afterwards these blocks are marked as free in per-group bitmap. Since fstrim is a long operation it is good to have an ability to interrupt it by a signal. This was added by Dmitry Monakhov. Thanks Dimitry. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: Use return value from sb_issue_discard()Lukas Czerner
Use return value from sb_issue_discard() as return value in ext4_issue_discard(). Since sb_issue_discard() may result in more serious errors than just -EOPNOTSUPP it is worth to inform user of this function about them to handle error cases properly. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: Check return value of sb_getblk() and friendsNamhyung Kim
Fail block allocation if sb_getblk() returns NULL. In that case, sb_find_get_block() also likely to fail so that it should skip calling ext4_forget(). Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: use bio layer instead of buffer layer in mpage_da_submit_ioTheodore Ts'o
Call the block I/O layer directly instad of going through the buffer layer. This should give us much better performance and scalability, as well as lowering our CPU utilization when doing buffered writeback. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: move mpage_put_bnr_to_bhs()'s functionality to mpage_da_submit_io()Theodore Ts'o
This massively simplifies the ext4_da_writepages() code path by completely removing mpage_put_bnr_bhs(), which is almost 100 lines of code iterating over a set of pages using pagevec_lookup(), and folds that functionality into mpage_da_submit_io()'s existing pagevec_lookup() loop. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: inline walk_page_buffers() into mpage_da_submit_ioTheodore Ts'o
Expand the call: if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, ext4_bh_delay_or_unwritten)) goto redirty_page into mpage_da_submit_io(). This will allow us to merge in mpage_put_bnr_to_bhs() in the next patch. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: inline ext4_writepage() into mpage_da_submit_io()Theodore Ts'o
As a prepratory step to switching to bio_submit, inline ext4_writepage() into mpage_da_submit() and then simplify things a bit. This makes it clearer what mpage_da_submit needs to do. Also, move the ClearPageChecked(page) call into __ext4_journalled_writepage(), as a minor bit of cleanup refactoring. This also allows us to pull i_size_read() and ext4_should_journal_data() out of the loop, which should be a very minor CPU savings. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: simplify ext4_writepage()Theodore Ts'o
The actual code in ext4_writepage() is unnecessarily convoluted. Simplify it so it is easier to understand, but otherwise logically equivalent. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: call mpage_da_submit_io() from mpage_da_map_blocks()Theodore Ts'o
Eventually we need to completely reorganize the ext4 writepage callpath, but for now, we simplify things a little by calling mpage_da_submit_io() from mpage_da_map_blocks(), since all of the places where we call mpage_da_map_blocks() it is followed up by a call to mpage_da_submit_io(). We're also a wee bit better with respect to error handling, but there are still a number of issues where it's not clear what the right thing is to do with ext4 functions deep in the writeback codepath fails. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: use KMEM_CACHE instead of kmem_cache_createTheodore Ts'o
Also remove the SLAB_RECLAIM_ACCOUNT flag from the system zone kmem cache. This slab tends to be fairly static, so it shouldn't be marked as likely to have free pages that can be reclaimed. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: use search_dirblock() in ext4_dx_find_entry()Theodore Ts'o
Use the search_dirblock() in ext4_dx_find_entry(). It makes the code easier to read, and it takes advantage of common code. It also saves 100 bytes or so of text space. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Brad Spengler <spender@grsecurity.net>
2010-10-28ext4: avoid uninitialized memory references in ext3_htree_next_block()Theodore Ts'o
If the first block of htree directory is missing '.' or '..' but is otherwise a valid directory, and we do a lookup for '.' or '..', it's possible to dereference an uninitialized memory pointer in ext4_htree_next_block(). We avoid this by moving the special case from ext4_dx_find_entry() to ext4_find_entry(); this also means we can optimize ext4_find_entry() slightly when NFS looks up "..". Thanks to Brad Spengler for pointing a Clang warning that led me to look more closely at this code. The warning was harmless, but it was useful in pointing out code that was too ugly to live. This warning was also reported by Roman Borisov. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Brad Spengler <spender@grsecurity.net>
2010-10-28ext4: remove unused ext4_sb_info membersEric Sandeen
Not that these take up a lot of room, but the structure is long enough as it is, and there's no need to confuse people with these various undocumented & unused structure members... Signed-off-by: Eric Sandeen <sandeen@redaht.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: queue conversion after adding to inode's completed IO listEric Sandeen
By queuing the io end on the unwritten workqueue before adding it to our inode's list of completed IOs, I think we run the risk of the work getting completed, and the IO freed, before we try to add it to the inode's i_completed_io_list. It should be safe to add it to the inode's list of completed IOs, and -then- queue it for completion, I think. Thanks to Dave Chinner for pointing out the race. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: don't use ext4_allocation_contexts for tracingEric Sandeen
Many tracepoints were populating an ext4_allocation_context to pass in, but this requires a slab allocation even when tracepoints are off. In fact, 4 of 5 of these allocations were only for tracing. In addition, we were only using a small fraction of the 144 bytes of this structure for this purpose. We can do away with all these alloc/frees of the ac and simply pass in the bits we care about, instead. I tested this by turning on tracing and running through xfstests on x86_64. I did not actually do anything with the trace output, however. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28ext4: fix potential infinite loop in ext4_da_writepages()Toshiyuki Okajima
On linux-2.6.36-rc2, if we execute the following script, we can hang the system when the /bin/sync command is executed: ======================================================================== #!/bin/sh echo -n "HANG UP TEST: " /bin/dd if=/dev/zero of=/tmp/img bs=1k count=1 seek=1M 2> /dev/null /sbin/mkfs.ext4 -Fq /tmp/img /bin/mount -o loop -t ext4 /tmp/img /mnt /bin/dd if=/dev/zero of=/mnt/file bs=1 count=1 \ seek=$((16*1024*1024*1024*1024-4096)) 2> /dev/null /bin/sync /bin/umount /mnt echo "DONE" exit 0 ======================================================================== We can see the following backtrace if we get the kdump when this hangup occurs: ====================================================================== kthread() => bdi_writeback_thread() => wb_do_writeback() => wb_writeback() => writeback_inodes_wb() => writeback_sb_inodes() => writeback_single_inode() => ext4_da_writepages() ---+ ^ infinite | | loop | +-------------+ ====================================================================== The reason why this hangup happens is described as follows: 1) We write the last extent block of the file whose size is the filesystem maximum size. 2) "BH_Delay" flag is set on the buffer_head of its block. 3) - the member, "m_lblk" of struct mpage_da_data is 4294967295 (UINT_MAX) - the member, "m_len" of struct mpage_da_data is 1 mpage_put_bnr_to_bhs() which is called via ext4_da_writepages() cannot clear "BH_Delay" flag of the buffer_head because the type of m_lblk is ext4_lblk_t and then m_lblk + m_len is overflow. Therefore an infinite loop occurs because ext4_da_writepages() cannot write the page (which corresponds to the block) since "BH_Delay" flag isn't cleared. ---------------------------------------------------------------------- static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, struct ext4_map_blocks *map) { ... int blocks = map->m_len; ... do { // cur_logical = 4294967295 // map->m_lblk = 4294967295 // blocks = 1 // *** map->m_lblk + blocks == 0 (OVERFLOW!) *** // (cur_logical >= map->m_lblk + blocks) => true if (cur_logical >= map->m_lblk + blocks) break; ---------------------------------------------------------------------- NOTE: Mounting with the nodelalloc option will avoid this codepath, and thus, avoid this hang Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>