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2013-07-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second set of VFS changes from Al Viro: "Assorted f_pos race fixes, making do_splice_direct() safe to call with i_mutex on parent, O_TMPFILE support, Jeff's locks.c series, ->d_hash/->d_compare calling conventions changes from Linus, misc stuff all over the place." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) Document ->tmpfile() ext4: ->tmpfile() support vfs: export lseek_execute() to modules lseek_execute() doesn't need an inode passed to it block_dev: switch to fixed_size_llseek() cpqphp_sysfs: switch to fixed_size_llseek() tile-srom: switch to fixed_size_llseek() proc_powerpc: switch to fixed_size_llseek() ubi/cdev: switch to fixed_size_llseek() pci/proc: switch to fixed_size_llseek() isapnp: switch to fixed_size_llseek() lpfc: switch to fixed_size_llseek() locks: give the blocked_hash its own spinlock locks: add a new "lm_owner_key" lock operation locks: turn the blocked_list into a hashtable locks: convert fl_link to a hlist_node locks: avoid taking global lock if possible when waking up blocked waiters locks: protect most of the file_lock handling with i_lock locks: encapsulate the fl_link list handling locks: make "added" in __posix_lock_file a bool ...
2013-07-03ext4: ->tmpfile() supportAl Viro
very similar to ext3 counterpart... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-03vfs: export lseek_execute() to modulesJie Liu
For those file systems(btrfs/ext4/ocfs2/tmpfs) that support SEEK_DATA/SEEK_HOLE functions, we end up handling the similar matter in lseek_execute() to update the current file offset to the desired offset if it is valid, ceph also does the simliar things at ceph_llseek(). To reduce the duplications, this patch make lseek_execute() public accessible so that we can call it directly from the underlying file systems. Thanks Dave Chinner for this suggestion. [AV: call it vfs_setpos(), don't bring the removed 'inode' argument back] v2->v1: - Add kernel-doc comments for lseek_execute() - Call lseek_execute() in ceph->llseek() Signed-off-by: Jie Liu <jeff.liu@oracle.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Mason <chris.mason@fusionio.com> Cc: Josef Bacik <jbacik@fusionio.com> Cc: Ben Myers <bpm@sgi.com> Cc: Ted Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Sage Weil <sage@inktank.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-02Merge tag 'ext4_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 update from Ted Ts'o: "Lots of bug fixes, cleanups and optimizations. In the bug fixes category, of note is a fix for on-line resizing file systems where the block size is smaller than the page size (i.e., file systems 1k blocks on x86, or more interestingly file systems with 4k blocks on Power or ia64 systems.) In the cleanup category, the ext4's punch hole implementation was significantly improved by Lukas Czerner, and now supports bigalloc file systems. In addition, Jan Kara significantly cleaned up the write submission code path. We also improved error checking and added a few sanity checks. In the optimizations category, two major optimizations deserve mention. The first is that ext4_writepages() is now used for nodelalloc and ext3 compatibility mode. This allows writes to be submitted much more efficiently as a single bio request, instead of being sent as individual 4k writes into the block layer (which then relied on the elevator code to coalesce the requests in the block queue). Secondly, the extent cache shrink mechanism, which was introduce in 3.9, no longer has a scalability bottleneck caused by the i_es_lru spinlock. Other optimizations include some changes to reduce CPU usage and to avoid issuing empty commits unnecessarily." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (86 commits) ext4: optimize starting extent in ext4_ext_rm_leaf() jbd2: invalidate handle if jbd2_journal_restart() fails ext4: translate flag bits to strings in tracepoints ext4: fix up error handling for mpage_map_and_submit_extent() jbd2: fix theoretical race in jbd2__journal_restart ext4: only zero partial blocks in ext4_zero_partial_blocks() ext4: check error return from ext4_write_inline_data_end() ext4: delete unnecessary C statements ext3,ext4: don't mess with dir_file->f_pos in htree_dirblock_to_tree() jbd2: move superblock checksum calculation to jbd2_write_superblock() ext4: pass inode pointer instead of file pointer to punch hole ext4: improve free space calculation for inline_data ext4: reduce object size when !CONFIG_PRINTK ext4: improve extent cache shrink mechanism to avoid to burn CPU time ext4: implement error handling of ext4_mb_new_preallocation() ext4: fix corruption when online resizing a fs with 1K block size ext4: delete unused variables ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extents jbd2: remove debug dependency on debug_fs and update Kconfig help text jbd2: use a single printk for jbd_debug() ...
2013-07-01ext4: optimize starting extent in ext4_ext_rm_leaf()Ashish Sangwan
Both hole punch and truncate use ext4_ext_rm_leaf() for removing blocks. Currently we choose the last extent as the starting point for removing blocks: ex = EXT_LAST_EXTENT(eh); This is OK for truncate but for hole punch we can optimize the extent selection as the path is already initialized. We could use this information to select proper starting extent. The code change in this patch will not affect truncate as for truncate path[depth].p_ext will always be NULL. Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: translate flag bits to strings in tracepointsTheodore Ts'o
Translate the bitfields used in various flags argument to strings to make the tracepoint output more human-readable. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: fix up error handling for mpage_map_and_submit_extent()Theodore Ts'o
The function mpage_released_unused_page() must only be called once; otherwise the kernel will BUG() when the second call to mpage_released_unused_page() tries to unlock the pages which had been unlocked by the first call. Also restructure the error handling so that we only give up on writing the dirty pages in the case of ENOSPC where retrying the allocation won't help. Otherwise, a transient failure, such as a kmalloc() failure in calling ext4_map_blocks() might cause us to give up on those pages, leading to a scary message in /var/log/messages plus data loss. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2013-07-01ext4: only zero partial blocks in ext4_zero_partial_blocks()Lukas Czerner
Currently if we pass range into ext4_zero_partial_blocks() which covers entire block we would attempt to zero it even though we should only zero unaligned part of the block. Fix this by checking whether the range covers the whole block skip zeroing if so. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: check error return from ext4_write_inline_data_end()Theodore Ts'o
The function ext4_write_inline_data_end() can return an error. So we need to assign it to a signed integer variable to check for an error return (since copied is an unsigned int). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Zheng Liu <wenqing.lz@taobao.com> Cc: stable@vger.kernel.org
2013-07-01ext4: delete unnecessary C statementsjon ernst
Comparing unsigned variable with 0 always returns false. err = 0 is duplicated and unnecessary. [ tytso: Also cleaned up error handling in ext4_block_zero_page_range() ] Signed-off-by: "Jon Ernst" <jonernst07@gmx.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext3,ext4: don't mess with dir_file->f_pos in htree_dirblock_to_tree()Al Viro
Both ext3 and ext4 htree_dirblock_to_tree() is just filling the in-core rbtree for use by call_filldir(). All updates of ->f_pos are done by the latter; bumping it here (on error) is obviously wrong - we might very well have it nowhere near the block we'd found an error in. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2013-07-01ext4: pass inode pointer instead of file pointer to punch holeAshish Sangwan
No need to pass file pointer when we can directly pass inode pointer. Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: improve free space calculation for inline_databoxi liu
In ext4 feature inline_data,it use the xattr's space to store the inline data in inode.When we calculate the inline data as the xattr,we add the pad.But in get_max_inline_xattr_value_size() function we count the free space without pad.It cause some contents are moved to a block even if it can be stored in the inode. Signed-off-by: liulei <lewis.liulei@huawei.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Tao Ma <boyu.mt@taobao.com>
2013-07-01ext4: reduce object size when !CONFIG_PRINTKJoe Perches
Reduce the object size ~10% could be useful for embedded systems. Add #ifdef CONFIG_PRINTK #else #endif blocks to hold formats and arguments, passing " " to functions when !CONFIG_PRINTK and still verifying format and arguments with no_printk. $ size fs/ext4/built-in.o* text data bss dec hex filename 239375 610 888 240873 3ace9 fs/ext4/built-in.o.new 264167 738 888 265793 40e41 fs/ext4/built-in.o.old $ grep -E "CONFIG_EXT4|CONFIG_PRINTK" .config # CONFIG_PRINTK is not set CONFIG_EXT4_FS=y CONFIG_EXT4_USE_FOR_EXT23=y CONFIG_EXT4_FS_POSIX_ACL=y # CONFIG_EXT4_FS_SECURITY is not set # CONFIG_EXT4_DEBUG is not set Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: improve extent cache shrink mechanism to avoid to burn CPU timeZheng Liu
Now we maintain an proper in-order LRU list in ext4 to reclaim entries from extent status tree when we are under heavy memory pressure. For keeping this order, a spin lock is used to protect this list. But this lock burns a lot of CPU time. We can use the following steps to trigger it. % cd /dev/shm % dd if=/dev/zero of=ext4-img bs=1M count=2k % mkfs.ext4 ext4-img % mount -t ext4 -o loop ext4-img /mnt % cd /mnt % for ((i=0;i<160;i++)); do truncate -s 64g $i; done % for ((i=0;i<160;i++)); do cp $i /dev/null &; done % perf record -a -g % perf report This commit tries to fix this problem. Now a new member called i_touch_when is added into ext4_inode_info to record the last access time for an inode. Meanwhile we never need to keep a proper in-order LRU list. So this can avoid to burns some CPU time. When we try to reclaim some entries from extent status tree, we use list_sort() to get a proper in-order list. Then we traverse this list to discard some entries. In ext4_sb_info, we use s_es_last_sorted to record the last time of sorting this list. When we traverse the list, we skip the inode that is newer than this time, and move this inode to the tail of LRU list. When the head of the list is newer than s_es_last_sorted, we will sort the LRU list again. In this commit, we break the loop if s_extent_cache_cnt == 0 because that means that all extents in extent status tree have been reclaimed. Meanwhile in this commit, ext4_es_{un}register_shrinker()'s prototype is changed to save a local variable in these functions. Reported-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: implement error handling of ext4_mb_new_preallocation()Alexey Khoroshilov
If memory allocation in ext4_mb_new_group_pa() is failed, it returns error code, ext4_mb_new_preallocation() propages it, but ext4_mb_new_blocks() ignores it. An observed result was: - allocation fail means ext4_mb_new_group_pa() does not update ext4_allocation_context; - ext4_mb_new_blocks() sets ext4_allocation_request->len (ar->len = ac->ac_b_ex.fe_len;) to number of blocks preallocated (512) instead of number of blocks requested (1); - that activates update cycle in ext4_splice_branch(): for (i = 1; i < blks; i++) <-- blks is 512 instead of 1 here *(where->p + i) = cpu_to_le32(current_block++); - it iterates 511 times and corrupts a chunk of memory including inode structure; - page fault happens at EXT4_SB(inode->i_sb) in ext4_mark_inode_dirty(); - system hangs with 'scheduling while atomic' BUG. The patch implements a check for ext4_mb_new_preallocation() error code and handles its failure as if ext4_mb_regular_allocator() fails. Found by Linux File System Verification project (linuxtesting.org). [ Patch restructed by tytso to make the flow of control easier to follow. ] Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01ext4: fix corruption when online resizing a fs with 1K block sizeMaarten ter Huurne
Subtracting the number of the first data block places the superblock backups one block too early, corrupting the file system. When the block size is larger than 1K, the first data block is 0, so the subtraction has no effect and no corruption occurs. Signed-off-by: Maarten ter Huurne <maarten@treewalker.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> CC: stable@vger.kernel.org
2013-06-29[readdir] convert ext4Al Viro
and trim the living hell out bogosities in inline dir case Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-17ext4: delete unused variablesJon Ernst
This patch removed several unused variables. Signed-off-by: Jon Ernst <jonernst07@gmx.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-13ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extentsJie Liu
Return the FIEMAP_EXTENT_UNKNOWN flag as well except the FIEMAP_EXTENT_DELALLOC because the data location of an delayed allocation extent is unknown. Signed-off-by: Jie Liu <jeff.liu@oracle.com>
2013-06-13ext4: Fix fsync error handling after filesystem abortDmitry Monakhov
If filesystem was aborted after inode's write back is complete but before its metadata was updated we may return success results in data loss. In order to handle fs abort correctly we have to check fs state once we discover that it is in MS_RDONLY state Test case: http://patchwork.ozlabs.org/patch/244297 Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-13ext4: fix data integrity for ext4_sync_fsDmitry Monakhov
Inode's data or non journaled quota may be written w/o jounral so we _must_ send a barrier at the end of ext4_sync_fs. But it can be skipped if journal commit will do it for us. Also fix data integrity for nojournal mode. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12ext4: don't use EXT4_FREE_BLOCKS_FORGET unnecessarilyTheodore Ts'o
Commit 18888cf0883c: "ext4: speed up truncate/unlink by not using bforget() unless needed" removed the use of EXT4_FREE_BLOCKS_FORGET in the most important codepath for file systems using extents, but a similar optimization also can be done for file systems using indirect blocks, and for the two special cases in the ext4 extents code. Cc: Andrey Sidorov <qrxd43@motorola.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12ext4: add cond_resched() to ext4_free_blocks() & ext4_mb_regular_allocator()Theodore Ts'o
For a file systems with a very large number of block groups, if all of the block group bitmaps are in memory and the file system is relatively badly fragmented, it's possible ext4_mb_regular_allocator() to take a long time trying to find a good match. This is especially true if the tuning parameter mb_max_to_scan has been sent to a very large number. So add a cond_resched() to avoid soft lockup warnings and to provide better system responsiveness. For ext4_free_blocks(), if we are deleting a large range of blocks, and data=journal is enabled so that EXT4_FREE_BLOCKS_FORGET is passed, the loop to call sb_find_get_block() and to call ext4_forget() can take over 10-15 milliseocnds or more. So it's better to add a cond_resched() here a well. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-06ext4: use ext4_da_writepages() for all modesTheodore Ts'o
Rename ext4_da_writepages() to ext4_writepages() and use it for all modes. We still need to iterate over all the pages in the case of data=journalling, but in the case of nodelalloc/data=ordered (which is what file systems mounted using ext3 backwards compatibility will use) this will allow us to use a much more efficient I/O submission path. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-06ext4: optimize test_root()Theodore Ts'o
The test_root() function could potentially loop forever due to overflow issues. So rewrite test_root() to avoid this issue; as a bonus, it is 38% faster when benchmarked via a test loop: int main(int argc, char **argv) { int i; for (i = 0; i < 1 << 24; i++) { if (test_root(i, 7)) printf("%d\n", i); } } Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-06ext4: add sanity check to ext4_get_group_info()Theodore Ts'o
The group number passed to ext4_get_group_info() should be valid, but let's add an assert to check this before we start creating a pointer based on that group number and dereferencing it. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-06ext4: verify group number in verify_group_input() before using itTheodore Ts'o
Check the group number for sanity earilier, before calling routines such as ext4_bg_has_super() or ext4_group_overhead_blocks(). Reported-by: Jonathan Salwan <jonathan.salwan@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-06ext4: add check to io_submit_init_bioTheodore Ts'o
The bio_alloc() function can return NULL if the memory allocation fails. So we need to check for this. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: remove ext4_ioend_wait()Jan Kara
Now that we clear PageWriteback after extent conversion, there's no need to wait for io_end processing in ext4_evict_inode(). Running AIO/DIO keeps file reference until aio_complete() is called so ext4_evict_inode() cannot be called. For io_end structures resulting from buffered IO waiting is happening because we wait for PageWriteback in truncate_inode_pages(). Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: don't wait for extent conversion in ext4_punch_hole()Jan Kara
We don't have to wait for extent conversion in ext4_punch_hole() as buffered IO for the punched range has been flushed and waited upon (thus all extent conversions for that range have completed). Also we wait for all DIO to finish using inode_dio_wait() so there cannot be any extent conversions pending due to direct IO. Also remove ext4_flush_unwritten_io() since it's unused now. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: Remove wait for unwritten extents in ext4_ind_direct_IO()Jan Kara
We don't have to wait for unwritten extent conversion in ext4_ind_direct_IO() as all writes that happened before DIO are flushed by the generic code and extent conversion has happened before we cleared PageWriteback bit. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: remove i_mutex from ext4_file_sync()Jan Kara
After removal of ext4_flush_unwritten_io() call, ext4_file_sync() doesn't need i_mutex anymore. Forcing of transaction commits doesn't need i_mutex as there's nothing inode specific in that code apart from grabbing transaction ids from the inode. So remove the lock. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: use generic_file_fsync() in ext4_file_fsync() in nojournal modeJan Kara
Just use the generic function instead of duplicating it. We only need to reshuffle the read-only check a bit (which is there to prevent writing to a filesystem which has been remounted read-only after error I assume). Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: remove wait for unwritten extent conversion from ext4_truncate()Jan Kara
Since PageWriteback bit is now cleared after extents are converted from unwritten to written ones, we have full exclusion of writeback path from truncate (truncate_inode_pages() waits for PageWriteback bits to get cleared on all invalidated pages). Exclusion from DIO path is achieved by inode_dio_wait() call in ext4_setattr(). So there's no need to wait for extent convertion in ext4_truncate() anymore. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: protect extent conversion after DIO with i_dio_countJan Kara
Make sure extent conversion after DIO happens while i_dio_count is still elevated so that inode_dio_wait() waits until extent conversion is done. This removes the need for explicit waiting for extent conversion in some cases. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: defer clearing of PageWriteback after extent conversionJan Kara
Currently PageWriteback bit gets cleared from put_io_page() called from ext4_end_bio(). This is somewhat inconvenient as extent tree is not fully updated at that time (unwritten extents are not marked as written) so we cannot read the data back yet. This design was dictated by lock ordering as we cannot start a transaction while PageWriteback bit is set (we could easily deadlock with ext4_da_writepages()). But now that we use transaction reservation for extent conversion, locking issues are solved and we can move PageWriteback bit clearing after extent conversion is done. As a result we can remove wait for unwritten extent conversion from ext4_sync_file() because it already implicitely happens through wait_on_page_writeback(). We implement deferring of PageWriteback clearing by queueing completed bios to appropriate io_end and processing all the pages when io_end is going to be freed instead of at the moment ext4_io_end() is called. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: split extent conversion lists to reserved & unreserved partsJan Kara
Now that we have extent conversions with reserved transaction, we have to prevent extent conversions without reserved transaction (from DIO code) to block these (as that would effectively void any transaction reservation we did). So split lists, work items, and work queues to reserved and unreserved parts. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: use transaction reservation for extent conversion in ext4_end_ioJan Kara
Later we would like to clear PageWriteback bit only after extent conversion from unwritten to written extents is performed. However it is not possible to start a transaction after PageWriteback is set because that violates lock ordering (and is easy to deadlock). So we have to reserve a transaction before locking pages and sending them for IO and later we use the transaction for extent conversion from ext4_end_io(). Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: remove buffer_uninit handlingJan Kara
There isn't any need for setting BH_Uninit on buffers anymore. It was only used to signal we need to mark io_end as needing extent conversion in add_bh_to_extent() but now we can mark the io_end directly when mapping extent. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: restructure writeback pathJan Kara
There are two issues with current writeback path in ext4. For one we don't necessarily map complete pages when blocksize < pagesize and thus needn't do any writeback in one iteration. We always map some blocks though so we will eventually finish mapping the page. Just if writeback races with other operations on the file, forward progress is not really guaranteed. The second problem is that current code structure makes it hard to associate all the bios to some range of pages with one io_end structure so that unwritten extents can be converted after all the bios are finished. This will be especially difficult later when io_end will be associated with reserved transaction handle. We restructure the writeback path to a relatively simple loop which first prepares extent of pages, then maps one or more extents so that no page is partially mapped, and once page is fully mapped it is submitted for IO. We keep all the mapping and IO submission information in mpage_da_data structure to somewhat reduce stack usage. Resulting code is somewhat shorter than the old one and hopefully also easier to read. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: better estimate credits needed for ext4_da_writepages()Jan Kara
We limit the number of blocks written in a single loop of ext4_da_writepages() to 64 when inode uses indirect blocks. That is unnecessary as credit estimates for mapping logically continguous run of blocks is rather low even for inode with indirect blocks. So just lift this limitation and properly calculate the number of necessary credits. This better credit estimate will also later allow us to always write at least a single page in one iteration. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: improve writepage credit estimate for files with indirect blocksJan Kara
ext4_ind_trans_blocks() wrongly used 'chunk' argument to decide whether blocks mapped are logically contiguous. That is wrong since the argument informs whether the blocks are physically contiguous. As the blocks mapped are always logically contiguous and that's all ext4_ind_trans_blocks() cares about, just remove the 'chunk' argument. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: deprecate max_writeback_mb_bump sysfs attributeJan Kara
This attribute is now unused so deprecate it. We still show the old default value to keep some compatibility but we don't allow writing to that attribute anymore. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: stop messing with nr_to_write in ext4_da_writepages()Jan Kara
Writeback code got better in how it submits IO and now the number of pages requested to be written is usually higher than original 1024. The number is now dynamically computed based on observed throughput and is set to be about 0.5 s worth of writeback. E.g. on ordinary SATA drive this ends up somewhere around 10000 as my testing shows. So remove the unnecessary smarts from ext4_da_writepages(). Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: provide wrappers for transaction reservation callsJan Kara
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: transaction reservation supportJan Kara
In some cases we cannot start a transaction because of locking constraints and passing started transaction into those places is not handy either because we could block transaction commit for too long. Transaction reservation is designed to solve these issues. It reserves a handle with given number of credits in the journal and the handle can be later attached to the running transaction without blocking on commit or checkpointing. Reserved handles do not block transaction commit in any way, they only reduce maximum size of the running transaction (because we have to always be prepared to accomodate request for attaching reserved handle). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04ext4: use io_end for multiple biosJan Kara
Change writeback path to create just one io_end structure for the extent to which we submit IO and share it among bios writing that extent. This prevents needless splitting and joining of unwritten extents when they cannot be submitted as a single bio. Bugs in ENOMEM handling found by Linux File System Verification project (linuxtesting.org) and fixed by Alexey Khoroshilov <khoroshilov@ispras.ru>. CC: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-05-31ext4: fix overflow when counting used blocks on 32-bit architecturesJan Kara
The arithmetics adding delalloc blocks to the number of used blocks in ext4_getattr() can easily overflow on 32-bit archs as we first multiply number of blocks by blocksize and then divide back by 512. Make the arithmetics more clever and also use proper type (unsigned long long instead of unsigned long). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-05-31ext4: fix data offset overflow in ext4_xattr_fiemap() on 32-bit archsJan Kara
On 32-bit architectures with 32-bit sector_t computation of data offset in ext4_xattr_fiemap() can overflow resulting in reporting bogus data location. Fix the problem by typing block number to proper type before shifting. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>