linux/fs/buffer.c, branch v3.8

vfs: add missing virtual cache flush after editing partial pages

2013-01-14T21:17:50Z

Andrew Morton pointed this out a month ago, and then I completely forgot about it. If we read a partial last page of a block device, we will zero out the end of the page, but since that page can then be mapped into user space, we should also make sure to flush the cache on architectures that have virtual caches. We have the flush_dcache_page() function for this, so use it. Now, in practice this really never matters, because nobody sane uses virtual caches to begin with, and they largely exist on old broken RISC arhitectures. And even if you did run on one of those obsolete CPU's, the whole "mmap and access the last partial page of a block device" behavior probably doesn't actually exist. The normal IO functions (read/write) will never see the zeroed-out part of the page that migth not be coherent in the cache, because they honor the size of the device. So I'm marking this for stable (3.7 only), but I'm not sure anybody will ever care. Pointed-out-by: Andrew Morton Cc: stable@vger.kernel.org # 3.7 Signed-off-by: Linus Torvalds

fs/buffer.c: remove redundant initialization in alloc_page_buffers()

2012-12-13T01:38:35Z

buffer_head comes from kmem_cache_zalloc(), no need to zero its fields. Signed-off-by: Yan Hong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/buffer.c: do not inline exported function

2012-12-13T01:38:34Z

It makes no sense to inline an exported function. Signed-off-by: Yan Hong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: redefine address_space.assoc_mapping

2012-12-12T01:22:26Z

Overhaul struct address_space.assoc_mapping renaming it to address_space.private_data and its type is redefined to void*. By this approach we consistently name the .private_* elements from struct address_space as well as allow extended usage for address_space association with other data structures through ->private_data. Also, all users of old ->assoc_mapping element are converted to reflect its new name and type change (->private_data). Signed-off-by: Rafael Aquini Cc: Rusty Russell Cc: "Michael S. Tsirkin" Cc: Rik van Riel Cc: Mel Gorman Cc: Andi Kleen Cc: Konrad Rzeszutek Wilk Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: clear to the end of the buffer on partial buffer reads

2012-12-05T18:32:59Z

READ is zero so the "rw & READ" test is always false. The intended test was "((rw & RW_MASK) == READ)". Signed-off-by: Dan Carpenter Signed-off-by: Linus Torvalds

vfs: avoid "attempt to access beyond end of device" warnings

2012-12-04T16:25:11Z

The block device access simplification that avoided accessing the (racy) block size information (commit bbec0270bdd8: "blkdev_max_block: make private to fs/buffer.c") no longer checks the maximum block size in the block mapping path. That was _almost_ as simple as just removing the code entirely, because the readers and writers all check the size of the device anyway, so under normal circumstances it "just worked". However, the block size may be such that the end of the device may straddle one single buffer_head. At which point we may still want to access the end of the device, but the buffer we use to access it partially extends past the end. The 'bd_set_size()' function intentionally sets the block size to avoid this, but mounting the device - or setting the block size by hand to some other value - can modify that block size. So instead, teach 'submit_bh()' about the special case of the buffer head straddling the end of the device, and turning such an access into a smaller IO access, avoiding the problem. This, btw, also means that unlike before, we can now access the whole device regardless of device block size setting. So now, even if the device size is only 512-byte aligned, we can read and write even the last sector even when having a much bigger block size for accessing the rest of the device. So with this, we could now get rid of the 'bd_set_size()' block size code entirely - resulting in faster IO for the common case - but that would be a separate patch. Reported-and-tested-by: Romain Francoise Reporeted-and-tested-by: Meelis Roos Reported-by: Tony Luck Signed-off-by: Linus Torvalds

blkdev_max_block: make private to fs/buffer.c

2012-11-30T01:48:12Z

We really don't want to look at the block size for the raw block device accesses in fs/block-dev.c, because it may be changing from under us. So get rid of the max_block logic entirely, since the caller should already have done it anyway. That leaves the only user of this function in fs/buffer.c, so move the whole function there and make it static. Signed-off-by: Linus Torvalds

fs/buffer.c: make block-size be per-page and protected by the page lock

2012-11-29T18:47:20Z

This makes the buffer size handling be a per-page thing, which allows us to not have to worry about locking too much when changing the buffer size. If a page doesn't have buffers, we still need to read the block size from the inode, but we can do that with ACCESS_ONCE(), so that even if the size is changing, we get a consistent value. This doesn't convert all functions - many of the buffer functions are used purely by filesystems, which in turn results in the buffer size being fixed at mount-time. So they don't have the same consistency issues that the raw device access can have. Signed-off-by: Linus Torvalds

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2012-10-07T21:36:39Z

Pull ext4 updates from Ted Ts'o: "The big new feature added this time is supporting online resizing using the meta_bg feature. This allows us to resize file systems which are greater than 16TB. In addition, the speed of online resizing has been improved in general. We also fix a number of races, some of which could lead to deadlocks, in ext4's Asynchronous I/O and online defrag support, thanks to good work by Dmitry Monakhov. There are also a large number of more minor bug fixes and cleanups from a number of other ext4 contributors, quite of few of which have submitted fixes for the first time." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (69 commits) ext4: fix ext4_flush_completed_IO wait semantics ext4: fix mtime update in nodelalloc mode ext4: fix ext_remove_space for punch_hole case ext4: punch_hole should wait for DIO writers ext4: serialize truncate with owerwrite DIO workers ext4: endless truncate due to nonlocked dio readers ext4: serialize unlocked dio reads with truncate ext4: serialize dio nonlocked reads with defrag workers ext4: completed_io locking cleanup ext4: fix unwritten counter leakage ext4: give i_aiodio_unwritten a more appropriate name ext4: ext4_inode_info diet ext4: convert to use leXX_add_cpu() ext4: ext4_bread usage audit fs: reserve fallocate flag codepoint ext4: remove redundant offset check in mext_check_arguments() ext4: don't clear orphan list on ro mount with errors jbd2: fix assertion failure in commit code due to lacking transaction credits ext4: release donor reference when EXT4_IOC_MOVE_EXT ioctl fails ext4: enable FITRIM ioctl on bigalloc file system ...

ext4: fix mtime update in nodelalloc mode

2012-10-01T03:04:56Z

Commits 5e8830dc85d0 and 41c4d25f78c0 introduced a regression into v3.6-rc1 for ext4 in nodealloc mode, such that mtime updates would not take place for files modified via mmap if the page was already in the page cache. This would also affect ext3 file systems mounted using the ext4 file system driver. The problem was that ext4_page_mkwrite() had a shortcut which would avoid calling __block_page_mkwrite() under some circumstances, and the above two commit transferred the responsibility of calling file_update_time() to __block_page_mkwrite --- which woudln't get called in some circumstances. Since __block_page_mkwrite() only has three callers, block_page_mkwrite(), ext4_page_mkwrite, and nilfs_page_mkwrite(), the best way to solve this is to move the responsibility for calling file_update_time() to its caller. This problem was found via xfstests #215 with a file system mounted with -o nodelalloc. Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara Cc: KONISHI Ryusuke Cc: stable@vger.kernel.org