kernel.git/fs/ext4/indirect.c, branch linux-4.7.y

ext4: refactor direct IO code

2016-05-13T04:44:16Z

Currently ext4 direct IO handling is split between ext4_ext_direct_IO() and ext4_ind_direct_IO(). However the extent based function calls into the indirect based one for some cases and for example it is not able to handle file extending. Previously it was not also properly handling retries in case of ENOSPC errors. With DAX things would get even more contrieved so just refactor the direct IO code and instead of indirect / extent split do the split to read vs writes. Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: return hole from ext4_map_blocks()

2016-03-10T03:54:00Z

Currently, ext4_map_blocks() just returns 0 when it finds a hole and allocation is not requested. However we have all the information available to tell how large the hole actually is and there are callers of ext4_map_blocks() which would save some block-by-block hole iteration if they knew this information. So fill in struct ext4_map_blocks even for holes with the information we have. We keep returning 0 for holes to maintain backward compatibility of the function. Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: rename and split get blocks functions

2016-03-09T04:08:10Z

Rename ext4_get_blocks_write() to ext4_get_blocks_unwritten() to better describe what it does. Also split out get blocks functions for direct IO. Later we move functionality from _ext4_get_blocks() there. There's no functional change in this patch. Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: clean up feature test macros with predicate functions

2015-10-17T20:18:43Z

Create separate predicate functions to test/set/clear feature flags, thereby replacing the wordy old macros. Furthermore, clean out the places where we open-coded feature tests. Signed-off-by: Darrick J. Wong

ext4: call out CRC and corruption errors with specific error codes

2015-10-17T20:16:04Z

Instead of overloading EIO for CRC errors and corrupt structures, return the same error codes that XFS returns for the same issues. Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o

dax: move DAX-related functions to a new header

2015-09-08T22:35:28Z

In order to handle the !CONFIG_TRANSPARENT_HUGEPAGES case, we need to return VM_FAULT_FALLBACK from the inlined dax_pmd_fault(), which is defined in linux/mm.h. Given that we don't want to include in , the easiest solution is to move the DAX-related functions to a new header, . We could also have moved VM_FAULT_* definitions to a new header, or a different header that isn't quite such a boil-the-ocean header as , but this felt like the best option. Signed-off-by: Matthew Wilcox Cc: Hillf Danton Cc: "Kirill A. Shutemov" Cc: Theodore Ts'o Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ext4: don't retry file block mapping on bigalloc fs with non-extent file

2015-06-22T01:10:51Z

ext4 isn't willing to map clusters to a non-extent file. Don't signal this with an out of space error, since the FS will retry the allocation (which didn't fail) forever. Instead, return EUCLEAN so that the operation will fail immediately all the way back to userspace. (The fix is either to run e2fsck -E bmap2extent, or to chattr +e the file.) Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: prevent ext4_quota_write() from failing due to ENOSPC

2015-06-21T05:25:29Z

In order to prevent quota block tracking to be inaccurate when ext4_quota_write() fails with ENOSPC, we make two changes. The quota file can now use the reserved block (since the quota file is arguably file system metadata), and ext4_quota_write() now uses ext4_should_retry_alloc() to retry the block allocation after a commit has completed and released some blocks for allocation. This fixes failures of xfstests generic/270: Quota error (device vdc): write_blk: dquota write failed Quota error (device vdc): qtree_write_dquot: Error -28 occurred while creating quota Signed-off-by: Theodore Ts'o

direct-io: only inc/dec inode->i_dio_count for file systems

2015-04-24T19:45:28Z

do_blockdev_direct_IO() increments and decrements the inode ->i_dio_count for each IO operation. It does this to protect against truncate of a file. Block devices don't need this sort of protection. For a capable multiqueue setup, this atomic int is the only shared state between applications accessing the device for O_DIRECT, and it presents a scaling wall for that. In my testing, as much as 30% of system time is spent incrementing and decrementing this value. A mixed read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with better latencies too. Before: clat percentiles (usec): | 1.00th=[ 33], 5.00th=[ 34], 10.00th=[ 34], 20.00th=[ 34], | 30.00th=[ 34], 40.00th=[ 34], 50.00th=[ 35], 60.00th=[ 35], | 70.00th=[ 35], 80.00th=[ 35], 90.00th=[ 37], 95.00th=[ 80], | 99.00th=[ 98], 99.50th=[ 151], 99.90th=[ 155], 99.95th=[ 155], | 99.99th=[ 165] After: clat percentiles (usec): | 1.00th=[ 95], 5.00th=[ 108], 10.00th=[ 129], 20.00th=[ 149], | 30.00th=[ 155], 40.00th=[ 161], 50.00th=[ 167], 60.00th=[ 171], | 70.00th=[ 177], 80.00th=[ 185], 90.00th=[ 201], 95.00th=[ 270], | 99.00th=[ 390], 99.50th=[ 398], 99.90th=[ 418], 99.95th=[ 422], | 99.99th=[ 438] In other setups, Robert Elliott reported seeing good performance improvements: https://lkml.org/lkml/2015/4/3/557 The more applications accessing the device, the worse it gets. Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells do_blockdev_direct_IO() that it need not worry about incrementing or decrementing the inode i_dio_count for this caller. Cc: Andrew Morton Cc: Christoph Hellwig Cc: Theodore Ts'o Cc: Elliott, Robert (Server Storage) Cc: Al Viro Signed-off-by: Jens Axboe Signed-off-by: Al Viro

direct_IO: use iov_iter_rw() instead of rw everywhere

2015-04-12T02:29:45Z

The rw parameter to direct_IO is redundant with iov_iter->type, and treated slightly differently just about everywhere it's used: some users do rw & WRITE, and others do rw == WRITE where they should be doing a bitwise check. Simplify this with the new iov_iter_rw() helper, which always returns either READ or WRITE. Signed-off-by: Omar Sandoval Signed-off-by: Al Viro