linux/fs/xfs
Dan Williams d6dc57e251 xfs, dax: introduce xfs_break_dax_layouts()
xfs_break_dax_layouts(), similar to xfs_break_leased_layouts(), scans
for busy / pinned dax pages and waits for those pages to go idle before
any potential extent unmap operation.

dax_layout_busy_page() handles synchronizing against new page-busy
events (get_user_pages). It invalidates all mappings to trigger the
get_user_pages slow path which will eventually block on the xfs inode
lock held in XFS_MMAPLOCK_EXCL mode. If dax_layout_busy_page() finds a
busy page it returns it for xfs to wait for the page-idle event that
will fire when the page reference count reaches 1 (recall ZONE_DEVICE
pages are idle at count 1, see generic_dax_pagefree()).

While waiting, the XFS_MMAPLOCK_EXCL lock is dropped in order to not
deadlock the process that might be trying to elevate the page count of
more pages before arranging for any of them to go idle. I.e. the typical
case of submitting I/O is that iov_iter_get_pages() elevates the
reference count of all pages in the I/O before starting I/O on the first
page. The process of elevating the reference count of all pages involved
in an I/O may cause faults that need to take XFS_MMAPLOCK_EXCL.

Although XFS_MMAPLOCK_EXCL is dropped while waiting, XFS_IOLOCK_EXCL is
held while sleeping. We need this to prevent starvation of the truncate
path as continuous submission of direct-I/O could starve the truncate
path indefinitely if the lock is dropped.

Cc: Dave Chinner <david@fromorbit.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-22 07:19:08 -07:00
..
libxfs xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
scrub xfs: xfs_scrub_iallocbt_xref_rmap_inodes should use xref_set_corrupt 2018-03-23 18:05:09 -07:00
Kconfig fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
kmem.c xfs: fall back to vmalloc when allocation log vector buffers 2018-03-11 20:27:55 -07:00
kmem.h xfs: fall back to vmalloc when allocation log vector buffers 2018-03-11 20:27:55 -07:00
Makefile xfs: use a b+tree for the in-core extent list 2017-11-06 11:53:41 -08:00
mrlock.h
xfs_acl.c xfs: don't change inode mode if ACL update fails 2017-10-11 10:21:06 -07:00
xfs_acl.h xfs: Don't clear SGID when inheriting ACLs 2017-06-27 18:23:21 -07:00
xfs_aops.c export __set_page_dirty 2018-04-11 10:28:39 -07:00
xfs_aops.h xfs, dax: introduce xfs_dax_aops 2018-03-30 11:34:55 -07:00
xfs_attr_inactive.c xfs: fail if xattr inactivation hits a hole 2017-10-26 15:38:22 -07:00
xfs_attr_list.c xfs: remove u_int* type usage 2017-11-09 15:50:29 -08:00
xfs_attr.h xfs: scrub extended attributes 2017-10-26 15:38:26 -07:00
xfs_bmap_item.c xfs: fix intent use-after-free on abort 2018-04-02 20:08:27 -07:00
xfs_bmap_item.h xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_bmap_util.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_bmap_util.h xfs: simplify the xfs_getbmap interface 2017-10-26 15:38:20 -07:00
xfs_buf_item.c xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_buf_item.h Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_buf.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_buf.h xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_dir2_readdir.c xfs: directory scrubber must walk through data block to offset 2018-01-17 21:00:46 -08:00
xfs_discard.c Force log to disk before reading the AGF during a fstrim 2018-04-10 22:39:04 -07:00
xfs_discard.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_dquot_item.c xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_dquot_item.h
xfs_dquot.c xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_dquot.h
xfs_error.c xfs: refactor inode buffer verifier error logging 2018-03-23 18:05:07 -07:00
xfs_error.h xfs: refactor inode buffer verifier error logging 2018-03-23 18:05:07 -07:00
xfs_export.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2018-04-05 11:56:35 -07:00
xfs_export.h
xfs_extent_busy.c xfs: merge _xfs_log_force and xfs_log_force 2018-03-14 11:12:52 -07:00
xfs_extent_busy.h xfs: improve handling of busy extents in the low-level allocator 2017-02-09 10:50:25 -08:00
xfs_extfree_item.c xfs: fix intent use-after-free on abort 2018-04-02 20:08:27 -07:00
xfs_extfree_item.h
xfs_file.c xfs, dax: introduce xfs_break_dax_layouts() 2018-05-22 07:19:08 -07:00
xfs_filestream.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_filestream.h
xfs_fsmap.c xfs: move two more RT specific functions into CONFIG_XFS_RT 2017-10-16 12:26:50 -07:00
xfs_fsmap.h xfs: implement the GETFSMAP ioctl 2017-04-03 15:18:17 -07:00
xfs_fsops.c xfs: convert XFS_AGFL_SIZE to a helper function 2018-03-11 20:27:56 -07:00
xfs_fsops.h xfs: hoist xfs_fs_geometry to libxfs 2018-01-08 10:54:48 -08:00
xfs_globals.c xfs: define fatal assert build time tunable 2017-06-19 08:59:10 -07:00
xfs_icache.c xfs: catch inode allocation state mismatch corruption 2018-03-23 18:05:09 -07:00
xfs_icache.h xfs: remove leftover CoW reservations when remounting ro 2017-12-21 08:47:32 -08:00
xfs_icreate_item.c fs: xfs: xfs_icreate_item: constify xfs_item_ops structure 2016-11-28 14:57:42 +11:00
xfs_icreate_item.h
xfs_inode_item.c xfs: remove an outdated comment for xfs_inode_item_committing 2018-03-14 11:12:51 -07:00
xfs_inode_item.h xfs: remove inode log format typedef 2017-11-01 15:03:16 -07:00
xfs_inode.c xfs: only cancel cow blocks when truncating the data fork 2018-04-10 08:28:33 -07:00
xfs_inode.h xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_ioctl32.c xfs: refactor the geometry structure filling function 2018-01-08 10:54:48 -08:00
xfs_ioctl32.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_ioctl.c xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_ioctl.h xfs: remove u_int* type usage 2017-11-09 15:50:29 -08:00
xfs_iomap.c xfs: don't block on the ilock for RWF_NOWAIT 2018-03-01 14:12:45 -08:00
xfs_iomap.h xfs: update i_size after unwritten conversion in dio completion 2017-09-26 10:55:19 -07:00
xfs_iops.c xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_iops.h
xfs_itable.c xfs: remove if_rdev 2017-10-26 15:38:27 -07:00
xfs_itable.h xfs: create inode pointer verifiers 2017-10-26 15:38:23 -07:00
xfs_linux.h xfs: use %px for data pointers when debugging 2018-01-12 14:09:08 -08:00
xfs_log_cil.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_log_priv.h locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
xfs_log_recover.c xfs: do not log/recover swapext extent owner changes for deleted inodes 2018-03-29 10:19:15 -07:00
xfs_log.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_log.h xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_message.c xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
xfs_message.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_mount.c xfs: clean up xfs_mount allocation and dynamic initializers 2018-03-26 08:54:15 -07:00
xfs_mount.h xfs: detect agfl count corruption and reset agfl 2018-03-23 18:05:06 -07:00
xfs_mru_cache.c xfs: remove filestream item xfs_inode reference 2018-04-09 10:23:39 -07:00
xfs_mru_cache.h xfs: remove filestream item xfs_inode reference 2018-04-09 10:23:39 -07:00
xfs_ondisk.h xfs: Don't log uninitialised fields in inode structures 2017-10-11 10:21:06 -07:00
xfs_pnfs.c xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_pnfs.h xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_qm_bhv.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_qm_syscalls.c xfs: wait on new inodes during quotaoff dquot release 2017-04-28 08:11:08 -07:00
xfs_qm.c xfs: Remove "committed" argument of xfs_dir_ialloc 2018-04-02 15:47:43 -07:00
xfs_qm.h
xfs_quota.h
xfs_quotaops.c VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) 2017-07-17 08:45:34 +01:00
xfs_refcount_item.c xfs: fix intent use-after-free on abort 2018-04-02 20:08:27 -07:00
xfs_refcount_item.h xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_reflink.c xfs: minor cleanup for xfs_reflink_end_cow 2018-03-15 10:31:38 -07:00
xfs_reflink.h xfs: separate function to check if inode shares extents 2017-06-19 14:11:35 -07:00
xfs_rmap_item.c xfs: fix intent use-after-free on abort 2018-04-02 20:08:27 -07:00
xfs_rmap_item.h
xfs_rtalloc.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_rtalloc.h xfs: cross-reference the realtime bitmap 2018-01-17 21:00:46 -08:00
xfs_stats.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_stats.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_super.c xfs: non-scrub - remove unused function parameters 2018-04-09 10:23:42 -07:00
xfs_super.h xfs: add scrub to XFS_BUILD_OPTIONS 2018-02-01 21:06:15 -08:00
xfs_symlink.c xfs: Remove "committed" argument of xfs_dir_ialloc 2018-04-02 15:47:43 -07:00
xfs_symlink.h xfs: allow reading of already-locked remote symbolic link 2017-06-20 10:45:22 -07:00
xfs_sysctl.c xfs: garbage collect old cowextsz reservations 2016-10-05 16:26:28 -07:00
xfs_sysctl.h xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
xfs_sysfs.c xfs: replace log_badcrc_factor knob with error injection tag 2017-06-27 18:23:21 -07:00
xfs_sysfs.h
xfs_trace.c fs: xfs: remove duplicate includes 2017-12-08 17:51:05 -08:00
xfs_trace.h xfs: remove filestream item xfs_inode reference 2018-04-09 10:23:39 -07:00
xfs_trans_ail.c xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_trans_bmap.c xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent 2017-06-19 08:59:10 -07:00
xfs_trans_buf.c xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_trans_dquot.c
xfs_trans_extfree.c
xfs_trans_inode.c xfs: implement the lazytime mount option 2018-03-11 20:27:55 -07:00
xfs_trans_priv.h xfs: Rename xa_ elements to ail_ 2018-03-11 20:27:56 -07:00
xfs_trans_refcount.c xfs: connect refcount adjust functions to upper layers 2016-10-03 09:11:22 -07:00
xfs_trans_rmap.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_trans.c xfs: merge _xfs_log_force_lsn and xfs_log_force_lsn 2018-03-14 11:12:52 -07:00
xfs_trans.h Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_xattr.c xfs: several xattr functions can be void 2016-12-05 12:32:14 +11:00
xfs.h xfs: always define STATIC to static noinline 2017-11-06 11:53:58 -08:00