From: Christoph Hellwig <[email protected]> Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare blocks for writing and the inode is pinned, and has dirty fields other than the timestamps. In __xfs_filemap_fault() we then detect this case and call dax_finish_sync_fault() to make sure all metadata is committed, and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is what we want - fsync(2) will still provide data integrity guarantees for applications not using userspace flushing. And applications using userspace flushing can avoid calling fsync(2) and thus avoid the performance overhead. [JK: Added VM_SYNC flag handling] Reviewed-by: Ross Zwisler <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Jan Kara <[email protected]> --- fs/xfs/xfs_file.c | 15 ++++++++++++++- fs/xfs/xfs_iomap.c | 5 +++++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 4496b45678de..4827e82d5d2c 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -44,6 +44,7 @@ #include <linux/falloc.h> #include <linux/pagevec.h> #include <linux/backing-dev.h> +#include <linux/mman.h> static const struct vm_operations_struct xfs_file_vm_ops; @@ -1040,7 +1041,11 @@ __xfs_filemap_fault( xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { - ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops); + pfn_t pfn; + + ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops); + if (ret & VM_FAULT_NEEDDSYNC) + ret = dax_finish_sync_fault(vmf, pe_size, pfn); } else { if (write_fault) ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops); @@ -1110,6 +1115,13 @@ xfs_file_mmap( struct file *filp, struct vm_area_struct *vma) { + /* + * We don't support synchronous mappings for non-DAX files. At least + * until someone comes with a sensible use case. + */ + if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC)) + return -EOPNOTSUPP; + file_accessed(filp); vma->vm_ops = &xfs_file_vm_ops; if (IS_DAX(file_inode(filp))) @@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = { .compat_ioctl = xfs_file_compat_ioctl, #endif .mmap = xfs_file_mmap, + .mmap_supported_flags = MAP_SYNC, .open = xfs_file_open, .release = xfs_file_release, .fsync = xfs_file_fsync, diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index f179bdf1644d..b43be199fbdf 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -33,6 +33,7 @@ #include "xfs_error.h" #include "xfs_trans.h" #include "xfs_trans_space.h" +#include "xfs_inode_item.h" #include "xfs_iomap.h" #include "xfs_trace.h" #include "xfs_icache.h" @@ -1086,6 +1087,10 @@ xfs_file_iomap_begin( trace_xfs_iomap_found(ip, offset, length, 0, &imap); } + if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) && + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) + iomap->flags |= IOMAP_F_DIRTY; + xfs_bmbt_to_iomap(ip, iomap, &imap); if (shared) -- 2.12.3 _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
