From: Christoph Hellwig Date: Tue, 29 Aug 2017 17:08:41 +0000 (-0700) Subject: xfs: consolidate the various page fault handlers X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=d522d569d6adf72ceda90153a086e089e6c2fbc6;p=openwrt%2Fstaging%2Fblogic.git xfs: consolidate the various page fault handlers Add a new __xfs_filemap_fault helper that implements all four page fault callouts, and make these methods themselves small stubs that set the correct write_fault flag, and exit early for the non-DAX case for the hugepage related ones. Also remove the extra size checking in the pfn_fault path, which is now handled in the core DAX code. Life would be so much simpler if we only had one method for all this. Signed-off-by: Christoph Hellwig Reviewed-by: Ross Zwisler Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 8b0181c6d2a6..0debbc7e3f03 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1011,95 +1011,67 @@ xfs_file_llseek( * page_lock (MM) * i_lock (XFS - extent map serialisation) */ - -/* - * mmap()d file has taken write protection fault and is being made writable. We - * can set the page state up correctly for a writable page, which means we can - * do correct delalloc accounting (ENOSPC checking!) and unwritten extent - * mapping. - */ -STATIC int -xfs_filemap_page_mkwrite( - struct vm_fault *vmf) +static int +__xfs_filemap_fault( + struct vm_fault *vmf, + enum page_entry_size pe_size, + bool write_fault) { struct inode *inode = file_inode(vmf->vma->vm_file); + struct xfs_inode *ip = XFS_I(inode); int ret; - trace_xfs_filemap_page_mkwrite(XFS_I(inode)); + trace_xfs_filemap_fault(ip, pe_size, write_fault); - sb_start_pagefault(inode->i_sb); - file_update_time(vmf->vma->vm_file); - xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + if (write_fault) { + sb_start_pagefault(inode->i_sb); + file_update_time(vmf->vma->vm_file); + } + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops); + ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops); } else { - ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops); + if (write_fault) + ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops); + else + ret = filemap_fault(vmf); } - xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - sb_end_pagefault(inode->i_sb); + if (write_fault) + sb_end_pagefault(inode->i_sb); return ret; } -STATIC int +static int xfs_filemap_fault( struct vm_fault *vmf) { - struct inode *inode = file_inode(vmf->vma->vm_file); - int ret; - - trace_xfs_filemap_fault(XFS_I(inode)); - /* DAX can shortcut the normal fault path on write faults! */ - if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode)) - return xfs_filemap_page_mkwrite(vmf); - - xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - if (IS_DAX(inode)) - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops); - else - ret = filemap_fault(vmf); - xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - - return ret; + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, + IS_DAX(file_inode(vmf->vma->vm_file)) && + (vmf->flags & FAULT_FLAG_WRITE)); } -/* - * Similar to xfs_filemap_fault(), the DAX fault path can call into here on - * both read and write faults. Hence we need to handle both cases. There is no - * ->huge_mkwrite callout for huge pages, so we have a single function here to - * handle both cases here. @flags carries the information on the type of fault - * occuring. - */ -STATIC int +static int xfs_filemap_huge_fault( struct vm_fault *vmf, enum page_entry_size pe_size) { - struct inode *inode = file_inode(vmf->vma->vm_file); - struct xfs_inode *ip = XFS_I(inode); - int ret; - - if (!IS_DAX(inode)) + if (!IS_DAX(file_inode(vmf->vma->vm_file))) return VM_FAULT_FALLBACK; - trace_xfs_filemap_huge_fault(ip); - - if (vmf->flags & FAULT_FLAG_WRITE) { - sb_start_pagefault(inode->i_sb); - file_update_time(vmf->vma->vm_file); - } - - xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops); - xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - - if (vmf->flags & FAULT_FLAG_WRITE) - sb_end_pagefault(inode->i_sb); + /* DAX can shortcut the normal fault path on write faults! */ + return __xfs_filemap_fault(vmf, pe_size, + (vmf->flags & FAULT_FLAG_WRITE)); +} - return ret; +static int +xfs_filemap_page_mkwrite( + struct vm_fault *vmf) +{ + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true); } /* diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index e839ab4db483..bb5514688d47 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -688,11 +688,34 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag); DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag); DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid); -DEFINE_INODE_EVENT(xfs_filemap_fault); -DEFINE_INODE_EVENT(xfs_filemap_huge_fault); -DEFINE_INODE_EVENT(xfs_filemap_page_mkwrite); DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite); +TRACE_EVENT(xfs_filemap_fault, + TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size, + bool write_fault), + TP_ARGS(ip, pe_size, write_fault), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(xfs_ino_t, ino) + __field(enum page_entry_size, pe_size) + __field(bool, write_fault) + ), + TP_fast_assign( + __entry->dev = VFS_I(ip)->i_sb->s_dev; + __entry->ino = ip->i_ino; + __entry->pe_size = pe_size; + __entry->write_fault = write_fault; + ), + TP_printk("dev %d:%d ino 0x%llx %s write_fault %d", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->ino, + __print_symbolic(__entry->pe_size, + { PE_SIZE_PTE, "PTE" }, + { PE_SIZE_PMD, "PMD" }, + { PE_SIZE_PUD, "PUD" }), + __entry->write_fault) +) + DECLARE_EVENT_CLASS(xfs_iref_class, TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip), TP_ARGS(ip, caller_ip),