From 22446423108f3687167c9fdc080e6f21dd784d18 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Sun, 7 Jan 2018 16:41:01 -0500 Subject: ext4: fix ENOSPC handling in DAX page fault handler When allocation of underlying block for a page fault fails, we fail the fault with SIGBUS. However we may well hit ENOSPC just due to lots of free blocks being held by the running / committing transaction. So propagate the error from ext4_iomap_begin() and implement do standard allocation retry loop in ext4_dax_huge_fault(). Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o --- fs/ext4/file.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 1c7cd882d998..fb6f023622fe 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -280,7 +280,8 @@ out: static int ext4_dax_huge_fault(struct vm_fault *vmf, enum page_entry_size pe_size) { - int result; + int result, error = 0; + int retries = 0; handle_t *handle = NULL; struct inode *inode = file_inode(vmf->vma->vm_file); struct super_block *sb = inode->i_sb; @@ -304,6 +305,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf, sb_start_pagefault(sb); file_update_time(vmf->vma->vm_file); down_read(&EXT4_I(inode)->i_mmap_sem); +retry: handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, EXT4_DATA_TRANS_BLOCKS(sb)); if (IS_ERR(handle)) { @@ -314,9 +316,13 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf, } else { down_read(&EXT4_I(inode)->i_mmap_sem); } - result = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &ext4_iomap_ops); + result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops); if (write) { ext4_journal_stop(handle); + + if ((result & VM_FAULT_ERROR) && error == -ENOSPC && + ext4_should_retry_alloc(sb, &retries)) + goto retry; /* Handling synchronous page fault? */ if (result & VM_FAULT_NEEDDSYNC) result = dax_finish_sync_fault(vmf, pe_size, pfn); -- cgit v1.2.3