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authorJan Kara <jack@suse.cz>2018-01-07 16:41:01 -0500
committerTheodore Ts'o <tytso@mit.edu>2018-01-07 16:41:01 -0500
commit22446423108f3687167c9fdc080e6f21dd784d18 (patch)
tree38cad36cd241ce7ffdfd65058ebb128e643bb9b4 /fs/ext4
parentc0b24625979284dd212423320fe1c84fe244ed7f (diff)
downloadlinux-22446423108f3687167c9fdc080e6f21dd784d18.tar.bz2
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 <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/file.c10
1 files changed, 8 insertions, 2 deletions
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);