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authorJan Kara <jack@suse.cz>2016-10-21 11:33:49 +0200
committerDan Williams <dan.j.williams@intel.com>2016-12-26 20:29:25 -0800
commit1db175428ee374489448361213e9c3b749d14900 (patch)
tree32e4eebdad84d1c6e84508186b0f1fb63df7bdfc
parent9f141d6ef6258a3a37a045842d9ba7e68f368956 (diff)
ext4: Simplify DAX fault path
Now that dax_iomap_fault() calls ->iomap_begin() without entry lock, we can use transaction starting in ext4_iomap_begin() and thus simplify ext4_dax_fault(). It also provides us proper retries in case of ENOSPC. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--fs/ext4/file.c48
1 files changed, 10 insertions, 38 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b5f184493c57..d663d3d7c81c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -258,7 +258,6 @@ out:
static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
int result;
- handle_t *handle = NULL;
struct inode *inode = file_inode(vma->vm_file);
struct super_block *sb = inode->i_sb;
bool write = vmf->flags & FAULT_FLAG_WRITE;
@@ -266,24 +265,12 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if (write) {
sb_start_pagefault(sb);
file_update_time(vma->vm_file);
- down_read(&EXT4_I(inode)->i_mmap_sem);
- handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
- EXT4_DATA_TRANS_BLOCKS(sb));
- } else
- down_read(&EXT4_I(inode)->i_mmap_sem);
-
- if (IS_ERR(handle))
- result = VM_FAULT_SIGBUS;
- else
- result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops);
-
- if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
- up_read(&EXT4_I(inode)->i_mmap_sem);
+ }
+ down_read(&EXT4_I(inode)->i_mmap_sem);
+ result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops);
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ if (write)
sb_end_pagefault(sb);
- } else
- up_read(&EXT4_I(inode)->i_mmap_sem);
return result;
}
@@ -292,7 +279,6 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd, unsigned int flags)
{
int result;
- handle_t *handle = NULL;
struct inode *inode = file_inode(vma->vm_file);
struct super_block *sb = inode->i_sb;
bool write = flags & FAULT_FLAG_WRITE;
@@ -300,27 +286,13 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
if (write) {
sb_start_pagefault(sb);
file_update_time(vma->vm_file);
- down_read(&EXT4_I(inode)->i_mmap_sem);
- handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
- ext4_chunk_trans_blocks(inode,
- PMD_SIZE / PAGE_SIZE));
- } else
- down_read(&EXT4_I(inode)->i_mmap_sem);
-
- if (IS_ERR(handle))
- result = VM_FAULT_SIGBUS;
- else {
- result = dax_iomap_pmd_fault(vma, addr, pmd, flags,
- &ext4_iomap_ops);
}
-
- if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
- up_read(&EXT4_I(inode)->i_mmap_sem);
+ down_read(&EXT4_I(inode)->i_mmap_sem);
+ result = dax_iomap_pmd_fault(vma, addr, pmd, flags,
+ &ext4_iomap_ops);
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ if (write)
sb_end_pagefault(sb);
- } else
- up_read(&EXT4_I(inode)->i_mmap_sem);
return result;
}