From: Jan Kara <jack@suse.cz>
To: <linux-fsdevel@vger.kernel.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>, <linux-mm@kvack.org>,
<linux-ext4@vger.kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>, Jan Kara <jack@suse.cz>
Subject: [PATCH 6/6] ext4: Simplify DAX fault path
Date: Mon, 12 Dec 2016 17:47:08 +0100 [thread overview]
Message-ID: <20161212164708.23244-7-jack@suse.cz> (raw)
In-Reply-To: <20161212164708.23244-1-jack@suse.cz>
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>
---
fs/ext4/file.c | 48 ++++++++++--------------------------------------
1 file 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 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
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;
}
--
2.10.2
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next prev parent reply other threads:[~2016-12-12 16:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-12 16:47 [PATCH 0/6 v3] dax: Page invalidation fixes Jan Kara
2016-12-12 16:47 ` [PATCH 1/6] ext2: Return BH_New buffers for zeroed blocks Jan Kara
2016-12-12 16:47 ` [PATCH 2/6] mm: Invalidate DAX radix tree entries only if appropriate Jan Kara
2016-12-12 17:50 ` Johannes Weiner
2016-12-12 16:47 ` [PATCH 3/6] dax: Avoid page invalidation races and unnecessary radix tree traversals Jan Kara
2016-12-12 16:47 ` [PATCH 4/6] dax: Finish fault completely when loading holes Jan Kara
2016-12-12 16:47 ` [PATCH 5/6] dax: Call ->iomap_begin without entry lock during dax fault Jan Kara
2016-12-12 16:47 ` Jan Kara [this message]
2016-12-12 17:51 ` [PATCH 0/6 v3] dax: Page invalidation fixes Johannes Weiner
2016-12-13 11:52 ` Jan Kara
2016-12-13 18:57 ` Dan Williams
2016-12-17 1:35 ` Dan Williams
2016-12-17 1:49 ` Dan Williams
2016-12-19 9:56 ` Jan Kara
2016-12-19 21:51 ` Dan Williams
2016-12-20 7:59 ` Jan Kara
2016-12-20 20:09 ` Dan Williams
2016-12-13 20:01 ` Dave Chinner
2016-12-13 20:42 ` Theodore Ts'o
-- strict thread matches above, loose matches on Subject: below --
2016-11-24 9:46 [PATCH 0/6 v2] " Jan Kara
2016-11-24 9:46 ` [PATCH 6/6] ext4: Simplify DAX fault path Jan Kara
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