Re: [PATCH v8 06/18] ext2, dax: introduce ext2_dax_aops
On Fri 30-03-18 21:02:41, Dan Williams wrote:
> In preparation for the dax implementation to start associating dax pages
> to inodes via page->mapping, we need to provide a 'struct
> address_space_operations' instance for dax. Otherwise, direct-I/O
> triggers incorrect page cache assumptions and warnings.
>
> Cc: Jan Kara
> Reported-by: kbuild test robot
> Signed-off-by: Dan Williams
Looks good. You can add:
Reviewed-by: Jan Kara
Honza
> ---
> fs/ext2/ext2.h |1 +
> fs/ext2/inode.c | 46 +++---
> fs/ext2/namei.c | 18 ++
> 3 files changed, 30 insertions(+), 35 deletions(-)
>
> diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
> index 032295e1d386..cc40802ddfa8 100644
> --- a/fs/ext2/ext2.h
> +++ b/fs/ext2/ext2.h
> @@ -814,6 +814,7 @@ extern const struct inode_operations
> ext2_file_inode_operations;
> extern const struct file_operations ext2_file_operations;
>
> /* inode.c */
> +extern void ext2_set_file_ops(struct inode *inode);
> extern const struct address_space_operations ext2_aops;
> extern const struct address_space_operations ext2_nobh_aops;
> extern const struct iomap_ops ext2_iomap_ops;
> diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
> index 9b2ac55ac34f..1e01fabef130 100644
> --- a/fs/ext2/inode.c
> +++ b/fs/ext2/inode.c
> @@ -940,9 +940,6 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
> loff_t offset = iocb->ki_pos;
> ssize_t ret;
>
> - if (WARN_ON_ONCE(IS_DAX(inode)))
> - return -EIO;
> -
> ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
> if (ret < 0 && iov_iter_rw(iter) == WRITE)
> ext2_write_failed(mapping, offset + count);
> @@ -952,17 +949,16 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter
> *iter)
> static int
> ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
> {
> -#ifdef CONFIG_FS_DAX
> - if (dax_mapping(mapping)) {
> - return dax_writeback_mapping_range(mapping,
> -mapping->host->i_sb->s_bdev,
> -wbc);
> - }
> -#endif
> -
> return mpage_writepages(mapping, wbc, ext2_get_block);
> }
>
> +static int
> +ext2_dax_writepages(struct address_space *mapping, struct writeback_control
> *wbc)
> +{
> + return dax_writeback_mapping_range(mapping,
> + mapping->host->i_sb->s_bdev, wbc);
> +}
> +
> const struct address_space_operations ext2_aops = {
> .readpage = ext2_readpage,
> .readpages = ext2_readpages,
> @@ -990,6 +986,13 @@ const struct address_space_operations ext2_nobh_aops = {
> .error_remove_page = generic_error_remove_page,
> };
>
> +static const struct address_space_operations ext2_dax_aops = {
> + .writepages = ext2_dax_writepages,
> + .direct_IO = noop_direct_IO,
> + .set_page_dirty = noop_set_page_dirty,
> + .invalidatepage = noop_invalidatepage,
> +};
> +
> /*
> * Probably it should be a library function... search for first non-zero word
> * or memcmp with zero_page, whatever is better for particular architecture.
> @@ -1388,6 +1391,18 @@ void ext2_set_inode_flags(struct inode *inode)
> inode->i_flags |= S_DAX;
> }
>
> +void ext2_set_file_ops(struct inode *inode)
> +{
> + inode->i_op = &ext2_file_inode_operations;
> + inode->i_fop = &ext2_file_operations;
> + if (IS_DAX(inode))
> + inode->i_mapping->a_ops = &ext2_dax_aops;
> + else if (test_opt(inode->i_sb, NOBH))
> + inode->i_mapping->a_ops = &ext2_nobh_aops;
> + else
> + inode->i_mapping->a_ops = &ext2_aops;
> +}
> +
> struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
> {
> struct ext2_inode_info *ei;
> @@ -1480,14 +1495,7 @@ struct inode *ext2_iget (struct super_block *sb,
> unsigned long ino)
> ei->i_data[n] = raw_inode->i_block[n];
>
> if (S_ISREG(inode->i_mode)) {
> - inode->i_op = &ext2_file_inode_operations;
> - if (test_opt(inode->i_sb, NOBH)) {
> - inode->i_mapping->a_ops = &ext2_nobh_aops;
> - inode->i_fop = &ext2_file_operations;
> - } else {
> - inode->i_mapping->a_ops = &ext2_aops;
> - inode->i_fop = &ext2_file_operations;
> - }
> + ext2_set_file_ops(inode);
> } else if (S_ISDIR(inode->i_mode)) {
> inode->i_op = &ext2_dir_inode_operations;
> inode->i_fop = &ext2_dir_operations;
> diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
> index e078075dc66f..55f7caadb093 100644
> --- a/fs/ext2/namei.c
> +++ b/fs/ext2/namei.c
> @@ -107,14 +107,7 @@ static int ext2_create (struct inode * dir, struct
> dentry * dentry,
[PATCH v8 06/18] ext2, dax: introduce ext2_dax_aops
In preparation for the dax implementation to start associating dax pages
to inodes via page->mapping, we need to provide a 'struct
address_space_operations' instance for dax. Otherwise, direct-I/O
triggers incorrect page cache assumptions and warnings.
Cc: Jan Kara
Reported-by: kbuild test robot
Signed-off-by: Dan Williams
---
fs/ext2/ext2.h |1 +
fs/ext2/inode.c | 46 +++---
fs/ext2/namei.c | 18 ++
3 files changed, 30 insertions(+), 35 deletions(-)
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 032295e1d386..cc40802ddfa8 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -814,6 +814,7 @@ extern const struct inode_operations
ext2_file_inode_operations;
extern const struct file_operations ext2_file_operations;
/* inode.c */
+extern void ext2_set_file_ops(struct inode *inode);
extern const struct address_space_operations ext2_aops;
extern const struct address_space_operations ext2_nobh_aops;
extern const struct iomap_ops ext2_iomap_ops;
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 9b2ac55ac34f..1e01fabef130 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -940,9 +940,6 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
loff_t offset = iocb->ki_pos;
ssize_t ret;
- if (WARN_ON_ONCE(IS_DAX(inode)))
- return -EIO;
-
ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
if (ret < 0 && iov_iter_rw(iter) == WRITE)
ext2_write_failed(mapping, offset + count);
@@ -952,17 +949,16 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
static int
ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
-#ifdef CONFIG_FS_DAX
- if (dax_mapping(mapping)) {
- return dax_writeback_mapping_range(mapping,
- mapping->host->i_sb->s_bdev,
- wbc);
- }
-#endif
-
return mpage_writepages(mapping, wbc, ext2_get_block);
}
+static int
+ext2_dax_writepages(struct address_space *mapping, struct writeback_control
*wbc)
+{
+ return dax_writeback_mapping_range(mapping,
+ mapping->host->i_sb->s_bdev, wbc);
+}
+
const struct address_space_operations ext2_aops = {
.readpage = ext2_readpage,
.readpages = ext2_readpages,
@@ -990,6 +986,13 @@ const struct address_space_operations ext2_nobh_aops = {
.error_remove_page = generic_error_remove_page,
};
+static const struct address_space_operations ext2_dax_aops = {
+ .writepages = ext2_dax_writepages,
+ .direct_IO = noop_direct_IO,
+ .set_page_dirty = noop_set_page_dirty,
+ .invalidatepage = noop_invalidatepage,
+};
+
/*
* Probably it should be a library function... search for first non-zero word
* or memcmp with zero_page, whatever is better for particular architecture.
@@ -1388,6 +1391,18 @@ void ext2_set_inode_flags(struct inode *inode)
inode->i_flags |= S_DAX;
}
+void ext2_set_file_ops(struct inode *inode)
+{
+ inode->i_op = &ext2_file_inode_operations;
+ inode->i_fop = &ext2_file_operations;
+ if (IS_DAX(inode))
+ inode->i_mapping->a_ops = &ext2_dax_aops;
+ else if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+}
+
struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
{
struct ext2_inode_info *ei;
@@ -1480,14 +1495,7 @@ struct inode *ext2_iget (struct super_block *sb,
unsigned long ino)
ei->i_data[n] = raw_inode->i_block[n];
if (S_ISREG(inode->i_mode)) {
- inode->i_op = &ext2_file_inode_operations;
- if (test_opt(inode->i_sb, NOBH)) {
- inode->i_mapping->a_ops = &ext2_nobh_aops;
- inode->i_fop = &ext2_file_operations;
- } else {
- inode->i_mapping->a_ops = &ext2_aops;
- inode->i_fop = &ext2_file_operations;
- }
+ ext2_set_file_ops(inode);
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &ext2_dir_inode_operations;
inode->i_fop = &ext2_dir_operations;
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index e078075dc66f..55f7caadb093 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -107,14 +107,7 @@ static int ext2_create (struct inode * dir, struct dentry
* dentry, umode_t mode
if (IS_ERR(inode))
return PTR_ERR(inode);
- inode->i_op = &ext2_file_inode_operations;
- if (test_opt(inode->i_sb, NOBH)) {
- inode->i_mapping->a_ops = &ext2_nobh_aops;
- inode->i_fop = &ext2_file_operations;
- } else {
- inod
