[3/4] ext4: Add iomap support for inline data

Message ID 20170829142942.21594-4-agruenba@redhat.com
State New
Headers show
Series
  • ext4: SEEK_HOLE / SEEK_DATA via iomap
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Commit Message

Andreas Gruenbacher Aug. 29, 2017, 2:29 p.m.
Report inline data as an IOMAP_F_DATA_INLINE mapping.  This allows to
switch to iomap_seek_hole and iomap_seek_data in ext4_llseek, and will
make switching to iomap_fiemap in ext4_fiemap easier as well.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/ext4/ext4.h   |  4 ++++
 fs/ext4/inline.c | 33 +++++++++++++++++++++++++++++++++
 fs/ext4/inode.c  | 10 ++++++++--
 3 files changed, 45 insertions(+), 2 deletions(-)

Comments

Jan Kara Aug. 30, 2017, 12:47 p.m. | #1
On Tue 29-08-17 16:29:41, Andreas Gruenbacher wrote:
> Report inline data as an IOMAP_F_DATA_INLINE mapping.  This allows to
> switch to iomap_seek_hole and iomap_seek_data in ext4_llseek, and will
> make switching to iomap_fiemap in ext4_fiemap easier as well.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Just one nit and one comment below. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>


> ---
>  fs/ext4/ext4.h   |  4 ++++
>  fs/ext4/inline.c | 33 +++++++++++++++++++++++++++++++++
>  fs/ext4/inode.c  | 10 ++++++++--
>  3 files changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index a2bb7d2870e4..017e55942a49 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -3048,6 +3048,10 @@ extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
>  extern int ext4_inline_data_fiemap(struct inode *inode,
>  				   struct fiemap_extent_info *fieinfo,
>  				   int *has_inline, __u64 start, __u64 len);
> +
> +struct iomap;
> +extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
> +
>  extern int ext4_try_to_evict_inline_data(handle_t *handle,
>  					 struct inode *inode,
>  					 int needed);
> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
> index 28c5c3abddb3..21a078fef80f 100644
> --- a/fs/ext4/inline.c
> +++ b/fs/ext4/inline.c
> @@ -12,6 +12,7 @@
>   * GNU General Public License for more details.
>   */
>  
> +#include <linux/iomap.h>
>  #include <linux/fiemap.h>
>  
>  #include "ext4_jbd2.h"
> @@ -1827,6 +1828,38 @@ int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
>  	return ret;
>  }
>  
> +int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap)
> +{
> +	__u64 addr;
> +	int error = -ENOENT;
> +	struct ext4_iloc iloc;
> +
> +	down_read(&EXT4_I(inode)->xattr_sem);
> +	if (!ext4_has_inline_data(inode))
> +		goto out;

Hum, ENOENT looks rather arbitrary for a lost race with inode conversion.
Maybe EAGAIN would be better? We use it in some other place as well to
indicate that inode has been converted...

> +
> +	error = ext4_get_inode_loc(inode, &iloc);
> +	if (error)
> +		goto out;

Using ext4_get_inode_loc() just to get block + offset of the inode is a bit
overkill since it will also allocate buffer_head, load the block with inode
from disk, etc. But since this is not performance critical and the buffer
is likely to be in cache anyway, I can live with this I guess.

								Honza
Jan Kara Aug. 30, 2017, 12:54 p.m. | #2
On Tue 29-08-17 16:29:41, Andreas Gruenbacher wrote:
> Report inline data as an IOMAP_F_DATA_INLINE mapping.  This allows to
> switch to iomap_seek_hole and iomap_seek_data in ext4_llseek, and will
> make switching to iomap_fiemap in ext4_fiemap easier as well.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

...

> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 429f0afde9f2..ab6ab835255e 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3411,8 +3411,14 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>  	struct ext4_map_blocks map;
>  	int ret;
>  
> -	if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
> -		return -ERANGE;
> +	if ((flags & IOMAP_REPORT) && ext4_has_inline_data(inode)) {
> +		ret = ext4_inline_data_iomap(inode, iomap);
> +		if (ret != -ENOENT) {
> +			if (ret == 0 && offset >= iomap->length)
> +				ret = -ENOENT;
> +			return ret;
> +		}
> +	}

One more thing: Please keep that WARN_ON and bail out for !IOMAP_REPORT
cases. Thanks!

								Honza

Patch

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a2bb7d2870e4..017e55942a49 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3048,6 +3048,10 @@  extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
 extern int ext4_inline_data_fiemap(struct inode *inode,
 				   struct fiemap_extent_info *fieinfo,
 				   int *has_inline, __u64 start, __u64 len);
+
+struct iomap;
+extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap);
+
 extern int ext4_try_to_evict_inline_data(handle_t *handle,
 					 struct inode *inode,
 					 int needed);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 28c5c3abddb3..21a078fef80f 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -12,6 +12,7 @@ 
  * GNU General Public License for more details.
  */
 
+#include <linux/iomap.h>
 #include <linux/fiemap.h>
 
 #include "ext4_jbd2.h"
@@ -1827,6 +1828,38 @@  int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
 	return ret;
 }
 
+int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap)
+{
+	__u64 addr;
+	int error = -ENOENT;
+	struct ext4_iloc iloc;
+
+	down_read(&EXT4_I(inode)->xattr_sem);
+	if (!ext4_has_inline_data(inode))
+		goto out;
+
+	error = ext4_get_inode_loc(inode, &iloc);
+	if (error)
+		goto out;
+
+	addr = (__u64)iloc.bh->b_blocknr << inode->i_sb->s_blocksize_bits;
+	addr += (char *)ext4_raw_inode(&iloc) - iloc.bh->b_data;
+	addr += offsetof(struct ext4_inode, i_block);
+
+	brelse(iloc.bh);
+
+	iomap->addr = addr;
+	iomap->offset = 0;
+	iomap->length = min_t(loff_t, ext4_get_inline_size(inode),
+			      i_size_read(inode));
+	iomap->type = 0;
+	iomap->flags = IOMAP_F_DATA_INLINE;
+
+out:
+	up_read(&EXT4_I(inode)->xattr_sem);
+	return error;
+}
+
 int ext4_inline_data_fiemap(struct inode *inode,
 			    struct fiemap_extent_info *fieinfo,
 			    int *has_inline, __u64 start, __u64 len)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 429f0afde9f2..ab6ab835255e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3411,8 +3411,14 @@  static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 	struct ext4_map_blocks map;
 	int ret;
 
-	if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
-		return -ERANGE;
+	if ((flags & IOMAP_REPORT) && ext4_has_inline_data(inode)) {
+		ret = ext4_inline_data_iomap(inode, iomap);
+		if (ret != -ENOENT) {
+			if (ret == 0 && offset >= iomap->length)
+				ret = -ENOENT;
+			return ret;
+		}
+	}
 
 	map.m_lblk = first_block;
 	map.m_len = last_block - first_block + 1;