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

Andreas Gruenbacher
2017-08-29T14:29:55Z

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(-)

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;
--
2.13.3