This flag was not accepted when fiemap was proposed [2] due to lack of
in-kernel users. Btrfs has compression for a long time and we'd like to
see that an extent is compressed in the output of 'filefrag' utility
once it's taught about it.
For that purpose, a reserved field from fiemap_extent is used to let the
filesystem store along the physcial extent length when the flag is set.
This keeps compatibility with applications that use FIEMAP.
Extend arguments of fiemap_fill_next_extent and update all users.
[1] http://article.gmane.org/gmane.comp.file-systems.ext4/8871
[2] http://thread.gmane.org/gmane.comp.file-systems.ext4/8870
[3] http://thread.gmane.org/gmane.linux.file-systems/77632 (v1)
[4] http://www.spinics.net/lists/linux-fsdevel/msg69078.html (v2)
Cc: Al Viro <***@zeniv.linux.org.uk>
CC: Andreas Dilger <***@dilger.ca>
CC: Chris Mason <***@fb.com>
CC: Christoph Hellwig <***@infradead.org>
CC KONISHI Ryusuke <***@lab.ntt.co.jp>
CC: Mark Fasheh <***@suse.com>
CC: Steven Whitehouse <***@redhat.com>
CC: "Theodore Ts'o" <***@mit.edu>
CC: Ben Myers <***@sgi.com>
Signed-off-by: David Sterba <***@suse.cz>
---
fs/btrfs/extent_io.c | 2 +-
fs/ext4/extents.c | 3 ++-
fs/ext4/inline.c | 2 +-
fs/gfs2/inode.c | 2 +-
fs/ioctl.c | 27 +++++++++++++++++++++------
fs/nilfs2/inode.c | 8 +++++---
fs/ocfs2/extent_map.c | 4 ++--
fs/xfs/xfs_iops.c | 2 +-
include/linux/fs.h | 2 +-
include/uapi/linux/fiemap.h | 8 +++++++-
10 files changed, 42 insertions(+), 18 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a389820d158b..eec118bf77ae 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4357,7 +4357,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
end = 1;
}
ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
- em_len, flags);
+ em_len, em_len, flags);
if (ret)
goto out_free;
}
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 4da228a0e6d0..0bdd173ac728 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2253,6 +2253,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
(__u64)es.es_lblk << blksize_bits,
(__u64)es.es_pblk << blksize_bits,
(__u64)es.es_len << blksize_bits,
+ (__u64)es.es_len << blksize_bits,
flags);
if (err < 0)
break;
@@ -5125,7 +5126,7 @@ static int ext4_xattr_fiemap(struct inode *inode,
if (physical)
error = fiemap_fill_next_extent(fieinfo, 0, physical,
- length, flags);
+ length, length, flags);
return (error < 0 ? error : 0);
}
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 645205d8ada6..3825ff9dc40d 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1825,7 +1825,7 @@ int ext4_inline_data_fiemap(struct inode *inode,
if (physical)
error = fiemap_fill_next_extent(fieinfo, 0, physical,
- length, flags);
+ length, length, flags);
brelse(iloc.bh);
out:
up_read(&EXT4_I(inode)->xattr_sem);
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index e62e59477884..5b45cf4e5465 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1931,7 +1931,7 @@ static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
len = size - start;
if (start < size)
ret = fiemap_fill_next_extent(fieinfo, start, phys,
- len, flags);
+ len, len, flags);
if (ret == 1)
ret = 0;
} else {
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 8ac3fad36192..24a9d912d1e6 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -70,20 +70,26 @@ static int ioctl_fibmap(struct file *filp, int __user *p)
* @logical: Extent logical start offset, in bytes
* @phys: Extent physical start offset, in bytes
* @len: Extent length, in bytes
+ * @phys_len: Physical extent length in bytes
* @flags: FIEMAP_EXTENT flags that describe this extent
*
* Called from file system ->fiemap callback. Will populate extent
* info as passed in via arguments and copy to user memory. On
* success, extent count on fieinfo is incremented.
*
+ * Extents without any encoding must set the physical and logical length
+ * to the same value. Otherwise, set flags to FIEMAP_EXTENT_ENCODED
+ * and possibly specify encoding type.
+ *
* Returns 0 on success, -errno on error, 1 if this was the last
* extent that will fit in user array.
*/
#define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
-#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED)
+#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED | \
+ FIEMAP_EXTENT_DATA_COMPRESSED)
#define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
- u64 phys, u64 len, u32 flags)
+ u64 phys, u64 len, u64 phys_len, u32 flags)
{
struct fiemap_extent extent;
struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
@@ -110,6 +116,14 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
extent.fe_length = len;
extent.fe_flags = flags;
+ WARN_ONCE((flags & FIEMAP_EXTENT_DATA_COMPRESSED)
+ && !(flags & FIEMAP_EXTENT_ENCODED));
+ WARN_ONCE(phys_len != len && !(flags & FIEMAP_EXTENT_DATA_COMPRESSED),
+ "physical length %llu != logical length %llu without = DATA_COMPRESSED\n",
+ phys_len, len);
+
+ extent.fe_phys_length = phys_len;
+
dest += fieinfo->fi_extents_mapped;
if (copy_to_user(dest, &extent, sizeof(extent)))
return -EFAULT;
@@ -318,10 +332,11 @@ int __generic_block_fiemap(struct inode *inode,
flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size,
- flags);
+ size, flags);
} else if (size) {
ret = fiemap_fill_next_extent(fieinfo, logical,
- phys, size, flags);
+ phys, size,
+ size, flags);
size = 0;
}
@@ -347,7 +362,7 @@ int __generic_block_fiemap(struct inode *inode,
if (start_blk > last_blk && !whole_file) {
ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size,
- flags);
+ size, flags);
break;
}
@@ -358,7 +373,7 @@ int __generic_block_fiemap(struct inode *inode,
if (size) {
ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size,
- flags);
+ size, flags);
if (ret)
break;
}
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 6252b173a465..a74d3a0e670a 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -1017,7 +1017,8 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
if (size) {
/* End of the current extent */
ret = fiemap_fill_next_extent(
- fieinfo, logical, phys, size, flags);
+ fieinfo, logical, phys, size, size,
+ flags);
if (ret)
break;
}
@@ -1067,7 +1068,8 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
flags |= FIEMAP_EXTENT_LAST;
ret = fiemap_fill_next_extent(
- fieinfo, logical, phys, size, flags);
+ fieinfo, logical, phys, size,
+ size, flags);
if (ret)
break;
size = 0;
@@ -1083,7 +1085,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
/* Terminate the current extent */
ret = fiemap_fill_next_extent(
fieinfo, logical, phys, size,
- flags);
+ size, flags);
if (ret || blkoff > end_blkoff)
break;
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 767370b656ca..45c95aa2a00f 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -736,7 +736,7 @@ static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
id2.i_data.id_data);
ret = fiemap_fill_next_extent(fieinfo, 0, phys, id_count,
- flags);
+ id_count, flags);
if (ret < 0)
return ret;
}
@@ -809,7 +809,7 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
virt_bytes = (u64)le32_to_cpu(rec.e_cpos) << osb->s_clustersize_bits;
ret = fiemap_fill_next_extent(fieinfo, virt_bytes, phys_bytes,
- len_bytes, fe_flags);
+ len_bytes, len_bytes, fe_flags);
if (ret)
break;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 205613a06068..eeef5381debb 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1030,7 +1030,7 @@ xfs_fiemap_format(
fiemap_flags |= FIEMAP_EXTENT_LAST;
error = fiemap_fill_next_extent(fieinfo, logical, physical,
- length, fiemap_flags);
+ length, length, fiemap_flags);
if (error > 0) {
error = 0;
*full = 1; /* user array now full */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e11d60cc867b..609e1d72c3e0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1412,7 +1412,7 @@ struct fiemap_extent_info {
fiemap_extent array */
};
int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
- u64 phys, u64 len, u32 flags);
+ u64 phys, u64 len, u64 phys_len, u32 flags);
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
/*
diff --git a/include/uapi/linux/fiemap.h b/include/uapi/linux/fiemap.h
index 93abfcd9ac47..11b51887b94a 100644
--- a/include/uapi/linux/fiemap.h
+++ b/include/uapi/linux/fiemap.h
@@ -19,7 +19,9 @@ struct fiemap_extent {
__u64 fe_physical; /* physical offset in bytes for the start
* of the extent from the beginning of the disk */
__u64 fe_length; /* length in bytes for this extent */
- __u64 fe_reserved64[2];
+ __u64 fe_phys_length; /* physical length in bytes, may be different from
+ * fe_length and sets additional extent flags */
+ __u64 fe_reserved64;
__u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
__u32 fe_reserved[3];
};
@@ -50,6 +52,10 @@ struct fiemap {
* Sets EXTENT_UNKNOWN. */
#define FIEMAP_EXTENT_ENCODED 0x00000008 /* Data can not be read
* while fs is unmounted */
+#define FIEMAP_EXTENT_DATA_COMPRESSED 0x00000040 /* Data is compressed by fs.
+ * Sets EXTENT_ENCODED and
+ * the compressed size is
+ * stored in fe_phys_length */
#define FIEMAP_EXTENT_DATA_ENCRYPTED 0x00000080 /* Data is encrypted by fs.
* Sets EXTENT_ENCODED */
#define FIEMAP_EXTENT_NOT_ALIGNED 0x00000100 /* Extent offsets may not be
--
1.8.4.5