Following is our take on fiemap support for btrfs.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
---
fs/btrfs/extent_io.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/extent_io.h | 2 +
fs/btrfs/inode.c | 7 ++++
3 files changed, 93 insertions(+), 0 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 25ce2d1..a27bb39 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2900,6 +2900,89 @@ out:
return sector;
}
+int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len, get_extent_t *get_extent)
+{
+ int ret;
+ u64 off = start;
+ u64 max = start + len;
+ u32 flags = 0;
+ u64 disko = 0;
+ struct extent_map *em = NULL;
+ int end = 0;
+ u64 em_start = 0, em_len = 0;
+ ret = 0;
+
+ lock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
+ GFP_NOFS);
+ em = get_extent(inode, NULL, 0, off, max - off, 0);
+ if (!em)
+ goto out;
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto out;
+ }
+ while (!end) {
+ off = em->start + em->len;
+
+ em_start = em->start;
+ em_len = em->len;
+
+ disko = 0;
+ flags = 0;
+
+ switch (em->block_start) {
+ case EXTENT_MAP_LAST_BYTE:
+ end = 1;
+ flags |= FIEMAP_EXTENT_LAST;
+ break;
+ case EXTENT_MAP_HOLE:
+ flags |= FIEMAP_EXTENT_UNWRITTEN;
+ break;
+ case EXTENT_MAP_INLINE:
+ flags |= (FIEMAP_EXTENT_DATA_INLINE |
+ FIEMAP_EXTENT_NOT_ALIGNED);
+ break;
+ case EXTENT_MAP_DELALLOC:
+ flags |= (FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_UNKNOWN);
+ break;
+ default:
+ disko = em->block_start;
+ break;
+ }
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+ flags |= FIEMAP_EXTENT_ENCODED;
+
+ free_extent_map(em);
+
+ if (!end) {
+ em = get_extent(inode, NULL, 0, off, max - off, 0);
+ if (!em)
+ goto out;
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto out;
+ }
+ }
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ flags |= FIEMAP_EXTENT_LAST;
+ end = 1;
+ }
+
+ ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
+ em_len, flags);
+ if (ret)
+ goto out_free;
+ }
+out_free:
+ free_extent_map(em);
+out:
+ unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
+ GFP_NOFS);
+ return ret;
+}
+
static inline struct page *extent_buffer_page(struct extent_buffer *eb,
unsigned long i)
{
@@ -3786,3 +3869,4 @@ out:
return ret;
}
EXPORT_SYMBOL(try_release_extent_buffer);
+
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index c5b483a..e80c6d9 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -193,6 +193,8 @@ int extent_commit_write(struct extent_io_tree *tree,
unsigned from, unsigned to);
sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
get_extent_t *get_extent);
+int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len, get_extent_t *get_extent);
int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end);
int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 068bad4..ff182be 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4171,6 +4171,12 @@ static sector_t btrfs_bmap(struct address_space
*mapping, sector_t iblock)
return extent_bmap(mapping, iblock, btrfs_get_extent);
}
+static int btrfs_fiemap(struct inode *inode, struct
fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len)
+{
+ return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent);
+}
+
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
@@ -5023,6 +5029,7 @@ static struct inode_operations
btrfs_file_inode_operations = {
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
.fallocate = btrfs_fallocate,
+ .fiemap = btrfs_fiemap,
};
static struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
--
1.5.6.5
Thanks,
Yehuda
PS, please let me know is there''s any patch formatting issue.
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