Re: [PATCH 1/3] btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
On Fri, Sep 22, 2017 at 01:58:45PM -0400, Zygo Blaxell wrote: > The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and > offset (encoded as a single logical address) to a list of extent refs. > LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping > (extent ref -> extent bytenr and offset, or logical address). These are > useful capabilities for programs that manipulate extents and extent > references from userspace (e.g. dedup and defrag utilities). > > When the extents are uncompressed (and not encrypted and not other), > check_extent_in_eb performs filtering of the extent refs to remove any > extent refs which do not contain the same extent offset as the 'logical' > parameter's extent offset. This prevents LOGICAL_INO from returning > references to more than a single block. > > To find the set of extent references to an uncompressed extent from [a, > b), userspace has to run a loop like this pseudocode: > > for (i = a; i < b; ++i) > extent_ref_set += LOGICAL_INO(i); > > At each iteration of the loop (up to 32768 iterations for a 128M extent), > data we are interested in is collected in the kernel, then deleted by > the filter in check_extent_in_eb. > > When the extents are compressed (or encrypted or other), the 'logical' > parameter must be an extent bytenr (the 'a' parameter in the loop). > No filtering by extent offset is done (or possible?) so the result is > the complete set of extent refs for the entire extent. This removes > the need for the loop, since we get all the extent refs in one call. > > Add an 'ignore_offset' argument to iterate_inodes_from_logical, > [...several levels of function call graph...], and check_extent_in_eb, so > that we can disable the extent offset filtering for uncompressed extents. > This flag can be set by an improved version of the LOGICAL_INO ioctl to > get either behavior as desired. > > There is no functional change in this patch. The new flag is always > false. > > Signed-off-by: Zygo Blaxell Reviewed-by: David Sterba -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 1/3] btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address). These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).
When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset. This prevents LOGICAL_INO from returning
references to more than a single block.
To find the set of extent references to an uncompressed extent from [a,
b), userspace has to run a loop like this pseudocode:
for (i = a; i < b; ++i)
extent_ref_set += LOGICAL_INO(i);
At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.
When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent. This removes
the need for the loop, since we get all the extent refs in one call.
Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.
There is no functional change in this patch. The new flag is always
false.
Signed-off-by: Zygo Blaxell
---
fs/btrfs/backref.c| 63 ++-
fs/btrfs/backref.h| 8 +++---
fs/btrfs/inode.c | 2 +-
fs/btrfs/ioctl.c | 2 +-
fs/btrfs/qgroup.c | 8 +++---
fs/btrfs/scrub.c | 6 ++---
fs/btrfs/send.c | 2 +-
fs/btrfs/tests/qgroup-tests.c | 20 +++---
8 files changed, 63 insertions(+), 48 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index b517ef1477ea..a2609786cd86 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -40,12 +40,14 @@ static int check_extent_in_eb(const struct btrfs_key *key,
const struct extent_buffer *eb,
const struct btrfs_file_extent_item *fi,
u64 extent_item_pos,
- struct extent_inode_elem **eie)
+ struct extent_inode_elem **eie,
+ bool ignore_offset)
{
u64 offset = 0;
struct extent_inode_elem *e;
- if (!btrfs_file_extent_compression(eb, fi) &&
+ if (!ignore_offset &&
+ !btrfs_file_extent_compression(eb, fi) &&
!btrfs_file_extent_encryption(eb, fi) &&
!btrfs_file_extent_other_encoding(eb, fi)) {
u64 data_offset;
@@ -84,7 +86,8 @@ static void free_inode_elem_list(struct extent_inode_elem
*eie)
static int find_extent_in_eb(const struct extent_buffer *eb,
u64 wanted_disk_byte, u64 extent_item_pos,
-struct extent_inode_elem **eie)
+struct extent_inode_elem **eie,
+bool ignore_offset)
{
u64 disk_byte;
struct btrfs_key key;
@@ -113,7 +116,7 @@ static int find_extent_in_eb(const struct extent_buffer *eb,
if (disk_byte != wanted_disk_byte)
continue;
- ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie);
+ ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie,
ignore_offset);
if (ret < 0)
return ret;
}
@@ -419,7 +422,7 @@ static int add_indirect_ref(const struct btrfs_fs_info
*fs_info,
static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
struct ulist *parents, struct prelim_ref *ref,
int level, u64 time_seq, const u64 *extent_item_pos,
- u64 total_refs)
+ u64 total_refs, bool ignore_offset)
{
int ret = 0;
int slot;
@@ -472,7 +475,7 @@ static int add_all_parents(struct btrfs_root *root, struct
btrfs_path *path,
if (extent_item_pos) {
ret = check_extent_in_eb(&key, eb, fi,
*extent_item_pos,
- &eie);
+ &eie, ignore_offset);
[PATCH 1/3] btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address). These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).
When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset. This prevents LOGICAL_INO from returning
references to more than a single block.
To find the set of extent references to an uncompressed extent from [a,
b), userspace has to run a loop like this pseudocode:
for (i = a; i < b; ++i)
extent_ref_set += LOGICAL_INO(i);
At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.
When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent. This removes
the need for the loop, since we get all the extent refs in one call.
Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.
There is no functional change in this patch. The new flag is always
false.
Signed-off-by: Zygo Blaxell
---
fs/btrfs/backref.c| 63 ++-
fs/btrfs/backref.h| 8 +++---
fs/btrfs/inode.c | 2 +-
fs/btrfs/ioctl.c | 2 +-
fs/btrfs/qgroup.c | 8 +++---
fs/btrfs/scrub.c | 6 ++---
fs/btrfs/send.c | 2 +-
fs/btrfs/tests/qgroup-tests.c | 20 +++---
8 files changed, 63 insertions(+), 48 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index b517ef1477ea..a2609786cd86 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -40,12 +40,14 @@ static int check_extent_in_eb(const struct btrfs_key *key,
const struct extent_buffer *eb,
const struct btrfs_file_extent_item *fi,
u64 extent_item_pos,
- struct extent_inode_elem **eie)
+ struct extent_inode_elem **eie,
+ bool ignore_offset)
{
u64 offset = 0;
struct extent_inode_elem *e;
- if (!btrfs_file_extent_compression(eb, fi) &&
+ if (!ignore_offset &&
+ !btrfs_file_extent_compression(eb, fi) &&
!btrfs_file_extent_encryption(eb, fi) &&
!btrfs_file_extent_other_encoding(eb, fi)) {
u64 data_offset;
@@ -84,7 +86,8 @@ static void free_inode_elem_list(struct extent_inode_elem
*eie)
static int find_extent_in_eb(const struct extent_buffer *eb,
u64 wanted_disk_byte, u64 extent_item_pos,
-struct extent_inode_elem **eie)
+struct extent_inode_elem **eie,
+bool ignore_offset)
{
u64 disk_byte;
struct btrfs_key key;
@@ -113,7 +116,7 @@ static int find_extent_in_eb(const struct extent_buffer *eb,
if (disk_byte != wanted_disk_byte)
continue;
- ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie);
+ ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie,
ignore_offset);
if (ret < 0)
return ret;
}
@@ -419,7 +422,7 @@ static int add_indirect_ref(const struct btrfs_fs_info
*fs_info,
static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
struct ulist *parents, struct prelim_ref *ref,
int level, u64 time_seq, const u64 *extent_item_pos,
- u64 total_refs)
+ u64 total_refs, bool ignore_offset)
{
int ret = 0;
int slot;
@@ -472,7 +475,7 @@ static int add_all_parents(struct btrfs_root *root, struct
btrfs_path *path,
if (extent_item_pos) {
ret = check_extent_in_eb(&key, eb, fi,
*extent_item_pos,
- &eie);
+ &eie, ignore_offset);
[PATCH 1/3] btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address). These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).
When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset. This prevents LOGICAL_INO from returning
references to more than a single block.
To find the set of extent references to an uncompressed extent from [a,
b), userspace has to run a loop like this pseudocode:
for (i = a; i < b; ++i)
extent_ref_set += LOGICAL_INO(i);
At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.
When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent. This removes
the need for the loop, since we get all the extent refs in one call.
Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.
There is no functional change in this patch. The new flag is always
false.
Signed-off-by: Zygo Blaxell
---
fs/btrfs/backref.c | 62 --
fs/btrfs/backref.h | 8 ---
fs/btrfs/inode.c | 2 +-
fs/btrfs/ioctl.c | 2 +-
fs/btrfs/qgroup.c | 8 +++
fs/btrfs/scrub.c | 6 +++---
fs/btrfs/send.c| 2 +-
7 files changed, 52 insertions(+), 38 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 1d71a5a4b1b9..3bffd36c6897 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -302,12 +302,14 @@ static int ref_tree_add(struct ref_root *ref_tree, u64
root_id, u64 object_id,
static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,
struct btrfs_file_extent_item *fi,
u64 extent_item_pos,
- struct extent_inode_elem **eie)
+ struct extent_inode_elem **eie,
+ bool ignore_offset)
{
u64 offset = 0;
struct extent_inode_elem *e;
- if (!btrfs_file_extent_compression(eb, fi) &&
+ if (!ignore_offset &&
+ !btrfs_file_extent_compression(eb, fi) &&
!btrfs_file_extent_encryption(eb, fi) &&
!btrfs_file_extent_other_encoding(eb, fi)) {
u64 data_offset;
@@ -346,7 +348,8 @@ static void free_inode_elem_list(struct extent_inode_elem
*eie)
static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte,
u64 extent_item_pos,
- struct extent_inode_elem **eie)
+ struct extent_inode_elem **eie,
+ bool ignore_offset)
{
u64 disk_byte;
struct btrfs_key key;
@@ -375,7 +378,7 @@ static int find_extent_in_eb(struct extent_buffer *eb, u64
wanted_disk_byte,
if (disk_byte != wanted_disk_byte)
continue;
- ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie);
+ ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie,
ignore_offset);
if (ret < 0)
return ret;
}
@@ -511,7 +514,7 @@ static int __add_prelim_ref(struct list_head *head, u64
root_id,
static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
struct ulist *parents, struct __prelim_ref *ref,
int level, u64 time_seq, const u64 *extent_item_pos,
- u64 total_refs)
+ u64 total_refs, bool ignore_offset)
{
int ret = 0;
int slot;
@@ -564,7 +567,7 @@ static int add_all_parents(struct btrfs_root *root, struct
btrfs_path *path,
if (extent_item_pos) {
ret = check_extent_in_eb(&key, eb, fi,
*extent_item_pos,
- &eie);
+ &eie, ignore_offset);
if (ret < 0)
