Christoph Hellwig wrote:
This code looks a little confusing to me..
*/
static char *decode_inode(struct super_block *s, char *addr,
reiser4_object_on_wire * obj)
@@ -41,7 +42,8 @@
fplug = file_plugin_by_disk_id(reiser4_get_tree(s), (d16 *) addr);
if (fplug != NULL) {
addr += sizeof(d16);
- obj->plugin = fplug;
+ if (obj)
+ obj->plugin = fplug;
You are adding quite a few of those if (obj) clauses. I can't see a
reason for that - care to explain? The new aops
new _export_ ops
should not disallow for
any functionality that has been there before.
Actually they don't disallow existing functionality, but
require a new one: earlier we performed decoding in
_each_ iteration (decode_fh), and now you want it to be
done separately (fh_to_dentry, fh_to_parent). So we need
something like "empty" iteration, which only moves to the
next position.
Every object in reiser4, that can be serialized, has
special non-zero "wire" methods. I guess that "empty"
iteration should be performed via wire->read() method
which is responsible for extracting on-wire object.
Can not promise to avoid "if" here: I think it is not
a good reason to add a new plugin method for such
empty skip.
The attached patch avoids other two ifs.
static struct dentry *reiser4_decode_fh(struct super_block *super, __u32 *fh,
+ int len, int fhtype, int parent)
{
reiser4_context *ctx;
reiser4_object_on_wire object;
char *addr;
ctx = reiser4_init_context(super);
if (IS_ERR(ctx))
@@ -80,25 +77,19 @@
assert("vs-1482",
fhtype == FH_WITH_PARENT || fhtype == FH_WITHOUT_PARENT);
addr = (char *)fh;
object_on_wire_init(&object);
+
+ if (parent)
+ /* skip first onwire object */
+ addr = decode_inode(super, addr, NULL);
if (!IS_ERR(addr)) {
+ addr = decode_inode(super, addr, &object);
if (!IS_ERR(addr)) {
struct dentry *d;
+ d = reiser4_get_dentry(super, &object);
I'd suggest to directly poke into the place where the parent handle
is stored. XFS used a similar construct to the decode_inode helper,
but with the new aops it's faster and easier to read if you just have
a helper on how many bytes to skip. Did you take a look at how the
various other filesystem handle the export ops?
We don't have a number of u32s to poke, like other filesystems do;
packing/extracting serialized objects in reiser4 is more complex:
first extract object's plugin, which knows how to extract further, etc..
--- linux-2.6.23-mm1/fs/reiser4/dscale.c.orig
+++ linux-2.6.23-mm1/fs/reiser4/dscale.c
@@ -126,6 +126,24 @@
How are the changes to all these other files related to the export
operations changes?
So we have to define an "if" branch for wire_read_common()
(plugin/file_plugin_common.c). The best place to do it is kassign.c
(as we actually pack/extract key components). Plus a small change in
dscale.c where a packing taxonomy is implemented. Have I missed
something?
Thanks,
Edward.
Adjust reiser4 to new export ops.
Signed-off-by: Edward Shishkin <[email protected]>
---
linux-2.6.23-mm1/fs/reiser4/dscale.c | 20 ++
linux-2.6.23-mm1/fs/reiser4/dscale.h | 3
linux-2.6.23-mm1/fs/reiser4/export_ops.c | 128 +++++++++-------
linux-2.6.23-mm1/fs/reiser4/kassign.c | 20 ++
linux-2.6.23-mm1/fs/reiser4/kassign.h | 1
linux-2.6.23-mm1/fs/reiser4/plugin/file_plugin_common.c | 2
6 files changed, 117 insertions(+), 57 deletions(-)
--- linux-2.6.23-mm1/fs/reiser4/dscale.c.orig
+++ linux-2.6.23-mm1/fs/reiser4/dscale.c
@@ -126,6 +126,24 @@
return 1 << tag;
}
+/* number of bytes consumed */
+int dscale_bytes_to_read(unsigned char *address)
+{
+ int tag;
+
+ tag = gettag(address);
+ switch (tag) {
+ case 0:
+ case 1:
+ case 2:
+ return 1 << tag;
+ case 3:
+ return 9;
+ default:
+ return RETERR(-EIO);
+ }
+}
+
/* store @value at @address and return number of bytes consumed */
int dscale_write(unsigned char *address, __u64 value)
{
@@ -144,7 +162,7 @@
}
/* number of bytes required to store @value */
-int dscale_bytes(__u64 value)
+int dscale_bytes_to_write(__u64 value)
{
int bytes;
--- linux-2.6.23-mm1/fs/reiser4/dscale.h.orig
+++ linux-2.6.23-mm1/fs/reiser4/dscale.h
@@ -10,7 +10,8 @@
extern int dscale_read(unsigned char *address, __u64 * value);
extern int dscale_write(unsigned char *address, __u64 value);
-extern int dscale_bytes(__u64 value);
+extern int dscale_bytes_to_read(unsigned char *address);
+extern int dscale_bytes_to_write(__u64 value);
extern int dscale_fit(__u64 value, __u64 other);
/* __FS_REISER4_DSCALE_H__ */
--- linux-2.6.23-mm1/fs/reiser4/export_ops.c.orig
+++ linux-2.6.23-mm1/fs/reiser4/export_ops.c
@@ -50,69 +50,91 @@
return addr;
}
+static struct dentry *reiser4_get_dentry(struct super_block *super,
+ void *data);
/**
- * reiser4_decode_fh - decode_fh of export operations
- * @super: super block
- * @fh: nfsd file handle
- * @len: length of file handle
- * @fhtype: type of file handle
- * @acceptable: acceptability testing function
- * @context: argument for @acceptable
- *
- * Returns dentry referring to the same file as @fh.
- */
-static struct dentry *reiser4_decode_fh(struct super_block *super, __u32 *fh,
- int len, int fhtype,
- int (*acceptable) (void *context,
- struct dentry *de),
- void *context)
+ * reiser4_decode_fh: decode on-wire object - helper function
+ * for fh_to_dentry, fh_to_parent export operations;
+ * @super: super block;
+ * @addr: onwire object to be decoded;
+ *
+ * Returns dentry referring to the object being decoded.
+ */
+static struct dentry *reiser4_decode_fh(struct super_block * super,
+ char * addr)
{
- reiser4_context *ctx;
reiser4_object_on_wire object;
- reiser4_object_on_wire parent;
- char *addr;
- int with_parent;
- ctx = reiser4_init_context(super);
+ object_on_wire_init(&object);
+
+ addr = decode_inode(super, addr, &object);
+ if (!IS_ERR(addr)) {
+ struct dentry *d;
+ d = reiser4_get_dentry(super, &object);
+ if (d != NULL && !IS_ERR(d))
+ /* FIXME check for -ENOMEM */
+ reiser4_get_dentry_fsdata(d)->stateless = 1;
+ addr = (char *)d;
+ }
+ object_on_wire_done(&object);
+ return (void *)addr;
+}
+
+static struct dentry *reiser4_fh_to_dentry(struct super_block *sb,
+ struct fid *fid,
+ int fh_len, int fh_type)
+{
+ reiser4_context *ctx;
+ struct dentry *d;
+
+ assert("edward-1536",
+ fh_type == FH_WITH_PARENT || fh_type == FH_WITHOUT_PARENT);
+
+ ctx = reiser4_init_context(sb);
if (IS_ERR(ctx))
return (struct dentry *)ctx;
- assert("vs-1482",
- fhtype == FH_WITH_PARENT || fhtype == FH_WITHOUT_PARENT);
+ d = reiser4_decode_fh(sb, (char *)fid->raw);
- with_parent = (fhtype == FH_WITH_PARENT);
+ reiser4_exit_context(ctx);
+ return d;
+}
- addr = (char *)fh;
+static struct dentry *reiser4_fh_to_parent(struct super_block *sb,
+ struct fid *fid,
+ int fh_len, int fh_type)
+{
+ char * addr;
+ struct dentry * d;
+ reiser4_context *ctx;
+ file_plugin *fplug;
- object_on_wire_init(&object);
- object_on_wire_init(&parent);
-#if 0
- addr = decode_inode(super, addr, &object);
- if (!IS_ERR(addr)) {
- if (with_parent)
- addr = decode_inode(super, addr, &parent);
- if (!IS_ERR(addr)) {
- struct dentry *d;
- typeof(super->s_export_op->find_exported_dentry) fn;
-
- fn = super->s_export_op->find_exported_dentry;
- assert("nikita-3521", fn != NULL);
- d = fn(super, &object, with_parent ? &parent : NULL,
- acceptable, context);
- if (d != NULL && !IS_ERR(d))
- /* FIXME check for -ENOMEM */
- reiser4_get_dentry_fsdata(d)->stateless = 1;
- addr = (char *)d;
- }
- }
- object_on_wire_done(&object);
- object_on_wire_done(&parent);
+ if (fh_type == FH_WITHOUT_PARENT)
+ return NULL;
+ assert("edward-1537", fh_type == FH_WITH_PARENT);
+ ctx = reiser4_init_context(sb);
+ if (IS_ERR(ctx))
+ return (struct dentry *)ctx;
+ addr = (char *)fid->raw;
+ /* extract 2-bytes file plugin id */
+ fplug = file_plugin_by_disk_id(reiser4_get_tree(sb), (d16 *)addr);
+ if (fplug == NULL) {
+ d = ERR_PTR(RETERR(-EINVAL));
+ goto exit;
+ }
+ addr += sizeof(d16);
+ /* skip previously encoded object */
+ addr = fplug->wire.read(addr, NULL /* skip */);
+ if (IS_ERR(addr)) {
+ d = (struct dentry *)addr;
+ goto exit;
+ }
+ /* @extract and decode parent object */
+ d = reiser4_decode_fh(sb, addr);
+ exit:
reiser4_exit_context(ctx);
- return (void *)addr;
-#else
- return ERR_PTR(-EINVAL);
-#endif
+ return d;
}
/*
@@ -281,9 +303,9 @@
struct export_operations reiser4_export_operations = {
.encode_fh = reiser4_encode_fh,
-// .decode_fh = reiser4_decode_fh,
+ .fh_to_dentry = reiser4_fh_to_dentry,
+ .fh_to_parent = reiser4_fh_to_parent,
.get_parent = reiser4_get_dentry_parent,
-// .get_dentry = reiser4_get_dentry
};
/*
--- linux-2.6.23-mm1/fs/reiser4/kassign.c.orig
+++ linux-2.6.23-mm1/fs/reiser4/kassign.c
@@ -604,8 +604,8 @@
{
int result;
- result = dscale_bytes(get_inode_oid(inode));
- result += dscale_bytes(get_inode_locality(inode));
+ result = dscale_bytes_to_write(get_inode_oid(inode));
+ result += dscale_bytes_to_write(get_inode_locality(inode));
/*
* ordering is large (it usually has highest bits set), so it makes
@@ -650,6 +650,22 @@
return addr;
}
+/*
+ * skip a key that was previously encoded by build_inode_onwire() at @addr
+ * FIXME: handle IO errors.
+ */
+char * locate_obj_key_id_onwire(char * addr)
+{
+ /* locality */
+ addr += dscale_bytes_to_read(addr);
+ /* objectid */
+ addr += dscale_bytes_to_read(addr);
+#if REISER4_LARGE_KEY
+ addr += sizeof ((obj_key_id *)0)->ordering;
+#endif
+ return addr;
+}
+
/* Make Linus happy.
Local variables:
c-indentation-style: "K&R"
--- linux-2.6.23-mm1/fs/reiser4/kassign.h.orig
+++ linux-2.6.23-mm1/fs/reiser4/kassign.h
@@ -64,6 +64,7 @@
extern int inode_onwire_size(const struct inode *obj);
extern char *build_inode_onwire(const struct inode *obj, char *area);
+extern char *locate_obj_key_id_onwire(char *area);
extern char *extract_obj_key_id_from_onwire(char *area, obj_key_id * key_id);
extern int build_inode_key_id(const struct inode *obj, obj_key_id * id);
--- linux-2.6.23-mm1/fs/reiser4/plugin/file_plugin_common.c.orig
+++ linux-2.6.23-mm1/fs/reiser4/plugin/file_plugin_common.c
@@ -459,6 +459,8 @@
char *wire_read_common(char *addr, reiser4_object_on_wire * obj)
{
+ if (!obj)
+ return locate_obj_key_id_onwire(addr);
return extract_obj_key_id_from_onwire(addr, &obj->u.std.key_id);
}
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
