Message-ID: <20131203055241.3160@gmx.com>
Date:	Tue, 03 Dec 2013 00:52:40 -0500
From:	"Fabian Frederick" <fabian.frederick@...anoid.net>
To:	linux-kernel@...r.kernel.org
Subject: [PATCH] befs : Add small_data support through xattr handlers

Beos Filesystem stores small attributes in first inode block automagically read during lookup.
Current driver implementation does nothing about it.
 
Those attributes feature both window manager and user metadata.
 
-This patch wakes up the small_data dump functionality when mounting in debug mode (iget)
-The same is done "for real" by creating a list_head merged in befs_inode_info.
-getfattr -n "attributename" is handled as well to retrieve small attributes
 through xattr_handlers.
 
I hope someone (Andrew, Al ?) can help me improve that feature despite that driver is declared "Orphan" in maintainer list.
 
Signed off by Fabian Frederick
diff --git a/fs/befs/befs.h b/fs/befs/befs.h
index b266428..02eb7ae 100644
--- a/fs/befs/befs.h
+++ b/fs/befs/befs.h
@@ -57,6 +57,14 @@ typedef struct befs_sb_info {
 
 } befs_sb_info;
 
+typedef struct befs_small_datamem {
+ u32 type;
+ char name[BEFS_ATTRIBUTE_LEN];
+ char value[BEFS_ATTRIBUTE_VALUE_LEN];
+ struct list_head list;
+
+} befs_small_datamem;
+
 typedef struct befs_inode_info {
  u32 i_flags;
  u32 i_type;
@@ -71,6 +79,7 @@ typedef struct befs_inode_info {
  } i_data;
 
  struct inode vfs_inode;
+ struct befs_small_datamem datamem;
 
 } befs_inode_info;
 
@@ -96,6 +105,8 @@ void befs_dump_super_block(const struct super_block *sb, befs_super_block *);
 void befs_dump_inode(const struct super_block *sb, befs_inode *);
 void befs_dump_index_entry(const struct super_block *sb, befs_disk_btree_super *);
 void befs_dump_index_node(const struct super_block *sb, befs_btree_nodehead *);
+void befs_dump_small_data(const struct super_block *sb, befs_small_data * sd);
+
 /****************************/
 
 
diff --git a/fs/befs/befs_fs_types.h b/fs/befs/befs_fs_types.h
index eb557d9..47e2ac0 100644
--- a/fs/befs/befs_fs_types.h
+++ b/fs/befs/befs_fs_types.h
@@ -26,6 +26,8 @@
 
 #define BEFS_NAME_LEN 255
 
+#define BEFS_ATTRIBUTE_LEN 255
+#define BEFS_ATTRIBUTE_VALUE_LEN 1024
 #define BEFS_SYMLINK_LEN 144
 #define BEFS_NUM_DIRECT_BLOCKS 12
 #define B_OS_NAME_LENGTH 32
diff --git a/fs/befs/debug.c b/fs/befs/debug.c
index 622e737..d23dda2 100644
--- a/fs/befs/debug.c
+++ b/fs/befs/debug.c
@@ -222,13 +222,38 @@ befs_dump_super_block(const struct super_block *sb, befs_super_block * sup)
 #endif //CONFIG_BEFS_DEBUG
 }
 
-#if 0
-/* unused */
 void
 befs_dump_small_data(const struct super_block *sb, befs_small_data * sd)
 {
+#ifdef CONFIG_BEFS_DEBUG
+
+ char *oft, *ioft;
+ ioft=(char*)sd;
+
+ while(1){
+ befs_debug(sb, "befs_small_data information");
+ befs_debug(sb, "   type : %x", sd->type);
+ befs_debug(sb, "   name size : %d", sd->name_size);
+ befs_debug(sb, "   name size : %d", sd->data_size);
+ if(sd->name[0]==0x13)
+ befs_debug(sb, "   name : %d", sd->data_size);
+     else befs_debug(sb, "   name : %s", sd->name);
+ oft=sd->name;
+ while(oft[0])oft++; //eos
+ oft+=3; //padding
+ befs_debug(sb, "   value :%s", oft);
+ oft=oft+(sd->data_size);
+ while(!oft[0])oft++; 
+ sd=(befs_small_data*)oft;
+ befs_debug(sb, "   ioft : %x oft : %x delta : %x", ioft, oft, oft-ioft);
+ if(oft-ioft > sb->s_blocksize-sizeof(befs_inode))
+ break;
+ }
+
+#endif //CONFIG_BEFS_DEBUG
 }
 
+#if 0
 /* unused */
 void
 befs_dump_run(const struct super_block *sb, befs_disk_block_run run)
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index daa15d6..ba7d3e8 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -3,6 +3,8 @@
  *
  * Copyright (C) 2001 Will Dyson <will_dyson@...ox.com
  *
+ * 12/2013 : Fabian Frederick : Adding xattr support.
+ *
  */
 
 #include <linux/module.h>
@@ -16,6 +18,7 @@
 #include <linux/parser.h>
 #include <linux/namei.h>
 #include <linux/sched.h>
+#include <linux/xattr.h>
 
 #include "befs.h"
 #include "btree.h"
@@ -36,6 +39,7 @@ static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 static int befs_readpage(struct file *file, struct page *page);
 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
+static void befs_getsmalldata(struct super_block *, befs_small_data *, struct befs_small_datamem *);
 static struct inode *befs_iget(struct super_block *, unsigned long);
 static struct inode *befs_alloc_inode(struct super_block *sb);
 static void befs_destroy_inode(struct inode *inode);
@@ -43,6 +47,7 @@ static int befs_init_inodecache(void);
 static void befs_destroy_inodecache(void);
 static void *befs_follow_link(struct dentry *, struct nameidata *);
 static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
+static int befs_xattr_get(struct dentry *, const char *, void *, size_t, int);
 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
  char **out, int *out_len);
 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
@@ -74,6 +79,10 @@ static const struct inode_operations befs_dir_inode_operations = {
  .lookup = befs_lookup,
 };
 
+static const struct inode_operations befs_file_inode_operations = {
+ .getxattr = generic_getxattr,
+};
+
 static const struct address_space_operations befs_aops = {
  .readpage = befs_readpage,
  .bmap = befs_bmap,
@@ -90,6 +99,16 @@ static const struct inode_operations befs_symlink_inode_operations = {
  .put_link = kfree_put_link,
 };
 
+static const struct xattr_handler befs_xattr_handler = {
+ .prefix = "",
+ .get = befs_xattr_get,
+};
+
+static const struct xattr_handler *befs_xattr_handlers[] = {
+ &befs_xattr_handler,
+ NULL
+};
+
 /* 
  * Called by generic_file_read() to read a page of data
  * 
@@ -311,6 +330,35 @@ static void init_once(void *foo)
  inode_init_once(&bi->vfs_inode);
 }
 
+static void befs_getsmalldata(struct super_block *sb, befs_small_data *sd, struct befs_small_datamem *datamem)
+{
+ char *oft, *ioft;
+ struct befs_small_datamem *newdatamem;
+ struct befs_small_datamem *testdatamem;
+
+ ioft = (char*) sd;
+
+ INIT_LIST_HEAD(&datamem->list);
+
+ while(1){
+ newdatamem = kmalloc(sizeof(*newdatamem), GFP_KERNEL);
+ newdatamem->type=sd->type;
+ strcpy(newdatamem->name, sd->name);
+ oft = sd->name;
+ while(oft[0])oft++;
+ oft+=3; //padding
+ strcpy(newdatamem->value, oft);
+ INIT_LIST_HEAD(&newdatamem->list);
+ oft = oft+(sd->data_size);
+ while(!oft[0])oft++;
+ sd = oft;
+ list_add_tail(&(newdatamem->list), &(datamem->list));
+ if(oft-ioft > sb->s_blocksize-sizeof(befs_inode))
+ break;
+ }
+
+}
+
 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
 {
  struct buffer_head *bh = NULL;
@@ -411,7 +459,10 @@ static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
  inode->i_mapping->a_ops = &befs_aops;
 
  if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &befs_file_inode_operations;
  inode->i_fop = &generic_ro_fops;
+ befs_dump_small_data(sb, raw_inode->small_data);
+ befs_getsmalldata(sb,raw_inode->small_data, &(befs_ino->datamem));
  } else if (S_ISDIR(inode->i_mode)) {
  inode->i_op = &befs_dir_inode_operations;
  inode->i_fop = &befs_dir_operations;
@@ -521,6 +572,42 @@ befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
  return NULL;
 }
 
+static int
+befs_xattr_get(struct dentry *dentry, const char *name, 
+ void *buffer, size_t buffer_size, int type)
+{
+
+
+ struct befs_small_datamem *currentdatamem;
+ struct befs_small_datamem *datamem;
+ befs_inode_info *befs_ino = NULL;
+ int name_len, error;
+
+ if (name == NULL)
+ return -EINVAL;
+
+ name_len = strlen(name);
+ if(name_len > BEFS_ATTRIBUTE_LEN)
+ return -ERANGE;
+ error = -ENODATA;
+
+ befs_ino = BEFS_I(dentry->d_inode);
+ datamem=&(befs_ino->datamem);
+
+ list_for_each_entry(currentdatamem, &(datamem->list), list){
+ if(!strcmp(currentdatamem->name, name)){
+ if(buffer){
+ if(strlen(currentdatamem->value)<=buffer_size){
+ strcpy(buffer, currentdatamem->value);
+ error=strlen(currentdatamem->value);
+  } else  error=-ERANGE; 
+ }else error=strlen(currentdatamem->value);
+
+ }
+ }
+ return(error);
+}
+
 /*
  * UTF-8 to NLS charset  convert routine
  * 
@@ -846,6 +933,7 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
  if (befs_load_sb(sb, disk_sb) != BEFS_OK)
  goto unacquire_bh;
 
+ sb->s_xattr = befs_xattr_handlers;
  befs_dump_super_block(sb, disk_sb);
 
  brelse(bh);
--
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