Changeset a8e1aae in mainline

Timestamp:

2011-02-24T21:03:42Z (14 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

9ffbdf1

Parents:

102d400

Message:

Add support for reading directories to libext2

Location:

uspace

Files:

• app/ext2info/ext2info.c (modified) (11 diffs)
• lib/ext2/libext2_directory.c (modified) (2 diffs)
• lib/ext2/libext2_directory.h (modified) (3 diffs)

uspace/app/ext2info/ext2info.c

@@ -56 +56 @@
 static void print_block_groups(ext2_filesystem_t *);
 static void print_block_group(ext2_block_group_t *);
-static void print_inode_by_number(ext2_filesystem_t *, uint32_t, bool, uint32_t);
+static void print_inode_by_number(ext2_filesystem_t *, uint32_t, bool, uint32_t,
+    bool);
+static void print_data(unsigned char *, size_t);
 static void print_inode(ext2_filesystem_t *, ext2_inode_t *);
 static void print_inode_data(ext2_filesystem_t *, ext2_inode_t *, uint32_t);
+static void print_directory_contents(ext2_filesystem_t *, ext2_inode_ref_t *);
 
 #define ARG_SUPERBLOCK 1
@@ -65 +68 @@
 #define ARG_STRICT_CHECK 8
 #define ARG_INODE_DATA 16
+#define ARG_INODE_LIST 32
 #define ARG_COMMON (ARG_SUPERBLOCK | ARG_BLOCK_GROUPS)
 #define ARG_ALL (ARG_COMMON | ARG_INODE)
@@ -141 +145 @@
                         --argc; ++argv;
                 }
+                
+                if (str_cmp(*argv, "--list") == 0) {
+                        --argc; ++argv;
+                        arg_flags |= ARG_INODE_LIST;
+                }
         }
 
@@ -186 +195 @@
         if (arg_flags & ARG_INODE) {
                 print_inode_by_number(&filesystem, inode, arg_flags & ARG_INODE_DATA,
-                    inode_data);
+                    inode_data, arg_flags & ARG_INODE_LIST);
         }
 
@@ -198 +207 @@
 {
         printf("syntax: ext2info [--strict-check] [--superblock] [--block-groups] "
-            "[--inode <i-number> [--inode-data <block-number>]] <device_name>\n");
+            "[--inode <i-number> [--inode-data <block-number>] [--list]] <device_name>\n");
 }
 
@@ -346 +355 @@
 
 void print_inode_by_number(ext2_filesystem_t *fs, uint32_t inode, 
-    bool print_data, uint32_t data)
+    bool print_data, uint32_t data, bool list)
 {
         int rc;
@@ -362 +371 @@
         if (print_data) {
                 print_inode_data(fs, inode_ref->inode, data);
+        }
+        
+        if (list && ext2_inode_is_type(fs->superblock, inode_ref->inode,
+            EXT2_INODE_MODE_DIRECTORY)) {
+                print_directory_contents(fs, inode_ref);
         }
         
@@ -444 +458 @@
 }
 
+void print_data(unsigned char *data, size_t size)
+{
+        unsigned char c;
+        size_t i;
+        
+        for (i = 0; i < size; i++) {
+                c = data[i];
+                if (c >= 32 && c < 127) {
+                        putchar(c);
+                }
+                else {
+                        putchar('.');
+                }
+        }
+}
+
 void print_inode_data(ext2_filesystem_t *fs, ext2_inode_t *inode, uint32_t data)
 {
@@ -449 +479 @@
         uint32_t data_block_index;
         block_t *block;
-        size_t i;
-        unsigned char c;
         
         rc = ext2_filesystem_get_inode_data_block_index(fs, inode, data,
@@ -471 +499 @@
         }
         
-        for (i = 0; i < block->size; i++) {
-                c = ((unsigned char *)block->data)[i];
-                if (c >= 32 && c < 127) {
-                        putchar(c);
-                }
-                else {
-                        putchar('.');
-                }
-        }
-        
+        print_data(block->data, block->size);
         printf("\n");   
         
@@ -486 +505 @@
         if (rc != EOK) {
                 printf("Failed putting filesystem block\n");
+        }
+        
+}
+
+void print_directory_contents(ext2_filesystem_t *fs,
+    ext2_inode_ref_t *inode_ref)
+{
+        int rc;
+        ext2_directory_iterator_t it;
+        size_t name_size;
+        
+        printf("  Directory contents:\n");
+        
+        rc = ext2_directory_iterator_init(&it, fs, inode_ref);
+        if (rc != EOK) {
+                printf("Failed initializing directory iterator\n");
+                return;
+        }
+        
+        while (it.current != NULL) {
+                name_size = ext2_directory_entry_ll_get_name_length(fs->superblock,
+                    it.current);
+                printf("    ");
+                print_data(&it.current->name, name_size);
+                printf(" --> %u\n", it.current->inode);
+                
+                rc = ext2_directory_iterator_next(&it);
+                if (rc != EOK) {
+                        printf("Failed reading directory contents\n");
+                        goto cleanup;
+                }
+        }
+
+cleanup:
+        rc = ext2_directory_iterator_fini(&it);
+        if (rc != EOK) {
+                printf("Failed cleaning-up directory iterator\n");
         }
         

uspace/lib/ext2/libext2_directory.c

@@ -37 +37 @@
 #include "libext2_directory.h"
 #include <byteorder.h>
+#include <errno.h>
+#include <assert.h>
 
 /**
@@ -75 +77 @@
 }
 
+/**
+ * Initialize a directory iterator
+ * 
+ * @param it pointer to iterator to initialize
+ * @param fs pointer to filesystem structure
+ * @param inode pointer to inode reference structure
+ * @return EOK on success or negative error code on failure
+ */
+int ext2_directory_iterator_init(ext2_directory_iterator_t *it,
+    ext2_filesystem_t *fs, ext2_inode_ref_t *inode_ref)
+{
+        int rc;
+        uint32_t block_id;
+        it->inode_ref = inode_ref;
+        it->fs = fs;
+        
+        // Get the first data block, so we can get first entry
+        rc = ext2_filesystem_get_inode_data_block_index(fs, inode_ref->inode, 0, 
+            &block_id);
+        if (rc != EOK) {
+                return rc;
+        }
+        
+        rc = block_get(&it->current_block, fs->device, block_id, 0);
+        if (rc != EOK) {
+                return rc;
+        }
+        
+        it->current = it->current_block->data;
+        it->current_offset = 0;
+        
+        return EOK;
+}
+
+/**
+ * Advance the directory iterator to the next entry
+ * 
+ * @param it pointer to iterator to initialize
+ * @return EOK on success or negative error code on failure
+ */
+int ext2_directory_iterator_next(ext2_directory_iterator_t *it)
+{
+        int rc;
+        uint16_t skip;
+        uint64_t size;
+        aoff64_t current_block_idx;
+        aoff64_t next_block_idx;
+        uint32_t next_block_phys_idx;
+        uint32_t block_size;
+        uint32_t offset_in_block;
+        
+        assert(it->current != NULL);
+        
+        skip = ext2_directory_entry_ll_get_entry_length(it->current);
+        size = ext2_inode_get_size(it->fs->superblock, it->inode_ref->inode);
+        
+        // Are we at the end?
+        if (it->current_offset + skip >= size) {
+                rc = block_put(it->current_block);
+                it->current_block = NULL;
+                it->current = NULL;
+                if (rc != EOK) {
+                        return rc;
+                }
+                
+                it->current_offset += skip;
+                return EOK;
+        }
+        
+        block_size = ext2_superblock_get_block_size(it->fs->superblock);
+        current_block_idx = it->current_offset / block_size;
+        next_block_idx = (it->current_offset + skip) / block_size;
+        
+        // If we are moving accross block boundary,
+        // we need to get another block
+        if (current_block_idx != next_block_idx) {
+                rc = block_put(it->current_block);
+                it->current_block = NULL;
+                it->current = NULL;
+                if (rc != EOK) {
+                        return rc;
+                }
+                
+                rc = ext2_filesystem_get_inode_data_block_index(it->fs,
+                    it->inode_ref->inode, next_block_idx, &next_block_phys_idx);
+                if (rc != EOK) {
+                        return rc;
+                }
+                
+                rc = block_get(&it->current_block, it->fs->device, next_block_phys_idx,
+                    BLOCK_FLAGS_NONE);
+                if (rc != EOK) {
+                        it->current_block = NULL;
+                        return rc;
+                }
+        }
+        
+        offset_in_block = (it->current_offset + skip) % block_size;
+        
+        // Ensure proper alignment
+        if ((offset_in_block % 4) != 0) {
+                it->current = NULL;
+                return EIO;
+        }
+        
+        // Ensure that the core of the entry does not overflow the block
+        if (offset_in_block > block_size - 8) {
+                it->current = NULL;
+                return EIO;
+        }
+                
+        it->current = it->current_block->data + offset_in_block;
+        it->current_offset += skip;
+        
+        // Ensure that the whole entry does not overflow the block
+        skip = ext2_directory_entry_ll_get_entry_length(it->current);
+        if (offset_in_block + skip > block_size) {
+                it->current = NULL;
+                return EIO;
+        }
+        
+        // Ensure the name length is not too large
+        if (ext2_directory_entry_ll_get_name_length(it->fs->superblock, 
+            it->current) > skip-8) {
+                it->current = NULL;
+                return EIO;
+        }
+        
+        return EOK;
+}
+
+/**
+ * Release all resources asociated with the directory iterator
+ * 
+ * @param it pointer to iterator to initialize
+ * @return EOK on success or negative error code on failure
+ */
+int ext2_directory_iterator_fini(ext2_directory_iterator_t *it)
+{
+        int rc;
+        
+        it->fs = NULL;
+        it->inode_ref = NULL;
+        it->current = NULL;
+        
+        if (it->current_block) {
+                rc = block_put(it->current_block);
+                if (rc != EOK) {
+                        return rc;
+                }
+        }
+        
+        return EOK;
+}
+
 /** @}
  */

uspace/lib/ext2/libext2_directory.h

@@ -38 +38 @@
 
 #include <libblock.h>
+#include "libext2_filesystem.h"
+#include "libext2_inode.h"
 
 /**
@@ -53 +55 @@
 } __attribute__ ((packed)) ext2_directory_entry_ll_t;
 
+typedef struct ext2_directory_iterator {
+        ext2_filesystem_t *fs;
+        ext2_inode_ref_t *inode_ref;
+        block_t *current_block;
+        aoff64_t current_offset;
+        ext2_directory_entry_ll_t *current;
+} ext2_directory_iterator_t;
+
 
 inline uint32_t ext2_directory_entry_ll_get_inode(ext2_directory_entry_ll_t *);
@@ -60 +70 @@
     ext2_superblock_t *, ext2_directory_entry_ll_t *);
 
+extern int ext2_directory_iterator_init(ext2_directory_iterator_t *,
+    ext2_filesystem_t *, ext2_inode_ref_t *);
+extern int ext2_directory_iterator_next(ext2_directory_iterator_t *);
+extern int ext2_directory_iterator_fini(ext2_directory_iterator_t *);
+
 #endif