Changeset eef306c in mainline

Timestamp:

2011-03-09T16:16:27Z (14 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

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

Children:

868ef40

Parents:

e2abab03

Message:

Check filesystem feature flags when mounting

Location:

uspace

Files:

• lib/ext2/libext2_filesystem.c (modified) (1 diff)
• lib/ext2/libext2_filesystem.h (modified) (1 diff)
• lib/ext2/libext2_superblock.c (modified) (1 diff)
• lib/ext2/libext2_superblock.h (modified) (2 diffs)
• srv/fs/ext2fs/ext2fs_ops.c (modified) (2 diffs)

uspace/lib/ext2/libext2_filesystem.c

@@ -109 +109 @@
 
 /**
+ * Check feature flags
+ * 
+ * @param fs Pointer to ext2_filesystem_t to check
+ * @param read_only bool to set to true if the fs needs to be read-only
+ * @return EOK on success or negative error code on failure
+ */
+int ext2_filesystem_check_flags(ext2_filesystem_t *fs, bool *o_read_only)
+{
+        // feature flags are present in rev 1 and later
+        if (ext2_superblock_get_rev_major(fs->superblock) == 0) {
+                *o_read_only = false;
+                return 0;
+        }
+        
+        uint32_t incompatible;
+        uint32_t read_only;
+        
+        incompatible = ext2_superblock_get_features_incompatible(fs->superblock);
+        read_only = ext2_superblock_get_features_read_only(fs->superblock);
+        
+        // unset any supported features
+        incompatible &= ~EXT2_SUPPORTED_INCOMPATIBLE_FEATURES;
+        read_only &= ~EXT2_SUPPORTED_READ_ONLY_FEATURES;
+        
+        if (incompatible > 0) {
+                *o_read_only = true;
+                return ENOTSUP;
+        }
+        
+        if (read_only > 0) {
+                *o_read_only = true;
+        }
+        
+        return EOK;
+}
+
+/**
  * Get a reference to block descriptor
  * 

uspace/lib/ext2/libext2_filesystem.h

@@ -52 +52 @@
 #define EXT2_REV0_INODE_SIZE            128
 
+#define EXT2_FEATURE_RO_SPARSE_SUPERBLOCK       1
+#define EXT2_FEATURE_RO_LARGE_FILE                      2
+#define EXT2_FEATURE_I_TYPE_IN_DIR                      2
+
+#define EXT2_SUPPORTED_INCOMPATIBLE_FEATURES EXT2_FEATURE_I_TYPE_IN_DIR
+#define EXT2_SUPPORTED_READ_ONLY_FEATURES 0
+
 extern int ext2_filesystem_init(ext2_filesystem_t *, devmap_handle_t);
 extern int ext2_filesystem_check_sanity(ext2_filesystem_t *);
+extern int ext2_filesystem_check_flags(ext2_filesystem_t *, bool *);
 extern int ext2_filesystem_get_block_group_ref(ext2_filesystem_t *, uint32_t, 
     ext2_block_group_ref_t **);

uspace/lib/ext2/libext2_superblock.c

@@ -258 +258 @@
 
 /**
+ * Get compatible features flags
+ * 
+ * @param sb pointer to superblock
+ */
+inline uint32_t ext2_superblock_get_features_compatible(ext2_superblock_t *sb)
+{
+        return uint32_t_le2host(sb->features_compatible);
+}
+
+/**
+ * Get incompatible features flags
+ * 
+ * @param sb pointer to superblock
+ */
+inline uint32_t ext2_superblock_get_features_incompatible(ext2_superblock_t *sb)
+{
+        return uint32_t_le2host(sb->features_incompatible);
+}
+
+/**
+ * Get read-only compatible features flags
+ * 
+ * @param sb pointer to superblock
+ */
+inline uint32_t ext2_superblock_get_features_read_only(ext2_superblock_t *sb)
+{
+        return uint32_t_le2host(sb->features_read_only);
+}
+
+/**
  * Compute count of block groups present in the filesystem
  * 

uspace/lib/ext2/libext2_superblock.h

@@ -64 +64 @@
         uint32_t        first_inode;
         uint16_t        inode_size;
-        uint8_t         unused5[14];
+        uint16_t        unused5;
+        uint32_t        features_compatible;
+        uint32_t        features_incompatible;
+        uint32_t        features_read_only;
         uint8_t         uuid[16]; // UUID TODO: Create a library for UUIDs
         uint8_t         volume_name[16];
@@ -103 +106 @@
 inline uint32_t ext2_superblock_get_block_group_count(ext2_superblock_t *);
 inline uint32_t ext2_superblock_get_inodes_per_group(ext2_superblock_t *);
+inline uint32_t ext2_superblock_get_features_compatible(ext2_superblock_t *);
+inline uint32_t ext2_superblock_get_features_incompatible(ext2_superblock_t *);
+inline uint32_t ext2_superblock_get_features_read_only(ext2_superblock_t *);
 
 extern int ext2_superblock_read_direct(devmap_handle_t, ext2_superblock_t **);

uspace/srv/fs/ext2fs/ext2fs_ops.c

@@ -484 +484 @@
         ext2_filesystem_t *fs;
         ext2fs_instance_t *inst;
+        bool read_only;
         
         /* Accept the mount options */
@@ -522 +523 @@
         /* Do some sanity checking */
         rc = ext2_filesystem_check_sanity(fs);
+        if (rc != EOK) {
+                ext2_filesystem_fini(fs);
+                free(fs);
+                free(inst);
+                async_answer_0(rid, rc);
+                return;
+        }
+        
+        /* Check flags */
+        rc = ext2_filesystem_check_flags(fs, &read_only);
         if (rc != EOK) {
                 ext2_filesystem_fini(fs);