RAM based directory layer for a flash file system

A method for maintaining a directory structure for a flash file system, the flash file system having one or more flash cards with files on them, each of the files having a name field, the method comprising:

• storing an absolute oath name for each of the files in the name field in each of the files;
• accessing the name fields of each of the files in one or more of the flash cards of the flash file system during initialization of flash file system;
• building a directory having a tree structure using the absolute oath names in the name fields;
• and
• storing said directory in RAM, wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node further having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node further having a name field containing a name for the directory or file corresponding to said node.

A flash file system, including:

• one or more flash cards, said flash cards having files on them, said files each having a name field with an absolute path name;
• a name field accessor coupled to each of said flash cards;
• a directory builder coupled to said name field accessor;
• a RAM;
• and
• a directory storer coupled to said directory builder and to said RAM, wherein said directory builder creates a tree structure and said directory storer stores said tree structure in said RAM and wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node further having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node further having a name field containing a name for the directory or file corresponding to said node.

An internetwork operating system, including:

• one or more flash cards, said flash cards having files on them, said files each having a name field with an absolute path name;
• a name field accessor module coupled to each of said flash cards;
• a directory builder module coupled to said name field accessor;
• a RAM;
• and
• a directory storer module coupled to said directory builder and to said RAM, wherein said directory builder module creates a tree structure and said directory storer module stores said tree structure in said RAM and wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node further having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node further having a name field containing a name for the directory or file corresponding to said node.

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for creating a directory structure for a flash file system, the flash file system having one or more flash cards with files on them, said files each having a name field with an absolute path name, the method comprising:

• accessing the name fields of each of the files in one or more of the flash cards of the flash file system during initialization of flash file system;
• building a directory having a tree structure using the absolute path names in the name fields;
• and
• storing said directory in RAM wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node farther having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node father having a name field containing a name for the directory or file corresponding to said node.

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for maintaining a directory structure for a flash file system, the flash file system having one or more flash cards with files on them, each of the files having a name field, the method comprising:

• storing an absolute oath name for each of the files in the name field in each of the files;
• accessing the name fields of the files in one or more of the flash cards of the flash file system during initialization of flash file system;
• building a directory having a tree structure using the absolute path names in the name fields;
• and
• storing said directory in RAM wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node further having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node further having a name field containing a name for the directory or file corresponding to said node.

A flash file system for creating a directory structure for a flash file system, the flash file system having one or more flash cards with files on them, said files each having a name field with an absolute path name, the method comprising:

• means for accessing the name fields of each of the files in one or more of the flash cards of the flash file system during initialization of flash file system;
• means for building a directory having a tree structure using the absolute path names in the name fields;
• and
• means for storing said directory in RAM wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and one or more child fields, said parent field containing a pointer to a parent node if the node has a parent, said one or more child fields containing pointers to child nodes if the node has one or more children, and said one or more child fields containing a pointer to a file on a flash card if the node has no children.

A flash file system for maintaining a directory structure for a flash file system, the flash file system having one or more flash cards with files on them, each of the files having a name field, the method comprising:

• means for storing an absolute path name for each of the files in the name field in each of the files;
• means for accessing the name fields of each of the files in one or more of the flash cards of the flash file system during initialization of flash file system;
• means for building a directory having a tree structure using the absolute path names in the name fields;
• and
• means for storing said directory in RAM, wherein said tree structure includes a plurality of nodes, each of said nodes containing a parent field and a next node field, said parent field containing a pointer to a parent node, said next node field containing a pointer to a peer node, if any more exist, said node further having a first child field containing a pointer to a first child node if said node corresponds to a directory containing one or more subdirectories or files, said node further having a leaf location field containing a pointer to the location of the corresponding file if said node is a leaf node, and said node further having a name field containing a name for the directory or file corresponding to said node.