Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
In a computer system having a shared disk file system running on multiple computers each having their own instance of an operating system and being coupled for data sharing with network attached shared disks, the method of: providing extended file attributes for support of Access Control Lists of the kind known in the Unix environment for a file system, where each file system includes an attribute file, attribute references, an attribute index, and an attribute garbage collector for sharing of physical attribute storage among all files that have attributes with identical values by storage of all attribute data in said attribute file.
Claim 2
Dependent Claim
102 words
In a computer system having a shared disk file system running on multiple computers each having their own instance of an operating system and being coupled for data sharing with network attached shared disks, the method of: providing extended file attributes for support of Access Control Lists of the kind known in the Unix environment for a file system, where each file system includes an attribute file, attribute references, an attribute index, and an attribute garbage collector for sharing of physical attribute storage among all files that have attributes with identical values by storage of all attribute data in said attribute file.
Claim 3
Dependent Claim
56 words
The method for a computer system according to claim 1, wherein an attribute reference is stored in an inode of a file and contains the location of an entry that holds attribute data for said file in the attribute file, and said attribute reference is represented as an offset of the entry in the attribute file.
Claim 4
Dependent Claim
25 words
The method for a computer system according to claim 2, wherein files with identical attribute values contain the same attribute reference values in their inodes.
Claim 5
Dependent Claim
61 words
The method for a computer system according to claim 2, wherein the method includes attribute sharing by inheritance by setting extended attributes for a new file when it is created by setting its extended attributes to the same values as an existing file from which said new file is derived such that said new file had attributes determined by its inheritance.
Claim 6
Dependent Claim
59 words
The method for a computer system according to claim 4, wherein said inheritance is obtained by copying the attribute reference from the inode of the file or directory from which the attribute is inherited so as to determine for said new file an inherited attribute which shares the same physical storage as the attribute from which it is inherited.
Claim 7
Dependent Claim
60 words
The method for a computer system according to claim 2, wherein the method includes attribute sharing by attribute value lookup by changing or setting an extended attribute for a file to a value that is not inherited from another file by utilizing an attribute index to determine whether an entry with the same value already exists in said attribute file.
Claim 8
Dependent Claim
168 words
The method for a computer system according to claim 6, wherein to set or change an attribute value, a hash function is applied to the attribute data for the attribute file and the resulting hash value used as an index in a hash table so that a list of attribute references will be found that refer to entries in said attribute file with attribute date that hash to the same hash value, and wherein when new attribute data is to be stored it is compared against all data in said attribute file so that if a match if found, an attribute reference referring to the existing entry is stored in the files inode, while if no match is found, a new entry containing the new attribute value is added to the attribute file and an attribute reference to the new entry is stored in the file's inode as well as in the hash table so that future attribute updates using the same attribute will find the new entry.
Claim 9
Dependent Claim
26 words
The method for a computer system according to claim 6, wherein new attribute values are converted to a canonical form before storing or looking them tip.
Claim 10
Dependent Claim
27 words
The method for a computer system according to claim 1, wherein garbage collection synchronizes with a lookup operation which is used for changing of a file attribute.
Claim 11
Dependent Claim
61 words
The method for a computer system according to claim 9, wherein said garbage collection is started by first monitoring the total size of attribute data and starting the garbage collection only after the amount of attribute data has grown by a predetermined factor so as to prevent the attribute file from growing if the amount of active attribute data stays constant.