Method and apparatus for file server addressing
First Claim
1. In a file system in which a client pathname and a unique numerical value identify each file and in which certain operations return to the client a file handle including the unique numerical value and other operations transfer the file handle back to the file system and wherein the file system includes a first set of links for establishing correspondences between the client pathnames and unique numerical values, the improvement of alternate path addressing means for facilitating the location of a file in the file system in response to all other operations subsequent to the return of the file handle, said alternate path addressing means comprising:
- (A) means for converting the unique numerical value in the returned file handle into an alternate pathname,(B) a second set of links for establishing correspondences between the alternate pathnames and the locations of files in the file system identified by each unique numerical value; and
(C) means for obtaining the location of a file by selecting a corresponding link in said second set of links as determined by the alternate path name.
1 Assignment
0 Petitions
Accused Products
Abstract
An addressing scheme for file servers. The file handle in a call that accesses a file includes a file system identification, a file identification or inode number and a generation number. The addressing system converts the multi-bit file identification number into an alternative path name that identifies a location for the file without the need for converting the real path name. In one particular embodiment the inode number in binary form is translated into a multiple digit hexadecimal form that is parsed into directory names. The last directory name provides the location of the designated file.
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Citations
15 Claims
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1. In a file system in which a client pathname and a unique numerical value identify each file and in which certain operations return to the client a file handle including the unique numerical value and other operations transfer the file handle back to the file system and wherein the file system includes a first set of links for establishing correspondences between the client pathnames and unique numerical values, the improvement of alternate path addressing means for facilitating the location of a file in the file system in response to all other operations subsequent to the return of the file handle, said alternate path addressing means comprising:
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(A) means for converting the unique numerical value in the returned file handle into an alternate pathname, (B) a second set of links for establishing correspondences between the alternate pathnames and the locations of files in the file system identified by each unique numerical value; and (C) means for obtaining the location of a file by selecting a corresponding link in said second set of links as determined by the alternate path name. - View Dependent Claims (2, 3, 4)
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5. In a network including a client and a server interconnected by a communication link wherein the server comprises at least one file system in which individual files are organized in at least one directory for identification by client pathnames, wherein the server includes control programs located in user space and kernel space, wherein certain requests for file system operations sent from the client to the server contain client pathnames and produce file handles including a portion for specifying the server, an inode number specifying a file in the server and a file generation number, and wherein each file system includes a first set of links for establishing correspondences between client pathnames and inode numbers and an attribute table for storing certain characteristics of each file including the file generation number, the improvement of alternate path addressing means for allowing access from user space to an identified file by decoding file handles sent by all other commands subsequent to the return of the file handle, said alternate path addressing means comprising:
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(A) means for receiving the returned file handle, (B) means in the user space for converting the inode number in a received file handle into an alternate pathname, (C) a second set of links in the file system establishing correspondences between the alternate pathname and an index node value, and (D) a second attribute table in user space indexed from the inode number, each entry in said second attribute table comprising a file generation number for the corresponding file. - View Dependent Claims (6, 7, 8)
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9. A method for addressing one of a plurality of files in a file system at a server wherein each of the files is identified by an unique numerical value and by a client pathname, wherein the file system includes a first set of links for establishing correspondences between client pathnames and the unique numerical values and wherein certain client initiated operations convert a client pathname to a file handle with the corresponding unique numerical value that is returned to the client, all subsequent client initiated operations identifying a file with the returned file handle, the method comprising the steps of:
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(A) responding to the subsequent client initiated operation by converting the unique numerical value in the file handle into an alternate pathname, and (B) retrieving the location of the file from a second set of links in response to the alternate pathname, said second set of links establishing correspondences between the alternate pathnames and the location of files in the file system. - View Dependent Claims (10, 11, 12)
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13. A method for addressing a file in a server in a network including a client station interconnected to the server by a communication link wherein the server comprises at least one file system in which individual files are organized in at least one directory for identification by client pathnames and includes control programs located in user space and kernel space, wherein certain user requests for file system operations sent from the client to the server contain user pathnames and produce file handles returned to the client state for use by subsequent commands including a portion for specifying the server, an inode number specifying a file in the server and a file generation number, and wherein each file system includes a first set of links for establishing correspondences between each client pathname and inode number and an attribute table for storing certain characteristics of each file including the generation number, a method for allowing access from user space to an identified file by decoding in user space the server file handles sent by the subsequent commands comprising the steps of:
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(A) receiving the file handle, (B) converting the received file handle into an alternate pathname based upon the inode number, (C) retrieving from a second set of links the contents of a storage location identified by the alternate pathname containing information about the inode number, (D) retrieving from an entry in a second attribute table indexed from the inode number, each entry in the second attribute table including the file generation number for the corresponding file, and (E) validating in user space the received file handle by comparing the file generation number in the file handle with the file generation number from the entry in the second attribute table. - View Dependent Claims (14, 15)
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Specification