EP0278312A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Distributed file and record locking
Assignee: International Business Machines Corp
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Filing: 1988-01-26
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Granted: —
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Expires: 2008-01-26
Abstract
Abstract An improvement is disclosed to the conventional single node operating system to provide a distributed file management system (DFS) with a plurality of nodes (A,B) and a plurality of files (5). The DFS uses the UNIX operating system tree structure employing inodes (data structure containing administrative information for each file (151,152) to manage the local files and surrogate inodes (s_inode) to manage access to files existing on another node. In addition, the DFS uses a lock table to manage the lock status of files. The method which implements the DFS locking of records and files involves the following steps. If the file is a local file, then the UNIX operating system standard file is used. However, if a remote file is to be locked, the UNIX operating system LOCLF and FCNTL system calls are intercepted and a remote process call (RPC) DFS_LOCK_CONTROL is executed. The server node (A) receives the remote process call and carries out the lock request. The request could entail locking a single record, a set records or the whole file. The server then acknowledges receipt of the RPC by sending a signal while the client surrogate inode is waiting for a reply from the DFS_LOCK_CONTROL RPC. The client confirms the reception of the lock and sends an acknowledgement to the remote server. The server updates the lock table after receiving the ackowledgement, then DFS_LOCK_CONTROL'S acknowledgement, then DFS_LOCK_CONTROL updates the lock table.
Inventors
- 👤 Larry William Henson
- 👤 Amal Ahmed Shaheen-Gouda
- 👤 Todd Allen Smith
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 06:09
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/46; G06F9/52; G06F16/00; G06F16/10; G06F16/17; G06F16/176; G06F16/1767; G06F16/1774
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
76 words
A method for locking a range of bytes of a file (5) residing at a first node (A) and acessible by processes located at the first node and by processes located at at least one second node (B,C) said method comprising : creating and maintaining information describing at least one lock for said file at said first node (A), and moving said information and storing it in one of said at least one second node (B,C)
Claim 2
Independent Claim
76 words
A method for locking a range of bytes of a file (5) residing at a first node (A) and acessible by processes located at the first node and by processes located at at least one second node (B,C) said method comprising : creating and maintaining information describing at least one lock for said file at said first node (A), and moving said information and storing it in one of said at least one second node (B,C)
Claim 3
Dependent Claim
29 words
The method of Claim 1 wherein said information is stored in said at least one second node when all processes having said fild open reside in said second node.
Claim 4
Dependent Claim
25 words
The method of Claim 2 further comprising the step storing said information in said first node when an enforcement mode of the file is enforced.
Claim 5
Independent Claim
70 words
The method of any of the second node to the first comprising the steps of sending a message from the second node to the first node requesting a lock; sending notification from the first node to the second node that the lock is available; and releasing the lock at the first node when a confirmation of said sent notification is not received by said first node from said second node.
Claim 6
Independent Claim
70 words
The method of any of the second node to the first comprising the steps of sending a message from the second node to the first node requesting a lock; sending notification from the first node to the second node that the lock is available; and releasing the lock at the first node when a confirmation of said sent notification is not received by said first node from said second node.
Claim 7
Independent Claim
71 words
A system for locking a range of bytes of a file (5) residing at a first node (A) and accessible by processes located at at least one second node (B,C), said system comprising: a data structure describing at least one lock for said file at said first node (A); and means for moving data in said data structure and storing it in one of said at least one second node (B,C)
Claim 8
Independent Claim
71 words
A system for locking a range of bytes of a file (5) residing at a first node (A) and accessible by processes located at at least one second node (B,C), said system comprising: a data structure describing at least one lock for said file at said first node (A); and means for moving data in said data structure and storing it in one of said at least one second node (B,C)
Claim 9
Dependent Claim
36 words
The system of Claim 5 wherein said data in said data structure is stored in said at least one second node when all processes having said file open reside in said at least one second node.
Claim 10
Dependent Claim
29 words
The system of Claim 6 further comprising means for storing said data in said data structure in said first node when an enforcement mode of the file is enforce.
Claim 11
Independent Claim
71 words
The system of any of the claims 5 to 7 further comprising a first message from the second node to the first node requesting a lock; means for sending notification from the first node to the second node that the lock is available; and means for releasing the lock at the first node when a confirmation of said sent notification is not received by said first node from said second node.
Claim 12
Independent Claim
248 words
A method of providing file locks in a distributed data processing system of the type having a plurality of nodes and a plurality of files physically residing at different ones of said nodes and a distributed file management system comprising a tree data structure with a plurality of inodes comprising administrative information for each of said plurality of files and a plurality of surrogate inodes, a server inode of said plurality of inodes comprising access control means for a local file or a portion of said local file of said plurality of files, a lock table, and a client surrogate inode of said plurality of surrogate inodes corresponding to said server inode providing remote access control means for said local file, said remote access control means comprising locking means for locking said server inode to secure said local file or said portion of said local file for said client surrogate inode, said method of providing file locks in a distributed data processing system comprising: intercepting any remote file locking system calls from a client application; replacing said remote file locking system calls with a remote process call; processing said remote process call and locking local file or said local file or said portion of said local file at said server inode; sending a signal to said client surrogate inode to acknowledge receipt of said remote process call; sending an acknowledgement from said clienta surrogate inode to said server inode; and updating said lock table at said server inode.
Claim 13
Independent Claim
248 words
A method of providing file locks in a distributed data processing system of the type having a plurality of nodes and a plurality of files physically residing at different ones of said nodes and a distributed file management system comprising a tree data structure with a plurality of inodes comprising administrative information for each of said plurality of files and a plurality of surrogate inodes, a server inode of said plurality of inodes comprising access control means for a local file or a portion of said local file of said plurality of files, a lock table, and a client surrogate inode of said plurality of surrogate inodes corresponding to said server inode providing remote access control means for said local file, said remote access control means comprising locking means for locking said server inode to secure said local file or said portion of said local file for said client surrogate inode, said method of providing file locks in a distributed data processing system comprising: intercepting any remote file locking system calls from a client application; replacing said remote file locking system calls with a remote process call; processing said remote process call and locking local file or said local file or said portion of said local file at said server inode; sending a signal to said client surrogate inode to acknowledge receipt of said remote process call; sending an acknowledgement from said clienta surrogate inode to said server inode; and updating said lock table at said server inode.
Claim 14
Dependent Claim
68 words
The method of Claim 9 further including locking said local files from a local node comprising the steps of: requesting a lock on said local file from said local node; checking said lock table to insure that no deadlock situations are possible; waiting on said lock table to said local file to indicate that said local file is available; locking said local file; and updating said lock table.
Claim 15
Dependent Claim
31 words
The method of Claim 10 further comprising the steps of : requesting an unlock of said local file from said local node; unlocking sais local file; and updating said lock table.
Claim 16
Dependent Claim
101 words
The method of Claim 9 further including remote access control for unlocking said local file remotely comprising the steps of: intercepting any remote file locking system calls from a client application; replacing said remote file locking system calls with a remote process call; processing said remote process call and unlocking said local fiel or said portion of said local file at said server inode; sending a signal to said client surrogate inode to acknowledge receipt of said remote process call; sending an acknowledgement from said client surrogate inode to said server inode; and updating said lock table at said server inode.
References Cited (Backward Citations)
No citation records indexed.
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