US5913227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Agent-implemented locking mechanism
Assignee: EMC Corp
•
Filing: 1997-03-24
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Granted: 1999-06-15
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Expires: 2017-03-24
Abstract
Abstract A method of synchronizing access to a data object that is stored within a shared storage area of a data storage system to which a plurality of host processors are connected, the method including the steps of establishing one of the plurality of host processors as a master host processor, wherein the master host processor owns the shared object within the data storage system; sending an access request from a slave host processor to the master host processor to access the shared object within the data storage system, wherein the slave host processor is one of the plurality of host processors other than the master host processor; in response to receiving the access request at the master host processor, checking whether any conflicting locks are still pending from prior access requests from any of the plurality of host processors; if no locks are still pending, granting the access request from the slave host processor; and notifying the slave processor whether its access request was granted.
Inventors
- 👤 Yoav Raz
- 👤 Walter Michael Caritj
- 👤 Douglas V. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:17
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/46; G06F9/52; G06F9/54; G06F9/544
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
170 words
A method of synchronizing access to an identified data object that is stored within a shared storage area of a data storage system to which a plurality of processors are connected, each of said plurality of processors being connected to said data storage system through a corresponding different channel, said method comprising: establishing one of said plurality of processors as a master processor, wherein said master processor owns the identified shared object within the data storage system; sending an access request from a slave processor to the master processor to access the identified shared object within the data storage system, said slave processor being one of said plurality of processors other than the master processor; in response to receiving the access request at the master processor, checking whether any conflicting locks are still pending from prior access requests from any of the plurality of processors; if no locks are still pending, granting the access request from the slave processor; and notifying the slave processor whether its access request was granted.
Claim 2
Independent Claim
170 words
A method of synchronizing access to an identified data object that is stored within a shared storage area of a data storage system to which a plurality of processors are connected, each of said plurality of processors being connected to said data storage system through a corresponding different channel, said method comprising: establishing one of said plurality of processors as a master processor, wherein said master processor owns the identified shared object within the data storage system; sending an access request from a slave processor to the master processor to access the identified shared object within the data storage system, said slave processor being one of said plurality of processors other than the master processor; in response to receiving the access request at the master processor, checking whether any conflicting locks are still pending from prior access requests from any of the plurality of processors; if no locks are still pending, granting the access request from the slave processor; and notifying the slave processor whether its access request was granted.
Claim 3
Dependent Claim
42 words
The method of claim 1 further comprising the step of denying the access request from the slave processor if a conflicting lock is still pending and wherein notifying step includes notifying the slave processor whether its access request was granted or denied.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein the step of granting an access request comprises recording in local memory that the access request was granted to the requesting processor.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein the object is a file system.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein the access request is a request to access a file in the file system.
Claim 7
Dependent Claim
160 words
Agent software on computer-readable medium, said agent software for running on a master host processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said agent software comprising: means for receiving an access request from another one of said plurality of processors, said access request being a request to access an identified object in the shared storage area of the data storage system; means for determining whether any conflicting locks are pending for the identified object stored within the shared storage area of the data storage system; means for granting the access request from the requesting processor if it is determined that no conflicting locks are pending for any other processor; and means for notifying the requesting processor whether its access request was granted.
Claim 8
Dependent Claim
160 words
Agent software on computer-readable medium, said agent software for running on a master host processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said agent software comprising: means for receiving an access request from another one of said plurality of processors, said access request being a request to access an identified object in the shared storage area of the data storage system; means for determining whether any conflicting locks are pending for the identified object stored within the shared storage area of the data storage system; means for granting the access request from the requesting processor if it is determined that no conflicting locks are pending for any other processor; and means for notifying the requesting processor whether its access request was granted.
Claim 9
Dependent Claim
48 words
The agent software of claim 6 further comprising means for denying the access request from the requesting processor if it is determined that a conflicting lock is pending for another processor, and wherein the notifying means notifies the requesting processor whether its access request was granted or denied.
Claim 10
Dependent Claim
13 words
The agent software of claim 7 wherein the object is a file system.
Claim 11
Dependent Claim
21 words
The agent software of claim 8 wherein the access request is a request to access a file in the file system.
Claim 12
Dependent Claim
165 words
Interface software on computer-readable medium, said interface software for running on a slave processor which is one of a plurality of processors connected to a data storage system, said plurality of host processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said interface software comprising: means for preventing said slave processor from accessing an identified object stored in the shared storage area when no authorization has been received from a master processor which is another one of said plurality of processors; means for sending an access request from the slave processor to the master processor, said access request being a request for accessing said identified object in the shared storage area; means for receiving an acknowledgment from the master processor indicating whether the access request was granted; and means for permitting the slave processor to access the object if the received acknowledgment grants the access request.
Claim 13
Dependent Claim
165 words
Interface software on computer-readable medium, said interface software for running on a slave processor which is one of a plurality of processors connected to a data storage system, said plurality of host processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said interface software comprising: means for preventing said slave processor from accessing an identified object stored in the shared storage area when no authorization has been received from a master processor which is another one of said plurality of processors; means for sending an access request from the slave processor to the master processor, said access request being a request for accessing said identified object in the shared storage area; means for receiving an acknowledgment from the master processor indicating whether the access request was granted; and means for permitting the slave processor to access the object if the received acknowledgment grants the access request.
Claim 14
Dependent Claim
23 words
The interface software of claim 10 further comprising means for notifying the master processor when an access operation involving the object is complete.
Claim 15
Dependent Claim
13 words
The interface software of claim 11 wherein the object is a file system.
Claim 16
Dependent Claim
21 words
The interface software of claim 12 wherein the access request is a request to access a file in the file system.
Claim 17
Dependent Claim
148 words
An access control method running on a processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said access control method comprising: receiving an access request from another one of said plurality of processors, said access request being a request to access an identified object stored in the shared storage area of the data storage system; determining whether any conflicting locks are pending for the identified object stored within the shared storage area of the data storage system; granting the access request from the requesting processor if it is determined that no conflicting locks are pending for any other processor; and notifying the requesting host processor whether its access request was granted.
Claim 18
Dependent Claim
148 words
An access control method running on a processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said access control method comprising: receiving an access request from another one of said plurality of processors, said access request being a request to access an identified object stored in the shared storage area of the data storage system; determining whether any conflicting locks are pending for the identified object stored within the shared storage area of the data storage system; granting the access request from the requesting processor if it is determined that no conflicting locks are pending for any other processor; and notifying the requesting host processor whether its access request was granted.
Claim 19
Dependent Claim
47 words
The method of claim 14 further comprising denying the access request from the requesting processor if it is determined that a conflicting lock is pending for another processor, and wherein the step of notifying comprises notifying the requesting processor whether its access request was granted or denied.
Claim 20
Dependent Claim
12 words
The method of claim 15 wherein the object is a file system.
Claim 21
Dependent Claim
20 words
The method of claim 16 wherein the access request is a request to access a file in the file system.
Claim 22
Dependent Claim
150 words
An access control method running on a slave processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said method comprising: preventing said slave processor from accessing an identified object stored in the shared storage area when no authorization has been received from a master processor which is another one of said plurality of processors; sending an access request from the slave processor to the master processor, said access request being a request for accessing said identified object in the shared storage area; receiving an acknowledgment from the master processor indicating whether the access request was granted; and permitting the slave processor to access the object if the received acknowledgment grants the access request.
Claim 23
Dependent Claim
150 words
An access control method running on a slave processor which is one of a plurality of processors connected to a data storage system, said plurality of processors all having access to a shared storage area in the data storage system and each being connected to said data storage system through a corresponding different channel, said method comprising: preventing said slave processor from accessing an identified object stored in the shared storage area when no authorization has been received from a master processor which is another one of said plurality of processors; sending an access request from the slave processor to the master processor, said access request being a request for accessing said identified object in the shared storage area; receiving an acknowledgment from the master processor indicating whether the access request was granted; and permitting the slave processor to access the object if the received acknowledgment grants the access request.
Claim 24
Dependent Claim
20 words
The method of claim 18 further comprising notifying the master processor when an access operation involving the object is complete.
Claim 25
Dependent Claim
12 words
The method of claim 19 wherein the object is a file system.
Claim 26
Dependent Claim
20 words
The method of claim 20 wherein the access request is a request to access a file in the file system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-06-14 | 2002-12-14 | 2003-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-14 | 2006-12-14 | 2007-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-14 | 2010-12-14 | 2011-06-15 | $7700.00 | Window Closed / Lapsed |