# US 2014/0156695 A1 · Method for identifying corresponding directories in a union-mounted file system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156695 A1 - Document ID: US20140156695A1 - Status: Published application - Kind: A1 - Application number: 13/690,733 - Filed: 2012-11-30 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Brent P. Callaghan - Web page: https://patentgrep.com/patent/US20140156695A1 ## CPC - G06F 16/148: {File search processing} - G06F 16/13: File access structures, e.g. distributed indices (arrangements of input from, or output to, record carriers G06F3/06) - G06F 16/188: Virtual file systems - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract In one embodiment, in response to a request for searching a file stored in a first directory, a first lookup is performed by a virtual file system in a first file system to locate the file. The virtual file system traverses from the first directory back to a mount point of the first file system to recreate a search path from the mount point to the first directory. The virtual file system performs a second lookup in a second directory of a second file system that is associated with the mount point to locate the file in the second file system, where second directory is identified by the recreated search path. ## Claims ### Claim 1 A computer-implemented method, comprising: in response to a request for searching a file stored in a first directory, performing a first lookup in a first file system to locate the file; traversing from the first directory back to a mount point of the first file system to recreate a search path from the mount point to the first directory; and performing a second lookup in a second directory of a second file system that is associated with the mount point to locate the file in the second file system, wherein the second directory is identified by the recreated search path. ### Claim 2 (depends on 1) The method of claim 1, wherein the request is received by a virtual file system (VFS) of an operating system, and wherein the first and second lookups are performed by the VFS in the first and second file systems, respectively. ### Claim 3 (depends on 2) The method of claim 2, wherein the first file system and the second file system are union mounted. ### Claim 4 (depends on 2) The method of claim 2, wherein the VFS includes a union mount point that references to mount points of the first and second file systems. ### Claim 5 (depends on 2) The method of claim 2, further comprising incorporating, by the VFS, lookup results of the first and second file systems to provide a unified file system view. ### Claim 6 (depends on 1) The method of claim 1, wherein traversal of the search path is performed only if the first directory does not contain the file. ### Claim 7 (depends on 1) The method of claim 1, wherein the first and second file systems are different types of file systems. ### Claim 8 A non-transitory computer-readable medium having instructions stored therein, which when executed by a computer, cause the computer to perform a method, the method comprising: in response to a request for searching a file stored in a first directory, performing a first lookup in a first file system to locate the file; traversing from the first directory back to a mount point of the first file system to recreate a search path from the mount point to the first directory; and performing a second lookup in a second directory of a second file system that is associated with the mount point to locate the file in the second file system, wherein the second directory is identified by the recreated search path. ### Claim 9 (depends on 8) The non-transitory computer-readable medium of claim 8, wherein the request is received by a virtual file system (VFS) of an operating system, and wherein the first and second lookups are performed by the VFS in the first and second file systems, respectively. ### Claim 10 (depends on 9) The non-transitory computer-readable medium of claim 9, wherein the first file system and the second file system are union mounted. ### Claim 11 (depends on 9) The non-transitory computer-readable medium of claim 9, wherein the VFS includes a union mount point that references to mount points of the first and second file systems. ### Claim 12 (depends on 9) The non-transitory computer-readable medium of claim 9, wherein the method further comprises incorporating, by the VFS, lookup results of the first and second file systems to provide a unified file system view. ### Claim 13 (depends on 8) The non-transitory computer-readable medium of claim 8, wherein traversal of the search path is performed only if the first directory does not contain the file. ### Claim 14 (depends on 8) The non-transitory computer-readable medium of claim 8, wherein the first and second file systems are different types of file systems. ### Claim 15 A data processing system, comprising: a processor; and a memory having instructions stored therein, which when executed from the memory, cause the processor to in response to a request for searching a file stored in a first directory, perform a first lookup in a first file system to locate the file, traverse from the first directory back to a mount point of the first file system to recreate a search path from the mount point to the first directory, and perform a second lookup in a second directory of a second file system that is associated with the mount point to locate the file in the second file system, wherein the second directory is identified by the recreated search path. ### Claim 16 (depends on 15) The system of claim 15, wherein the request is received by a virtual file system (VFS) of an operating system, and wherein the first and second lookups are performed by the VFS in the first and second file systems, respectively. ### Claim 17 (depends on 16) The system of claim 16, wherein the first file system and the second file system are union mounted. ### Claim 18 (depends on 16) The system of claim 16, wherein the VFS includes a union mount point that references to mount points of the first and second file systems. ### Claim 19 (depends on 16) The system of claim 16, wherein the VFS incorporates lookup results of the first and second file systems to provide a unified file system view. ### Claim 20 (depends on 15) The system of claim 15, wherein traversal of the search path is performed only if the first directory does not contain the file. ### Claim 21 (depends on 15) The system of claim 15, wherein the first and second file systems are different types of file systems.