JP2636969B2 - File system processing unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention manages a file system constructed on a logical volume composed of a plurality of volumes, and incorporates / disconnects a volume in the same manner as adding / deleting a name to / from a file. The present invention relates to a file system processing device capable of performing such operations.

[0002]

2. Description of the Related Art FIG. 12 shows an example of a file system configured on a volume for explaining the prior art.
In a computer system, for example, as shown in FIG. 12A, a file system having a hierarchical structure in which a directory file for managing file names is a node and an arbitrary file is a leaf.

When such a file system is constructed on one logical volume (hereinafter, referred to as a logical volume) composed of a plurality of volumes, the root directory of the file system constructed in each volume (hereinafter referred to as a logical volume) is constructed. (Represented by "/") is virtually superimposed on a directory having a basic file system. The operation of virtually superimposing these directories is called mounting.

In FIG. 1B, reference numeral 18 denotes a logical volume, and reference numerals 19, 19a, and 19b denote volumes. In this example, the directory (sys) in the file system on the volume (hp00) 19 is added to the volume (hp0a).
A single logical volume 18 is configured as a whole by virtually superimposing the root directory of 19a and superimposing the root directory of volume (hp0b) 19b on the directory (usr) virtually.

[0005]

The above-mentioned conventional system has the following problems. (a) When resolving a path name, it is necessary to determine whether or not a directory is a mount point, and if it is a mount point, search for an entry in the root directory of the mounted volume instead of the actual directory. Careful consideration is required. The mount point is a directory that is superimposed on the root directory of another volume, such as the sys or usr directory shown in FIG.

[0006] The path name is a name for uniquely identifying a file in the file system. The relationship between the file and the path name is 1: n (n ≧ 1). Path name resolution refers to specifying a file in a file system from a path name.

(B) The directory entry of the mount point becomes invisible to the user. Therefore, in order to make all the files on the basic file system visible to the user (they can be processed by specifying the path name), the free directory for the mount point must be
Required for each volume to be mounted.

[0008] The directory entry is information for linking a file name and a file, and is information stored in the directory. What is a file name?
This is a name for uniquely identifying files managed in a certain directory (these files are referred to as files under the directory).

For example, in the case of (b) in FIG.
Specify the path name of “/ sys / klib” and specify the volume (hp0
0) The files in 19 cannot be processed. Therefore, in order to eliminate such files, a directory (free directory) having no files under it must be used as a mount point.

When many volumes are mounted to form a huge logical volume, as the number of volumes constituting the logical volume increases, the number of directories for mount points increases and the space of the volume is consumed.

(C) In the conventional mount, since directories are virtually superimposed and shown, when the system stops, the relationship between the mount point and the volume disappears. For this reason, since it is necessary to perform the mounting process every time the IPL is performed, when mounting many volumes, the performance of the IPL is affected, and it takes a long time to start up the system and start the service.

The present invention solves the above-mentioned problems, and does not require special consideration of a mount point even when a logical volume is composed of a plurality of volumes. The purpose is to make the file visible, and to eliminate the need for a mount operation the next time the system is started after the system is stopped.

[0013]

FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, reference numeral 10 denotes a processing device including a CPU and a memory, 11 denotes a volume installation request,
2 is a volume disconnection request, 13 is a request receiving mechanism from the user for the file system, 14 is a volume incorporation request receiving unit that receives and processes the volume incorporation request 11, and 15 is a volume disconnection request that receives and processes the volume disconnection request 12. Receiving means, 16 is a volume incorporating means, 17 is a volume separating means, 1
Reference numeral 8 denotes a logical volume, and reference numerals 19x and 19y denote volumes which are units in which a root directory is provided.

The volume incorporation request receiving means 14 performs a process of receiving a volume incorporation request 11 requesting that a certain volume (for example, volume 19y) be incorporated in a directory (for example, a) of a basic file system. is there. In the volume installation request 11, the volume name (vol.
y) and a path name (/ a / b) including a file name to be assigned to the root directory.

When the volume incorporation request 11 is received, the volume incorporation means 16 changes the root directory of the file system in the volume 19y constituting the logical volume from the designated directory (a) in the basic file system. Linking is performed by the designated file name (b).

A link refers to the relationship between a file and a directory that can be created by adding a directory entry to the directory. Adding a directory entry of a file in a certain directory is called linking a file from the directory. It is possible to add a plurality of links to one file. When the number of links of a file becomes 0 and there is no process that has opened the file, the space of the file is collected. However, this space collection is suppressed only for the root directory.

The volume disconnection request receiving means 15 performs processing for receiving a volume disconnection request 12 requesting that a volume (for example, volume 19y) constituting a logical volume be disconnected.

The volume disconnecting means 17 receives the volume 1 to be disconnected when the volume disconnection request 12 is received.
The parent directory (a) linked to the root directory of 9y is updated, and the link is released.

In the processing of the volume separating means 17, the link is deleted only in the root directory of the volume, even if the directory has an entry in the directory. Further, only in the root directory of the volume, even if the directory is empty, the collection of space by deleting the link is suppressed.

A file serial number is used as an identifier for specifying a file in such a file system.
The relationship between the file serial number and the file is one-to-one. The file serial number includes a volume name for uniquely identifying a volume and a number for uniquely identifying a file in the volume. With this configuration, according to the present invention, information for identifying the volume in which the file exists can be obtained by the file serial number.

[0021]

[Action]

(l) A file name (b) is added to the root directory of the volume 19y constituting the logical volume, and the directory entry is added to a directory in the basic file system. As a result, there is no special directory called a mount point, and path name resolution in a file system including a plurality of volumes can be performed in the same manner as in the case of a single volume.

(2) Other directory entries (for example, c) of the directory which is the parent directory (a) of the root directory of the volume 19y constituting the logical volume also appear in the directory tree. This eliminates the need to create a free directory for the mount point.

(3) A file name (b) is added to the root directory of the volume 19y constituting the logical volume, and the directory entry is added to a directory in the basic file system, so that the system is stopped. However, the link information does not disappear, and there is no need to reconfigure the logical volume every time the system is restarted.

(4) Even after the volume 19y constituting the logical volume is separated, the file system in the volume is retained, so that it can be easily re-installed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A volume installation request 11 is, for example, a command of the following format (command name = condir). “Condir path name Incorporated volume name” Here, the path name is a path name added to the root directory of the volume. As shown in FIG.
The command "/ a / b voly" instructs that the root directory of the volume 19y having the volume name "vol" be linked to the directory "/ a" of the basic file system by the file name "b". doing.

The volume disconnection request 12 is, for example, a command of the following format (command name = discondi).
r). “Discondir path name” The command “discondir / a / b” as shown in FIG.
The directory "a" is updated, and the root directory of the volume 19y having the file name "b" is instructed to be separated from the basic file system.

FIG. 2 is an explanatory diagram of a file management mechanism according to an embodiment of the present invention. For example, a file system is constructed on a logical volume 18 composed of a plurality of volumes by a file management mechanism 21 as shown in FIG. The file management mechanism 21 includes the following components.

(1) User's request receiving mechanism 13 Using the mechanism of the volume assembling / disconnecting means 22,
Process requests from users. (2) Path name resolution mechanism 23 This mechanism uniquely identifies a file in the file system from the path name. Using the file access mechanism 26, a file serial number of the file is acquired while searching for a directory appearing in the path name.

(3) Path name operation mechanism 24 A mechanism for adding / deleting a directory entry to / from a directory when a file is created, deleted, renamed and a link to a file is added. When adding / deleting a directory entry to / from the directory, the file access mechanism 26 is used. The components of the directory entry are a file name, a file serial number, and the like.

(4) File operation mechanism 25 This mechanism secures and collects a file space on a volume. The file operation mechanism 25 collects the space of the file when the file is not linked to any file, and when no processes have opened the file. However, space is not collected for the root directory of the volume.

(5) File access mechanism 26 A mechanism for inputting / outputting a file. When writing data to a file, if space expansion is necessary, the file operation mechanism 25 is requested to secure the space.

FIG. 3 is an explanatory diagram of link information according to the embodiment of the present invention. For example, the volume 19 shown in FIG.
In the directory a of the file system which is the basis of x,
Assume that the volume 19y is incorporated.

The directory entry to be registered in the directory a of the basic file system is shown in FIG.
The information is as shown in FIG. That is, the volume 19y
File name "b" to be assigned to the root directory of
The file type (directory) and the file serial number.

The file serial number is composed of a volume name “voly” of the volume 19y and a file serial number in the volume which is a number for uniquely identifying a file in the volume. In the case of this embodiment, the root directory number is used. Is set to “1”, the file serial number of the file b is “vol−1”.

The link information held in the root directory of the volume 19y by mounting is information as shown in FIG. 3B, and includes the number of links, the assigned file name,
File serial number of the parent directory.

The number of links indicates how many upper directories are linked. The file name is determined from the path name specified by the volume build request command. The file serial number of the parent directory is the file serial number of the directory a in the example of FIG.
"volx-5" is obtained from the volume name of "x" and the serial number in the volume (5 in this example).

FIGS. 4 to 7 show the processing of the file management mechanism 21 when processing a volume installation request. Hereinafter, the processing at the time of incorporating the volume will be described.

The volume incorporation request receiving means 14 in the request receiving mechanism 13 from the user receives the volume incorporation request 11. The information notified by the user is
These are the path name added to the root directory of the volume to be embedded and the volume name of the volume to be embedded.

The request receiving mechanism 13 from the user requests the path name resolving mechanism 23 by a process 40 shown in FIG.
Acquires the file serial number of the directory that is the parent directory of the root directory of the volume to be installed. Also make sure that there is no file referenced by the specified path name to prevent double registration.

In response to this request, the path name resolution mechanism 23
Processing 50 to processing 59 shown in FIG. 5 are executed. That is,
By notifying the file access number 26 to the file serial number, the operation of referring to the directory entry of the directory appearing in the path name and acquiring the file serial number of the next directory is repeated, thereby acquiring the file serial number of the parent directory.

The file access mechanism 26 responds to the request from the path name resolution mechanism 23 by processing 53-1 or the like.
File name i from among the files indicated by the file serial numbers
Search for data (directory entry) corresponding to
Report the results.

It is an error if there is no directory appearing in the middle of the path name, and it is also an error if there is a directory appearing last in the path name.
Otherwise, in step 59, the request reception mechanism 1 receives the file serial number of the parent directory from the requesting user.
Notify 3.

The request receiving mechanism 13 receives a request from the user.
If it is determined in step 1 that the file referred to by the specified path name already exists, an error is notified to the user in step 45.

If there is no error, the process obtains the file serial number of the root directory of the volume to be incorporated by the process 42, and then requests the file operation mechanism 25 to update the link information of the root directory of the volume by the process 43. The delivery information at the time of this request is a file serial number of the root directory of the volume, a file name to be added, and a file serial number of the parent directory.

In response to this request, the file operation mechanism 25
Executes processing 60 and processing 61 shown in FIG. First,
It creates link information and requests the file access mechanism 26 to update the link information of the file with the file serial number as a key. In step 62, the file access mechanism 26 stores, in the attribute information of the file specified by the file serial number, the number of links, the added file name, the file serial number of the parent directory, and the like as shown in FIG. Write data.

Next, the request receiving mechanism 13 from the user notifies the path name operating mechanism 24 of the file serial number of the parent directory and the file name of the root directory of the volume by the processing 44, and the volume of the volume to be incorporated is determined. Request to add a directory entry for the root directory.

In response to this request, the path name operation mechanism 24
The processing 70 and the processing 71 shown in FIG. 7 are executed. In the process 70, a directory entry is created from the notified information. The file serial number of the root directory of the volume can be easily assembled because the file serial number in the volume of the root directory is fixed to “1”. In the process 71, the file access number 26 is notified of the file serial number and the directory entry of the parent directory, and the addition is requested.

In response to the request, the file access mechanism 26 adds a directory entry to the file indicated by the file serial number of the parent directory through processing 72.

When the above processing is completed, the request receiving mechanism 13 from the user notifies the user of the completion of the volume mounting processing through the processing 45, and ends the mounting processing.

FIGS. 8 to 11 show the processing of the file management mechanism 21 when processing a volume disconnection request. Hereinafter, the processing at the time of volume disconnection will be described.

The volume disconnection request receiving means 15 in the request receiving mechanism 13 from the user receives the volume disconnection request 12. The information notified by the user is
This is the path name to the root directory of the volume to be detached.

The request receiving mechanism 13 from the user requests the path name resolving mechanism 23 through a process 80 shown in FIG.
Get the file serial number of the parent directory of the root directory of the volume to be detached. Also checks that the file referenced by the specified path name is the root directory of the volume.

In response to this request, the path name resolution mechanism 23
Processing 90 to processing 99 shown in FIG. 9 are executed. That is,
By notifying the file access number 26 to the file serial number, the operation of referring to the directory entry of the directory appearing in the path name and acquiring the file serial number of the next directory is repeated, thereby acquiring the file serial number of the parent directory.

In response to the request from the path name resolving mechanism 23, the file access mechanism 26 searches for data (directory entry) corresponding to the file name i from the file indicated by the file serial number by processing 93 or the like. Report the results.

If the corresponding directory entry does not exist, it is determined that an error has occurred. If the directory entry does exist, the file serial number of the parent directory and the file serial number of the root directory of the volume to be separated are transmitted from the requesting user through processing 99. Is notified to the request receiving mechanism 13.

The request receiving mechanism 13 receives the processing 8
If the file referred to by the specified path name is not the root directory as a result of the determination in step 1, an error is notified to the user by a process 84.

If there is no error, the process 82 requests the path name operation mechanism 24 to delete the directory entry in the parent directory for the root directory of the volume to be separated.

The path name operation mechanism 24 requests the file access mechanism 26 to delete the directory entry for managing the corresponding file name from the parent directory by the processing 100 shown in FIG. At this time, since the entry is the root directory of the volume, the directory is deleted even if there are files under the entry. The file access mechanism 26 deletes the directory entry by the process 101.

Next, the request receiving mechanism 13 receives the link information (the file serial number of the parent directory, the name of the deleted file, and the number of links) of the root directory of the volume to be incorporated by the processing 83 to the file operating mechanism 25 in step 83. Ask to update.

The file operation mechanism 25 creates the link information through the processing 110 and the processing 111 shown in FIG. 11, and requests the file access mechanism 26 to update the link information of the corresponding file using the file serial number as a key. Since the file is the root directory of the volume, no space is collected even if the number of links is 0 and the number of open processes is 0. The file access mechanism 26 writes the specified data into the attribute information of the file specified by the key by the process 112.

When the above process is completed, the request receiving mechanism 13 from the user notifies the user of the completion of the volume disconnection process by a process 84, and terminates the disconnection process.

[0062]

As described above, according to the present invention,
The following effects are obtained. (1) In the path name resolution of a path name including a link such that the directory and the files under the directory exist on another volume, as in the case where the directory and the files under the directory exist on the same volume. Since it is only necessary to search for a directory entry, even if a file exists on another volume, the same performance of path name resolution as that obtained on the same volume can be obtained.

(2) When mounting a volume, there is no need to create an empty directory for embedding the volume so that existing files can be displayed on a directory tree, and the space of the volume can be used effectively.

(3) Since information relating to volume incorporation is held in the directory, it is not necessary to reconfigure the logical volume every time the IPL is performed, and the processing performance from the IPL to the start of the service is improved accordingly. These effects become more significant as the number of volumes constituting the logical volume increases.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is an explanatory diagram of a file management mechanism according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of link information according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a volume incorporation process according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a path name resolution process when a volume is incorporated according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of a file operation process when a volume is incorporated according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of a path name operation process when a volume is installed according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram of a volume disconnection process according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram of a path name solving process at the time of disconnecting a volume according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram of a path name operation process at the time of disconnecting a volume according to the embodiment of the present invention.

FIG. 11 is an explanatory diagram of a file operation process at the time of disconnecting a volume according to the embodiment of the present invention.

FIG. 12 is a diagram showing an example of a file system configured on a volume for explaining a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 processing device 11 volume incorporation request 12 volume disconnection request 13 request receiving mechanism from user 14 volume incorporation request receiving means 15 volume disconnection request receiving means 16 volume incorporation means 17 volume disconnection means 18 logical volume 19x, 19y volume

Claims (1)

(57) [Claims] 1. A processing device (10) for managing a file system having a root directory for each volume and a directory having a hierarchical structure, wherein the file system is capable of forming a logical volume by a plurality of volumes. Incorporating a certain volume into the directory of the underlying file system means that the root of the volume to be incorporated
A file name to be added to the directory.
Include a file name that does not exist in the file system
Volume and the volume that uniquely identifies the volume to be included
A volume incorporation request receiving means (14) for receiving an instruction to specify and request a file name, and a root directory of a file system in a volume to be incorporated when a volume incorporation request is made. From the specified directory in the file system, the file name included in the path name and the combination
File containing the volume name of the volume
The volume incorporation means (16) for linking using the correspondence information with the file identification information, and the separation of the volumes making up the logical volume are given to the root directory of the volume to be separated.
Volume disconnection request receiving means (15) for receiving an instruction to specify and request a path name including a file name, and updating the parent directory linked to the root directory of the volume to be disconnected when a volume disconnection request is made. And a volume disconnecting means (17) for releasing the link.