| vfsconf.9 (ffc0b97fd087519392b19a9d43056d7099b831eb) | vfsconf.9 (1f620c2ead117e9b4f698560053721d05a6637a3) |
|---|---|
| 1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as --- 28 unchanged lines hidden (view full) --- 37.In sys/mount.h 38.Ft int 39.Fn vfs_register "struct vfsconf *vfc" 40.Ft int 41.Fn vfs_unregister "struct vfsconf *vfc" 42.Ft int 43.Fn vfs_modevent "module_t mod" "int type" "void *data" 44.Sh DESCRIPTION | 1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as --- 28 unchanged lines hidden (view full) --- 37.In sys/mount.h 38.Ft int 39.Fn vfs_register "struct vfsconf *vfc" 40.Ft int 41.Fn vfs_unregister "struct vfsconf *vfc" 42.Ft int 43.Fn vfs_modevent "module_t mod" "int type" "void *data" 44.Sh DESCRIPTION |
| 45Each filesystem type known to the kernel has a vfsconf structure that contains the | 45Each filesystem type known to the kernel has a 46.Vt vfsconf 47structure that contains the |
| 46information required to create a new mount of that filesystems type. 47.Bd -literal | 48information required to create a new mount of that filesystems type. 49.Bd -literal |
| 48 struct vfsconf { 49 struct vfsops *vfc_vfsops; /* filesystem operations vector */ 50 char vfc_name[MFSNAMELEN]; /* filesystem type name */ 51 int vfc_typenum; /* historic filesystem type number */ 52 int vfc_refcount; /* number mounted of this type */ 53 int vfc_flags; /* permanent flags */ 54 struct vfsconf *vfc_next; /* next in list */ 55 }; 56 | 50struct vfsconf { 51 struct vfsops *vfc_vfsops; /* filesystem operations vector */ 52 char vfc_name[MFSNAMELEN]; /* filesystem type name */ 53 int vfc_typenum; /* historic filesystem type number */ 54 int vfc_refcount; /* number mounted of this type */ 55 int vfc_flags; /* permanent flags */ 56 struct vfsconf *vfc_next; /* next in list */ 57}; |
| 57.Ed | 58.Ed |
| 58When a new filesystem is mounted 59.Fn vfs_mount 60does a lookup of the vfcconf structure by its name, and if it is not already registered, | 59.Pp 60When a new filesystem is mounted, 61.Xr vfs_mount 9 62does a lookup of the 63.Vt vfsconf 64structure by its name, and if it is not already registered, |
| 61attempts to load a kernel module for it. | 65attempts to load a kernel module for it. |
| 62The filesystem operations for the new mount point are taken from vfc_vfsops, and mnt_vfc 63in the mount structure is made to point directly at the vfcconf structure for the | 66The filesystem operations for the new mount point are taken from 67.Va vfc_vfsops , 68and 69.Va mnt_vfc 70in the 71.Vt mount 72structure is made to point directly at the 73.Vt vfsconf 74structure for the |
| 64filesystem type. | 75filesystem type. |
| 65The filesystem type number is taken from vfs_typenum which was assigned in | 76The filesystem type number is taken from 77.Va vfc_typenum 78which was assigned in |
| 66.Fn vfs_register , | 79.Fn vfs_register , |
| 67and the mount flags are taken from a mask of vfc_flags. 68Each time a filesystem of a given type is mounted vfc_refcount is incremented. | 80and the mount flags are taken from a mask of 81.Va vfc_flags . 82Each time a filesystem of a given type is mounted, 83.Va vfc_refcount 84is incremented. |
| 69.Pp 70.Fn vfs_register | 85.Pp 86.Fn vfs_register |
| 71takes a new vfsconf structure and adds it to the list of existing filesystems. 72If the type has not already been registered it is initialize by calling the | 87takes a new 88.Vt vfsconf 89structure and adds it to the list of existing filesystems. 90If the type has not already been registered, it is initialized by calling the |
| 73.Fn vfs_init 74function in the filesystem operations vector. 75.Fn vfs_register 76also updates the oid's of any sysctl nodes for this filesystem type 77to be the same as the newly assigned type number. 78.Pp 79.Fn vfs_unregister 80unlinks 81.Fa vfc 82from the list of registered filesystem types if there are currently no mounted instances. 83If the 84.Fn vfs_uninit | 91.Fn vfs_init 92function in the filesystem operations vector. 93.Fn vfs_register 94also updates the oid's of any sysctl nodes for this filesystem type 95to be the same as the newly assigned type number. 96.Pp 97.Fn vfs_unregister 98unlinks 99.Fa vfc 100from the list of registered filesystem types if there are currently no mounted instances. 101If the 102.Fn vfs_uninit |
| 85function in the filesystems initialization vector is defined it is called. | 103function in the filesystems initialization vector is defined, it is called. |
| 86.Pp 87.Fn vfs_modevent 88is registered by 89.Fn VFS_SET 90to handle the loading and unloading of filesystem kernel modules. 91In the case of | 104.Pp 105.Fn vfs_modevent 106is registered by 107.Fn VFS_SET 108to handle the loading and unloading of filesystem kernel modules. 109In the case of |
| 92.Dv MOD_LOAD | 110.Dv MOD_LOAD , |
| 93.Fn vfs_register 94is called. 95In the case of | 111.Fn vfs_register 112is called. 113In the case of |
| 96.Dv MOD_UNLOAD | 114.Dv MOD_UNLOAD , |
| 97.Fn vfs_unregister 98is called. 99.Sh RETURN VALUES 100.Fn vfs_register 101returns 0 if successful; otherwise, | 115.Fn vfs_unregister 116is called. 117.Sh RETURN VALUES 118.Fn vfs_register 119returns 0 if successful; otherwise, |
| 102.Dv EEXIST | 120.Er EEXIST |
| 103is returned indicating that the filesystem type has already been registered. 104.Pp 105.Fn vfs_unregister 106returns 0 if successful. | 121is returned indicating that the filesystem type has already been registered. 122.Pp 123.Fn vfs_unregister 124returns 0 if successful. |
| 107If no vfsconf entry can be found matching the name in | 125If no 126.Vt vfsconf 127entry can be found matching the name in |
| 108.Fa vfc , | 128.Fa vfc , |
| 109.Dv EINVAL | 129.Er EINVAL |
| 110is returned. | 130is returned. |
| 111If the reference count of mounted instances of the filesystem type is not zero 112.Dv EBUSY | 131If the reference count of mounted instances of the filesystem type is not zero, 132.Er EBUSY |
| 113is returned. 114If 115.Fn vfs_uninit | 133is returned. 134If 135.Fn vfs_uninit |
| 116is called any errors it returns will be returned by | 136is called, any errors it returns will be returned by |
| 117.Fn vfs_unregister . 118.Pp 119.Fn vfs_modevent 120returns the result of the call to 121.Fn vfs_register 122or | 137.Fn vfs_unregister . 138.Pp 139.Fn vfs_modevent 140returns the result of the call to 141.Fn vfs_register 142or |
| 123.Fn vfs_unregister | 143.Fn vfs_unregister , |
| 124whatever the case. 125.Sh SEE ALSO | 144whatever the case. 145.Sh SEE ALSO |
| 146.Xr vfs_mount 9 , |
|
| 126.Xr vfs_rootmountalloc 9 , | 147.Xr vfs_rootmountalloc 9 , |
| 127.Xr vfs_mount , | |
| 128.Xr VFS_SET 9 129.Sh AUTHORS 130This man page was written by 131.An Chad David Aq davidc@acns.ab.ca . | 148.Xr VFS_SET 9 149.Sh AUTHORS 150This man page was written by 151.An Chad David Aq davidc@acns.ab.ca . |