20.2 The ’mount’ table (0272)

The “mount” table contained an entry for each mounted file system volume. Each entry defines the device on which the file system volume is mounted, a pointer to the buffer which stores the “super block” for the device, and an “inode” pointer. The table is referenced as follows:

iinit (6922)

which is called by “main” (1615), makes an entry for the root device;

smount (6086)

is a system call which makes entries for additional devices;

iget (7276)

searches the “mount” table if it encounters an “inode” with the ‘IMOUNT’ flag set;

getfs (7167)

searches the “mount” table to find and return a pointer to the “super block” for a particular device;

update (7201)

is called periodically and searches the “mount” table to locate information which should be written from core tables into the tables maintained on the file system volumes;

sumount (6144)

is a system call which deletes entries from the table.