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Diffstat (limited to 'doc/how-fuse-works')
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diff --git a/doc/how-fuse-works b/doc/how-fuse-works deleted file mode 100644 index a5febe3..0000000 --- a/doc/how-fuse-works +++ /dev/null @@ -1,54 +0,0 @@ - How Fuse-1.3 Works - -[Written by Terje Oseberg] - -1. The fuse library. - -When your user mode program calls fuse_main() (lib/helper.c), -fuse_main() parses the arguments passed to your user mode program, -then calls fuse_mount() (lib/mount.c). - -fuse_mount() creates a UNIX domain socket pair, then forks and execs -fusermount (util/fusermount.c) passing it one end of the socket in the -FUSE_COMMFD_ENV environment variable. - -fusermount (util/fusermount.c) makes sure that the fuse module is -loaded. fusermount then open /dev/fuse and send the file handle over a -UNIX domain socket back to fuse_mount(). - -fuse_mount() returns the filehandle for /dev/fuse to fuse_main(). - -fuse_main() calls fuse_new() (lib/fuse.c) which allocates the struct -fuse datastructure that stores and maintains a cached image of the -filesystem data. - -Lastly, fuse_main() calls either fuse_loop() (lib/fuse.c) or -fuse_loop_mt() (lib/fuse_mt.c) which both start to read the filesystem -system calls from the /dev/fuse, call the usermode functions -stored in struct fuse_operations datastructure before calling -fuse_main(). The results of those calls are then written back to the -/dev/fuse file where they can be forwarded back to the system -calls. - -2. The kernel module. - -The kernel module consists of two parts. First the proc filesystem -component in kernel/dev.c -and second the filesystem system calls -kernel/file.c, kernel/inode.c, and kernel/dir.c - -All the system calls in kernel/file.c, kernel/inode.c, and -kernel/dir.c make calls to either request_send(), -request_send_noreply(), or request_send_nonblock(). Most of the calls -(all but 2) are to request_send(). request_send() adds the request to, -"list of requests" structure (fc->pending), then waits for a response. -request_send_noreply() and request_send_nonblock() are both similar in -function to request_send() except that one is non-blocking, and the -other does not respond with a reply. - -The proc filesystem component in kernel/dev.c responds to file io -requests to the file /dev/fuse. fuse_dev_read() handles the -file reads and returns commands from the "list of requests" structure -to the calling program. fuse_dev_write() handles file writes and takes -the data written and places them into the req->out datastructure where -they can be returned to the system call through the "list of requests" -structure and request_send(). |