454e2398be
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.
The filesystem is then required to manually set the superblock and root dentry
pointers. For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).
The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.
This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing. In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.
The patch also makes the following changes:
(*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
pointer argument and return an integer, so most filesystems have to change
very little.
(*) If one of the convenience function is not used, then get_sb() should
normally call simple_set_mnt() to instantiate the vfsmount. This will
always return 0, and so can be tail-called from get_sb().
(*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
dcache upon superblock destruction rather than shrink_dcache_anon().
This is required because the superblock may now have multiple trees that
aren't actually bound to s_root, but that still need to be cleaned up. The
currently called functions assume that the whole tree is rooted at s_root,
and that anonymous dentries are not the roots of trees which results in
dentries being left unculled.
However, with the way NFS superblock sharing are currently set to be
implemented, these assumptions are violated: the root of the filesystem is
simply a dummy dentry and inode (the real inode for '/' may well be
inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
with child trees.
[*] Anonymous until discovered from another tree.
(*) The documentation has been adjusted, including the additional bit of
changing ext2_* into foo_* in the documentation.
[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
450 lines
11 KiB
C
450 lines
11 KiB
C
/*
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* fs/bfs/inode.c
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* BFS superblock and inode operations.
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* Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
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* From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
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*
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* Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/smp_lock.h>
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#include <linux/buffer_head.h>
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#include <linux/vfs.h>
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#include <asm/uaccess.h>
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#include "bfs.h"
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MODULE_AUTHOR("Tigran A. Aivazian <tigran@veritas.com>");
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MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
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MODULE_LICENSE("GPL");
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#undef DEBUG
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#ifdef DEBUG
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#define dprintf(x...) printf(x)
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#else
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#define dprintf(x...)
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#endif
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void dump_imap(const char *prefix, struct super_block * s);
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static void bfs_read_inode(struct inode * inode)
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{
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unsigned long ino = inode->i_ino;
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struct bfs_inode * di;
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struct buffer_head * bh;
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int block, off;
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if (ino < BFS_ROOT_INO || ino > BFS_SB(inode->i_sb)->si_lasti) {
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printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
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make_bad_inode(inode);
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return;
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}
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block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(inode->i_sb, block);
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if (!bh) {
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printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id, ino);
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make_bad_inode(inode);
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return;
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}
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off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *)bh->b_data + off;
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inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
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if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
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inode->i_mode |= S_IFDIR;
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inode->i_op = &bfs_dir_inops;
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inode->i_fop = &bfs_dir_operations;
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} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
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inode->i_mode |= S_IFREG;
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inode->i_op = &bfs_file_inops;
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inode->i_fop = &bfs_file_operations;
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inode->i_mapping->a_ops = &bfs_aops;
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}
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BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
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BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
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inode->i_uid = le32_to_cpu(di->i_uid);
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inode->i_gid = le32_to_cpu(di->i_gid);
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inode->i_nlink = le32_to_cpu(di->i_nlink);
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inode->i_size = BFS_FILESIZE(di);
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inode->i_blocks = BFS_FILEBLOCKS(di);
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if (inode->i_size || inode->i_blocks) dprintf("Registered inode with %lld size, %ld blocks\n", inode->i_size, inode->i_blocks);
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inode->i_blksize = PAGE_SIZE;
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inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
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inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
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inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
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inode->i_atime.tv_nsec = 0;
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inode->i_mtime.tv_nsec = 0;
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inode->i_ctime.tv_nsec = 0;
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BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino); /* can be 0 so we store a copy */
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brelse(bh);
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}
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static int bfs_write_inode(struct inode * inode, int unused)
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{
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unsigned int ino = (u16)inode->i_ino;
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unsigned long i_sblock;
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struct bfs_inode * di;
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struct buffer_head * bh;
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int block, off;
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dprintf("ino=%08x\n", ino);
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if (ino < BFS_ROOT_INO || ino > BFS_SB(inode->i_sb)->si_lasti) {
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printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
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return -EIO;
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}
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lock_kernel();
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block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(inode->i_sb, block);
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if (!bh) {
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printf("Unable to read inode %s:%08x\n", inode->i_sb->s_id, ino);
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unlock_kernel();
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return -EIO;
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}
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off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *)bh->b_data + off;
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if (ino == BFS_ROOT_INO)
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di->i_vtype = cpu_to_le32(BFS_VDIR);
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else
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di->i_vtype = cpu_to_le32(BFS_VREG);
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di->i_ino = cpu_to_le16(ino);
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di->i_mode = cpu_to_le32(inode->i_mode);
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di->i_uid = cpu_to_le32(inode->i_uid);
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di->i_gid = cpu_to_le32(inode->i_gid);
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di->i_nlink = cpu_to_le32(inode->i_nlink);
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di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
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di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
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di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
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i_sblock = BFS_I(inode)->i_sblock;
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di->i_sblock = cpu_to_le32(i_sblock);
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di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
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di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
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mark_buffer_dirty(bh);
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dprintf("Written ino=%d into %d:%d\n",le16_to_cpu(di->i_ino),block,off);
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brelse(bh);
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unlock_kernel();
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return 0;
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}
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static void bfs_delete_inode(struct inode * inode)
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{
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unsigned long ino = inode->i_ino;
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struct bfs_inode * di;
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struct buffer_head * bh;
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int block, off;
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struct super_block * s = inode->i_sb;
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struct bfs_sb_info * info = BFS_SB(s);
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struct bfs_inode_info * bi = BFS_I(inode);
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dprintf("ino=%08lx\n", ino);
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truncate_inode_pages(&inode->i_data, 0);
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if (ino < BFS_ROOT_INO || ino > info->si_lasti) {
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printf("invalid ino=%08lx\n", ino);
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return;
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}
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inode->i_size = 0;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
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lock_kernel();
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mark_inode_dirty(inode);
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block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(s, block);
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if (!bh) {
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printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id, ino);
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unlock_kernel();
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return;
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}
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off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *) bh->b_data + off;
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if (bi->i_dsk_ino) {
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info->si_freeb += 1 + bi->i_eblock - bi->i_sblock;
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info->si_freei++;
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clear_bit(ino, info->si_imap);
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dump_imap("delete_inode", s);
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}
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di->i_ino = 0;
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di->i_sblock = 0;
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mark_buffer_dirty(bh);
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brelse(bh);
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/* if this was the last file, make the previous
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block "last files last block" even if there is no real file there,
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saves us 1 gap */
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if (info->si_lf_eblk == BFS_I(inode)->i_eblock) {
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info->si_lf_eblk = BFS_I(inode)->i_sblock - 1;
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mark_buffer_dirty(info->si_sbh);
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}
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unlock_kernel();
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clear_inode(inode);
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}
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static void bfs_put_super(struct super_block *s)
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{
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struct bfs_sb_info *info = BFS_SB(s);
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brelse(info->si_sbh);
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kfree(info->si_imap);
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kfree(info);
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s->s_fs_info = NULL;
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}
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static int bfs_statfs(struct super_block *s, struct kstatfs *buf)
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{
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struct bfs_sb_info *info = BFS_SB(s);
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u64 id = huge_encode_dev(s->s_bdev->bd_dev);
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buf->f_type = BFS_MAGIC;
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buf->f_bsize = s->s_blocksize;
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buf->f_blocks = info->si_blocks;
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buf->f_bfree = buf->f_bavail = info->si_freeb;
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buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
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buf->f_ffree = info->si_freei;
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buf->f_fsid.val[0] = (u32)id;
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buf->f_fsid.val[1] = (u32)(id >> 32);
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buf->f_namelen = BFS_NAMELEN;
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return 0;
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}
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static void bfs_write_super(struct super_block *s)
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{
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lock_kernel();
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if (!(s->s_flags & MS_RDONLY))
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mark_buffer_dirty(BFS_SB(s)->si_sbh);
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s->s_dirt = 0;
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unlock_kernel();
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}
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static kmem_cache_t * bfs_inode_cachep;
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static struct inode *bfs_alloc_inode(struct super_block *sb)
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{
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struct bfs_inode_info *bi;
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bi = kmem_cache_alloc(bfs_inode_cachep, SLAB_KERNEL);
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if (!bi)
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return NULL;
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return &bi->vfs_inode;
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}
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static void bfs_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
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}
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static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
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{
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struct bfs_inode_info *bi = foo;
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if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
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SLAB_CTOR_CONSTRUCTOR)
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inode_init_once(&bi->vfs_inode);
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}
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static int init_inodecache(void)
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{
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bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
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sizeof(struct bfs_inode_info),
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0, (SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD),
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init_once, NULL);
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if (bfs_inode_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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static void destroy_inodecache(void)
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{
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if (kmem_cache_destroy(bfs_inode_cachep))
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printk(KERN_INFO "bfs_inode_cache: not all structures were freed\n");
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}
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static struct super_operations bfs_sops = {
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.alloc_inode = bfs_alloc_inode,
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.destroy_inode = bfs_destroy_inode,
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.read_inode = bfs_read_inode,
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.write_inode = bfs_write_inode,
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.delete_inode = bfs_delete_inode,
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.put_super = bfs_put_super,
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.write_super = bfs_write_super,
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.statfs = bfs_statfs,
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};
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void dump_imap(const char *prefix, struct super_block * s)
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{
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#ifdef DEBUG
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int i;
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char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
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if (!tmpbuf)
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return;
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for (i=BFS_SB(s)->si_lasti; i>=0; i--) {
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if (i > PAGE_SIZE-100) break;
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if (test_bit(i, BFS_SB(s)->si_imap))
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strcat(tmpbuf, "1");
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else
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strcat(tmpbuf, "0");
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}
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printk(KERN_ERR "BFS-fs: %s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
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free_page((unsigned long)tmpbuf);
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#endif
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}
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static int bfs_fill_super(struct super_block *s, void *data, int silent)
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{
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struct buffer_head * bh;
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struct bfs_super_block * bfs_sb;
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struct inode * inode;
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unsigned i, imap_len;
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struct bfs_sb_info * info;
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info = kmalloc(sizeof(*info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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s->s_fs_info = info;
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memset(info, 0, sizeof(*info));
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sb_set_blocksize(s, BFS_BSIZE);
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bh = sb_bread(s, 0);
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if(!bh)
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goto out;
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bfs_sb = (struct bfs_super_block *)bh->b_data;
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if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
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if (!silent)
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printf("No BFS filesystem on %s (magic=%08x)\n",
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s->s_id, le32_to_cpu(bfs_sb->s_magic));
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goto out;
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}
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if (BFS_UNCLEAN(bfs_sb, s) && !silent)
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printf("%s is unclean, continuing\n", s->s_id);
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s->s_magic = BFS_MAGIC;
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info->si_sbh = bh;
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info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE)/sizeof(struct bfs_inode)
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+ BFS_ROOT_INO - 1;
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imap_len = info->si_lasti/8 + 1;
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info->si_imap = kmalloc(imap_len, GFP_KERNEL);
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if (!info->si_imap)
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goto out;
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memset(info->si_imap, 0, imap_len);
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for (i=0; i<BFS_ROOT_INO; i++)
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set_bit(i, info->si_imap);
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s->s_op = &bfs_sops;
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inode = iget(s, BFS_ROOT_INO);
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if (!inode) {
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kfree(info->si_imap);
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goto out;
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}
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s->s_root = d_alloc_root(inode);
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if (!s->s_root) {
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iput(inode);
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kfree(info->si_imap);
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goto out;
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}
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info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1)>>BFS_BSIZE_BITS; /* for statfs(2) */
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info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start))>>BFS_BSIZE_BITS;
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info->si_freei = 0;
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info->si_lf_eblk = 0;
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info->si_lf_sblk = 0;
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info->si_lf_ioff = 0;
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bh = NULL;
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for (i=BFS_ROOT_INO; i<=info->si_lasti; i++) {
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struct bfs_inode *di;
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int block = (i - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
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int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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unsigned long sblock, eblock;
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if (!off) {
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brelse(bh);
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bh = sb_bread(s, block);
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}
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if (!bh)
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continue;
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di = (struct bfs_inode *)bh->b_data + off;
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if (!di->i_ino) {
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info->si_freei++;
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continue;
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}
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set_bit(i, info->si_imap);
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info->si_freeb -= BFS_FILEBLOCKS(di);
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sblock = le32_to_cpu(di->i_sblock);
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eblock = le32_to_cpu(di->i_eblock);
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if (eblock > info->si_lf_eblk) {
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info->si_lf_eblk = eblock;
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info->si_lf_sblk = sblock;
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info->si_lf_ioff = BFS_INO2OFF(i);
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}
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}
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brelse(bh);
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if (!(s->s_flags & MS_RDONLY)) {
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mark_buffer_dirty(info->si_sbh);
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s->s_dirt = 1;
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}
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dump_imap("read_super", s);
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return 0;
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out:
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brelse(bh);
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kfree(info);
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s->s_fs_info = NULL;
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return -EINVAL;
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}
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static int bfs_get_sb(struct file_system_type *fs_type,
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|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type bfs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "bfs",
|
|
.get_sb = bfs_get_sb,
|
|
.kill_sb = kill_block_super,
|
|
.fs_flags = FS_REQUIRES_DEV,
|
|
};
|
|
|
|
static int __init init_bfs_fs(void)
|
|
{
|
|
int err = init_inodecache();
|
|
if (err)
|
|
goto out1;
|
|
err = register_filesystem(&bfs_fs_type);
|
|
if (err)
|
|
goto out;
|
|
return 0;
|
|
out:
|
|
destroy_inodecache();
|
|
out1:
|
|
return err;
|
|
}
|
|
|
|
static void __exit exit_bfs_fs(void)
|
|
{
|
|
unregister_filesystem(&bfs_fs_type);
|
|
destroy_inodecache();
|
|
}
|
|
|
|
module_init(init_bfs_fs)
|
|
module_exit(exit_bfs_fs)
|