diff options
Diffstat (limited to 'fs/sysv/symlink.c')
-rw-r--r-- | fs/sysv/symlink.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/fs/sysv/symlink.c b/fs/sysv/symlink.c new file mode 100644 index 000000000..d392816bc --- /dev/null +++ b/fs/sysv/symlink.c @@ -0,0 +1,110 @@ +/* + * linux/fs/sysv/symlink.c + * + * minix/symlink.c + * Copyright (C) 1991, 1992 Linus Torvalds + * + * coh/symlink.c + * Copyright (C) 1993 Pascal Haible, Bruno Haible + * + * sysv/symlink.c + * Copyright (C) 1993 Bruno Haible + * + * SystemV/Coherent symlink handling code + */ + +#include <asm/segment.h> + +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/sysv_fs.h> +#include <linux/stat.h> + +static int sysv_readlink(struct inode *, char *, int); +static int sysv_follow_link(struct inode *, struct inode *, int, int, struct inode **); + +/* + * symlinks can't do much... + */ +struct inode_operations sysv_symlink_inode_operations = { + NULL, /* no file-operations */ + NULL, /* create */ + NULL, /* lookup */ + NULL, /* link */ + NULL, /* unlink */ + NULL, /* symlink */ + NULL, /* mkdir */ + NULL, /* rmdir */ + NULL, /* mknod */ + NULL, /* rename */ + sysv_readlink, /* readlink */ + sysv_follow_link, /* follow_link */ + NULL, /* bmap */ + NULL, /* truncate */ + NULL /* permission */ +}; + +static int sysv_follow_link(struct inode * dir, struct inode * inode, + int flag, int mode, struct inode ** res_inode) +{ + int error; + struct buffer_head * bh; + + *res_inode = NULL; + if (!dir) { + dir = current->fs->root; + dir->i_count++; + } + if (!inode) { + iput(dir); + return -ENOENT; + } + if (!S_ISLNK(inode->i_mode)) { + iput(dir); + *res_inode = inode; + return 0; + } + if (current->link_count > 5) { + iput(inode); + iput(dir); + return -ELOOP; + } + if (!(bh = sysv_file_bread(inode, 0, 0))) { /* is reading 1 block enough ?? */ + iput(inode); + iput(dir); + return -EIO; + } + iput(inode); + current->link_count++; + error = open_namei(bh->b_data,flag,mode,res_inode,dir); + current->link_count--; + brelse(bh); + return error; +} + +static int sysv_readlink(struct inode * inode, char * buffer, int buflen) +{ + struct buffer_head * bh; + char * bh_data; + int i; + char c; + + if (!S_ISLNK(inode->i_mode)) { + iput(inode); + return -EINVAL; + } + if (buflen > inode->i_sb->sv_block_size_1) + buflen = inode->i_sb->sv_block_size_1; + bh = sysv_file_bread(inode, 0, 0); + iput(inode); + if (!bh) + return 0; + bh_data = bh->b_data; + i = 0; + while (i<buflen && (c = bh_data[i])) { + i++; + put_fs_byte(c,buffer++); + } + brelse(bh); + return i; +} |