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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | /* * linux/fs/nfs/symlink.c * * Copyright (C) 1992 Rick Sladkey * * Optimization changes Copyright (C) 1994 Florian La Roche * * nfs symlink handling code */ #include <linux/sched.h> #include <linux/errno.h> #include <linux/nfs_fs.h> #include <linux/stat.h> #include <linux/mm.h> #include <linux/malloc.h> #include <linux/string.h> #include <asm/segment.h> static int nfs_readlink(struct inode *, char *, int); static int nfs_follow_link(struct inode *, struct inode *, int, int, struct inode **); /* * symlinks can't do much... */ struct inode_operations nfs_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 */ nfs_readlink, /* readlink */ nfs_follow_link, /* follow_link */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL /* permission */ }; static int nfs_follow_link(struct inode *dir, struct inode *inode, int flag, int mode, struct inode **res_inode) { int error, *mem; unsigned int len; char *res, *res2; *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; } error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), &mem, &res, &len, NFS_MAXPATHLEN); if (error) { iput(inode); iput(dir); kfree(mem); return error; } while ((res2 = (char *) kmalloc(NFS_MAXPATHLEN + 1, GFP_NFS)) == NULL) { schedule(); } memcpy(res2, res, len); res2[len] = '\0'; kfree(mem); iput(inode); current->link_count++; error = open_namei(res2, flag, mode, res_inode, dir); current->link_count--; kfree_s(res2, NFS_MAXPATHLEN + 1); return error; } static int nfs_readlink(struct inode *inode, char *buffer, int buflen) { int error, *mem; unsigned int len; char *res; if (!S_ISLNK(inode->i_mode)) { iput(inode); return -EINVAL; } if (buflen > NFS_MAXPATHLEN) buflen = NFS_MAXPATHLEN; error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), &mem, &res, &len, buflen); iput(inode); if (! error) { memcpy_tofs(buffer, res, len); put_user('\0', buffer + len); error = len; } kfree(mem); return error; } |