1 /* cnode related routines for the coda kernel code 2 (C) 1996 Peter Braam 3 */ 4 5 #include <linux/types.h> 6 #include <linux/string.h> 7 #include <linux/time.h> 8 9 #include <linux/coda.h> 10 #include <linux/coda_linux.h> 11 #include <linux/coda_fs_i.h> 12 #include <linux/coda_psdev.h> 13 14 static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2) 15 { 16 return memcmp(fid1, fid2, sizeof(*fid1)) == 0; 17 } 18 19 static const struct inode_operations coda_symlink_inode_operations = { 20 .readlink = generic_readlink, 21 .follow_link = page_follow_link_light, 22 .put_link = page_put_link, 23 .setattr = coda_setattr, 24 }; 25 26 /* cnode.c */ 27 static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr) 28 { 29 coda_vattr_to_iattr(inode, attr); 30 31 if (S_ISREG(inode->i_mode)) { 32 inode->i_op = &coda_file_inode_operations; 33 inode->i_fop = &coda_file_operations; 34 } else if (S_ISDIR(inode->i_mode)) { 35 inode->i_op = &coda_dir_inode_operations; 36 inode->i_fop = &coda_dir_operations; 37 } else if (S_ISLNK(inode->i_mode)) { 38 inode->i_op = &coda_symlink_inode_operations; 39 inode->i_data.a_ops = &coda_symlink_aops; 40 inode->i_mapping = &inode->i_data; 41 } else 42 init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev)); 43 } 44 45 static int coda_test_inode(struct inode *inode, void *data) 46 { 47 struct CodaFid *fid = (struct CodaFid *)data; 48 struct coda_inode_info *cii = ITOC(inode); 49 return coda_fideq(&cii->c_fid, fid); 50 } 51 52 static int coda_set_inode(struct inode *inode, void *data) 53 { 54 struct CodaFid *fid = (struct CodaFid *)data; 55 struct coda_inode_info *cii = ITOC(inode); 56 cii->c_fid = *fid; 57 return 0; 58 } 59 60 struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid, 61 struct coda_vattr * attr) 62 { 63 struct inode *inode; 64 struct coda_inode_info *cii; 65 unsigned long hash = coda_f2i(fid); 66 67 inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid); 68 69 if (!inode) 70 return ERR_PTR(-ENOMEM); 71 72 if (inode->i_state & I_NEW) { 73 cii = ITOC(inode); 74 /* we still need to set i_ino for things like stat(2) */ 75 inode->i_ino = hash; 76 /* inode is locked and unique, no need to grab cii->c_lock */ 77 cii->c_mapcount = 0; 78 unlock_new_inode(inode); 79 } 80 81 /* always replace the attributes, type might have changed */ 82 coda_fill_inode(inode, attr); 83 return inode; 84 } 85 86 /* this is effectively coda_iget: 87 - get attributes (might be cached) 88 - get the inode for the fid using vfs iget 89 - link the two up if this is needed 90 - fill in the attributes 91 */ 92 int coda_cnode_make(struct inode **inode, struct CodaFid *fid, struct super_block *sb) 93 { 94 struct coda_vattr attr; 95 int error; 96 97 /* We get inode numbers from Venus -- see venus source */ 98 error = venus_getattr(sb, fid, &attr); 99 if ( error ) { 100 *inode = NULL; 101 return error; 102 } 103 104 *inode = coda_iget(sb, fid, &attr); 105 if ( IS_ERR(*inode) ) { 106 printk("coda_cnode_make: coda_iget failed\n"); 107 return PTR_ERR(*inode); 108 } 109 return 0; 110 } 111 112 113 /* Although we treat Coda file identifiers as immutable, there is one 114 * special case for files created during a disconnection where they may 115 * not be globally unique. When an identifier collision is detected we 116 * first try to flush the cached inode from the kernel and finally 117 * resort to renaming/rehashing in-place. Userspace remembers both old 118 * and new values of the identifier to handle any in-flight upcalls. 119 * The real solution is to use globally unique UUIDs as identifiers, but 120 * retrofitting the existing userspace code for this is non-trivial. */ 121 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 122 struct CodaFid *newfid) 123 { 124 struct coda_inode_info *cii = ITOC(inode); 125 unsigned long hash = coda_f2i(newfid); 126 127 BUG_ON(!coda_fideq(&cii->c_fid, oldfid)); 128 129 /* replace fid and rehash inode */ 130 /* XXX we probably need to hold some lock here! */ 131 remove_inode_hash(inode); 132 cii->c_fid = *newfid; 133 inode->i_ino = hash; 134 __insert_inode_hash(inode, hash); 135 } 136 137 /* convert a fid to an inode. */ 138 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 139 { 140 struct inode *inode; 141 unsigned long hash = coda_f2i(fid); 142 143 if ( !sb ) { 144 printk("coda_fid_to_inode: no sb!\n"); 145 return NULL; 146 } 147 148 inode = ilookup5(sb, hash, coda_test_inode, fid); 149 if ( !inode ) 150 return NULL; 151 152 /* we should never see newly created inodes because we intentionally 153 * fail in the initialization callback */ 154 BUG_ON(inode->i_state & I_NEW); 155 156 return inode; 157 } 158 159 /* the CONTROL inode is made without asking attributes from Venus */ 160 int coda_cnode_makectl(struct inode **inode, struct super_block *sb) 161 { 162 int error = -ENOMEM; 163 164 *inode = new_inode(sb); 165 if (*inode) { 166 (*inode)->i_ino = CTL_INO; 167 (*inode)->i_op = &coda_ioctl_inode_operations; 168 (*inode)->i_fop = &coda_ioctl_operations; 169 (*inode)->i_mode = 0444; 170 error = 0; 171 } 172 173 return error; 174 } 175 176