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