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 struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb) 92 { 93 struct coda_vattr attr; 94 struct inode *inode; 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 return ERR_PTR(error); 101 102 inode = coda_iget(sb, fid, &attr); 103 if (IS_ERR(inode)) 104 printk("coda_cnode_make: coda_iget failed\n"); 105 return inode; 106 } 107 108 109 /* Although we treat Coda file identifiers as immutable, there is one 110 * special case for files created during a disconnection where they may 111 * not be globally unique. When an identifier collision is detected we 112 * first try to flush the cached inode from the kernel and finally 113 * resort to renaming/rehashing in-place. Userspace remembers both old 114 * and new values of the identifier to handle any in-flight upcalls. 115 * The real solution is to use globally unique UUIDs as identifiers, but 116 * retrofitting the existing userspace code for this is non-trivial. */ 117 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 118 struct CodaFid *newfid) 119 { 120 struct coda_inode_info *cii = ITOC(inode); 121 unsigned long hash = coda_f2i(newfid); 122 123 BUG_ON(!coda_fideq(&cii->c_fid, oldfid)); 124 125 /* replace fid and rehash inode */ 126 /* XXX we probably need to hold some lock here! */ 127 remove_inode_hash(inode); 128 cii->c_fid = *newfid; 129 inode->i_ino = hash; 130 __insert_inode_hash(inode, hash); 131 } 132 133 /* convert a fid to an inode. */ 134 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 135 { 136 struct inode *inode; 137 unsigned long hash = coda_f2i(fid); 138 139 if ( !sb ) { 140 printk("coda_fid_to_inode: no sb!\n"); 141 return NULL; 142 } 143 144 inode = ilookup5(sb, hash, coda_test_inode, fid); 145 if ( !inode ) 146 return NULL; 147 148 /* we should never see newly created inodes because we intentionally 149 * fail in the initialization callback */ 150 BUG_ON(inode->i_state & I_NEW); 151 152 return inode; 153 } 154 155 /* the CONTROL inode is made without asking attributes from Venus */ 156 struct inode *coda_cnode_makectl(struct super_block *sb) 157 { 158 struct inode *inode = new_inode(sb); 159 if (inode) { 160 inode->i_ino = CTL_INO; 161 inode->i_op = &coda_ioctl_inode_operations; 162 inode->i_fop = &coda_ioctl_operations; 163 inode->i_mode = 0444; 164 return inode; 165 } 166 return ERR_PTR(-ENOMEM); 167 } 168 169