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 <linux/pagemap.h> 12 #include "coda_linux.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 .get_link = page_get_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_nohighmem(inode); 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 struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb) 93 { 94 struct coda_vattr attr; 95 struct inode *inode; 96 int error; 97 98 /* We get inode numbers from Venus -- see venus source */ 99 error = venus_getattr(sb, fid, &attr); 100 if (error) 101 return ERR_PTR(error); 102 103 inode = coda_iget(sb, fid, &attr); 104 if (IS_ERR(inode)) 105 pr_warn("%s: coda_iget failed\n", __func__); 106 return inode; 107 } 108 109 110 /* Although we treat Coda file identifiers as immutable, there is one 111 * special case for files created during a disconnection where they may 112 * not be globally unique. When an identifier collision is detected we 113 * first try to flush the cached inode from the kernel and finally 114 * resort to renaming/rehashing in-place. Userspace remembers both old 115 * and new values of the identifier to handle any in-flight upcalls. 116 * The real solution is to use globally unique UUIDs as identifiers, but 117 * retrofitting the existing userspace code for this is non-trivial. */ 118 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 119 struct CodaFid *newfid) 120 { 121 struct coda_inode_info *cii = ITOC(inode); 122 unsigned long hash = coda_f2i(newfid); 123 124 BUG_ON(!coda_fideq(&cii->c_fid, oldfid)); 125 126 /* replace fid and rehash inode */ 127 /* XXX we probably need to hold some lock here! */ 128 remove_inode_hash(inode); 129 cii->c_fid = *newfid; 130 inode->i_ino = hash; 131 __insert_inode_hash(inode, hash); 132 } 133 134 /* convert a fid to an inode. */ 135 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 136 { 137 struct inode *inode; 138 unsigned long hash = coda_f2i(fid); 139 140 if ( !sb ) { 141 pr_warn("%s: no sb!\n", __func__); 142 return NULL; 143 } 144 145 inode = ilookup5(sb, hash, coda_test_inode, fid); 146 if ( !inode ) 147 return NULL; 148 149 /* we should never see newly created inodes because we intentionally 150 * fail in the initialization callback */ 151 BUG_ON(inode->i_state & I_NEW); 152 153 return inode; 154 } 155 156 /* the CONTROL inode is made without asking attributes from Venus */ 157 struct inode *coda_cnode_makectl(struct super_block *sb) 158 { 159 struct inode *inode = new_inode(sb); 160 if (inode) { 161 inode->i_ino = CTL_INO; 162 inode->i_op = &coda_ioctl_inode_operations; 163 inode->i_fop = &coda_ioctl_operations; 164 inode->i_mode = 0444; 165 return inode; 166 } 167 return ERR_PTR(-ENOMEM); 168 } 169 170