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