cnode.c (5091B)
1// SPDX-License-Identifier: GPL-2.0 2/* cnode related routines for the coda kernel code 3 (C) 1996 Peter Braam 4 */ 5 6#include <linux/types.h> 7#include <linux/string.h> 8#include <linux/time.h> 9 10#include <linux/coda.h> 11#include <linux/pagemap.h> 12#include "coda_psdev.h" 13#include "coda_linux.h" 14 15static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2) 16{ 17 return memcmp(fid1, fid2, sizeof(*fid1)) == 0; 18} 19 20static const struct inode_operations coda_symlink_inode_operations = { 21 .get_link = page_get_link, 22 .setattr = coda_setattr, 23}; 24 25/* cnode.c */ 26static 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 45static 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 52static 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 60struct 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 umode_t inode_type = coda_inode_type(attr); 67 68retry: 69 inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid); 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 coda_fill_inode(inode, attr); 80 unlock_new_inode(inode); 81 } else if ((inode->i_mode & S_IFMT) != inode_type) { 82 /* Inode has changed type, mark bad and grab a new one */ 83 remove_inode_hash(inode); 84 coda_flag_inode(inode, C_PURGE); 85 iput(inode); 86 goto retry; 87 } 88 return inode; 89} 90 91/* this is effectively coda_iget: 92 - get attributes (might be cached) 93 - get the inode for the fid using vfs iget 94 - link the two up if this is needed 95 - fill in the attributes 96*/ 97struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb) 98{ 99 struct coda_vattr attr; 100 struct inode *inode; 101 int error; 102 103 /* We get inode numbers from Venus -- see venus source */ 104 error = venus_getattr(sb, fid, &attr); 105 if (error) 106 return ERR_PTR(error); 107 108 inode = coda_iget(sb, fid, &attr); 109 if (IS_ERR(inode)) 110 pr_warn("%s: coda_iget failed\n", __func__); 111 return inode; 112} 113 114 115/* Although we treat Coda file identifiers as immutable, there is one 116 * special case for files created during a disconnection where they may 117 * not be globally unique. When an identifier collision is detected we 118 * first try to flush the cached inode from the kernel and finally 119 * resort to renaming/rehashing in-place. Userspace remembers both old 120 * and new values of the identifier to handle any in-flight upcalls. 121 * The real solution is to use globally unique UUIDs as identifiers, but 122 * retrofitting the existing userspace code for this is non-trivial. */ 123void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 124 struct CodaFid *newfid) 125{ 126 struct coda_inode_info *cii = ITOC(inode); 127 unsigned long hash = coda_f2i(newfid); 128 129 BUG_ON(!coda_fideq(&cii->c_fid, oldfid)); 130 131 /* replace fid and rehash inode */ 132 /* XXX we probably need to hold some lock here! */ 133 remove_inode_hash(inode); 134 cii->c_fid = *newfid; 135 inode->i_ino = hash; 136 __insert_inode_hash(inode, hash); 137} 138 139/* convert a fid to an inode. */ 140struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 141{ 142 struct inode *inode; 143 unsigned long hash = coda_f2i(fid); 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 156struct coda_file_info *coda_ftoc(struct file *file) 157{ 158 struct coda_file_info *cfi = file->private_data; 159 160 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 161 162 return cfi; 163 164} 165 166/* the CONTROL inode is made without asking attributes from Venus */ 167struct inode *coda_cnode_makectl(struct super_block *sb) 168{ 169 struct inode *inode = new_inode(sb); 170 if (inode) { 171 inode->i_ino = CTL_INO; 172 inode->i_op = &coda_ioctl_inode_operations; 173 inode->i_fop = &coda_ioctl_operations; 174 inode->i_mode = 0444; 175 return inode; 176 } 177 return ERR_PTR(-ENOMEM); 178} 179