| |
| /* |
| * Directory operations for Coda filesystem |
| * Original version: (C) 1996 P. Braam and M. Callahan |
| * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University |
| * |
| * Carnegie Mellon encourages users to contribute improvements to |
| * the Coda project. Contact Peter Braam (coda@cs.cmu.edu). |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/time.h> |
| #include <linux/fs.h> |
| #include <linux/slab.h> |
| #include <linux/file.h> |
| #include <linux/stat.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> |
| #include <linux/spinlock.h> |
| #include <linux/namei.h> |
| |
| #include <asm/uaccess.h> |
| |
| #include <linux/coda.h> |
| #include <linux/coda_psdev.h> |
| #include "coda_linux.h" |
| #include "coda_cache.h" |
| |
| #include "coda_int.h" |
| |
| /* dir inode-ops */ |
| static int coda_create(struct inode *dir, struct dentry *new, umode_t mode, bool excl); |
| static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, unsigned int flags); |
| static int coda_link(struct dentry *old_dentry, struct inode *dir_inode, |
| struct dentry *entry); |
| static int coda_unlink(struct inode *dir_inode, struct dentry *entry); |
| static int coda_symlink(struct inode *dir_inode, struct dentry *entry, |
| const char *symname); |
| static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, umode_t mode); |
| static int coda_rmdir(struct inode *dir_inode, struct dentry *entry); |
| static int coda_rename(struct inode *old_inode, struct dentry *old_dentry, |
| struct inode *new_inode, struct dentry *new_dentry); |
| |
| /* dir file-ops */ |
| static int coda_readdir(struct file *file, struct dir_context *ctx); |
| |
| /* dentry ops */ |
| static int coda_dentry_revalidate(struct dentry *de, unsigned int flags); |
| static int coda_dentry_delete(const struct dentry *); |
| |
| /* support routines */ |
| static int coda_venus_readdir(struct file *, struct dir_context *); |
| |
| /* same as fs/bad_inode.c */ |
| static int coda_return_EIO(void) |
| { |
| return -EIO; |
| } |
| #define CODA_EIO_ERROR ((void *) (coda_return_EIO)) |
| |
| const struct dentry_operations coda_dentry_operations = |
| { |
| .d_revalidate = coda_dentry_revalidate, |
| .d_delete = coda_dentry_delete, |
| }; |
| |
| const struct inode_operations coda_dir_inode_operations = |
| { |
| .create = coda_create, |
| .lookup = coda_lookup, |
| .link = coda_link, |
| .unlink = coda_unlink, |
| .symlink = coda_symlink, |
| .mkdir = coda_mkdir, |
| .rmdir = coda_rmdir, |
| .mknod = CODA_EIO_ERROR, |
| .rename = coda_rename, |
| .permission = coda_permission, |
| .getattr = coda_getattr, |
| .setattr = coda_setattr, |
| }; |
| |
| const struct file_operations coda_dir_operations = { |
| .llseek = generic_file_llseek, |
| .read = generic_read_dir, |
| .iterate = coda_readdir, |
| .open = coda_open, |
| .release = coda_release, |
| .fsync = coda_fsync, |
| }; |
| |
| |
| /* inode operations for directories */ |
| /* access routines: lookup, readlink, permission */ |
| static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsigned int flags) |
| { |
| struct super_block *sb = dir->i_sb; |
| const char *name = entry->d_name.name; |
| size_t length = entry->d_name.len; |
| struct inode *inode; |
| int type = 0; |
| |
| if (length > CODA_MAXNAMLEN) { |
| printk(KERN_ERR "name too long: lookup, %s (%*s)\n", |
| coda_i2s(dir), (int)length, name); |
| return ERR_PTR(-ENAMETOOLONG); |
| } |
| |
| /* control object, create inode on the fly */ |
| if (coda_isroot(dir) && coda_iscontrol(name, length)) { |
| inode = coda_cnode_makectl(sb); |
| type = CODA_NOCACHE; |
| } else { |
| struct CodaFid fid = { { 0, } }; |
| int error = venus_lookup(sb, coda_i2f(dir), name, length, |
| &type, &fid); |
| inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error); |
| } |
| |
| if (!IS_ERR(inode) && (type & CODA_NOCACHE)) |
| coda_flag_inode(inode, C_VATTR | C_PURGE); |
| |
| if (inode == ERR_PTR(-ENOENT)) |
| inode = NULL; |
| |
| return d_splice_alias(inode, entry); |
| } |
| |
| |
| int coda_permission(struct inode *inode, int mask) |
| { |
| int error; |
| |
| if (mask & MAY_NOT_BLOCK) |
| return -ECHILD; |
| |
| mask &= MAY_READ | MAY_WRITE | MAY_EXEC; |
| |
| if (!mask) |
| return 0; |
| |
| if ((mask & MAY_EXEC) && !execute_ok(inode)) |
| return -EACCES; |
| |
| if (coda_cache_check(inode, mask)) |
| return 0; |
| |
| error = venus_access(inode->i_sb, coda_i2f(inode), mask); |
| |
| if (!error) |
| coda_cache_enter(inode, mask); |
| |
| return error; |
| } |
| |
| |
| static inline void coda_dir_update_mtime(struct inode *dir) |
| { |
| #ifdef REQUERY_VENUS_FOR_MTIME |
| /* invalidate the directory cnode's attributes so we refetch the |
| * attributes from venus next time the inode is referenced */ |
| coda_flag_inode(dir, C_VATTR); |
| #else |
| /* optimistically we can also act as if our nose bleeds. The |
| * granularity of the mtime is coarse anyways so we might actually be |
| * right most of the time. Note: we only do this for directories. */ |
| dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; |
| #endif |
| } |
| |
| /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a |
| * trick to fool GNU find's optimizations. If we can't be sure of the link |
| * (because of volume mount points) we set i_nlink to 1 which forces find |
| * to consider every child as a possible directory. We should also never |
| * see an increment or decrement for deleted directories where i_nlink == 0 */ |
| static inline void coda_dir_inc_nlink(struct inode *dir) |
| { |
| if (dir->i_nlink >= 2) |
| inc_nlink(dir); |
| } |
| |
| static inline void coda_dir_drop_nlink(struct inode *dir) |
| { |
| if (dir->i_nlink > 2) |
| drop_nlink(dir); |
| } |
| |
| /* creation routines: create, mknod, mkdir, link, symlink */ |
| static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, bool excl) |
| { |
| int error; |
| const char *name=de->d_name.name; |
| int length=de->d_name.len; |
| struct inode *inode; |
| struct CodaFid newfid; |
| struct coda_vattr attrs; |
| |
| if (coda_isroot(dir) && coda_iscontrol(name, length)) |
| return -EPERM; |
| |
| error = venus_create(dir->i_sb, coda_i2f(dir), name, length, |
| 0, mode, &newfid, &attrs); |
| if (error) |
| goto err_out; |
| |
| inode = coda_iget(dir->i_sb, &newfid, &attrs); |
| if (IS_ERR(inode)) { |
| error = PTR_ERR(inode); |
| goto err_out; |
| } |
| |
| /* invalidate the directory cnode's attributes */ |
| coda_dir_update_mtime(dir); |
| d_instantiate(de, inode); |
| return 0; |
| err_out: |
| d_drop(de); |
| return error; |
| } |
| |
| static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode) |
| { |
| struct inode *inode; |
| struct coda_vattr attrs; |
| const char *name = de->d_name.name; |
| int len = de->d_name.len; |
| int error; |
| struct CodaFid newfid; |
| |
| if (coda_isroot(dir) && coda_iscontrol(name, len)) |
| return -EPERM; |
| |
| attrs.va_mode = mode; |
| error = venus_mkdir(dir->i_sb, coda_i2f(dir), |
| name, len, &newfid, &attrs); |
| if (error) |
| goto err_out; |
| |
| inode = coda_iget(dir->i_sb, &newfid, &attrs); |
| if (IS_ERR(inode)) { |
| error = PTR_ERR(inode); |
| goto err_out; |
| } |
| |
| /* invalidate the directory cnode's attributes */ |
| coda_dir_inc_nlink(dir); |
| coda_dir_update_mtime(dir); |
| d_instantiate(de, inode); |
| return 0; |
| err_out: |
| d_drop(de); |
| return error; |
| } |
| |
| /* try to make de an entry in dir_inodde linked to source_de */ |
| static int coda_link(struct dentry *source_de, struct inode *dir_inode, |
| struct dentry *de) |
| { |
| struct inode *inode = source_de->d_inode; |
| const char * name = de->d_name.name; |
| int len = de->d_name.len; |
| int error; |
| |
| if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) |
| return -EPERM; |
| |
| error = venus_link(dir_inode->i_sb, coda_i2f(inode), |
| coda_i2f(dir_inode), (const char *)name, len); |
| if (error) { |
| d_drop(de); |
| return error; |
| } |
| |
| coda_dir_update_mtime(dir_inode); |
| ihold(inode); |
| d_instantiate(de, inode); |
| inc_nlink(inode); |
| return 0; |
| } |
| |
| |
| static int coda_symlink(struct inode *dir_inode, struct dentry *de, |
| const char *symname) |
| { |
| const char *name = de->d_name.name; |
| int len = de->d_name.len; |
| int symlen; |
| int error; |
| |
| if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) |
| return -EPERM; |
| |
| symlen = strlen(symname); |
| if (symlen > CODA_MAXPATHLEN) |
| return -ENAMETOOLONG; |
| |
| /* |
| * This entry is now negative. Since we do not create |
| * an inode for the entry we have to drop it. |
| */ |
| d_drop(de); |
| error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len, |
| symname, symlen); |
| |
| /* mtime is no good anymore */ |
| if (!error) |
| coda_dir_update_mtime(dir_inode); |
| |
| return error; |
| } |
| |
| /* destruction routines: unlink, rmdir */ |
| static int coda_unlink(struct inode *dir, struct dentry *de) |
| { |
| int error; |
| const char *name = de->d_name.name; |
| int len = de->d_name.len; |
| |
| error = venus_remove(dir->i_sb, coda_i2f(dir), name, len); |
| if (error) |
| return error; |
| |
| coda_dir_update_mtime(dir); |
| drop_nlink(de->d_inode); |
| return 0; |
| } |
| |
| static int coda_rmdir(struct inode *dir, struct dentry *de) |
| { |
| const char *name = de->d_name.name; |
| int len = de->d_name.len; |
| int error; |
| |
| error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len); |
| if (!error) { |
| /* VFS may delete the child */ |
| if (de->d_inode) |
| clear_nlink(de->d_inode); |
| |
| /* fix the link count of the parent */ |
| coda_dir_drop_nlink(dir); |
| coda_dir_update_mtime(dir); |
| } |
| return error; |
| } |
| |
| /* rename */ |
| static int coda_rename(struct inode *old_dir, struct dentry *old_dentry, |
| struct inode *new_dir, struct dentry *new_dentry) |
| { |
| const char *old_name = old_dentry->d_name.name; |
| const char *new_name = new_dentry->d_name.name; |
| int old_length = old_dentry->d_name.len; |
| int new_length = new_dentry->d_name.len; |
| int error; |
| |
| error = venus_rename(old_dir->i_sb, coda_i2f(old_dir), |
| coda_i2f(new_dir), old_length, new_length, |
| (const char *) old_name, (const char *)new_name); |
| if (!error) { |
| if (new_dentry->d_inode) { |
| if (S_ISDIR(new_dentry->d_inode->i_mode)) { |
| coda_dir_drop_nlink(old_dir); |
| coda_dir_inc_nlink(new_dir); |
| } |
| coda_dir_update_mtime(old_dir); |
| coda_dir_update_mtime(new_dir); |
| coda_flag_inode(new_dentry->d_inode, C_VATTR); |
| } else { |
| coda_flag_inode(old_dir, C_VATTR); |
| coda_flag_inode(new_dir, C_VATTR); |
| } |
| } |
| return error; |
| } |
| |
| |
| /* file operations for directories */ |
| static int coda_readdir(struct file *coda_file, struct dir_context *ctx) |
| { |
| struct coda_file_info *cfi; |
| struct file *host_file; |
| int ret; |
| |
| cfi = CODA_FTOC(coda_file); |
| BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
| host_file = cfi->cfi_container; |
| |
| if (!host_file->f_op) |
| return -ENOTDIR; |
| |
| if (host_file->f_op->iterate) { |
| struct inode *host_inode = file_inode(host_file); |
| mutex_lock(&host_inode->i_mutex); |
| ret = -ENOENT; |
| if (!IS_DEADDIR(host_inode)) { |
| ret = host_file->f_op->iterate(host_file, ctx); |
| file_accessed(host_file); |
| } |
| mutex_unlock(&host_inode->i_mutex); |
| return ret; |
| } |
| /* Venus: we must read Venus dirents from a file */ |
| return coda_venus_readdir(coda_file, ctx); |
| } |
| |
| static inline unsigned int CDT2DT(unsigned char cdt) |
| { |
| unsigned int dt; |
| |
| switch(cdt) { |
| case CDT_UNKNOWN: dt = DT_UNKNOWN; break; |
| case CDT_FIFO: dt = DT_FIFO; break; |
| case CDT_CHR: dt = DT_CHR; break; |
| case CDT_DIR: dt = DT_DIR; break; |
| case CDT_BLK: dt = DT_BLK; break; |
| case CDT_REG: dt = DT_REG; break; |
| case CDT_LNK: dt = DT_LNK; break; |
| case CDT_SOCK: dt = DT_SOCK; break; |
| case CDT_WHT: dt = DT_WHT; break; |
| default: dt = DT_UNKNOWN; break; |
| } |
| return dt; |
| } |
| |
| /* support routines */ |
| static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx) |
| { |
| struct coda_file_info *cfi; |
| struct coda_inode_info *cii; |
| struct file *host_file; |
| struct dentry *de; |
| struct venus_dirent *vdir; |
| unsigned long vdir_size = offsetof(struct venus_dirent, d_name); |
| unsigned int type; |
| struct qstr name; |
| ino_t ino; |
| int ret; |
| |
| cfi = CODA_FTOC(coda_file); |
| BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
| host_file = cfi->cfi_container; |
| |
| de = coda_file->f_path.dentry; |
| cii = ITOC(de->d_inode); |
| |
| vdir = kmalloc(sizeof(*vdir), GFP_KERNEL); |
| if (!vdir) return -ENOMEM; |
| |
| if (!dir_emit_dots(coda_file, ctx)) |
| goto out; |
| |
| while (1) { |
| /* read entries from the directory file */ |
| ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir, |
| sizeof(*vdir)); |
| if (ret < 0) { |
| printk(KERN_ERR "coda readdir: read dir %s failed %d\n", |
| coda_f2s(&cii->c_fid), ret); |
| break; |
| } |
| if (ret == 0) break; /* end of directory file reached */ |
| |
| /* catch truncated reads */ |
| if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) { |
| printk(KERN_ERR "coda readdir: short read on %s\n", |
| coda_f2s(&cii->c_fid)); |
| ret = -EBADF; |
| break; |
| } |
| /* validate whether the directory file actually makes sense */ |
| if (vdir->d_reclen < vdir_size + vdir->d_namlen) { |
| printk(KERN_ERR "coda readdir: invalid dir %s\n", |
| coda_f2s(&cii->c_fid)); |
| ret = -EBADF; |
| break; |
| } |
| |
| name.len = vdir->d_namlen; |
| name.name = vdir->d_name; |
| |
| /* Make sure we skip '.' and '..', we already got those */ |
| if (name.name[0] == '.' && (name.len == 1 || |
| (name.name[1] == '.' && name.len == 2))) |
| vdir->d_fileno = name.len = 0; |
| |
| /* skip null entries */ |
| if (vdir->d_fileno && name.len) { |
| ino = vdir->d_fileno; |
| type = CDT2DT(vdir->d_type); |
| if (!dir_emit(ctx, name.name, name.len, ino, type)) |
| break; |
| } |
| /* we'll always have progress because d_reclen is unsigned and |
| * we've already established it is non-zero. */ |
| ctx->pos += vdir->d_reclen; |
| } |
| out: |
| kfree(vdir); |
| return 0; |
| } |
| |
| /* called when a cache lookup succeeds */ |
| static int coda_dentry_revalidate(struct dentry *de, unsigned int flags) |
| { |
| struct inode *inode; |
| struct coda_inode_info *cii; |
| |
| if (flags & LOOKUP_RCU) |
| return -ECHILD; |
| |
| inode = de->d_inode; |
| if (!inode || coda_isroot(inode)) |
| goto out; |
| if (is_bad_inode(inode)) |
| goto bad; |
| |
| cii = ITOC(de->d_inode); |
| if (!(cii->c_flags & (C_PURGE | C_FLUSH))) |
| goto out; |
| |
| shrink_dcache_parent(de); |
| |
| /* propagate for a flush */ |
| if (cii->c_flags & C_FLUSH) |
| coda_flag_inode_children(inode, C_FLUSH); |
| |
| if (de->d_count > 1) |
| /* pretend it's valid, but don't change the flags */ |
| goto out; |
| |
| /* clear the flags. */ |
| spin_lock(&cii->c_lock); |
| cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH); |
| spin_unlock(&cii->c_lock); |
| bad: |
| return 0; |
| out: |
| return 1; |
| } |
| |
| /* |
| * This is the callback from dput() when d_count is going to 0. |
| * We use this to unhash dentries with bad inodes. |
| */ |
| static int coda_dentry_delete(const struct dentry * dentry) |
| { |
| int flags; |
| |
| if (!dentry->d_inode) |
| return 0; |
| |
| flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE; |
| if (is_bad_inode(dentry->d_inode) || flags) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| |
| |
| /* |
| * This is called when we want to check if the inode has |
| * changed on the server. Coda makes this easy since the |
| * cache manager Venus issues a downcall to the kernel when this |
| * happens |
| */ |
| int coda_revalidate_inode(struct dentry *dentry) |
| { |
| struct coda_vattr attr; |
| int error; |
| int old_mode; |
| ino_t old_ino; |
| struct inode *inode = dentry->d_inode; |
| struct coda_inode_info *cii = ITOC(inode); |
| |
| if (!cii->c_flags) |
| return 0; |
| |
| if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) { |
| error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr); |
| if (error) |
| return -EIO; |
| |
| /* this inode may be lost if: |
| - it's ino changed |
| - type changes must be permitted for repair and |
| missing mount points. |
| */ |
| old_mode = inode->i_mode; |
| old_ino = inode->i_ino; |
| coda_vattr_to_iattr(inode, &attr); |
| |
| if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) { |
| printk("Coda: inode %ld, fid %s changed type!\n", |
| inode->i_ino, coda_f2s(&(cii->c_fid))); |
| } |
| |
| /* the following can happen when a local fid is replaced |
| with a global one, here we lose and declare the inode bad */ |
| if (inode->i_ino != old_ino) |
| return -EIO; |
| |
| coda_flag_inode_children(inode, C_FLUSH); |
| |
| spin_lock(&cii->c_lock); |
| cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH); |
| spin_unlock(&cii->c_lock); |
| } |
| return 0; |
| } |