/* * Unlink all destinations (if they exist) to the left of the left-most * source */ static int __rename_all_unlink(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, struct rename_info *info) { int bindex; struct dentry *unlink_dentry; struct dentry *unlink_dir_dentry; int err = 0; print_entry_location(); for (bindex = info->old_bstart - 1; bindex > info->new_bstart; bindex--) { unlink_dentry = dtohd_index(new_dentry, bindex); if (!unlink_dentry) continue; /* lock, unlink if possible, copyup times, unlock */ unlink_dir_dentry = lock_parent(unlink_dentry); if (!(err = is_robranch_super(old_dir->i_sb, bindex))) err = vfs_unlink(unlink_dir_dentry->d_inode, unlink_dentry); fist_copy_attr_times(new_dentry->d_parent->d_inode, unlink_dir_dentry->d_inode); new_dentry->d_parent->d_inode->i_nlink = get_nlinks(new_dentry->d_parent->d_inode); unlock_dir(unlink_dir_dentry); if (!err) { if (bindex != info->new_bstart) { DPUT(unlink_dentry); set_dtohd_index(new_dentry, bindex, NULL); } } else if (IS_COPYUP_ERR(err)) { if (info->isdir) { err = -EXDEV; break; } info->do_copyup = bindex - 1; err = 0; /* reset error */ } else break; /* err is set by is_ro_branch_super or vfs_unlink */ } print_exit_status(err); return err; }
void unionfs_d_release(struct dentry *dentry) { struct dentry *hidden_dentry; int bindex, bstart, bend; print_entry_location(); /* There is no reason to lock the dentry, because we have the only * reference, but the printing functions verify that we have a lock * on the dentry before calling dbstart, etc. */ lock_dentry(dentry); __fist_print_dentry("unionfs_d_release IN dentry", dentry, 0); /* this could be a negative dentry, so check first */ if (!dtopd(dentry)) { fist_dprint(6, "dentry without private data: %*s", dentry->d_name.len, dentry->d_name.name); goto out; } else if (dbstart(dentry) < 0) { /* this is due to a failed lookup */ /* the failed lookup has a dtohd_ptr set to null, but this is a better check */ fist_dprint(6, "dentry without hidden dentries : %*s", dentry->d_name.len, dentry->d_name.name); goto out_free; } /* Release all the hidden dentries */ bstart = dbstart(dentry); bend = dbend(dentry); for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); DPUT(hidden_dentry); set_dtohd_index(dentry, bindex, NULL); } /* free private data (unionfs_dentry_info) here */ KFREE(dtohd_ptr(dentry)); dtohd_ptr(dentry) = NULL; out_free: /* No need to unlock it, because it is disappeared. */ #ifdef TRACKLOCK printk("DESTROYLOCK:%p\n", dentry); #endif free_dentry_private_data(dtopd(dentry)); dtopd_lhs(dentry) = NULL; /* just to be safe */ out: print_exit_location(); }
void update_bstart(struct dentry *dentry) { int bindex; int bstart = dbstart(dentry); int bend = dbend(dentry); struct dentry *hidden_dentry; for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); if (!hidden_dentry) continue; if (hidden_dentry->d_inode) { set_dbstart(dentry, bindex); break; } DPUT(hidden_dentry); set_dtohd_index(dentry, bindex, NULL); } }
/* This function replicates the directory structure upto given dentry * in the bindex branch. */ struct dentry *create_parents_named(struct inode *dir, struct dentry *dentry, const char *name, int bindex) { int err; struct dentry *child_dentry; struct dentry *parent_dentry; struct dentry *hidden_parent_dentry = NULL; struct dentry *hidden_dentry = NULL; const char *childname; unsigned int childnamelen; int old_kmalloc_size; int kmalloc_size; int num_dentry; int count; int old_bstart; int old_bend; struct dentry **path = NULL; struct dentry **tmp_path; print_entry_location(); verify_locked(dentry); /* There is no sense allocating any less than the minimum. */ #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0) kmalloc_size = malloc_sizes[0].cs_size; #else kmalloc_size = 32; #endif num_dentry = kmalloc_size / sizeof(struct dentry *); if ((err = is_robranch_super(dir->i_sb, bindex))) { hidden_dentry = ERR_PTR(err); goto out; } fist_print_dentry("IN: create_parents_named", dentry); fist_dprint(8, "name = %s\n", name); old_bstart = dbstart(dentry); old_bend = dbend(dentry); path = (struct dentry **)KMALLOC(kmalloc_size, GFP_KERNEL); memset(path, 0, kmalloc_size); /* assume the negative dentry of unionfs as the parent dentry */ parent_dentry = dentry; count = 0; /* This loop finds the first parent that exists in the given branch. * We start building the directory structure from there. At the end * of the loop, the following should hold: * child_dentry is the first nonexistent child * parent_dentry is the first existent parent * path[0] is the = deepest child * path[count] is the first child to create */ do { child_dentry = parent_dentry; /* find the parent directory dentry in unionfs */ parent_dentry = child_dentry->d_parent; lock_dentry(parent_dentry); /* find out the hidden_parent_dentry in the given branch */ hidden_parent_dentry = dtohd_index(parent_dentry, bindex); /* store the child dentry */ path[count++] = child_dentry; if (count == num_dentry) { old_kmalloc_size = kmalloc_size; kmalloc_size *= 2; num_dentry = kmalloc_size / sizeof(struct dentry *); tmp_path = (struct dentry **)KMALLOC(kmalloc_size, GFP_KERNEL); if (!tmp_path) { hidden_dentry = ERR_PTR(-ENOMEM); goto out; } memset(tmp_path, 0, kmalloc_size); memcpy(tmp_path, path, old_kmalloc_size); KFREE(path); path = tmp_path; tmp_path = NULL; } } while (!hidden_parent_dentry); count--; /* This is basically while(child_dentry != dentry). This loop is * horrible to follow and should be replaced with cleaner code. */ while (1) { PASSERT(child_dentry); PASSERT(parent_dentry); PASSERT(parent_dentry->d_inode); // get hidden parent dir in the current branch hidden_parent_dentry = dtohd_index(parent_dentry, bindex); unlock_dentry(parent_dentry); PASSERT(hidden_parent_dentry); PASSERT(hidden_parent_dentry->d_inode); // init the values to lookup childname = child_dentry->d_name.name; childnamelen = child_dentry->d_name.len; if (child_dentry != dentry) { // lookup child in the underlying file system hidden_dentry = LOOKUP_ONE_LEN(childname, hidden_parent_dentry, childnamelen); if (IS_ERR(hidden_dentry)) goto out; } else { int loop_start; int loop_end; int new_bstart = -1; int new_bend = -1; int i; /* is the name a whiteout of the childname ? */ //lookup the whiteout child in the underlying file system hidden_dentry = LOOKUP_ONE_LEN(name, hidden_parent_dentry, strlen(name)); if (IS_ERR(hidden_dentry)) goto out; /* Replace the current dentry (if any) with the new one. */ DPUT(dtohd_index(dentry, bindex)); set_dtohd_index(dentry, bindex, hidden_dentry); loop_start = (old_bstart < bindex) ? old_bstart : bindex; loop_end = (old_bend > bindex) ? old_bend : bindex; /* This loop sets the bstart and bend for the new * dentry by traversing from left to right. * It also dputs all negative dentries except * bindex (the newly looked dentry */ for (i = loop_start; i <= loop_end; i++) { if (!dtohd_index(dentry, i)) continue; if (i == bindex) { new_bend = i; if (new_bstart < 0) new_bstart = i; continue; } if (!dtohd_index(dentry, i)->d_inode) { DPUT(dtohd_index(dentry, i)); set_dtohd_index(dentry, i, NULL); } else { if (new_bstart < 0) new_bstart = i; new_bend = i; } } if (new_bstart < 0) new_bstart = bindex; if (new_bend < 0) new_bend = bindex; set_dbstart(dentry, new_bstart); set_dbend(dentry, new_bend); break; } if (hidden_dentry->d_inode) { /* since this already exists we dput to avoid * multiple references on the same dentry */ DPUT(hidden_dentry); } else { uid_t saved_uid = current->fsuid; gid_t saved_gid = current->fsgid; /* its a negative dentry, create a new dir */ hidden_parent_dentry = lock_parent(hidden_dentry); current->fsuid = hidden_parent_dentry->d_inode->i_uid; current->fsgid = hidden_parent_dentry->d_inode->i_gid; err = vfs_mkdir(hidden_parent_dentry->d_inode, hidden_dentry, S_IRWXUGO); current->fsuid = saved_uid; current->fsgid = saved_gid; unlock_dir(hidden_parent_dentry); if (err || !hidden_dentry->d_inode) { DPUT(hidden_dentry); hidden_dentry = ERR_PTR(err); goto out; } err = copyup_permissions(dir->i_sb, child_dentry, hidden_dentry); if (err) { DPUT(hidden_dentry); hidden_dentry = ERR_PTR(err); goto out; } set_itohi_index(child_dentry->d_inode, bindex, igrab(hidden_dentry->d_inode)); if (ibstart(child_dentry->d_inode) > bindex) ibstart(child_dentry->d_inode) = bindex; if (ibend(child_dentry->d_inode) < bindex) ibend(child_dentry->d_inode) = bindex; set_dtohd_index(child_dentry, bindex, hidden_dentry); if (dbstart(child_dentry) > bindex) set_dbstart(child_dentry, bindex); if (dbend(child_dentry) < bindex) set_dbend(child_dentry, bindex); } parent_dentry = child_dentry; child_dentry = path[--count]; } out: KFREE(path); fist_print_dentry("OUT: create_parents_named", dentry); print_exit_pointer(hidden_dentry); return hidden_dentry; }
int copyup_named_dentry(struct inode *dir, struct dentry *dentry, int bstart, int new_bindex, char *name, int namelen, struct file **copyup_file, int len) { struct dentry *new_hidden_dentry; struct dentry *old_hidden_dentry = NULL; struct super_block *sb; struct file *input_file = NULL; struct file *output_file = NULL; ssize_t read_bytes, write_bytes; mm_segment_t old_fs; int err = 0; char *buf; int old_bindex; int got_branch_input = -1; int got_branch_output = -1; int old_bstart; int old_bend; int size = len; struct dentry *new_hidden_parent_dentry; mm_segment_t oldfs; char *symbuf = NULL; uid_t saved_uid = current->fsuid; gid_t saved_gid = current->fsgid; print_entry_location(); verify_locked(dentry); fist_print_dentry("IN: copyup_named_dentry", dentry); old_bindex = bstart; old_bstart = dbstart(dentry); old_bend = dbend(dentry); ASSERT(new_bindex >= 0); ASSERT(new_bindex < old_bindex); PASSERT(dir); PASSERT(dentry); sb = dir->i_sb; if ((err = is_robranch_super(sb, new_bindex))) goto out; /* Create the directory structure above this dentry. */ new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex); PASSERT(new_hidden_dentry); if (IS_ERR(new_hidden_dentry)) { err = PTR_ERR(new_hidden_dentry); goto out; } fist_print_generic_dentry("Copyup Object", new_hidden_dentry); /* Now we actually create the object. */ old_hidden_dentry = dtohd_index(dentry, old_bindex); PASSERT(old_hidden_dentry); PASSERT(old_hidden_dentry->d_inode); DGET(old_hidden_dentry); /* For symlinks, we must read the link before we lock the directory. */ if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) { PASSERT(old_hidden_dentry->d_inode->i_op); PASSERT(old_hidden_dentry->d_inode->i_op->readlink); symbuf = KMALLOC(PATH_MAX, GFP_UNIONFS); if (!symbuf) { err = -ENOMEM; goto copyup_readlink_err; } oldfs = get_fs(); set_fs(KERNEL_DS); err = old_hidden_dentry->d_inode->i_op-> readlink(old_hidden_dentry, symbuf, PATH_MAX); set_fs(oldfs); if (err < 0) goto copyup_readlink_err; symbuf[err] = '\0'; } /* Now we lock the parent, and create the object in the new branch. */ new_hidden_parent_dentry = lock_parent(new_hidden_dentry); current->fsuid = new_hidden_parent_dentry->d_inode->i_uid; current->fsgid = new_hidden_parent_dentry->d_inode->i_gid; if (S_ISDIR(old_hidden_dentry->d_inode->i_mode)) { err = vfs_mkdir(new_hidden_parent_dentry->d_inode, new_hidden_dentry, S_IRWXU); } else if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) { #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) err = vfs_symlink(new_hidden_parent_dentry->d_inode, new_hidden_dentry, symbuf); #else err = vfs_symlink(new_hidden_parent_dentry->d_inode, new_hidden_dentry, symbuf, S_IRWXU); #endif } else if (S_ISBLK(old_hidden_dentry->d_inode->i_mode) || S_ISCHR(old_hidden_dentry->d_inode->i_mode) || S_ISFIFO(old_hidden_dentry->d_inode->i_mode) || S_ISSOCK(old_hidden_dentry->d_inode->i_mode)) { #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) err = vfs_mknod(new_hidden_parent_dentry->d_inode, new_hidden_dentry, old_hidden_dentry->d_inode->i_mode, kdev_t_to_nr(old_hidden_dentry->d_inode-> i_rdev)); #else err = vfs_mknod(new_hidden_parent_dentry->d_inode, new_hidden_dentry, old_hidden_dentry->d_inode->i_mode, old_hidden_dentry->d_inode->i_rdev); #endif } else if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) { #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) err = vfs_create(new_hidden_parent_dentry->d_inode, new_hidden_dentry, S_IRWXU); #else err = vfs_create(new_hidden_parent_dentry->d_inode, new_hidden_dentry, S_IRWXU, NULL); #endif } else { char diemsg[100]; snprintf(diemsg, sizeof(diemsg), "Unknown inode type %d\n", old_hidden_dentry->d_inode->i_mode); FISTBUG(diemsg); } current->fsuid = saved_uid; current->fsgid = saved_gid; unlock_dir(new_hidden_parent_dentry); copyup_readlink_err: KFREE(symbuf); if (err) { /* get rid of the hidden dentry and all its traces */ DPUT(new_hidden_dentry); set_dtohd_index(dentry, new_bindex, NULL); set_dbstart(dentry, old_bstart); set_dbend(dentry, old_bend); goto out; } /* We actually copyup the file here. */ if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) { mntget(stohiddenmnt_index(sb, old_bindex)); branchget(sb, old_bindex); got_branch_input = old_bindex; input_file = DENTRY_OPEN(old_hidden_dentry, stohiddenmnt_index(sb, old_bindex), O_RDONLY); if (IS_ERR(input_file)) { err = PTR_ERR(input_file); goto out; } if (!input_file->f_op || !input_file->f_op->read) { err = -EINVAL; goto out; } /* copy the new file */ DGET(new_hidden_dentry); mntget(stohiddenmnt_index(sb, new_bindex)); branchget(sb, new_bindex); got_branch_output = new_bindex; output_file = DENTRY_OPEN(new_hidden_dentry, stohiddenmnt_index(sb, new_bindex), O_WRONLY); if (IS_ERR(output_file)) { err = PTR_ERR(output_file); goto out; } if (!output_file->f_op || !output_file->f_op->write) { err = -EINVAL; goto out; } /* allocating a buffer */ buf = (char *)KMALLOC(PAGE_SIZE, GFP_UNIONFS); if (!buf) { err = -ENOMEM; goto out; } /* now read PAGE_SIZE bytes from offset 0 in a loop */ old_fs = get_fs(); input_file->f_pos = 0; output_file->f_pos = 0; set_fs(KERNEL_DS); do { if (len >= PAGE_SIZE) size = PAGE_SIZE; else if ((len < PAGE_SIZE) && (len > 0)) size = len; len -= PAGE_SIZE; read_bytes = input_file->f_op->read(input_file, buf, size, &input_file->f_pos); if (read_bytes <= 0) { err = read_bytes; break; } write_bytes = output_file->f_op->write(output_file, buf, read_bytes, &output_file->f_pos); if (write_bytes < 0 || (write_bytes < read_bytes)) { err = -EIO; break; } } while ((read_bytes > 0) && (len > 0)); set_fs(old_fs); KFREE(buf); } /* Set permissions. */ if ((err = copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry))) goto out; /* Selinux uses extended attributes for permissions. */ #if defined(UNIONFS_XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)) if ((err = copyup_xattrs(old_hidden_dentry, new_hidden_dentry))) goto out; #endif /* do not allow files getting deleted to be reinterposed */ if (!d_deleted(dentry)) unionfs_reinterpose(dentry); out: if (input_file && !IS_ERR(input_file)) { fput(input_file); } else { /* since input file was not opened, we need to explicitly * dput the old_hidden_dentry */ DPUT(old_hidden_dentry); } /* in any case, we have to branchput */ if (got_branch_input >= 0) branchput(sb, got_branch_input); if (output_file) { if (copyup_file && !err) { *copyup_file = output_file; } else { fput(output_file); branchput(sb, got_branch_output); } } fist_print_dentry("OUT: copyup_dentry", dentry); fist_print_inode("OUT: copyup_dentry", dentry->d_inode); print_exit_status(err); return err; }
/* This must be called with the super block already locked. */ int unionfs_ioctl_delbranch(struct super_block *sb, unsigned long arg) { struct dentry *hidden_dentry; struct inode *hidden_inode; struct super_block *hidden_sb; struct vfsmount *hidden_mnt; struct dentry *root_dentry; struct inode *root_inode; int err = 0; int pmindex, i, gen; print_entry("branch = %lu ", arg); lock_dentry(sb->s_root); err = -EBUSY; if (sbmax(sb) == 1) goto out; err = -EINVAL; if (arg < 0 || arg > stopd(sb)->b_end) goto out; err = -EBUSY; if (branch_count(sb, arg)) goto out; if ((err = newputmap(sb))) goto out; pmindex = stopd(sb)->usi_lastputmap; pmindex -= stopd(sb)->usi_firstputmap; atomic_inc(&stopd(sb)->usi_generation); gen = atomic_read(&stopd(sb)->usi_generation); root_dentry = sb->s_root; root_inode = sb->s_root->d_inode; hidden_dentry = dtohd_index(root_dentry, arg); hidden_mnt = stohiddenmnt_index(sb, arg); hidden_inode = itohi_index(root_inode, arg); hidden_sb = stohs_index(sb, arg); DPUT(hidden_dentry); iput(hidden_inode); mntput(hidden_mnt); for (i = arg; i <= (sbend(sb) - 1); i++) { set_branch_count(sb, i, branch_count(sb, i + 1)); set_stohiddenmnt_index(sb, i, stohiddenmnt_index(sb, i + 1)); set_stohs_index(sb, i, stohs_index(sb, i + 1)); set_branchperms(sb, i, branchperms(sb, i + 1)); set_dtohd_index(root_dentry, i, dtohd_index(root_dentry, i + 1)); set_itohi_index(root_inode, i, itohi_index(root_inode, i + 1)); stopd(sb)->usi_putmaps[pmindex]->map[i + 1] = i; } set_dtohd_index(root_dentry, sbend(sb), NULL); set_itohi_index(root_inode, sbend(sb), NULL); set_stohiddenmnt_index(sb, sbend(sb), NULL); set_stohs_index(sb, sbend(sb), NULL); stopd(sb)->b_end--; set_dbend(root_dentry, dbend(root_dentry) - 1); dtopd(root_dentry)->udi_bcount--; itopd(root_inode)->b_end--; atomic_set(&dtopd(root_dentry)->udi_generation, gen); atomic_set(&itopd(root_inode)->uii_generation, gen); fixputmaps(sb); /* This doesn't open a file, so we might have to free the map here. */ if (atomic_read(&stopd(sb)->usi_putmaps[pmindex]->count) == 0) { KFREE(stopd(sb)->usi_putmaps[pmindex]); stopd(sb)->usi_putmaps[pmindex] = NULL; } out: unlock_dentry(sb->s_root); print_exit_status(err); return err; }
int unionfs_ioctl_addbranch(struct inode *inode, unsigned int cmd, unsigned long arg) { int err; struct unionfs_addbranch_args *addargs = NULL; struct nameidata nd; char *path = NULL; int gen; int i; int count; int pobjects; struct vfsmount **new_hidden_mnt = NULL; struct inode **new_uii_inode = NULL; struct dentry **new_udi_dentry = NULL; struct super_block **new_usi_sb = NULL; int *new_branchperms = NULL; atomic_t *new_counts = NULL; print_entry_location(); err = -ENOMEM; addargs = KMALLOC(sizeof(struct unionfs_addbranch_args), GFP_UNIONFS); if (!addargs) goto out; err = -EFAULT; if (copy_from_user (addargs, (void *)arg, sizeof(struct unionfs_addbranch_args))) goto out; err = -EINVAL; if (addargs->ab_perms & ~(MAY_READ | MAY_WRITE)) goto out; if (!(addargs->ab_perms & MAY_READ)) goto out; err = -E2BIG; if (sbend(inode->i_sb) > FD_SETSIZE) goto out; err = -ENOMEM; if (!(path = getname(addargs->ab_path))) goto out; err = path_lookup(path, LOOKUP_FOLLOW, &nd); RECORD_PATH_LOOKUP(&nd); if (err) goto out; if ((err = check_branch(&nd))) { path_release(&nd); RECORD_PATH_RELEASE(&nd); goto out; } unionfs_write_lock(inode->i_sb); lock_dentry(inode->i_sb->s_root); err = -EINVAL; if (addargs->ab_branch < 0 || (addargs->ab_branch > (sbend(inode->i_sb) + 1))) goto out; if ((err = newputmap(inode->i_sb))) goto out; stopd(inode->i_sb)->b_end++; dtopd(inode->i_sb->s_root)->udi_bcount++; set_dbend(inode->i_sb->s_root, dbend(inode->i_sb->s_root) + 1); itopd(inode->i_sb->s_root->d_inode)->b_end++; atomic_inc(&stopd(inode->i_sb)->usi_generation); gen = atomic_read(&stopd(inode->i_sb)->usi_generation); pobjects = (sbend(inode->i_sb) + 1) - UNIONFS_INLINE_OBJECTS; if (pobjects > 0) { /* Reallocate the dynamic structures. */ new_hidden_mnt = KMALLOC(sizeof(struct vfsmount *) * pobjects, GFP_UNIONFS); new_udi_dentry = KMALLOC(sizeof(struct dentry *) * pobjects, GFP_UNIONFS); new_uii_inode = KMALLOC(sizeof(struct inode *) * pobjects, GFP_UNIONFS); new_usi_sb = KMALLOC(sizeof(struct super_block *) * pobjects, GFP_UNIONFS); new_counts = KMALLOC(sizeof(atomic_t) * pobjects, GFP_UNIONFS); new_branchperms = KMALLOC(sizeof(int) * pobjects, GFP_UNIONFS); if (!new_hidden_mnt || !new_udi_dentry || !new_uii_inode || !new_counts || !new_usi_sb || !new_branchperms) { err = -ENOMEM; goto out; } memset(new_hidden_mnt, 0, sizeof(struct vfsmount *) * pobjects); memset(new_udi_dentry, 0, sizeof(struct dentry *) * pobjects); memset(new_uii_inode, 0, sizeof(struct inode *) * pobjects); memset(new_usi_sb, 0, sizeof(struct super_block *) * pobjects); memset(new_branchperms, 0, sizeof(int) * pobjects); } /* Copy the in-place values to our new structure. */ for (i = UNIONFS_INLINE_OBJECTS; i < addargs->ab_branch; i++) { int j = i - UNIONFS_INLINE_OBJECTS; count = branch_count(inode->i_sb, i); atomic_set(&(new_counts[j]), count); new_branchperms[j] = branchperms(inode->i_sb, i); new_hidden_mnt[j] = stohiddenmnt_index(inode->i_sb, i); new_usi_sb[j] = stohs_index(inode->i_sb, i); new_udi_dentry[j] = dtohd_index(inode->i_sb->s_root, i); new_uii_inode[j] = itohi_index(inode->i_sb->s_root->d_inode, i); } /* Shift the ends to the right (only handle reallocated bits). */ for (i = sbend(inode->i_sb) - 1; i >= (int)addargs->ab_branch; i--) { int j = i + 1; int perms; struct vfsmount *hm; struct super_block *hs; struct dentry *hd; struct inode *hi; int pmindex; count = branch_count(inode->i_sb, i); perms = branchperms(inode->i_sb, i); hm = stohiddenmnt_index(inode->i_sb, i); hs = stohs_index(inode->i_sb, i); hd = dtohd_index(inode->i_sb->s_root, i); hi = itohi_index(inode->i_sb->s_root->d_inode, i); /* Update the newest putmap, so it is correct for later. */ pmindex = stopd(inode->i_sb)->usi_lastputmap; pmindex -= stopd(inode->i_sb)->usi_firstputmap; stopd(inode->i_sb)->usi_putmaps[pmindex]->map[i] = j; if (j >= UNIONFS_INLINE_OBJECTS) { j -= UNIONFS_INLINE_OBJECTS; atomic_set(&(new_counts[j]), count); new_branchperms[j] = perms; new_hidden_mnt[j] = hm; new_usi_sb[j] = hs; new_udi_dentry[j] = hd; new_uii_inode[j] = hi; } else { set_branch_count(inode->i_sb, j, count); set_branchperms(inode->i_sb, j, perms); set_stohiddenmnt_index(inode->i_sb, j, hm); set_stohs_index(inode->i_sb, j, hs); set_dtohd_index(inode->i_sb->s_root, j, hd); set_itohi_index(inode->i_sb->s_root->d_inode, j, hi); } } /* Now we can free the old ones. */ KFREE(dtopd(inode->i_sb->s_root)->udi_dentry_p); KFREE(itopd(inode->i_sb->s_root->d_inode)->uii_inode_p); KFREE(stopd(inode->i_sb)->usi_hidden_mnt_p); KFREE(stopd(inode->i_sb)->usi_sb_p); KFREE(stopd(inode->i_sb)->usi_sbcount_p); KFREE(stopd(inode->i_sb)->usi_branchperms_p); /* Update the real pointers. */ dtohd_ptr(inode->i_sb->s_root) = new_udi_dentry; itohi_ptr(inode->i_sb->s_root->d_inode) = new_uii_inode; stohiddenmnt_ptr(inode->i_sb) = new_hidden_mnt; stohs_ptr(inode->i_sb) = new_usi_sb; stopd(inode->i_sb)->usi_sbcount_p = new_counts; stopd(inode->i_sb)->usi_branchperms_p = new_branchperms; /* Re-NULL the new ones so we don't try to free them. */ new_hidden_mnt = NULL; new_udi_dentry = NULL; new_usi_sb = NULL; new_uii_inode = NULL; new_counts = NULL; new_branchperms = NULL; /* Put the new dentry information into it's slot. */ set_dtohd_index(inode->i_sb->s_root, addargs->ab_branch, nd.dentry); set_itohi_index(inode->i_sb->s_root->d_inode, addargs->ab_branch, igrab(nd.dentry->d_inode)); set_branchperms(inode->i_sb, addargs->ab_branch, addargs->ab_perms); set_branch_count(inode->i_sb, addargs->ab_branch, 0); set_stohiddenmnt_index(inode->i_sb, addargs->ab_branch, nd.mnt); set_stohs_index(inode->i_sb, addargs->ab_branch, nd.dentry->d_sb); atomic_set(&dtopd(inode->i_sb->s_root)->udi_generation, gen); atomic_set(&itopd(inode->i_sb->s_root->d_inode)->uii_generation, gen); fixputmaps(inode->i_sb); out: unlock_dentry(inode->i_sb->s_root); unionfs_write_unlock(inode->i_sb); KFREE(new_hidden_mnt); KFREE(new_udi_dentry); KFREE(new_uii_inode); KFREE(new_usi_sb); KFREE(new_counts); KFREE(new_branchperms); KFREE(addargs); if (path) putname(path); print_exit_status(err); return err; }
static int unionfs_rename_whiteout(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { int err = 0; int bindex, bwh_old; int old_bstart, old_bend; int new_bstart, new_bend; int do_copyup = -1; struct dentry *parent_dentry; int local_err = 0; int eio = 0; int revert = 0; struct dentry *wh_old = NULL; print_entry_location(); old_bstart = dbstart(old_dentry); bwh_old = old_bstart; old_bend = dbend(old_dentry); parent_dentry = old_dentry->d_parent; new_bstart = dbstart(new_dentry); new_bend = dbend(new_dentry); /* Rename source to destination. */ err = do_rename(old_dir, old_dentry, new_dir, new_dentry, old_bstart, &wh_old); if (err) { if (!IS_COPYUP_ERR(err)) { goto out; } do_copyup = old_bstart - 1; } else { revert = 1; } /* Unlink all instances of destination that exist to the left of * bstart of source. On error, revert back, goto out. */ for (bindex = old_bstart - 1; bindex >= new_bstart; bindex--) { struct dentry *unlink_dentry; struct dentry *unlink_dir_dentry; unlink_dentry = dtohd_index(new_dentry, bindex); if (!unlink_dentry) { continue; } unlink_dir_dentry = lock_parent(unlink_dentry); if (!(err = is_robranch_super(old_dir->i_sb, bindex))) { err = vfs_unlink(unlink_dir_dentry->d_inode, unlink_dentry); } fist_copy_attr_times(new_dentry->d_parent->d_inode, unlink_dir_dentry->d_inode); /* propagate number of hard-links */ new_dentry->d_parent->d_inode->i_nlink = get_nlinks(new_dentry->d_parent->d_inode); unlock_dir(unlink_dir_dentry); if (!err) { if (bindex != new_bstart) { DPUT(unlink_dentry); set_dtohd_index(new_dentry, bindex, NULL); } } else if (IS_COPYUP_ERR(err)) { do_copyup = bindex - 1; } else if (revert) { DPUT(wh_old); goto revert; } } if (do_copyup != -1) { for (bindex = do_copyup; bindex >= 0; bindex--) { /* copyup the file into some left directory, so that you can rename it */ err = copyup_dentry(old_dentry->d_parent->d_inode, old_dentry, old_bstart, bindex, NULL, old_dentry->d_inode->i_size); if (!err) { DPUT(wh_old); bwh_old = bindex; err = do_rename(old_dir, old_dentry, new_dir, new_dentry, bindex, &wh_old); break; } } } /* Create whiteout for source, only if: * (1) There is more than one underlying instance of source. * (2) We did a copy_up */ if ((old_bstart != old_bend) || (do_copyup != -1)) { struct dentry *hidden_parent; BUG_ON(!wh_old || IS_ERR(wh_old) || wh_old->d_inode || bwh_old < 0); hidden_parent = lock_parent(wh_old); local_err = vfs_create(hidden_parent->d_inode, wh_old, S_IRUGO, NULL); unlock_dir(hidden_parent); if (!local_err) set_dbopaque(old_dentry, bwh_old); else { /* We can't fix anything now, so we cop-out and use -EIO. */ printk ("<0>We can't create a whiteout for the source in rename!\n"); err = -EIO; } } out: DPUT(wh_old); print_exit_status(err); return err; revert: /* Do revert here. */ local_err = unionfs_refresh_hidden_dentry(new_dentry, old_bstart); if (local_err) { printk(KERN_WARNING "Revert failed in rename: the new refresh failed.\n"); eio = -EIO; } local_err = unionfs_refresh_hidden_dentry(old_dentry, old_bstart); if (local_err) { printk(KERN_WARNING "Revert failed in rename: the old refresh failed.\n"); eio = -EIO; goto revert_out; } if (!dtohd_index(new_dentry, bindex) || !dtohd_index(new_dentry, bindex)->d_inode) { printk(KERN_WARNING "Revert failed in rename: the object disappeared from under us!\n"); eio = -EIO; goto revert_out; } if (dtohd_index(old_dentry, bindex) && dtohd_index(old_dentry, bindex)->d_inode) { printk(KERN_WARNING "Revert failed in rename: the object was created underneath us!\n"); eio = -EIO; goto revert_out; } local_err = do_rename(new_dir, new_dentry, old_dir, old_dentry, old_bstart, NULL); /* If we can't fix it, then we cop-out with -EIO. */ if (local_err) { printk(KERN_WARNING "Revert failed in rename!\n"); eio = -EIO; } local_err = unionfs_refresh_hidden_dentry(new_dentry, bindex); if (local_err) eio = -EIO; local_err = unionfs_refresh_hidden_dentry(old_dentry, bindex); if (local_err) eio = -EIO; revert_out: if (eio) err = eio; print_exit_status(err); return err; }
struct dentry *unionfs_lookup_backend(struct dentry *dentry, int lookupmode) { int err = 0; struct dentry *hidden_dentry = NULL; struct dentry *wh_hidden_dentry = NULL; struct dentry *hidden_dir_dentry = NULL; struct dentry *parent_dentry = NULL; int bindex, bstart, bend, bopaque; int dentry_count = 0; /* Number of positive dentries. */ int first_dentry_offset = -1; struct dentry *first_hidden_dentry = NULL; int locked_parent = 0; int locked_child = 0; int opaque; char *whname = NULL; const char *name; int namelen; print_entry("mode = %d", lookupmode); /* We should already have a lock on this dentry in the case of a * partial lookup, or a revalidation. Otherwise it is returned from * new_dentry_private_data already locked. */ if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL || lookupmode == INTERPOSE_REVAL_NEG) { verify_locked(dentry); } else { BUG_ON(dtopd_nocheck(dentry) != NULL); locked_child = 1; } if (lookupmode != INTERPOSE_PARTIAL) if ((err = new_dentry_private_data(dentry))) goto out; /* must initialize dentry operations */ dentry->d_op = &unionfs_dops; parent_dentry = GET_PARENT(dentry); /* We never partial lookup the root directory. */ if (parent_dentry != dentry) { lock_dentry(parent_dentry); locked_parent = 1; } else { DPUT(parent_dentry); parent_dentry = NULL; goto out; } fist_print_dentry("IN unionfs_lookup (parent)", parent_dentry); fist_print_dentry("IN unionfs_lookup (child)", dentry); name = dentry->d_name.name; namelen = dentry->d_name.len; /* No dentries should get created for possible whiteout names. */ if (!is_validname(name)) { err = -EPERM; goto out_free; } /* Now start the actual lookup procedure. */ bstart = dbstart(parent_dentry); bend = dbend(parent_dentry); bopaque = dbopaque(parent_dentry); BUG_ON(bstart < 0); /* It would be ideal if we could convert partial lookups to only have * to do this work when they really need to. It could probably improve * performance quite a bit, and maybe simplify the rest of the code. */ if (lookupmode == INTERPOSE_PARTIAL) { bstart++; if ((bopaque != -1) && (bopaque < bend)) bend = bopaque; } fist_dprint(8, "bstart = %d, bend = %d\n", bstart, bend); for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry) continue; BUG_ON(hidden_dentry != NULL); hidden_dir_dentry = dtohd_index(parent_dentry, bindex); /* if the parent hidden dentry does not exist skip this */ if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode)) continue; /* also skip it if the parent isn't a directory. */ if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)) continue; /* Reuse the whiteout name because its value doesn't change. */ if (!whname) { whname = alloc_whname(name, namelen); if (IS_ERR(whname)) { err = PTR_ERR(whname); goto out_free; } } /* check if whiteout exists in this branch: lookup .wh.foo */ wh_hidden_dentry = LOOKUP_ONE_LEN(whname, hidden_dir_dentry, namelen + WHLEN); if (IS_ERR(wh_hidden_dentry)) { DPUT(first_hidden_dentry); err = PTR_ERR(wh_hidden_dentry); goto out_free; } if (wh_hidden_dentry->d_inode) { /* We found a whiteout so lets give up. */ fist_dprint(8, "whiteout found in %d\n", bindex); if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); DPUT(wh_hidden_dentry); break; } err = -EIO; printk(KERN_NOTICE "EIO: Invalid whiteout entry type" " %d.\n", wh_hidden_dentry->d_inode->i_mode); DPUT(wh_hidden_dentry); DPUT(first_hidden_dentry); goto out_free; } DPUT(wh_hidden_dentry); wh_hidden_dentry = NULL; /* Now do regular lookup; lookup foo */ hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry, namelen); fist_print_generic_dentry("hidden result", hidden_dentry); if (IS_ERR(hidden_dentry)) { DPUT(first_hidden_dentry); err = PTR_ERR(hidden_dentry); goto out_free; } /* Store the first negative dentry specially, because if they * are all negative we need this for future creates. */ if (!hidden_dentry->d_inode) { if (!first_hidden_dentry && (dbstart(dentry) == -1)) { first_hidden_dentry = hidden_dentry; first_dentry_offset = bindex; } else { DPUT(hidden_dentry); } continue; } /* number of positive dentries */ dentry_count++; /* store underlying dentry */ if (dbstart(dentry) == -1) set_dbstart(dentry, bindex); set_dtohd_index(dentry, bindex, hidden_dentry); set_dbend(dentry, bindex); /* update parent directory's atime with the bindex */ fist_copy_attr_atime(parent_dentry->d_inode, hidden_dir_dentry->d_inode); /* We terminate file lookups here. */ if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) { if (lookupmode == INTERPOSE_PARTIAL) continue; if (dentry_count == 1) goto out_positive; /* This can only happen with mixed D-*-F-* */ BUG_ON(!S_ISDIR(dtohd(dentry)->d_inode->i_mode)); continue; } opaque = is_opaque_dir(dentry, bindex); if (opaque < 0) { DPUT(first_hidden_dentry); err = opaque; goto out_free; } if (opaque) { set_dbend(dentry, bindex); set_dbopaque(dentry, bindex); break; } } if (dentry_count) goto out_positive; else goto out_negative; out_negative: if (lookupmode == INTERPOSE_PARTIAL) goto out; /* If we've only got negative dentries, then use the leftmost one. */ if (lookupmode == INTERPOSE_REVAL) { if (dentry->d_inode) { itopd(dentry->d_inode)->uii_stale = 1; } goto out; } /* This should only happen if we found a whiteout. */ if (first_dentry_offset == -1) { first_hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry, namelen); first_dentry_offset = bindex; if (IS_ERR(first_hidden_dentry)) { err = PTR_ERR(first_hidden_dentry); goto out; } } set_dtohd_index(dentry, first_dentry_offset, first_hidden_dentry); set_dbstart(dentry, first_dentry_offset); set_dbend(dentry, first_dentry_offset); if (lookupmode == INTERPOSE_REVAL_NEG) BUG_ON(dentry->d_inode != NULL); else d_add(dentry, NULL); goto out; /* This part of the code is for positive dentries. */ out_positive: BUG_ON(dentry_count <= 0); /* If we're holding onto the first negative dentry throw it out. */ DPUT(first_hidden_dentry); /* Partial lookups need to reinterpose, or throw away older negs. */ if (lookupmode == INTERPOSE_PARTIAL) { if (dentry->d_inode) { unionfs_reinterpose(dentry); goto out; } /* This somehow turned positive, so it is as if we had a * negative revalidation. */ lookupmode = INTERPOSE_REVAL_NEG; update_bstart(dentry); bstart = dbstart(dentry); bend = dbend(dentry); } err = unionfs_interpose(dentry, dentry->d_sb, lookupmode); if (err) goto out_drop; fist_checkinode(dentry->d_inode, "unionfs_lookup OUT: child"); fist_checkinode(parent_dentry->d_inode, "unionfs_lookup OUT: dir"); goto out; out_drop: d_drop(dentry); out_free: /* should dput all the underlying dentries on error condition */ bstart = dbstart(dentry); if (bstart >= 0) { bend = dbend(dentry); for (bindex = bstart; bindex <= bend; bindex++) DPUT(dtohd_index(dentry, bindex)); } KFREE(dtohd_ptr(dentry)); dtohd_ptr(dentry) = NULL; set_dbstart(dentry, -1); set_dbend(dentry, -1); out: if (!err && dtopd(dentry)) { BUG_ON(dbend(dentry) > dtopd(dentry)->udi_bcount); BUG_ON(dbend(dentry) > sbmax(dentry->d_sb)); BUG_ON(dbstart(dentry) < 0); } KFREE(whname); fist_print_dentry("OUT unionfs_lookup (parent)", parent_dentry); fist_print_dentry("OUT unionfs_lookup (child)", dentry); if (locked_parent) unlock_dentry(parent_dentry); DPUT(parent_dentry); if (locked_child) unlock_dentry(dentry); print_exit_status(err); return ERR_PTR(err); }
int unionfs_ioctl_addbranch(struct inode *inode, unsigned int cmd, unsigned long arg) { int err; struct unionfs_addbranch_args *addargs = NULL; struct nameidata nd; char *path = NULL; int gen; int i; int pobjects; struct unionfs_usi_data *new_data = NULL; struct dentry **new_udi_dentry = NULL; struct inode **new_uii_inode = NULL; struct dentry *root = NULL; struct dentry *hidden_root = NULL; print_entry_location(); err = -ENOMEM; addargs = KMALLOC(sizeof(struct unionfs_addbranch_args), GFP_KERNEL); if (!addargs) goto out; err = -EFAULT; if (copy_from_user (addargs, (const void __user *)arg, sizeof(struct unionfs_addbranch_args))) goto out; err = -EINVAL; if (addargs->ab_perms & ~(MAY_READ | MAY_WRITE | MAY_NFSRO)) goto out; if (!(addargs->ab_perms & MAY_READ)) goto out; err = -E2BIG; if (sbend(inode->i_sb) > FD_SETSIZE) goto out; err = -ENOMEM; if (!(path = getname((const char __user *)addargs->ab_path))) goto out; err = path_lookup(path, LOOKUP_FOLLOW, &nd); RECORD_PATH_LOOKUP(&nd); if (err) goto out; if ((err = check_branch(&nd))) { path_release(&nd); RECORD_PATH_RELEASE(&nd); goto out; } unionfs_write_lock(inode->i_sb); lock_dentry(inode->i_sb->s_root); root = inode->i_sb->s_root; for (i = dbstart(inode->i_sb->s_root); i <= dbend(inode->i_sb->s_root); i++) { hidden_root = dtohd_index(root, i); if (is_branch_overlap(hidden_root, nd.dentry)) { err = -EINVAL; goto out; } } err = -EINVAL; if (addargs->ab_branch < 0 || (addargs->ab_branch > (sbend(inode->i_sb) + 1))) goto out; if ((err = newputmap(inode->i_sb))) goto out; stopd(inode->i_sb)->b_end++; dtopd(inode->i_sb->s_root)->udi_bcount++; set_dbend(inode->i_sb->s_root, dbend(inode->i_sb->s_root) + 1); itopd(inode->i_sb->s_root->d_inode)->b_end++; atomic_inc(&stopd(inode->i_sb)->usi_generation); gen = atomic_read(&stopd(inode->i_sb)->usi_generation); pobjects = sbend(inode->i_sb) + 1; /* Reallocate the dynamic structures. */ new_data = alloc_new_data(pobjects); new_udi_dentry = alloc_new_dentries(pobjects); new_uii_inode = KZALLOC(sizeof(struct inode *) * pobjects, GFP_KERNEL); if (!new_udi_dentry || !new_uii_inode || !new_data) { err = -ENOMEM; goto out; } /* Copy the in-place values to our new structure. */ for (i = 0; i < addargs->ab_branch; i++) { atomic_set(&(new_data[i].sbcount), branch_count(inode->i_sb, i)); new_data[i].branchperms = branchperms(inode->i_sb, i); new_data[i].hidden_mnt = stohiddenmnt_index(inode->i_sb, i); new_data[i].sb = stohs_index(inode->i_sb, i); new_udi_dentry[i] = dtohd_index(inode->i_sb->s_root, i); new_uii_inode[i] = itohi_index(inode->i_sb->s_root->d_inode, i); } /* Shift the ends to the right (only handle reallocated bits). */ for (i = sbend(inode->i_sb) - 1; i >= (int)addargs->ab_branch; i--) { int j = i + 1; int pmindex; atomic_set(&new_data[j].sbcount, branch_count(inode->i_sb, i)); new_data[j].branchperms = branchperms(inode->i_sb, i); new_data[j].hidden_mnt = stohiddenmnt_index(inode->i_sb, i); new_data[j].sb = stohs_index(inode->i_sb, i); new_udi_dentry[j] = dtohd_index(inode->i_sb->s_root, i); new_uii_inode[j] = itohi_index(inode->i_sb->s_root->d_inode, i); /* Update the newest putmap, so it is correct for later. */ pmindex = stopd(inode->i_sb)->usi_lastputmap; pmindex -= stopd(inode->i_sb)->usi_firstputmap; stopd(inode->i_sb)->usi_putmaps[pmindex]->map[i] = j; } /* Now we can free the old ones. */ KFREE(dtopd(inode->i_sb->s_root)->udi_dentry); KFREE(itopd(inode->i_sb->s_root->d_inode)->uii_inode); KFREE(stopd(inode->i_sb)->usi_data); /* Update the real pointers. */ dtohd_ptr(inode->i_sb->s_root) = new_udi_dentry; itohi_ptr(inode->i_sb->s_root->d_inode) = new_uii_inode; stopd(inode->i_sb)->usi_data = new_data; /* Re-NULL the new ones so we don't try to free them. */ new_data = NULL; new_udi_dentry = NULL; new_uii_inode = NULL; /* Put the new dentry information into it's slot. */ set_dtohd_index(inode->i_sb->s_root, addargs->ab_branch, nd.dentry); set_itohi_index(inode->i_sb->s_root->d_inode, addargs->ab_branch, IGRAB(nd.dentry->d_inode)); set_branchperms(inode->i_sb, addargs->ab_branch, addargs->ab_perms); set_branch_count(inode->i_sb, addargs->ab_branch, 0); set_stohiddenmnt_index(inode->i_sb, addargs->ab_branch, nd.mnt); set_stohs_index(inode->i_sb, addargs->ab_branch, nd.dentry->d_sb); atomic_set(&dtopd(inode->i_sb->s_root)->udi_generation, gen); atomic_set(&itopd(inode->i_sb->s_root->d_inode)->uii_generation, gen); fixputmaps(inode->i_sb); out: unlock_dentry(inode->i_sb->s_root); unionfs_write_unlock(inode->i_sb); KFREE(new_udi_dentry); KFREE(new_uii_inode); KFREE(new_data); KFREE(addargs); if (path) putname(path); print_exit_status(err); return err; }
static struct dentry *unionfs_d_alloc_root(struct super_block *sb) { struct dentry *ret = NULL; if (sb) { static const struct qstr name = {.name = "/",.len = 1 }; ret = d_alloc(NULL, &name); if (ret) { ret->d_op = &unionfs_dops; ret->d_sb = sb; ret->d_parent = ret; } } return ret; } static int unionfs_read_super(struct super_block *sb, void *raw_data, int silent) { int err = 0; struct unionfs_dentry_info *hidden_root_info = NULL; int bindex, bstart, bend; unsigned long long maxbytes; print_entry_location(); if (!raw_data) { printk(KERN_WARNING "unionfs_read_super: missing data argument\n"); err = -EINVAL; goto out; } /* * Allocate superblock private data */ stopd_lhs(sb) = KZALLOC(sizeof(struct unionfs_sb_info), GFP_KERNEL); if (!stopd(sb)) { printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__); err = -ENOMEM; goto out; } stopd(sb)->b_end = -1; atomic_set(&stopd(sb)->usi_generation, 1); init_rwsem(&stopd(sb)->usi_rwsem); hidden_root_info = unionfs_parse_options(sb, raw_data); if (IS_ERR(hidden_root_info)) { printk(KERN_WARNING "unionfs_read_super: error while parsing options (err = %ld)\n", PTR_ERR(hidden_root_info)); err = PTR_ERR(hidden_root_info); hidden_root_info = NULL; goto out_free; } if (hidden_root_info->udi_bstart == -1) { err = -ENOENT; goto out_free; } /* set the hidden superblock field of upper superblock */ bstart = hidden_root_info->udi_bstart; BUG_ON(bstart != 0); sbend(sb) = bend = hidden_root_info->udi_bend; for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; set_stohs_index(sb, bindex, d->d_sb); } /* Unionfs: Max Bytes is the maximum bytes from among all the branches */ maxbytes = -1; for (bindex = bstart; bindex <= bend; bindex++) if (maxbytes < stohs_index(sb, bindex)->s_maxbytes) maxbytes = stohs_index(sb, bindex)->s_maxbytes; sb->s_maxbytes = maxbytes; sb->s_op = &unionfs_sops; sb->s_export_op = &unionfs_export_ops; /* * we can't use d_alloc_root if we want to use * our own interpose function unchanged, * so we simply call our own "fake" d_alloc_root */ sb->s_root = unionfs_d_alloc_root(sb); if (!sb->s_root) { err = -ENOMEM; goto out_dput; } /* link the upper and lower dentries */ dtopd_lhs(sb->s_root) = NULL; if ((err = new_dentry_private_data(sb->s_root))) goto out_freedpd; /* Set the hidden dentries for s_root */ for (bindex = bstart; bindex <= bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; set_dtohd_index(sb->s_root, bindex, d); } set_dbstart(sb->s_root, bstart); set_dbend(sb->s_root, bend); /* Set the generation number to one, since this is for the mount. */ atomic_set(&dtopd(sb->s_root)->udi_generation, 1); /* call interpose to create the upper level inode */ if ((err = unionfs_interpose(sb->s_root, sb, 0))) goto out_freedpd; unlock_dentry(sb->s_root); goto out; out_freedpd: if (dtopd(sb->s_root)) { KFREE(dtohd_ptr(sb->s_root)); free_dentry_private_data(dtopd(sb->s_root)); } DPUT(sb->s_root); out_dput: if (hidden_root_info && !IS_ERR(hidden_root_info)) { for (bindex = hidden_root_info->udi_bstart; bindex <= hidden_root_info->udi_bend; bindex++) { struct dentry *d; d = hidden_root_info->udi_dentry[bindex]; if (d) DPUT(d); if (stopd(sb) && stohiddenmnt_index(sb, bindex)) mntput(stohiddenmnt_index(sb, bindex)); } KFREE(hidden_root_info->udi_dentry); KFREE(hidden_root_info); hidden_root_info = NULL; } out_free: KFREE(stopd(sb)->usi_data); KFREE(stopd(sb)); stopd_lhs(sb) = NULL; out: if (hidden_root_info && !IS_ERR(hidden_root_info)) { KFREE(hidden_root_info->udi_dentry); KFREE(hidden_root_info); } print_exit_status(err); return err; }
static int unionfs_mkdir(struct inode *parent, struct dentry *dentry, int mode) { int err = 0; struct dentry *hidden_dentry = NULL, *whiteout_dentry = NULL; struct dentry *hidden_parent_dentry = NULL; int bindex = 0, bstart; char *name = NULL; int whiteout_unlinked = 0; uid_t saved_uid = current->fsuid; gid_t saved_gid = current->fsgid; print_entry_location(); lock_dentry(dentry); fist_print_dentry("IN unionfs_mkdir", dentry); bstart = dbstart(dentry); hidden_dentry = dtohd(dentry); // check if whiteout exists in this branch, i.e. lookup .wh.foo first name = alloc_whname(dentry->d_name.name, dentry->d_name.len); if (IS_ERR(name)) { err = PTR_ERR(name); goto out; } whiteout_dentry = LOOKUP_ONE_LEN(name, hidden_dentry->d_parent, dentry->d_name.len + WHLEN); if (IS_ERR(whiteout_dentry)) { err = PTR_ERR(whiteout_dentry); goto out; } if (!whiteout_dentry->d_inode) { DPUT(whiteout_dentry); whiteout_dentry = NULL; } else { hidden_parent_dentry = lock_parent(whiteout_dentry); /* Set the uid and gid to trick the fs into allowing us to create * the file */ current->fsuid = hidden_parent_dentry->d_inode->i_uid; current->fsgid = hidden_parent_dentry->d_inode->i_gid; //found a.wh.foo entry, remove it then do vfs_mkdir if (!(err = is_robranch_super(dentry->d_sb, bstart))) { err = vfs_unlink(hidden_parent_dentry->d_inode, whiteout_dentry); } DPUT(whiteout_dentry); current->fsuid = saved_uid; current->fsgid = saved_gid; unlock_dir(hidden_parent_dentry); if (err) { /* exit if the error returned was NOT -EROFS */ if (!IS_COPYUP_ERR(err)) goto out; bstart--; } else { whiteout_unlinked = 1; } } for (bindex = bstart; bindex >= 0; bindex--) { hidden_dentry = dtohd_index(dentry, bindex); if (!hidden_dentry) { hidden_dentry = create_parents(parent, dentry, bindex); if (!hidden_dentry || IS_ERR(hidden_dentry)) { fist_dprint(8, "hidden dentry NULL for bindex = %d\n", bindex); continue; } } hidden_parent_dentry = lock_parent(hidden_dentry); if (IS_ERR(hidden_parent_dentry)) { err = PTR_ERR(hidden_parent_dentry); goto out; } if (!(err = is_robranch_super(dentry->d_sb, bindex))) { err = vfs_mkdir(hidden_parent_dentry->d_inode, hidden_dentry, mode); } unlock_dir(hidden_parent_dentry); /* XXX this could potentially return a negative hidden_dentry! */ if (err || !hidden_dentry->d_inode) { /* break out of for loop if error returned was NOT -EROFS */ if (!IS_COPYUP_ERR(err)) break; } else { int i; int bend = dbend(dentry); for (i = bindex + 1; i < bend; i++) { if (dtohd_index(dentry, i)) { DPUT(dtohd_index(dentry, i)); set_dtohd_index(dentry, i, NULL); } } bend = bindex; set_dbend(dentry, bend); err = unionfs_interpose(dentry, parent->i_sb, 0); if (!err) { fist_copy_attr_timesizes(parent, hidden_parent_dentry-> d_inode); /* update number of links on parent directory */ parent->i_nlink = get_nlinks(parent); } whiteout_dentry = LOOKUP_ONE_LEN(UNIONFS_DIR_OPAQUE, hidden_dentry, sizeof (UNIONFS_DIR_OPAQUE) - 1); if (IS_ERR(whiteout_dentry)) { err = PTR_ERR(whiteout_dentry); goto out; } down(&hidden_dentry->d_inode->i_sem); err = vfs_create(hidden_dentry->d_inode, whiteout_dentry, 0600, NULL); up(&hidden_dentry->d_inode->i_sem); DPUT(whiteout_dentry); if (err) { fist_dprint(8, "mkdir: error creating directory override entry: %d\n", err); goto out; } break; } } out: if (!dentry->d_inode) d_drop(dentry); KFREE(name); fist_print_dentry("OUT unionfs_mkdir :", dentry); unlock_dentry(dentry); print_exit_status(err); return err; }
static int unionfs_create(struct inode *parent, struct dentry *dentry, int mode, struct nameidata *nd) { int err = 0; struct dentry *hidden_dentry = NULL; struct dentry *whiteout_dentry = NULL; struct dentry *new_hidden_dentry; struct dentry *hidden_parent_dentry = NULL; int bindex = 0, bstart; char *name = NULL; print_entry_location(); lock_dentry(dentry); fist_print_dentry("IN unionfs_create", dentry); /* We start out in the leftmost branch. */ bstart = dbstart(dentry); hidden_dentry = dtohd(dentry); /* check if whiteout exists in this branch, i.e. lookup .wh.foo first */ name = alloc_whname(dentry->d_name.name, dentry->d_name.len); if (IS_ERR(name)) { err = PTR_ERR(name); goto out; } whiteout_dentry = LOOKUP_ONE_LEN(name, hidden_dentry->d_parent, dentry->d_name.len + WHLEN); if (IS_ERR(whiteout_dentry)) { err = PTR_ERR(whiteout_dentry); whiteout_dentry = NULL; goto out; } if (whiteout_dentry->d_inode) { /* .wh.foo has been found. */ /* First truncate it and then rename it to foo (hence having * the same overall effect as a normal create. * * XXX: This is not strictly correct. If we have unlinked the * file and it still has a reference count, then we should * actually unlink the whiteout so that user's data isn't * hosed over. */ struct dentry *hidden_dir_dentry; struct iattr newattrs; down(&whiteout_dentry->d_inode->i_sem); newattrs.ia_valid = ATTR_CTIME | ATTR_MODE | ATTR_ATIME | ATTR_MTIME | ATTR_UID | ATTR_GID | ATTR_FORCE | ATTR_KILL_SUID | ATTR_KILL_SGID; newattrs.ia_mode = mode & ~current->fs->umask; newattrs.ia_uid = current->fsuid; newattrs.ia_gid = current->fsgid; if (whiteout_dentry->d_inode->i_size != 0) { newattrs.ia_valid |= ATTR_SIZE; newattrs.ia_size = 0; } err = notify_change(whiteout_dentry, &newattrs); up(&whiteout_dentry->d_inode->i_sem); if (err) printk(KERN_WARNING "unionfs: %s:%d: notify_change failed: %d, ignoring..\n", __FILE__, __LINE__, err); new_hidden_dentry = dtohd(dentry); DGET(new_hidden_dentry); hidden_dir_dentry = GET_PARENT(whiteout_dentry); lock_rename(hidden_dir_dentry, hidden_dir_dentry); if (!(err = is_robranch_super(dentry->d_sb, bstart))) { err = vfs_rename(hidden_dir_dentry->d_inode, whiteout_dentry, hidden_dir_dentry->d_inode, new_hidden_dentry); } if (!err) { fist_copy_attr_timesizes(parent, new_hidden_dentry->d_parent-> d_inode); parent->i_nlink = get_nlinks(parent); } unlock_rename(hidden_dir_dentry, hidden_dir_dentry); DPUT(hidden_dir_dentry); DPUT(new_hidden_dentry); if (err) { /* exit if the error returned was NOT -EROFS */ if (!IS_COPYUP_ERR(err)) goto out; /* We were not able to create the file in this branch, * so, we try to create it in one branch to left */ bstart--; } else { /* reset the unionfs dentry to point to the .wh.foo entry. */ /* Discard any old reference. */ DPUT(dtohd(dentry)); /* Trade one reference to another. */ set_dtohd_index(dentry, bstart, whiteout_dentry); whiteout_dentry = NULL; err = unionfs_interpose(dentry, parent->i_sb, 0); goto out; } } for (bindex = bstart; bindex >= 0; bindex--) { hidden_dentry = dtohd_index(dentry, bindex); if (!hidden_dentry) { /* if hidden_dentry is NULL, create the entire * dentry directory structure in branch 'bindex'. * hidden_dentry will NOT be null when bindex == bstart * because lookup passed as a negative unionfs dentry * pointing to a lone negative underlying dentry */ hidden_dentry = create_parents(parent, dentry, bindex); if (!hidden_dentry || IS_ERR(hidden_dentry)) { if (IS_ERR(hidden_dentry)) err = PTR_ERR(hidden_dentry); continue; } } fist_checkinode(parent, "unionfs_create"); hidden_parent_dentry = lock_parent(hidden_dentry); if (IS_ERR(hidden_parent_dentry)) { err = PTR_ERR(hidden_parent_dentry); goto out; } /* We shouldn't create things in a read-only branch. */ if (!(err = is_robranch_super(dentry->d_sb, bindex))) { //DQ: vfs_create has a different prototype in 2.6 err = vfs_create(hidden_parent_dentry->d_inode, hidden_dentry, mode, nd); } if (err || !hidden_dentry->d_inode) { unlock_dir(hidden_parent_dentry); /* break out of for loop if the error wasn't -EROFS */ if (!IS_COPYUP_ERR(err)) break; } else { err = unionfs_interpose(dentry, parent->i_sb, 0); if (!err) { fist_copy_attr_timesizes(parent, hidden_parent_dentry-> d_inode); /* update number of links on parent directory */ parent->i_nlink = get_nlinks(parent); } unlock_dir(hidden_parent_dentry); break; } } out: DPUT(whiteout_dentry); KFREE(name); fist_print_dentry("OUT unionfs_create :", dentry); unlock_dentry(dentry); print_exit_status(err); return err; }