static void unionfs_read_inode(struct inode *inode) { static struct address_space_operations unionfs_empty_aops; print_entry_location(); if (!itopd(inode)) { FISTBUG ("No kernel memory when allocating inode private data!\n"); } PASSERT(inode->i_sb); memset(itopd(inode), 0, sizeof(struct unionfs_inode_info)); itopd(inode)->b_start = -1; itopd(inode)->b_end = -1; atomic_set(&itopd(inode)->uii_generation, atomic_read(&stopd(inode->i_sb)->usi_generation)); itopd(inode)->uii_rdlock = SPIN_LOCK_UNLOCKED; itopd(inode)->uii_rdcount = 1; itopd(inode)->uii_hashsize = -1; INIT_LIST_HEAD(&itopd(inode)->uii_readdircache); if (sbmax(inode->i_sb) > UNIONFS_INLINE_OBJECTS) { int size = (sbmax(inode->i_sb) - UNIONFS_INLINE_OBJECTS) * sizeof(struct inode *); itohi_ptr(inode) = KMALLOC(size, GFP_UNIONFS); if (!itohi_ptr(inode)) { FISTBUG ("No kernel memory when allocating lower-pointer array!\n"); } memset(itohi_ptr(inode), 0, size); } memset(itohi_inline(inode), 0, UNIONFS_INLINE_OBJECTS * sizeof(struct inode *)); inode->i_version++; inode->i_op = &unionfs_main_iops; inode->i_fop = &unionfs_main_fops; /* I don't think ->a_ops is ever allowed to be NULL */ inode->i_mapping->a_ops = &unionfs_empty_aops; fist_dprint(7, "setting inode 0x%p a_ops to empty (0x%p)\n", inode, inode->i_mapping->a_ops); print_exit_location(); }
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; }
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; }
/* * THIS IS A BOOLEAN FUNCTION: returns 1 if valid, 0 otherwise. */ int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd) { int valid = 1; /* default is valid (1); invalid is 0. */ struct dentry *hidden_dentry; int bindex, bstart, bend; int sbgen, dgen; int positive = 0; int locked = 0; int restart = 0; int interpose_flag; print_util_entry_location(); restart: verify_locked(dentry); /* if the dentry is unhashed, do NOT revalidate */ if (d_deleted(dentry)) { fist_dprint(6, "unhashed dentry being revalidated: %*s\n", dentry->d_name.len, dentry->d_name.name); goto out; } BUG_ON(dbstart(dentry) == -1); if (dentry->d_inode) positive = 1; dgen = atomic_read(&dtopd(dentry)->udi_generation); sbgen = atomic_read(&stopd(dentry->d_sb)->usi_generation); /* If we are working on an unconnected dentry, then there is no * revalidation to be done, because this file does not exist within the * namespace, and Unionfs operates on the namespace, not data. */ if (sbgen != dgen) { struct dentry *result; int pdgen; unionfs_read_lock(dentry->d_sb); locked = 1; /* The root entry should always be valid */ BUG_ON(IS_ROOT(dentry)); /* We can't work correctly if our parent isn't valid. */ pdgen = atomic_read(&dtopd(dentry->d_parent)->udi_generation); if (!restart && (pdgen != sbgen)) { unionfs_read_unlock(dentry->d_sb); locked = 0; /* We must be locked before our parent. */ if (! (dentry->d_parent->d_op-> d_revalidate(dentry->d_parent, nd))) { valid = 0; goto out; } restart = 1; goto restart; } BUG_ON(pdgen != sbgen); /* Free the pointers for our inodes and this dentry. */ bstart = dbstart(dentry); bend = dbend(dentry); if (bstart >= 0) { struct dentry *hidden_dentry; for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index_nocheck(dentry, bindex); if (!hidden_dentry) continue; DPUT(hidden_dentry); } } set_dbstart(dentry, -1); set_dbend(dentry, -1); interpose_flag = INTERPOSE_REVAL_NEG; if (positive) { interpose_flag = INTERPOSE_REVAL; down(&dentry->d_inode->i_sem); bstart = ibstart(dentry->d_inode); bend = ibend(dentry->d_inode); if (bstart >= 0) { struct inode *hidden_inode; for (bindex = bstart; bindex <= bend; bindex++) { hidden_inode = itohi_index(dentry->d_inode, bindex); if (!hidden_inode) continue; IPUT(hidden_inode); } } KFREE(itohi_ptr(dentry->d_inode)); itohi_ptr(dentry->d_inode) = NULL; ibstart(dentry->d_inode) = -1; ibend(dentry->d_inode) = -1; up(&dentry->d_inode->i_sem); } result = unionfs_lookup_backend(dentry, interpose_flag); if (result) { if (IS_ERR(result)) { valid = 0; goto out; } /* current unionfs_lookup_backend() doesn't return a valid dentry */ DPUT(dentry); dentry = result; } if (positive && itopd(dentry->d_inode)->uii_stale) { make_stale_inode(dentry->d_inode); d_drop(dentry); valid = 0; goto out; } goto out; } /* The revalidation must occur across all branches */ bstart = dbstart(dentry); bend = dbend(dentry); BUG_ON(bstart == -1); for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); if (!hidden_dentry || !hidden_dentry->d_op || !hidden_dentry->d_op->d_revalidate) continue; if (!hidden_dentry->d_op->d_revalidate(hidden_dentry, nd)) valid = 0; } if (!dentry->d_inode) valid = 0; if (valid) fist_copy_attr_all(dentry->d_inode, itohi(dentry->d_inode)); out: if (locked) unionfs_read_unlock(dentry->d_sb); fist_print_dentry("revalidate out", dentry); print_util_exit_status(valid); return valid; }
/* sb we pass is unionfs's super_block */ int unionfs_interpose(struct dentry *dentry, struct super_block *sb, int flag) { struct inode *hidden_inode; struct dentry *hidden_dentry; int err = 0; struct inode *inode; int is_negative_dentry = 1; int bindex, bstart, bend; print_entry("flag = %d", flag); verify_locked(dentry); fist_print_dentry("In unionfs_interpose", dentry); bstart = dbstart(dentry); bend = dbend(dentry); /* Make sure that we didn't get a negative dentry. */ for (bindex = bstart; bindex <= bend; bindex++) { if (dtohd_index(dentry, bindex) && dtohd_index(dentry, bindex)->d_inode) { is_negative_dentry = 0; break; } } BUG_ON(is_negative_dentry); /* We allocate our new inode below, by calling iget. * iget will call our read_inode which will initialize some * of the new inode's fields */ /* On revalidate we've already got our own inode and just need * to fix it up. */ if (flag == INTERPOSE_REVAL) { inode = dentry->d_inode; itopd(inode)->b_start = -1; itopd(inode)->b_end = -1; atomic_set(&itopd(inode)->uii_generation, atomic_read(&stopd(sb)->usi_generation)); itohi_ptr(inode) = KZALLOC(sbmax(sb) * sizeof(struct inode *), GFP_KERNEL); if (!itohi_ptr(inode)) { err = -ENOMEM; goto out; } } else { ino_t ino; /* get unique inode number for unionfs */ #ifdef UNIONFS_IMAP if (stopd(sb)->usi_persistent) { err = read_uin(sb, bindex, dtohd_index(dentry, bindex)->d_inode->i_ino, O_CREAT, &ino); if (err) goto out; } else #endif ino = iunique(sb, UNIONFS_ROOT_INO); inode = IGET(sb, ino); if (!inode) { err = -EACCES; /* should be impossible??? */ goto out; } } down(&inode->i_sem); if (atomic_read(&inode->i_count) > 1) goto skip; for (bindex = bstart; bindex <= bend; bindex++) { hidden_dentry = dtohd_index(dentry, bindex); if (!hidden_dentry) { set_itohi_index(inode, bindex, NULL); continue; } /* Initialize the hidden inode to the new hidden inode. */ if (!hidden_dentry->d_inode) continue; set_itohi_index(inode, bindex, IGRAB(hidden_dentry->d_inode)); } ibstart(inode) = dbstart(dentry); ibend(inode) = dbend(dentry); /* Use attributes from the first branch. */ hidden_inode = itohi(inode); /* Use different set of inode ops for symlinks & directories */ if (S_ISLNK(hidden_inode->i_mode)) inode->i_op = &unionfs_symlink_iops; else if (S_ISDIR(hidden_inode->i_mode)) inode->i_op = &unionfs_dir_iops; /* Use different set of file ops for directories */ if (S_ISDIR(hidden_inode->i_mode)) inode->i_fop = &unionfs_dir_fops; /* properly initialize special inodes */ if (S_ISBLK(hidden_inode->i_mode) || S_ISCHR(hidden_inode->i_mode) || S_ISFIFO(hidden_inode->i_mode) || S_ISSOCK(hidden_inode->i_mode)) init_special_inode(inode, hidden_inode->i_mode, hidden_inode->i_rdev); /* Fix our inode's address operations to that of the lower inode (Unionfs is FiST-Lite) */ if (inode->i_mapping->a_ops != hidden_inode->i_mapping->a_ops) { fist_dprint(7, "fixing inode 0x%p a_ops (0x%p -> 0x%p)\n", inode, inode->i_mapping->a_ops, hidden_inode->i_mapping->a_ops); inode->i_mapping->a_ops = hidden_inode->i_mapping->a_ops; } /* all well, copy inode attributes */ fist_copy_attr_all(inode, hidden_inode); skip: /* only (our) lookup wants to do a d_add */ switch (flag) { case INTERPOSE_DEFAULT: case INTERPOSE_REVAL_NEG: d_instantiate(dentry, inode); break; case INTERPOSE_LOOKUP: err = PTR_ERR(d_splice_alias(inode, dentry)); break; case INTERPOSE_REVAL: /* Do nothing. */ break; default: printk(KERN_ERR "Invalid interpose flag passed!"); BUG(); } fist_print_dentry("Leaving unionfs_interpose", dentry); fist_print_inode("Leaving unionfs_interpose", inode); up(&inode->i_sem); out: print_exit_status(err); return err; }