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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2018 Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
*/
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include "apfs.h"
/**
* apfs_drec_from_query - Read the directory record found by a successful query
* @query: the query that found the record
* @drec: Return parameter. The directory record found.
* @hashed: is this record hashed?
*
* Reads the directory record into @drec and performs some basic sanity checks
* as a protection against crafted filesystems. Returns 0 on success or
* -EFSCORRUPTED otherwise.
*
* The caller must not free @query while @drec is in use, because @drec->name
* points to data on disk.
*/
static int apfs_drec_from_query(struct apfs_query *query, struct apfs_drec *drec, bool hashed)
{
struct super_block *sb = query->node->object.sb;
char *raw = query->node->object.data;
struct apfs_drec_hashed_key *de_hkey = NULL;
struct apfs_drec_key *de_ukey = NULL;
struct apfs_drec_val *de;
int namelen, xlen;
char *xval = NULL, *name;
namelen = query->key_len - (hashed ? sizeof(*de_hkey) : sizeof(*de_ukey));
if (namelen < 1) {
apfs_err(sb, "key is too small (%d)", query->key_len);
return -EFSCORRUPTED;
}
if (query->len < sizeof(*de)) {
apfs_err(sb, "value is too small (%d)", query->len);
return -EFSCORRUPTED;
}
de = (struct apfs_drec_val *)(raw + query->off);
if (hashed) {
de_hkey = (struct apfs_drec_hashed_key *)(raw + query->key_off);
if (namelen != (le32_to_cpu(de_hkey->name_len_and_hash) & APFS_DREC_LEN_MASK)) {
apfs_err(sb, "inconsistent name length");
return -EFSCORRUPTED;
}
name = de_hkey->name;
} else {
de_ukey = (struct apfs_drec_key *)(raw + query->key_off);
if (namelen != le16_to_cpu(de_ukey->name_len)) {
apfs_err(sb, "inconsistent name length");
return -EFSCORRUPTED;
}
name = de_ukey->name;
}
/* Filename must be NULL-terminated */
if (name[namelen - 1] != 0) {
apfs_err(sb, "null termination missing");
return -EFSCORRUPTED;
}
/* The dentry may have at most one xfield: the sibling id */
drec->sibling_id = 0;
xlen = apfs_find_xfield(de->xfields, query->len - sizeof(*de),
APFS_DREC_EXT_TYPE_SIBLING_ID, &xval);
if (xlen >= sizeof(__le64)) {
__le64 *sib_id = (__le64 *)xval;
drec->sibling_id = le64_to_cpup(sib_id);
}
drec->name = name;
drec->name_len = namelen - 1; /* Don't count the NULL termination */
drec->ino = le64_to_cpu(de->file_id);
drec->type = le16_to_cpu(de->flags) & APFS_DREC_TYPE_MASK;
if (drec->type != DT_FIFO && drec->type & 1) /* Invalid file type */
drec->type = DT_UNKNOWN;
return 0;
}
/**
* apfs_dentry_lookup - Lookup a dentry record in the catalog b-tree
* @dir: parent directory
* @child: filename
* @drec: on return, the directory record found
*
* Runs a catalog query for @name in the @dir directory. On success, sets
* @drec and returns a pointer to the query structure. On failure, returns
* an appropriate error pointer.
*/
static struct apfs_query *apfs_dentry_lookup(struct inode *dir,
const struct qstr *child,
struct apfs_drec *drec)
{
struct super_block *sb = dir->i_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_query *query;
u64 cnid = apfs_ino(dir);
bool hashed = apfs_is_normalization_insensitive(sb);
int err;
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return ERR_PTR(-ENOMEM);
apfs_init_drec_key(sb, cnid, child->name, child->len, &query->key);
/*
* Distinct filenames in the same directory may (rarely) share the same
* hash. The query code cannot handle that because their order in the
* b-tree would depend on their unnormalized original names. Just get
* all the candidates and check them one by one.
*
* This is very wasteful for normalization-sensitive filesystems: there
* are no hashes so we just check every single file in the directory for
* no reason. This would be easy to avoid but does it matter? (TODO)
*/
query->flags |= APFS_QUERY_CAT | APFS_QUERY_ANY_NAME | APFS_QUERY_EXACT;
do {
err = apfs_btree_query(sb, &query);
if (err)
goto fail;
err = apfs_drec_from_query(query, drec, hashed);
if (err)
goto fail;
} while (unlikely(apfs_filename_cmp(sb, child->name, child->len, drec->name, drec->name_len)));
/*
* We may need to refresh the query later, but the refresh code doesn't
* know how to deal with hash collisions. Instead set the key to the
* unnormalized name and pretend that this was never a multiple query
* in the first place.
*/
query->key.name = drec->name;
query->flags &= ~(APFS_QUERY_MULTIPLE | APFS_QUERY_DONE | APFS_QUERY_NEXT);
return query;
fail:
if (err != -ENODATA)
apfs_err(sb, "query failed in dir 0x%llx", cnid);
apfs_free_query(query);
return ERR_PTR(err);
}
/**
* apfs_inode_by_name - Find the cnid for a given filename
* @dir: parent directory
* @child: filename
* @ino: on return, the inode number found
*
* Returns 0 and the inode number (which is the cnid of the file
* record); otherwise, return the appropriate error code.
*/
int apfs_inode_by_name(struct inode *dir, const struct qstr *child, u64 *ino)
{
struct super_block *sb = dir->i_sb;
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_query *query;
struct apfs_drec drec;
int err = 0;
down_read(&nxi->nx_big_sem);
query = apfs_dentry_lookup(dir, child, &drec);
if (IS_ERR(query)) {
err = PTR_ERR(query);
goto out;
}
*ino = drec.ino;
apfs_free_query(query);
out:
up_read(&nxi->nx_big_sem);
return err;
}
static int apfs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_nxsb_info *nxi = APFS_NXI(sb);
struct apfs_query *query;
u64 cnid = apfs_ino(inode);
loff_t pos;
bool hashed = apfs_is_normalization_insensitive(sb);
int err = 0;
down_read(&nxi->nx_big_sem);
/* Inode numbers might overflow here; follow btrfs in ignoring that */
if (!dir_emit_dots(file, ctx))
goto out;
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query) {
err = -ENOMEM;
goto out;
}
/* We want all the children for the cnid, regardless of the name */
apfs_init_drec_key(sb, cnid, NULL /* name */, 0 /* name_len */, &query->key);
query->flags = APFS_QUERY_CAT | APFS_QUERY_MULTIPLE | APFS_QUERY_EXACT;
pos = ctx->pos - 2;
while (1) {
struct apfs_drec drec;
/*
* We query for the matching records, one by one. After we
* pass ctx->pos we begin to emit them.
*
* TODO: Faster approach for large directories?
*/
err = apfs_btree_query(sb, &query);
if (err == -ENODATA) { /* Got all the records */
err = 0;
break;
}
if (err)
break;
err = apfs_drec_from_query(query, &drec, hashed);
if (err) {
apfs_alert(sb, "bad dentry record in directory 0x%llx",
cnid);
break;
}
err = 0;
if (pos <= 0) {
if (!dir_emit(ctx, drec.name, drec.name_len,
drec.ino, drec.type))
break;
++ctx->pos;
}
pos--;
}
apfs_free_query(query);
out:
up_read(&nxi->nx_big_sem);
return err;
}
const struct file_operations apfs_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = apfs_readdir,
.fsync = apfs_fsync,
.unlocked_ioctl = apfs_dir_ioctl,
};
/**
* apfs_build_dentry_unhashed_key - Allocate and initialize the key for an unhashed dentry record
* @qname: filename
* @parent_id: inode number for the parent of the dentry
* @key_p: on return, a pointer to the new on-disk key structure
*
* Returns the length of the key, or a negative error code in case of failure.
*/
static int apfs_build_dentry_unhashed_key(struct qstr *qname, u64 parent_id,
struct apfs_drec_key **key_p)
{
struct apfs_drec_key *key;
u16 namelen = qname->len + 1; /* We count the null-termination */
int key_len;
key_len = sizeof(*key) + namelen;
key = kmalloc(key_len, GFP_KERNEL);
if (!key)
return -ENOMEM;
apfs_key_set_hdr(APFS_TYPE_DIR_REC, parent_id, key);
key->name_len = cpu_to_le16(namelen);
strscpy(key->name, qname->name, namelen);
*key_p = key;
return key_len;
}
/**
* apfs_build_dentry_hashed_key - Allocate and initialize the key for a hashed dentry record
* @qname: filename
* @hash: filename hash
* @parent_id: inode number for the parent of the dentry
* @key_p: on return, a pointer to the new on-disk key structure
*
* Returns the length of the key, or a negative error code in case of failure.
*/
static int apfs_build_dentry_hashed_key(struct qstr *qname, u64 hash, u64 parent_id,
struct apfs_drec_hashed_key **key_p)
{
struct apfs_drec_hashed_key *key;
u16 namelen = qname->len + 1; /* We count the null-termination */
int key_len;
key_len = sizeof(*key) + namelen;
key = kmalloc(key_len, GFP_KERNEL);
if (!key)
return -ENOMEM;
apfs_key_set_hdr(APFS_TYPE_DIR_REC, parent_id, key);
key->name_len_and_hash = cpu_to_le32(namelen | hash);
strscpy(key->name, qname->name, namelen);
*key_p = key;
return key_len;
}
/**
* apfs_build_dentry_val - Allocate and initialize the value for a dentry record
* @inode: vfs inode for the dentry
* @sibling_id: sibling id for this hardlink (0 for none)
* @val_p: on return, a pointer to the new on-disk value structure
*
* Returns the length of the value, or a negative error code in case of failure.
*/
static int apfs_build_dentry_val(struct inode *inode, u64 sibling_id,
struct apfs_drec_val **val_p)
{
struct apfs_drec_val *val;
struct apfs_x_field xkey;
int total_xlen = 0, val_len;
__le64 raw_sibling_id = cpu_to_le64(sibling_id);
struct timespec64 now = current_time(inode);
/* The dentry record may have one xfield: the sibling id */
if (sibling_id)
total_xlen += sizeof(struct apfs_xf_blob) +
sizeof(xkey) + sizeof(raw_sibling_id);
val_len = sizeof(*val) + total_xlen;
val = kmalloc(val_len, GFP_KERNEL);
if (!val)
return -ENOMEM;
*val_p = val;
val->file_id = cpu_to_le64(apfs_ino(inode));
val->date_added = cpu_to_le64(timespec64_to_ns(&now));
val->flags = cpu_to_le16((inode->i_mode >> 12) & 15); /* File type */
if (!sibling_id)
return val_len;
/* The buffer was just allocated: none of these functions should fail */
apfs_init_xfields(val->xfields, val_len - sizeof(*val));
xkey.x_type = APFS_DREC_EXT_TYPE_SIBLING_ID;
xkey.x_flags = 0; /* TODO: proper flags here? */
xkey.x_size = cpu_to_le16(sizeof(raw_sibling_id));
apfs_insert_xfield(val->xfields, total_xlen, &xkey, &raw_sibling_id);
return val_len;
}
/**
* apfs_create_dentry_rec - Create a dentry record in the catalog b-tree
* @inode: vfs inode for the dentry
* @qname: filename
* @parent_id: inode number for the parent of the dentry
* @sibling_id: sibling id for this hardlink (0 for none)
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_create_dentry_rec(struct inode *inode, struct qstr *qname,
u64 parent_id, u64 sibling_id)
{
struct super_block *sb = inode->i_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_query *query;
void *raw_key = NULL;
struct apfs_drec_val *raw_val = NULL;
int key_len, val_len;
bool hashed = apfs_is_normalization_insensitive(sb);
int ret;
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_drec_key(sb, parent_id, qname->name, qname->len, &query->key);
query->flags |= APFS_QUERY_CAT;
ret = apfs_btree_query(sb, &query);
if (ret && ret != -ENODATA) {
apfs_err(sb, "query failed in dir 0x%llx (hash 0x%llx)", parent_id, query->key.number);
goto fail;
}
if (hashed)
key_len = apfs_build_dentry_hashed_key(qname, query->key.number, parent_id,
(struct apfs_drec_hashed_key **)&raw_key);
else
key_len = apfs_build_dentry_unhashed_key(qname, parent_id,
(struct apfs_drec_key **)&raw_key);
if (key_len < 0) {
ret = key_len;
goto fail;
}
val_len = apfs_build_dentry_val(inode, sibling_id, &raw_val);
if (val_len < 0) {
ret = val_len;
goto fail;
}
/* TODO: deal with hash collisions */
ret = apfs_btree_insert(query, raw_key, key_len, raw_val, val_len);
if (ret)
apfs_err(sb, "insertion failed in dir 0x%llx (hash 0x%llx)", parent_id, query->key.number);
fail:
kfree(raw_val);
kfree(raw_key);
apfs_free_query(query);
return ret;
}
/**
* apfs_build_sibling_val - Allocate and initialize a sibling link's value
* @dentry: in-memory dentry for this hardlink
* @val_p: on return, a pointer to the new on-disk value structure
*
* Returns the length of the value, or a negative error code in case of failure.
*/
static int apfs_build_sibling_val(struct dentry *dentry,
struct apfs_sibling_val **val_p)
{
struct apfs_sibling_val *val;
struct qstr *qname = &dentry->d_name;
u16 namelen = qname->len + 1; /* We count the null-termination */
struct inode *parent = d_inode(dentry->d_parent);
int val_len;
val_len = sizeof(*val) + namelen;
val = kmalloc(val_len, GFP_KERNEL);
if (!val)
return -ENOMEM;
val->parent_id = cpu_to_le64(apfs_ino(parent));
val->name_len = cpu_to_le16(namelen);
strscpy(val->name, qname->name, namelen);
*val_p = val;
return val_len;
}
/**
* apfs_create_sibling_link_rec - Create a sibling link record for a dentry
* @dentry: the in-memory dentry
* @inode: vfs inode for the dentry
* @sibling_id: sibling id for this hardlink
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_create_sibling_link_rec(struct dentry *dentry,
struct inode *inode, u64 sibling_id)
{
struct super_block *sb = dentry->d_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_query *query = NULL;
struct apfs_sibling_link_key raw_key;
struct apfs_sibling_val *raw_val;
int val_len;
int ret;
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_sibling_link_key(apfs_ino(inode), sibling_id, &query->key);
query->flags |= APFS_QUERY_CAT;
ret = apfs_btree_query(sb, &query);
if (ret && ret != -ENODATA) {
apfs_err(sb, "query failed for ino 0x%llx, sibling 0x%llx", apfs_ino(inode), sibling_id);
goto fail;
}
apfs_key_set_hdr(APFS_TYPE_SIBLING_LINK, apfs_ino(inode), &raw_key);
raw_key.sibling_id = cpu_to_le64(sibling_id);
val_len = apfs_build_sibling_val(dentry, &raw_val);
if (val_len < 0)
goto fail;
ret = apfs_btree_insert(query, &raw_key, sizeof(raw_key), raw_val, val_len);
if (ret)
apfs_err(sb, "insertion failed for ino 0x%llx, sibling 0x%llx", apfs_ino(inode), sibling_id);
kfree(raw_val);
fail:
apfs_free_query(query);
return ret;
}
/**
* apfs_create_sibling_map_rec - Create a sibling map record for a dentry
* @dentry: the in-memory dentry
* @inode: vfs inode for the dentry
* @sibling_id: sibling id for this hardlink
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_create_sibling_map_rec(struct dentry *dentry,
struct inode *inode, u64 sibling_id)
{
struct super_block *sb = dentry->d_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_query *query = NULL;
struct apfs_sibling_map_key raw_key;
struct apfs_sibling_map_val raw_val;
int ret;
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_sibling_map_key(sibling_id, &query->key);
query->flags |= APFS_QUERY_CAT;
ret = apfs_btree_query(sb, &query);
if (ret && ret != -ENODATA) {
apfs_err(sb, "query failed for sibling 0x%llx", sibling_id);
goto fail;
}
apfs_key_set_hdr(APFS_TYPE_SIBLING_MAP, sibling_id, &raw_key);
raw_val.file_id = cpu_to_le64(apfs_ino(inode));
ret = apfs_btree_insert(query, &raw_key, sizeof(raw_key), &raw_val, sizeof(raw_val));
if (ret)
apfs_err(sb, "insertion failed for sibling 0x%llx", sibling_id);
fail:
apfs_free_query(query);
return ret;
}
/**
* apfs_create_sibling_recs - Create sibling link and map records for a dentry
* @dentry: the in-memory dentry
* @inode: vfs inode for the dentry
* @sibling_id: on return, the sibling id for this hardlink
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_create_sibling_recs(struct dentry *dentry,
struct inode *inode, u64 *sibling_id)
{
struct super_block *sb = dentry->d_sb;
struct apfs_superblock *vsb_raw = APFS_SB(sb)->s_vsb_raw;
u64 cnid;
int ret;
/* Sibling ids come from the same pool as the inode numbers */
apfs_assert_in_transaction(sb, &vsb_raw->apfs_o);
cnid = le64_to_cpu(vsb_raw->apfs_next_obj_id);
le64_add_cpu(&vsb_raw->apfs_next_obj_id, 1);
ret = apfs_create_sibling_link_rec(dentry, inode, cnid);
if (ret)
return ret;
ret = apfs_create_sibling_map_rec(dentry, inode, cnid);
if (ret)
return ret;
*sibling_id = cnid;
return 0;
}
/**
* apfs_create_dentry - Create all records for a new dentry
* @dentry: the in-memory dentry
* @inode: vfs inode for the dentry
*
* Creates the dentry record itself, as well as the sibling records if needed;
* also updates the child count for the parent inode. Returns 0 on success or
* a negative error code in case of failure.
*/
static int apfs_create_dentry(struct dentry *dentry, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct inode *parent = d_inode(dentry->d_parent);
u64 sibling_id = 0;
int err;
if (inode->i_nlink > 1) {
/* This is optional for a single link, so don't waste space */
err = apfs_create_sibling_recs(dentry, inode, &sibling_id);
if (err) {
apfs_err(sb, "failed to create sibling recs for ino 0x%llx", apfs_ino(inode));
return err;
}
}
err = apfs_create_dentry_rec(inode, &dentry->d_name, apfs_ino(parent), sibling_id);
if (err) {
apfs_err(sb, "failed to create drec for ino 0x%llx", apfs_ino(inode));
return err;
}
/* Now update the parent inode */
#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
parent->i_mtime = parent->i_ctime = current_time(inode);
#elif LINUX_VERSION_CODE < KERNEL_VERSION(6, 7, 0)
parent->i_mtime = inode_set_ctime_current(parent);
#else
inode_set_mtime_to_ts(parent, inode_set_ctime_current(parent));
#endif
++APFS_I(parent)->i_nchildren;
apfs_inode_join_transaction(parent->i_sb, parent);
return 0;
}
/**
* apfs_undo_create_dentry - Clean up apfs_create_dentry()
* @dentry: the in-memory dentry
*/
static void apfs_undo_create_dentry(struct dentry *dentry)
{
struct inode *parent = d_inode(dentry->d_parent);
--APFS_I(parent)->i_nchildren;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 19, 0)
static inline void discard_new_inode(struct inode *inode)
{
unlock_new_inode(inode);
iput(inode);
}
#endif
int apfs_mkany(struct inode *dir, struct dentry *dentry, umode_t mode,
dev_t rdev, const char *symname)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
int err;
err = apfs_transaction_start(sb, APFS_TRANS_REG);
if (err)
return err;
inode = apfs_new_inode(dir, mode, rdev);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_abort;
}
err = apfs_create_inode_rec(sb, inode, dentry);
if (err) {
apfs_err(sb, "failed to create inode rec for ino 0x%llx", apfs_ino(inode));
goto out_discard_inode;
}
err = apfs_create_dentry(dentry, inode);
if (err) {
apfs_err(sb, "failed to create dentry recs for ino 0x%llx", apfs_ino(inode));
goto out_discard_inode;
}
if (symname) {
err = apfs_xattr_set(inode, APFS_XATTR_NAME_SYMLINK, symname,
strlen(symname) + 1, 0 /* flags */);
if (err == -ERANGE) {
err = -ENAMETOOLONG;
goto out_undo_create;
}
if (err) {
apfs_err(sb, "failed to set symlink xattr for ino 0x%llx", apfs_ino(inode));
goto out_undo_create;
}
}
err = apfs_transaction_commit(sb);
if (err)
goto out_undo_create;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
/* Apparently there is a lockdep bug here, but it doesn't matter */
unlock_new_inode(inode);
d_instantiate(dentry, inode);
#else
d_instantiate_new(dentry, inode);
#endif
return 0;
out_undo_create:
apfs_undo_create_dentry(dentry);
out_discard_inode:
/* Don't reset nlink: on-disk cleanup is unneeded and would deadlock */
discard_new_inode(inode);
out_abort:
apfs_transaction_abort(sb);
return err;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 12, 0)
int apfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
dev_t rdev)
#elif LINUX_VERSION_CODE < KERNEL_VERSION(6, 3, 0)
int apfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
#else
int apfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
#endif
{
return apfs_mkany(dir, dentry, mode, rdev, NULL /* symname */);
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 12, 0)
int apfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
return apfs_mknod(dir, dentry, mode | S_IFDIR, 0 /* rdev */);
}
#elif LINUX_VERSION_CODE < KERNEL_VERSION(6, 3, 0)
int apfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
return apfs_mknod(mnt_userns, dir, dentry, mode | S_IFDIR, 0 /* rdev */);
}
#else
int apfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
return apfs_mknod(idmap, dir, dentry, mode | S_IFDIR, 0 /* rdev */);
}
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 12, 0)
int apfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
return apfs_mknod(dir, dentry, mode, 0 /* rdev */);
}
#elif LINUX_VERSION_CODE < KERNEL_VERSION(6, 3, 0)
int apfs_create(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return apfs_mknod(mnt_userns, dir, dentry, mode, 0 /* rdev */);
}
#else
int apfs_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return apfs_mknod(idmap, dir, dentry, mode, 0 /* rdev */);
}
#endif
/**
* apfs_prepare_dentry_for_link - Assign a sibling id and records to a dentry
* @dentry: the in-memory dentry (should be for a primary link)
*
* Returns 0 on success, or a negative error code in case of failure.
*/
static int apfs_prepare_dentry_for_link(struct dentry *dentry)
{
struct inode *parent = d_inode(dentry->d_parent);
struct super_block *sb = parent->i_sb;
struct apfs_query *query;
struct apfs_drec drec;
u64 sibling_id;
int ret;
query = apfs_dentry_lookup(parent, &dentry->d_name, &drec);
if (IS_ERR(query)) {
apfs_err(sb, "lookup failed in dir 0x%llx", apfs_ino(parent));
return PTR_ERR(query);
}
if (drec.sibling_id) {
/* This dentry already has a sibling id xfield */
apfs_free_query(query);
return 0;
}
/* Don't modify the dentry record, just delete it to make a new one */
ret = apfs_btree_remove(query);
apfs_free_query(query);
if (ret) {
apfs_err(sb, "removal failed in dir 0x%llx", apfs_ino(parent));
return ret;
}
ret = apfs_create_sibling_recs(dentry, d_inode(dentry), &sibling_id);
if (ret) {
apfs_err(sb, "failed to create sibling recs in dir 0x%llx", apfs_ino(parent));
return ret;
}
return apfs_create_dentry_rec(d_inode(dentry), &dentry->d_name,
apfs_ino(parent), sibling_id);
}
/**
* __apfs_undo_link - Clean up __apfs_link()
* @dentry: the in-memory dentry
* @inode: target inode
*/
static void __apfs_undo_link(struct dentry *dentry, struct inode *inode)
{
apfs_undo_create_dentry(dentry);
drop_nlink(inode);
}
/**
* __apfs_link - Link a dentry
* @old_dentry: dentry for the old link
* @dentry: new dentry to link
*
* Does the same as apfs_link(), but without starting a transaction, taking a
* new reference to @old_dentry->d_inode, or instantiating @dentry.
*/
static int __apfs_link(struct dentry *old_dentry, struct dentry *dentry)
{
struct inode *inode = d_inode(old_dentry);
struct super_block *sb = inode->i_sb;
int err;
/* First update the inode's link count */
inc_nlink(inode);
#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
inode->i_ctime = current_time(inode);
#else
inode_set_ctime_current(inode);
#endif
apfs_inode_join_transaction(inode->i_sb, inode);
if (inode->i_nlink == 2) {
/* A single link may lack sibling records, so create them now */
err = apfs_prepare_dentry_for_link(old_dentry);
if (err) {
apfs_err(sb, "failed to prepare original dentry");
goto fail;
}
}
err = apfs_create_dentry(dentry, inode);
if (err) {
apfs_err(sb, "failed to create new dentry");
goto fail;
}
return 0;
fail:
drop_nlink(inode);
return err;
}
int apfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = d_inode(old_dentry);
int err;
err = apfs_transaction_start(sb, APFS_TRANS_REG);
if (err)
return err;
err = __apfs_link(old_dentry, dentry);
if (err)
goto out_abort;
ihold(inode);
err = apfs_transaction_commit(sb);
if (err)
goto out_undo_link;
d_instantiate(dentry, inode);
return 0;
out_undo_link:
iput(inode);
__apfs_undo_link(dentry, inode);
out_abort:
apfs_transaction_abort(sb);
return err;
}
/**
* apfs_delete_sibling_link_rec - Delete the sibling link record for a dentry
* @dentry: the in-memory dentry
* @sibling_id: sibling id for this hardlink
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_delete_sibling_link_rec(struct dentry *dentry, u64 sibling_id)
{
struct super_block *sb = dentry->d_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct inode *inode = d_inode(dentry);
struct apfs_query *query = NULL;
int ret;
ASSERT(sibling_id);
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_sibling_link_key(apfs_ino(inode), sibling_id, &query->key);
query->flags |= APFS_QUERY_CAT | APFS_QUERY_EXACT;
ret = apfs_btree_query(sb, &query);
if (ret == -ENODATA) {
/* A dentry with a sibling id must have sibling records */
ret = -EFSCORRUPTED;
}
if (ret) {
apfs_err(sb, "query failed for ino 0x%llx, sibling 0x%llx", apfs_ino(inode), sibling_id);
goto fail;
}
ret = apfs_btree_remove(query);
if (ret)
apfs_err(sb, "removal failed for ino 0x%llx, sibling 0x%llx", apfs_ino(inode), sibling_id);
fail:
apfs_free_query(query);
return ret;
}
/**
* apfs_delete_sibling_map_rec - Delete the sibling map record for a dentry
* @dentry: the in-memory dentry
* @sibling_id: sibling id for this hardlink
*
* Returns 0 on success or a negative error code in case of failure.
*/
static int apfs_delete_sibling_map_rec(struct dentry *dentry, u64 sibling_id)
{
struct super_block *sb = dentry->d_sb;
struct apfs_sb_info *sbi = APFS_SB(sb);
struct apfs_query *query = NULL;
int ret;
ASSERT(sibling_id);
query = apfs_alloc_query(sbi->s_cat_root, NULL /* parent */);
if (!query)
return -ENOMEM;
apfs_init_sibling_map_key(sibling_id, &query->key);
query->flags |= APFS_QUERY_CAT | APFS_QUERY_EXACT;
ret = apfs_btree_query(sb, &query);
if (ret == -ENODATA) {
/* A dentry with a sibling id must have sibling records */
ret = -EFSCORRUPTED;
}
if (ret) {
apfs_err(sb, "query failed for sibling 0x%llx", sibling_id);
goto fail;
}
ret = apfs_btree_remove(query);
if (ret)
apfs_err(sb, "removal failed for sibling 0x%llx", sibling_id);
fail:
apfs_free_query(query);
return ret;
}
/**
* apfs_delete_dentry - Delete all records for a dentry
* @dentry: the in-memory dentry
*
* Deletes the dentry record itself, as well as the sibling records if they
* exist; also updates the child count for the parent inode. Returns 0 on
* success or a negative error code in case of failure.
*/
static int apfs_delete_dentry(struct dentry *dentry)
{
struct super_block *sb = dentry->d_sb;
struct inode *parent = d_inode(dentry->d_parent);
struct apfs_query *query;
struct apfs_drec drec;
int err;
query = apfs_dentry_lookup(parent, &dentry->d_name, &drec);
if (IS_ERR(query))
return PTR_ERR(query);
err = apfs_btree_remove(query);
apfs_free_query(query);
if (err) {
apfs_err(sb, "drec removal failed");
return err;
}