ubifs: Implement RENAME_EXCHANGE
Adds RENAME_EXCHANGE to UBIFS, the operation itself is completely disjunct from a regular rename() that's why we dispatch very early in ubifs_reaname(). RENAME_EXCHANGE used by the renameat2() system call allows the caller to exchange two paths atomically. Both paths have to exist and have to be on the same filesystem. Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Richard Weinberger
parent
9e0a1fff8d
commit
9ec64962af
|
|
@ -1095,11 +1095,6 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
|
|||
old_dentry, old_inode->i_ino, old_dir->i_ino,
|
||||
new_dentry, new_dir->i_ino, flags);
|
||||
|
||||
if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT))
|
||||
return -EINVAL;
|
||||
|
||||
ubifs_assert(inode_is_locked(old_dir));
|
||||
ubifs_assert(inode_is_locked(new_dir));
|
||||
if (unlink)
|
||||
ubifs_assert(inode_is_locked(new_inode));
|
||||
|
||||
|
|
@ -1283,6 +1278,64 @@ out_cancel:
|
|||
return err;
|
||||
}
|
||||
|
||||
static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
|
||||
struct inode *new_dir, struct dentry *new_dentry)
|
||||
{
|
||||
struct ubifs_info *c = old_dir->i_sb->s_fs_info;
|
||||
struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
|
||||
.dirtied_ino = 2 };
|
||||
int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
|
||||
struct inode *fst_inode = d_inode(old_dentry);
|
||||
struct inode *snd_inode = d_inode(new_dentry);
|
||||
struct timespec time;
|
||||
int err;
|
||||
|
||||
ubifs_assert(fst_inode && snd_inode);
|
||||
|
||||
lock_4_inodes(old_dir, new_dir, NULL, NULL);
|
||||
|
||||
time = ubifs_current_time(old_dir);
|
||||
fst_inode->i_ctime = time;
|
||||
snd_inode->i_ctime = time;
|
||||
old_dir->i_mtime = old_dir->i_ctime = time;
|
||||
new_dir->i_mtime = new_dir->i_ctime = time;
|
||||
|
||||
if (old_dir != new_dir) {
|
||||
if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
|
||||
inc_nlink(new_dir);
|
||||
drop_nlink(old_dir);
|
||||
}
|
||||
else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
|
||||
drop_nlink(new_dir);
|
||||
inc_nlink(old_dir);
|
||||
}
|
||||
}
|
||||
|
||||
err = ubifs_jnl_xrename(c, old_dir, old_dentry, new_dir, new_dentry,
|
||||
sync);
|
||||
|
||||
unlock_4_inodes(old_dir, new_dir, NULL, NULL);
|
||||
ubifs_release_budget(c, &req);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ubifs_rename2(struct inode *old_dir, struct dentry *old_dentry,
|
||||
struct inode *new_dir, struct dentry *new_dentry,
|
||||
unsigned int flags)
|
||||
{
|
||||
if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
|
||||
return -EINVAL;
|
||||
|
||||
ubifs_assert(inode_is_locked(old_dir));
|
||||
ubifs_assert(inode_is_locked(new_dir));
|
||||
|
||||
if (flags & RENAME_EXCHANGE)
|
||||
return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
|
||||
|
||||
return ubifs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
|
||||
}
|
||||
|
||||
int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
|
||||
struct kstat *stat)
|
||||
{
|
||||
|
|
@ -1331,7 +1384,7 @@ const struct inode_operations ubifs_dir_inode_operations = {
|
|||
.mkdir = ubifs_mkdir,
|
||||
.rmdir = ubifs_rmdir,
|
||||
.mknod = ubifs_mknod,
|
||||
.rename2 = ubifs_rename,
|
||||
.rename2 = ubifs_rename2,
|
||||
.setattr = ubifs_setattr,
|
||||
.getattr = ubifs_getattr,
|
||||
.setxattr = generic_setxattr,
|
||||
|
|
|
|||
|
|
@ -907,6 +907,147 @@ int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
|
|||
return err;
|
||||
}
|
||||
|
||||
/**
|
||||
* ubifs_jnl_xrename - cross rename two directory entries.
|
||||
* @c: UBIFS file-system description object
|
||||
* @fst_dir: parent inode of 1st directory entry to exchange
|
||||
* @fst_dentry: 1st directory entry to exchange
|
||||
* @snd_dir: parent inode of 2nd directory entry to exchange
|
||||
* @snd_dentry: 2nd directory entry to exchange
|
||||
* @sync: non-zero if the write-buffer has to be synchronized
|
||||
*
|
||||
* This function implements the cross rename operation which may involve
|
||||
* writing 2 inodes and 2 directory entries. It marks the written inodes as clean
|
||||
* and returns zero on success. In case of failure, a negative error code is
|
||||
* returned.
|
||||
*/
|
||||
int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
|
||||
const struct dentry *fst_dentry,
|
||||
const struct inode *snd_dir,
|
||||
const struct dentry *snd_dentry, int sync)
|
||||
{
|
||||
union ubifs_key key;
|
||||
struct ubifs_dent_node *dent1, *dent2;
|
||||
int err, dlen1, dlen2, lnum, offs, len, plen = UBIFS_INO_NODE_SZ;
|
||||
int aligned_dlen1, aligned_dlen2;
|
||||
int twoparents = (fst_dir != snd_dir);
|
||||
const struct inode *fst_inode = d_inode(fst_dentry);
|
||||
const struct inode *snd_inode = d_inode(snd_dentry);
|
||||
void *p;
|
||||
|
||||
dbg_jnl("dent '%pd' in dir ino %lu between dent '%pd' in dir ino %lu",
|
||||
fst_dentry, fst_dir->i_ino, snd_dentry, snd_dir->i_ino);
|
||||
|
||||
ubifs_assert(ubifs_inode(fst_dir)->data_len == 0);
|
||||
ubifs_assert(ubifs_inode(snd_dir)->data_len == 0);
|
||||
ubifs_assert(mutex_is_locked(&ubifs_inode(fst_dir)->ui_mutex));
|
||||
ubifs_assert(mutex_is_locked(&ubifs_inode(snd_dir)->ui_mutex));
|
||||
|
||||
dlen1 = UBIFS_DENT_NODE_SZ + snd_dentry->d_name.len + 1;
|
||||
dlen2 = UBIFS_DENT_NODE_SZ + fst_dentry->d_name.len + 1;
|
||||
aligned_dlen1 = ALIGN(dlen1, 8);
|
||||
aligned_dlen2 = ALIGN(dlen2, 8);
|
||||
|
||||
len = aligned_dlen1 + aligned_dlen2 + ALIGN(plen, 8);
|
||||
if (twoparents)
|
||||
len += plen;
|
||||
|
||||
dent1 = kmalloc(len, GFP_NOFS);
|
||||
if (!dent1)
|
||||
return -ENOMEM;
|
||||
|
||||
/* Make reservation before allocating sequence numbers */
|
||||
err = make_reservation(c, BASEHD, len);
|
||||
if (err)
|
||||
goto out_free;
|
||||
|
||||
/* Make new dent for 1st entry */
|
||||
dent1->ch.node_type = UBIFS_DENT_NODE;
|
||||
dent_key_init_flash(c, &dent1->key, snd_dir->i_ino, &snd_dentry->d_name);
|
||||
dent1->inum = cpu_to_le64(fst_inode->i_ino);
|
||||
dent1->type = get_dent_type(fst_inode->i_mode);
|
||||
dent1->nlen = cpu_to_le16(snd_dentry->d_name.len);
|
||||
memcpy(dent1->name, snd_dentry->d_name.name, snd_dentry->d_name.len);
|
||||
dent1->name[snd_dentry->d_name.len] = '\0';
|
||||
zero_dent_node_unused(dent1);
|
||||
ubifs_prep_grp_node(c, dent1, dlen1, 0);
|
||||
|
||||
/* Make new dent for 2nd entry */
|
||||
dent2 = (void *)dent1 + aligned_dlen1;
|
||||
dent2->ch.node_type = UBIFS_DENT_NODE;
|
||||
dent_key_init_flash(c, &dent2->key, fst_dir->i_ino, &fst_dentry->d_name);
|
||||
dent2->inum = cpu_to_le64(snd_inode->i_ino);
|
||||
dent2->type = get_dent_type(snd_inode->i_mode);
|
||||
dent2->nlen = cpu_to_le16(fst_dentry->d_name.len);
|
||||
memcpy(dent2->name, fst_dentry->d_name.name, fst_dentry->d_name.len);
|
||||
dent2->name[fst_dentry->d_name.len] = '\0';
|
||||
zero_dent_node_unused(dent2);
|
||||
ubifs_prep_grp_node(c, dent2, dlen2, 0);
|
||||
|
||||
p = (void *)dent2 + aligned_dlen2;
|
||||
if (!twoparents)
|
||||
pack_inode(c, p, fst_dir, 1);
|
||||
else {
|
||||
pack_inode(c, p, fst_dir, 0);
|
||||
p += ALIGN(plen, 8);
|
||||
pack_inode(c, p, snd_dir, 1);
|
||||
}
|
||||
|
||||
err = write_head(c, BASEHD, dent1, len, &lnum, &offs, sync);
|
||||
if (err)
|
||||
goto out_release;
|
||||
if (!sync) {
|
||||
struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
|
||||
|
||||
ubifs_wbuf_add_ino_nolock(wbuf, fst_dir->i_ino);
|
||||
ubifs_wbuf_add_ino_nolock(wbuf, snd_dir->i_ino);
|
||||
}
|
||||
release_head(c, BASEHD);
|
||||
|
||||
dent_key_init(c, &key, snd_dir->i_ino, &snd_dentry->d_name);
|
||||
err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &snd_dentry->d_name);
|
||||
if (err)
|
||||
goto out_ro;
|
||||
|
||||
offs += aligned_dlen1;
|
||||
dent_key_init(c, &key, fst_dir->i_ino, &fst_dentry->d_name);
|
||||
err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &fst_dentry->d_name);
|
||||
if (err)
|
||||
goto out_ro;
|
||||
|
||||
offs += aligned_dlen2;
|
||||
|
||||
ino_key_init(c, &key, fst_dir->i_ino);
|
||||
err = ubifs_tnc_add(c, &key, lnum, offs, plen);
|
||||
if (err)
|
||||
goto out_ro;
|
||||
|
||||
if (twoparents) {
|
||||
offs += ALIGN(plen, 8);
|
||||
ino_key_init(c, &key, snd_dir->i_ino);
|
||||
err = ubifs_tnc_add(c, &key, lnum, offs, plen);
|
||||
if (err)
|
||||
goto out_ro;
|
||||
}
|
||||
|
||||
finish_reservation(c);
|
||||
|
||||
mark_inode_clean(c, ubifs_inode(fst_dir));
|
||||
if (twoparents)
|
||||
mark_inode_clean(c, ubifs_inode(snd_dir));
|
||||
kfree(dent1);
|
||||
return 0;
|
||||
|
||||
out_release:
|
||||
release_head(c, BASEHD);
|
||||
out_ro:
|
||||
ubifs_ro_mode(c, err);
|
||||
finish_reservation(c);
|
||||
out_free:
|
||||
kfree(dent1);
|
||||
return err;
|
||||
}
|
||||
|
||||
/**
|
||||
* ubifs_jnl_rename - rename a directory entry.
|
||||
* @c: UBIFS file-system description object
|
||||
|
|
|
|||
|
|
@ -1521,6 +1521,10 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
|
|||
const union ubifs_key *key, const void *buf, int len);
|
||||
int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
|
||||
int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
|
||||
int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
|
||||
const struct dentry *fst_dentry,
|
||||
const struct inode *snd_dir,
|
||||
const struct dentry *snd_dentry, int sync);
|
||||
int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
|
||||
const struct dentry *old_dentry,
|
||||
const struct inode *new_dir,
|
||||
|
|
|
|||
Loading…
Reference in New Issue