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-rw-r--r--target/linux/generic/patches-4.4/052-03-ubifs-Implement-RENAME_EXCHANGE.patch267
1 files changed, 267 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/052-03-ubifs-Implement-RENAME_EXCHANGE.patch b/target/linux/generic/patches-4.4/052-03-ubifs-Implement-RENAME_EXCHANGE.patch
new file mode 100644
index 0000000000..20856c347d
--- /dev/null
+++ b/target/linux/generic/patches-4.4/052-03-ubifs-Implement-RENAME_EXCHANGE.patch
@@ -0,0 +1,267 @@
+From: Richard Weinberger <richard@nod.at>
+Date: Tue, 13 Sep 2016 16:18:57 +0200
+Subject: [PATCH] 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>
+---
+
+--- a/fs/ubifs/dir.c
++++ b/fs/ubifs/dir.c
+@@ -1095,11 +1095,6 @@ static int ubifs_rename(struct inode *ol
+ 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(mutex_is_locked(&old_dir->i_mutex));
+- ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
+ if (unlink)
+ ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
+
+@@ -1284,6 +1279,64 @@ 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(mutex_is_locked(&old_dir->i_mutex));
++ ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
++
++ 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)
+ {
+@@ -1332,7 +1385,7 @@ const struct inode_operations ubifs_dir_
+ .mkdir = ubifs_mkdir,
+ .rmdir = ubifs_rmdir,
+ .mknod = ubifs_mknod,
+- .rename2 = ubifs_rename,
++ .rename2 = ubifs_rename2,
+ .setattr = ubifs_setattr,
+ .getattr = ubifs_getattr,
+ .setxattr = ubifs_setxattr,
+--- a/fs/ubifs/journal.c
++++ b/fs/ubifs/journal.c
+@@ -908,6 +908,147 @@ int ubifs_jnl_delete_inode(struct ubifs_
+ }
+
+ /**
++ * 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
+ * @old_dir: parent inode of directory entry to rename
+--- a/fs/ubifs/ubifs.h
++++ b/fs/ubifs/ubifs.h
+@@ -1544,6 +1544,10 @@ int ubifs_jnl_write_data(struct ubifs_in
+ 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,
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