mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-23 07:22:33 +00:00
268 lines
8.5 KiB
Diff
268 lines
8.5 KiB
Diff
|
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,
|