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authorAl Viro <viro@zeniv.linux.org.uk>2018-05-04 08:23:01 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:48:52 +0200
commit03bb7588942a38623f108b3302c2d1aebb525696 (patch)
tree7221b546da232e805a3a91fc57ba090789ccd1c9 /fs
parent1a54258e10b23c6877d699ef6cf3f2b02b17b87f (diff)
do d_instantiate/unlock_new_inode combinations safely
commit 1e2e547a93a00ebc21582c06ca3c6cfea2a309ee upstream. For anything NFS-exported we do _not_ want to unlock new inode before it has grown an alias; original set of fixes got the ordering right, but missed the nasty complication in case of lockdep being enabled - unlock_new_inode() does lockdep_annotate_inode_mutex_key(inode) which can only be done before anyone gets a chance to touch ->i_mutex. Unfortunately, flipping the order and doing unlock_new_inode() before d_instantiate() opens a window when mkdir can race with open-by-fhandle on a guessed fhandle, leading to multiple aliases for a directory inode and all the breakage that follows from that. Correct solution: a new primitive (d_instantiate_new()) combining these two in the right order - lockdep annotate, then d_instantiate(), then the rest of unlock_new_inode(). All combinations of d_instantiate() with unlock_new_inode() should be converted to that. Cc: stable@kernel.org # 2.6.29 and later Tested-by: Mike Marshall <hubcap@omnibond.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/inode.c16
-rw-r--r--fs/dcache.c22
-rw-r--r--fs/ecryptfs/inode.c3
-rw-r--r--fs/ext2/namei.c6
-rw-r--r--fs/ext4/namei.c6
-rw-r--r--fs/f2fs/namei.c12
-rw-r--r--fs/jffs2/dir.c12
-rw-r--r--fs/jfs/namei.c12
-rw-r--r--fs/nilfs2/namei.c6
-rw-r--r--fs/reiserfs/namei.c12
-rw-r--r--fs/udf/namei.c6
-rw-r--r--fs/ufs/namei.c6
12 files changed, 53 insertions, 66 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 81b5a461d94e..1f01a8172308 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6413,8 +6413,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
goto out_unlock_inode;
} else {
btrfs_update_inode(trans, root, inode);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
}
out_unlock:
@@ -6489,8 +6488,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
goto out_unlock_inode;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
@@ -6633,12 +6631,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
if (err)
goto out_fail_inode;
- d_instantiate(dentry, inode);
- /*
- * mkdir is special. We're unlocking after we call d_instantiate
- * to avoid a race with nfsd calling d_instantiate.
- */
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
drop_on_err = 0;
out_fail:
@@ -9789,8 +9782,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
goto out_unlock_inode;
}
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
diff --git a/fs/dcache.c b/fs/dcache.c
index 751a0d88f049..250c1222e30c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1897,6 +1897,28 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
EXPORT_SYMBOL(d_instantiate_unique);
+/*
+ * This should be equivalent to d_instantiate() + unlock_new_inode(),
+ * with lockdep-related part of unlock_new_inode() done before
+ * anything else. Use that instead of open-coding d_instantiate()/
+ * unlock_new_inode() combinations.
+ */
+void d_instantiate_new(struct dentry *entry, struct inode *inode)
+{
+ BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
+ BUG_ON(!inode);
+ lockdep_annotate_inode_mutex_key(inode);
+ security_d_instantiate(entry, inode);
+ spin_lock(&inode->i_lock);
+ __d_instantiate(entry, inode);
+ WARN_ON(!(inode->i_state & I_NEW));
+ inode->i_state &= ~I_NEW;
+ smp_mb();
+ wake_up_bit(&inode->i_state, __I_NEW);
+ spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(d_instantiate_new);
+
/**
* d_instantiate_no_diralias - instantiate a non-aliased dentry
* @entry: dentry to complete
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index e2e47ba5d313..844d0c4da84f 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -287,8 +287,7 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
iput(ecryptfs_inode);
goto out;
}
- unlock_new_inode(ecryptfs_inode);
- d_instantiate(ecryptfs_dentry, ecryptfs_inode);
+ d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
out:
return rc;
}
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 3267a80dbbe2..da3d40ef1668 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -40,8 +40,7 @@ static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = ext2_add_link(dentry, inode);
if (!err) {
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
@@ -267,8 +266,7 @@ static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
if (err)
goto out_fail;
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
out:
return err;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 32960b3ecd4f..97472088d65a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2429,8 +2429,7 @@ static int ext4_add_nondir(handle_t *handle,
int err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
}
drop_nlink(inode);
@@ -2669,8 +2668,7 @@ out_clear_inode:
err = ext4_mark_inode_dirty(handle, dir);
if (err)
goto out_clear_inode;
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 484df6850747..e5553cd8fe4e 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -150,8 +150,7 @@ static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
alloc_nid_done(sbi, ino);
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
if (IS_DIRSYNC(dir))
f2fs_sync_fs(sbi->sb, 1);
@@ -399,8 +398,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
err = page_symlink(inode, p_str, p_len);
err_out:
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
/*
* Let's flush symlink data in order to avoid broken symlink as much as
@@ -454,8 +452,7 @@ static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
alloc_nid_done(sbi, inode->i_ino);
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
if (IS_DIRSYNC(dir))
f2fs_sync_fs(sbi->sb, 1);
@@ -499,8 +496,7 @@ static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
alloc_nid_done(sbi, inode->i_ino);
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
if (IS_DIRSYNC(dir))
f2fs_sync_fs(sbi->sb, 1);
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 30c4c9ebb693..e27317169697 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -207,8 +207,7 @@ static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
__func__, inode->i_ino, inode->i_mode, inode->i_nlink,
f->inocache->pino_nlink, inode->i_mapping->nrpages);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
fail:
@@ -428,8 +427,7 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
mutex_unlock(&dir_f->sem);
jffs2_complete_reservation(c);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
fail:
@@ -573,8 +571,7 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode
mutex_unlock(&dir_f->sem);
jffs2_complete_reservation(c);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
fail:
@@ -745,8 +742,7 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode
mutex_unlock(&dir_f->sem);
jffs2_complete_reservation(c);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
fail:
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 9d7551f5c32a..f217ae750adb 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -178,8 +178,7 @@ static int jfs_create(struct inode *dip, struct dentry *dentry, umode_t mode,
unlock_new_inode(ip);
iput(ip);
} else {
- unlock_new_inode(ip);
- d_instantiate(dentry, ip);
+ d_instantiate_new(dentry, ip);
}
out2:
@@ -313,8 +312,7 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
unlock_new_inode(ip);
iput(ip);
} else {
- unlock_new_inode(ip);
- d_instantiate(dentry, ip);
+ d_instantiate_new(dentry, ip);
}
out2:
@@ -1058,8 +1056,7 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
unlock_new_inode(ip);
iput(ip);
} else {
- unlock_new_inode(ip);
- d_instantiate(dentry, ip);
+ d_instantiate_new(dentry, ip);
}
out2:
@@ -1443,8 +1440,7 @@ static int jfs_mknod(struct inode *dir, struct dentry *dentry,
unlock_new_inode(ip);
iput(ip);
} else {
- unlock_new_inode(ip);
- d_instantiate(dentry, ip);
+ d_instantiate_new(dentry, ip);
}
out1:
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index c9a1a491aa91..cd7f5b0abe84 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -50,8 +50,7 @@ static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = nilfs_add_link(dentry, inode);
if (!err) {
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
@@ -246,8 +245,7 @@ static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
goto out_fail;
nilfs_mark_inode_dirty(inode);
- d_instantiate(dentry, inode);
- unlock_new_inode(inode);
+ d_instantiate_new(dentry, inode);
out:
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 3ebc70167e41..eb611bdd4725 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -687,8 +687,7 @@ static int reiserfs_create(struct inode *dir, struct dentry *dentry, umode_t mod
reiserfs_update_inode_transaction(inode);
reiserfs_update_inode_transaction(dir);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
retval = journal_end(&th);
out_failed:
@@ -771,8 +770,7 @@ static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode
goto out_failed;
}
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
retval = journal_end(&th);
out_failed:
@@ -871,8 +869,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
/* the above add_entry did not update dir's stat data */
reiserfs_update_sd(&th, dir);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
retval = journal_end(&th);
out_failed:
reiserfs_write_unlock(dir->i_sb);
@@ -1186,8 +1183,7 @@ static int reiserfs_symlink(struct inode *parent_dir,
goto out_failed;
}
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
retval = journal_end(&th);
out_failed:
reiserfs_write_unlock(parent_dir->i_sb);
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index c97b5a8d1e24..f34c545f4e54 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -611,8 +611,7 @@ static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
if (fibh.sbh != fibh.ebh)
brelse(fibh.ebh);
brelse(fibh.sbh);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
}
@@ -722,8 +721,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
inc_nlink(dir);
dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
mark_inode_dirty(dir);
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
if (fibh.sbh != fibh.ebh)
brelse(fibh.ebh);
brelse(fibh.sbh);
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 47966554317c..2ec7689c25cf 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -38,8 +38,7 @@ static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = ufs_add_link(dentry, inode);
if (!err) {
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
@@ -191,8 +190,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
if (err)
goto out_fail;
- unlock_new_inode(inode);
- d_instantiate(dentry, inode);
+ d_instantiate_new(dentry, inode);
return 0;
out_fail: