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Commit 2d2d3f1e authored by Al Viro's avatar Al Viro Committed by Greg Kroah-Hartman
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do d_instantiate/unlock_new_inode combinations safely 

commit 1e2e547a 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: default avatarMike Marshall <hubcap@omnibond.com>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 416808fb
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Inline Side-by-side
Showing with 57 additions and 72 deletions
fs/btrfs/inode.c
View file @ 2d2d3f1e
......@@ -6491,8 +6491,7 @@ 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:
......@@ -6567,8 +6566,7 @@ 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);
......@@ -6711,12 +6709,7 @@ 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:
......@@ -10354,8 +10347,7 @@ 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);
......
fs/dcache.c
View file @ 2d2d3f1e
......@@ -1859,6 +1859,28 @@ void d_instantiate(struct dentry *entry, struct inode * inode)
}
EXPORT_SYMBOL(d_instantiate);
/*
* 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
......
fs/ecryptfs/inode.c
View file @ 2d2d3f1e
......@@ -284,8 +284,7 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
iget_failed(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;
}
......
fs/ext2/namei.c
View file @ 2d2d3f1e
......@@ -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);
......@@ -268,8 +267,7 @@ 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;
......
fs/ext4/namei.c
View file @ 2d2d3f1e
......@@ -2442,8 +2442,7 @@ 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);
......@@ -2682,8 +2681,7 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
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);
......
fs/f2fs/namei.c
View file @ 2d2d3f1e
......@@ -158,8 +158,7 @@ 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);
......@@ -464,8 +463,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
err = page_symlink(inode, disk_link.name, disk_link.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
......@@ -519,8 +517,7 @@ 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);
......@@ -564,8 +561,7 @@ 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);
......
fs/jffs2/dir.c
View file @ 2d2d3f1e
......@@ -209,8 +209,7 @@ 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:
......@@ -430,8 +429,7 @@ 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:
......@@ -575,8 +573,7 @@ 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:
......@@ -747,8 +744,7 @@ 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:
......
fs/jfs/namei.c
View file @ 2d2d3f1e
......@@ -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:
......@@ -1059,8 +1057,7 @@ 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:
......@@ -1447,8 +1444,7 @@ 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:
......
fs/nilfs2/namei.c
View file @ 2d2d3f1e
......@@ -46,8 +46,7 @@ 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);
......@@ -243,8 +242,7 @@ 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);
......
fs/orangefs/namei.c
View file @ 2d2d3f1e
......@@ -70,8 +70,7 @@ static int orangefs_create(struct inode *dir,
get_khandle_from_ino(inode),
dentry);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
d_instantiate_new(dentry, inode);
orangefs_set_timeout(dentry);
ORANGEFS_I(inode)->getattr_time = jiffies - 1;
......@@ -318,8 +317,7 @@ static int orangefs_symlink(struct inode *dir,
"Assigned symlink inode new number of %pU\n",
get_khandle_from_ino(inode));
d_instantiate(dentry, inode);
unlock_new_inode(inode);
d_instantiate_new(dentry, inode);
orangefs_set_timeout(dentry);
ORANGEFS_I(inode)->getattr_time = jiffies - 1;
......@@ -382,8 +380,7 @@ static int orangefs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
"Assigned dir inode new number of %pU\n",
get_khandle_from_ino(inode));
d_instantiate(dentry, inode);
unlock_new_inode(inode);
d_instantiate_new(dentry, inode);
orangefs_set_timeout(dentry);
ORANGEFS_I(inode)->getattr_time = jiffies - 1;
......
fs/reiserfs/namei.c
View file @ 2d2d3f1e
......@@ -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);
......@@ -1187,8 +1184,7 @@ 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);
......
fs/udf/namei.c
View file @ 2d2d3f1e
......@@ -621,8 +621,7 @@ 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;
}
......@@ -732,8 +731,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
inc_nlink(dir);
dir->i_ctime = dir->i_mtime = current_time(dir);
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);
......
fs/ufs/namei.c
View file @ 2d2d3f1e
......@@ -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);
......@@ -192,8 +191,7 @@ 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:
......
include/linux/dcache.h
View file @ 2d2d3f1e
......@@ -219,6 +219,7 @@ extern seqlock_t rename_lock;
* These are the low-level FS interfaces to the dcache..
*/
extern void d_instantiate(struct dentry *, struct inode *);
extern void d_instantiate_new(struct dentry *, struct inode *);
extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
extern int d_instantiate_no_diralias(struct dentry *, struct inode *);
extern void __d_drop(struct dentry *dentry);
......
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