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author | Al Viro <viro@zeniv.linux.org.uk> | 2018-05-04 08:23:01 -0400 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2018-10-21 08:46:03 +0100 |
commit | d6fc6d7915322e3cc58a5ce919fe0c7a18d59be6 (patch) | |
tree | 6c450a33087dc86c429bdd2c5cd06255895bafcf | |
parent | 78cf460924e0a19633322c21609b606ab65c73a1 (diff) | |
download | linux-stable-d6fc6d7915322e3cc58a5ce919fe0c7a18d59be6.tar.gz linux-stable-d6fc6d7915322e3cc58a5ce919fe0c7a18d59be6.tar.bz2 linux-stable-d6fc6d7915322e3cc58a5ce919fe0c7a18d59be6.zip |
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.
Tested-by: Mike Marshall <hubcap@omnibond.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16:
- Drop changes in orangefs
- Apply similar change to ext3
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r-- | fs/btrfs/inode.c | 16 | ||||
-rw-r--r-- | fs/dcache.c | 22 | ||||
-rw-r--r-- | fs/ecryptfs/inode.c | 3 | ||||
-rw-r--r-- | fs/ext2/namei.c | 6 | ||||
-rw-r--r-- | fs/ext3/namei.c | 6 | ||||
-rw-r--r-- | fs/ext4/namei.c | 6 | ||||
-rw-r--r-- | fs/f2fs/namei.c | 12 | ||||
-rw-r--r-- | fs/jffs2/dir.c | 12 | ||||
-rw-r--r-- | fs/jfs/namei.c | 12 | ||||
-rw-r--r-- | fs/nilfs2/namei.c | 6 | ||||
-rw-r--r-- | fs/reiserfs/namei.c | 12 | ||||
-rw-r--r-- | fs/udf/namei.c | 6 | ||||
-rw-r--r-- | fs/ufs/namei.c | 6 | ||||
-rw-r--r-- | include/linux/dcache.h | 1 |
14 files changed, 56 insertions, 70 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 33c388fad66d..6d716c051b24 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6019,8 +6019,7 @@ 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: @@ -6096,8 +6095,7 @@ 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); @@ -6238,12 +6236,7 @@ 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: @@ -8926,8 +8919,7 @@ 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 e1380da5c183..7befa3a373cf 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1680,6 +1680,28 @@ 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_unique - instantiate a non-aliased dentry * @entry: dentry to instantiate diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 8bc9ec714467..9819a544a160 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -298,8 +298,7 @@ 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 c268d0af1db9..b31b12ddb99b 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -41,8 +41,7 @@ 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); @@ -265,8 +264,7 @@ 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/ext3/namei.c b/fs/ext3/namei.c index f197736dccfa..e0053011ce6e 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -1671,8 +1671,7 @@ static int ext3_add_nondir(handle_t *handle, int err = ext3_add_entry(handle, dentry, inode); if (!err) { ext3_mark_inode_dirty(handle, inode); - unlock_new_inode(inode); - d_instantiate(dentry, inode); + d_instantiate_new(dentry, inode); return 0; } drop_nlink(inode); @@ -1873,8 +1872,7 @@ out_clear_inode: if (err) goto out_clear_inode; - unlock_new_inode(inode); - d_instantiate(dentry, inode); + d_instantiate_new(dentry, inode); out_stop: brelse(dir_block); ext3_journal_stop(handle); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 6d6848a9891b..7edf1bee591b 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2227,8 +2227,7 @@ 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); @@ -2466,8 +2465,7 @@ 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 0b9108c8b5d8..53cb0731e287 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -127,8 +127,7 @@ 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); return 0; out: handle_failed_inode(inode); @@ -260,8 +259,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, err = page_symlink(inode, symname, symlen); alloc_nid_done(sbi, inode->i_ino); - d_instantiate(dentry, inode); - unlock_new_inode(inode); + d_instantiate_new(dentry, inode); return err; out: handle_failed_inode(inode); @@ -294,8 +292,7 @@ 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); return 0; @@ -340,8 +337,7 @@ static int f2fs_mknod(struct inode *dir, struct dentry *dentry, f2fs_unlock_op(sbi); alloc_nid_done(sbi, inode->i_ino); - d_instantiate(dentry, inode); - unlock_new_inode(inode); + d_instantiate_new(dentry, inode); return 0; out: handle_failed_inode(inode); diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c index 938556025d64..1313e32f66ea 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: @@ -427,8 +426,7 @@ 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: @@ -572,8 +570,7 @@ 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: diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c index d59c7defb1ef..d071500a2afa 100644 --- a/fs/jfs/namei.c +++ b/fs/jfs/namei.c @@ -176,8 +176,7 @@ 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: @@ -309,8 +308,7 @@ 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: @@ -1043,8 +1041,7 @@ 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: @@ -1424,8 +1421,7 @@ 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 0f84b257932c..da65882b5407 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); @@ -249,8 +248,7 @@ 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 cd11358b10c7..2e9d82f7c35c 100644 --- a/fs/reiserfs/namei.c +++ b/fs/reiserfs/namei.c @@ -682,8 +682,7 @@ 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: @@ -763,8 +762,7 @@ 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: @@ -857,8 +855,7 @@ 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); @@ -1162,8 +1159,7 @@ 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 3a3e444c39ec..2b5dd8043af5 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -576,8 +576,7 @@ 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; } @@ -697,8 +696,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL); inc_nlink(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); diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c index e8ee2985b068..2f446e79de9f 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); @@ -212,8 +211,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) goto out_fail; unlock_ufs(dir->i_sb); - unlock_new_inode(inode); - d_instantiate(dentry, inode); + d_instantiate_new(dentry, inode); out: return err; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index aa586fb8ee1a..de26c9463a5f 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -234,6 +234,7 @@ static inline int dname_external(const struct dentry *dentry) * 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 struct dentry * d_materialise_unique(struct dentry *, struct inode *); extern int d_instantiate_no_diralias(struct dentry *, struct inode *); |