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authorAl Viro <viro@zeniv.linux.org.uk>2014-09-04 09:38:11 -0400
committerJan Kara <jack@suse.cz>2014-09-04 21:37:41 +0200
commitb231509616feb911c2a7a8814d58c0014ef5b17f (patch)
treeda9d231b09ee58637fb671310291432929c9db56
parentd2be51cb34dc501791f3b8c01a99a3f2064bd8d1 (diff)
downloadblackbird-op-linux-b231509616feb911c2a7a8814d58c0014ef5b17f.tar.gz
blackbird-op-linux-b231509616feb911c2a7a8814d58c0014ef5b17f.zip
udf: fix the udf_iget() vs. udf_new_inode() races
Currently udf_iget() (triggered by NFS) can race with udf_new_inode() leading to two inode structures with the same inode number: nfsd: iget_locked() creates inode nfsd: try to read from disk, block on that. udf_new_inode(): allocate inode with that inumber udf_new_inode(): insert it into icache, set it up and dirty udf_write_inode(): write inode into buffer cache nfsd: get CPU again, look into buffer cache, see nice and sane on-disk inode, set the in-core inode from it Fix the problem by putting inode into icache in locked state (I_NEW set) and unlocking it only after it's fully set up. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/udf/ialloc.c7
-rw-r--r--fs/udf/namei.c7
2 files changed, 13 insertions, 1 deletions
diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c
index 647370d70175..598f33bdcd26 100644
--- a/fs/udf/ialloc.c
+++ b/fs/udf/ialloc.c
@@ -124,7 +124,12 @@ struct inode *udf_new_inode(struct inode *dir, umode_t mode, int *err)
iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
inode->i_mtime = inode->i_atime = inode->i_ctime =
iinfo->i_crtime = current_fs_time(inode->i_sb);
- insert_inode_hash(inode);
+ if (unlikely(insert_inode_locked(inode) < 0)) {
+ make_bad_inode(inode);
+ iput(inode);
+ *err = -EIO;
+ return NULL;
+ }
mark_inode_dirty(inode);
*err = 0;
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index abec86466735..d106fdd1bef7 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -559,6 +559,7 @@ static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err);
if (unlikely(!fi)) {
inode_dec_link_count(inode);
+ unlock_new_inode(inode);
iput(inode);
return err;
}
@@ -572,6 +573,7 @@ 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);
return 0;
@@ -619,6 +621,7 @@ static int udf_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
mark_inode_dirty(inode);
d_tmpfile(dentry, inode);
+ unlock_new_inode(inode);
return 0;
}
@@ -660,6 +663,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
fi = udf_add_entry(inode, NULL, &fibh, &cfi, &err);
if (!fi) {
inode_dec_link_count(inode);
+ unlock_new_inode(inode);
iput(inode);
goto out;
}
@@ -678,6 +682,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
if (!fi) {
clear_nlink(inode);
mark_inode_dirty(inode);
+ unlock_new_inode(inode);
iput(inode);
goto out;
}
@@ -689,6 +694,7 @@ 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);
if (fibh.sbh != fibh.ebh)
brelse(fibh.ebh);
@@ -996,6 +1002,7 @@ out:
out_no_entry:
up_write(&iinfo->i_data_sem);
inode_dec_link_count(inode);
+ unlock_new_inode(inode);
iput(inode);
goto out;
}
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