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author | Mike Kravetz <mike.kravetz@oracle.com> | 2019-11-30 17:56:34 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-01 12:59:08 -0800 |
commit | 8fc312b32b25c6b0a8b46fab4df8c68df5af1223 (patch) | |
tree | 8d263f997d3cf396de30dadd86a3bb4526e82713 /fs/hugetlbfs | |
parent | 552546366a30d88bd1d6f5efe848b2ab50fd57e5 (diff) | |
download | lwn-8fc312b32b25c6b0a8b46fab4df8c68df5af1223.tar.gz lwn-8fc312b32b25c6b0a8b46fab4df8c68df5af1223.zip |
mm/hugetlbfs: fix error handling when setting up mounts
It is assumed that the hugetlbfs_vfsmount[] array will contain either a
valid vfsmount pointer or NULL for each hstate after initialization.
Changes made while converting to use fs_context broke this assumption.
While fixing the hugetlbfs_vfsmount issue, it was discovered that
init_hugetlbfs_fs never did correctly clean up when encountering a vfs
mount error.
It was found during code inspection. A small memory allocation failure
would be the most likely cause of taking a error path with the bug.
This is unlikely to happen as this is early init code.
Link: http://lkml.kernel.org/r/94b6244d-2c24-e269-b12c-e3ba694b242d@oracle.com
Reported-by: Chengguang Xu <cgxu519@mykernel.net>
Fixes: 32021982a324 ("hugetlbfs: Convert to fs_context")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/hugetlbfs')
-rw-r--r-- | fs/hugetlbfs/inode.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 6e5eadee6b0d..0cacf99922cc 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -1461,28 +1461,41 @@ static int __init init_hugetlbfs_fs(void) sizeof(struct hugetlbfs_inode_info), 0, SLAB_ACCOUNT, init_once); if (hugetlbfs_inode_cachep == NULL) - goto out2; + goto out; error = register_filesystem(&hugetlbfs_fs_type); if (error) - goto out; + goto out_free; + /* default hstate mount is required */ + mnt = mount_one_hugetlbfs(&hstates[default_hstate_idx]); + if (IS_ERR(mnt)) { + error = PTR_ERR(mnt); + goto out_unreg; + } + hugetlbfs_vfsmount[default_hstate_idx] = mnt; + + /* other hstates are optional */ i = 0; for_each_hstate(h) { + if (i == default_hstate_idx) + continue; + mnt = mount_one_hugetlbfs(h); - if (IS_ERR(mnt) && i == 0) { - error = PTR_ERR(mnt); - goto out; - } - hugetlbfs_vfsmount[i] = mnt; + if (IS_ERR(mnt)) + hugetlbfs_vfsmount[i] = NULL; + else + hugetlbfs_vfsmount[i] = mnt; i++; } return 0; - out: + out_unreg: + (void)unregister_filesystem(&hugetlbfs_fs_type); + out_free: kmem_cache_destroy(hugetlbfs_inode_cachep); - out2: + out: return error; } fs_initcall(init_hugetlbfs_fs) |