diff options
| author | Nick Piggin <npiggin@suse.de> | 2008-09-22 13:57:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-09-23 08:09:14 -0700 |
| commit | db203d53d474aa068984e409d807628f5841da1b (patch) | |
| tree | 7c4352513d8a108b916d2cbe16234346addf179c /mm | |
| parent | 2d4c8266774188cda7f7e612e6dfb8ad12c579d5 (diff) | |
| download | lwn-db203d53d474aa068984e409d807628f5841da1b.tar.gz lwn-db203d53d474aa068984e409d807628f5841da1b.zip | |
mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex
tiny-shmem calls do_truncate in shmem_file_setup. do_truncate takes
i_mutex, and shmem_file_setup is called with mmap_sem held. However
i_mutex nests outside mmap_sem.
Copy the code in shmem.c to avoid this problem.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/tiny-shmem.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/mm/tiny-shmem.c b/mm/tiny-shmem.c index ae532f501943..d17cb6f6ab10 100644 --- a/mm/tiny-shmem.c +++ b/mm/tiny-shmem.c @@ -65,31 +65,25 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) if (!dentry) goto put_memory; - error = -ENOSPC; - inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0); - if (!inode) - goto put_dentry; - - d_instantiate(dentry, inode); error = -ENFILE; - file = alloc_file(shm_mnt, dentry, FMODE_WRITE | FMODE_READ, - &ramfs_file_operations); + file = get_empty_filp(); if (!file) goto put_dentry; - inode->i_nlink = 0; /* It is unlinked */ - - /* notify everyone as to the change of file size */ - error = do_truncate(dentry, size, 0, file); - if (error < 0) + error = -ENOSPC; + inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0); + if (!inode) goto close_file; + d_instantiate(dentry, inode); + inode->i_size = size; + inode->i_nlink = 0; /* It is unlinked */ + init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ, + &ramfs_file_operations); return file; close_file: put_filp(file); - return ERR_PTR(error); - put_dentry: dput(dentry); put_memory: |