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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2005-06-13 11:14:01 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-13 10:33:02 -0700 |
| commit | 980802e311088fda56c16650589faa4597c695fb (patch) | |
| tree | 37092823ea5ad1203253ee5e54e7c9631df4087d /fs | |
| parent | c22fa3acbc2ef79ea57217643f6cd6d226963069 (diff) | |
| download | linux-980802e311088fda56c16650589faa4597c695fb.tar.gz linux-980802e311088fda56c16650589faa4597c695fb.tar.bz2 linux-980802e311088fda56c16650589faa4597c695fb.zip | |
[PATCH] NFS: Ensure that we revalidate the cached file length for llseek(SEEK_END)
This fixes a data corruption error for mail delivery applications that
expect to be able to do posix locking and then append writes on NFS.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/file.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c index f06eee6dcff5..55c907592490 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -37,6 +37,7 @@ static int nfs_file_open(struct inode *, struct file *); static int nfs_file_release(struct inode *, struct file *); +static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin); static int nfs_file_mmap(struct file *, struct vm_area_struct *); static ssize_t nfs_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *); static ssize_t nfs_file_read(struct kiocb *, char __user *, size_t, loff_t); @@ -48,7 +49,7 @@ static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl); static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl); struct file_operations nfs_file_operations = { - .llseek = remote_llseek, + .llseek = nfs_file_llseek, .read = do_sync_read, .write = do_sync_write, .aio_read = nfs_file_read, @@ -114,6 +115,45 @@ nfs_file_release(struct inode *inode, struct file *filp) return NFS_PROTO(inode)->file_release(inode, filp); } +/** + * nfs_revalidate_size - Revalidate the file size + * @inode - pointer to inode struct + * @file - pointer to struct file + * + * Revalidates the file length. This is basically a wrapper around + * nfs_revalidate_inode() that takes into account the fact that we may + * have cached writes (in which case we don't care about the server's + * idea of what the file length is), or O_DIRECT (in which case we + * shouldn't trust the cache). + */ +static int nfs_revalidate_file_size(struct inode *inode, struct file *filp) +{ + struct nfs_server *server = NFS_SERVER(inode); + struct nfs_inode *nfsi = NFS_I(inode); + + if (server->flags & NFS_MOUNT_NOAC) + goto force_reval; + if (filp->f_flags & O_DIRECT) + goto force_reval; + if (nfsi->npages != 0) + return 0; + return nfs_revalidate_inode(server, inode); +force_reval: + return __nfs_revalidate_inode(server, inode); +} + +static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin) +{ + /* origin == SEEK_END => we must revalidate the cached file length */ + if (origin == 2) { + struct inode *inode = filp->f_mapping->host; + int retval = nfs_revalidate_file_size(inode, filp); + if (retval < 0) + return (loff_t)retval; + } + return remote_llseek(filp, offset, origin); +} + /* * Flush all dirty pages, and check for write errors. * |