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authorJeff Layton <jlayton@redhat.com>2012-03-23 14:40:56 -0400
committerJeff Layton <jlayton@redhat.com>2012-03-23 14:40:56 -0400
commit597b027f694481ffeebcffe634c24b807198d46c (patch)
tree2dce2da017aa89c9e7465014ffa7aced11393b28
parente9492871fb0546f1b73f309d9e8c0f030bfdfdca (diff)
downloadop-kernel-dev-597b027f694481ffeebcffe634c24b807198d46c.zip
op-kernel-dev-597b027f694481ffeebcffe634c24b807198d46c.tar.gz
cifs: call cifs_update_eof with i_lock held
cifs_update_eof has the potential to be racy if multiple threads are trying to modify it at the same time. Protect modifications of the server_eof value with the inode->i_lock. Signed-off-by: Jeff Layton <jlayton@redhat.com>
-rw-r--r--fs/cifs/cifsglob.h2
-rw-r--r--fs/cifs/cifssmb.c2
-rw-r--r--fs/cifs/file.c9
3 files changed, 11 insertions, 2 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d7e39b0..4ff6313 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -626,7 +626,7 @@ struct cifsInodeInfo {
bool delete_pending; /* DELETE_ON_CLOSE is set */
bool invalid_mapping; /* pagecache is invalid */
unsigned long time; /* jiffies of last update of inode */
- u64 server_eof; /* current file size on server */
+ u64 server_eof; /* current file size on server -- protected by i_lock */
u64 uniqueid; /* server inode number */
u64 createtime; /* creation time on server */
#ifdef CONFIG_CIFS_FSCACHE
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 5ec0b90..b63bf5f 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2044,7 +2044,9 @@ cifs_writev_complete(struct work_struct *work)
int i = 0;
if (wdata->result == 0) {
+ spin_lock(&inode->i_lock);
cifs_update_eof(CIFS_I(inode), wdata->offset, wdata->bytes);
+ spin_unlock(&inode->i_lock);
cifs_stats_bytes_written(tlink_tcon(wdata->cfile->tlink),
wdata->bytes);
} else if (wdata->sync_mode == WB_SYNC_ALL && wdata->result == -EAGAIN)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 58ac0f0..6883b08 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1399,7 +1399,10 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
return rc;
}
-/* update the file size (if needed) after a write */
+/*
+ * update the file size (if needed) after a write. Should be called with
+ * the inode->i_lock held
+ */
void
cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
unsigned int bytes_written)
@@ -1471,7 +1474,9 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid,
return rc;
}
} else {
+ spin_lock(&dentry->d_inode->i_lock);
cifs_update_eof(cifsi, *poffset, bytes_written);
+ spin_unlock(&dentry->d_inode->i_lock);
*poffset += bytes_written;
}
}
@@ -2197,7 +2202,9 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
if (written) {
len -= written;
total_written += written;
+ spin_lock(&inode->i_lock);
cifs_update_eof(CIFS_I(inode), *poffset, written);
+ spin_unlock(&inode->i_lock);
*poffset += written;
} else if (rc < 0) {
if (!total_written)
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