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[CIFS] Fix hang in find_writable_file

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Caused by unneeded reopen during reconnect while spinlock held.

Fixes kernel bugzilla bug #7903

Thanks to Lin Feng Shen for testing this, and Amit Arora for
some nice problem determination to narrow this down.

Acked-by: Dave Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Steve French
2007-07-26 15:54:16 +00:00
parent e4903fb595
commit a403a0a370
4 changed files with 35 additions and 13 deletions
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33
fs/cifs/file.c
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@ -1904,6 +1904,25 @@ static int cifs_readpage(struct file *file, struct page *page)
return rc;
}
static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
{
struct cifsFileInfo *open_file;
read_lock(&GlobalSMBSeslock);
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (open_file->closePend)
continue;
if (open_file->pfile &&
((open_file->pfile->f_flags & O_RDWR) ||
(open_file->pfile->f_flags & O_WRONLY))) {
read_unlock(&GlobalSMBSeslock);
return 1;
}
}
read_unlock(&GlobalSMBSeslock);
return 0;
}
/* We do not want to update the file size from server for inodes
open for write - to avoid races with writepage extending
the file - in the future we could consider allowing
@ -1912,19 +1931,13 @@ static int cifs_readpage(struct file *file, struct page *page)
page caching in the current Linux kernel design */
int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
{
struct cifsFileInfo *open_file = NULL;
if (!cifsInode)
return 1;
if (cifsInode)
open_file = find_writable_file(cifsInode);
if (open_file) {
if (is_inode_writable(cifsInode)) {
/* This inode is open for write at least once */
struct cifs_sb_info *cifs_sb;
/* there is not actually a write pending so let
this handle go free and allow it to
be closable if needed */
atomic_dec(&open_file->wrtPending);
cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
/* since no page cache to corrupt on directio