diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index c0a027ec63c8..20350a93ed99 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -43,6 +43,7 @@ #define CIFS_MIN_RCV_POOL 4 +#define MAX_REOPEN_ATT 5 /* these many maximum attempts to reopen a file */ /* * default attribute cache timeout (jiffies) */ diff --git a/fs/cifs/file.c b/fs/cifs/file.c index ed9b5a8fb51f..253170dfa716 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1565,10 +1565,11 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode, struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only) { - struct cifsFileInfo *open_file; + struct cifsFileInfo *open_file, *inv_file = NULL; struct cifs_sb_info *cifs_sb; bool any_available = false; int rc; + unsigned int refind = 0; /* Having a null inode here (because mapping->host was set to zero by the VFS or MM) should not happen but we had reports of on oops (due to @@ -1588,40 +1589,25 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode, spin_lock(&cifs_file_list_lock); refind_writable: + if (refind > MAX_REOPEN_ATT) { + spin_unlock(&cifs_file_list_lock); + return NULL; + } list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { if (!any_available && open_file->pid != current->tgid) continue; if (fsuid_only && open_file->uid != current_fsuid()) continue; if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { - cifsFileInfo_get(open_file); - if (!open_file->invalidHandle) { /* found a good writable file */ + cifsFileInfo_get(open_file); spin_unlock(&cifs_file_list_lock); return open_file; + } else { + if (!inv_file) + inv_file = open_file; } - - spin_unlock(&cifs_file_list_lock); - - /* Had to unlock since following call can block */ - rc = cifs_reopen_file(open_file, false); - if (!rc) - return open_file; - - /* if it fails, try another handle if possible */ - cFYI(1, "wp failed on reopen file"); - cifsFileInfo_put(open_file); - - spin_lock(&cifs_file_list_lock); - - /* else we simply continue to the next entry. Thus - we do not loop on reopen errors. If we - can not reopen the file, for example if we - reconnected to a server with another client - racing to delete or lock the file we would not - make progress if we restarted before the beginning - of the loop here. */ } } /* couldn't find useable FH with same pid, try any available */ @@ -1629,7 +1615,30 @@ refind_writable: any_available = true; goto refind_writable; } + + if (inv_file) { + any_available = false; + cifsFileInfo_get(inv_file); + } + spin_unlock(&cifs_file_list_lock); + + if (inv_file) { + rc = cifs_reopen_file(inv_file, false); + if (!rc) + return inv_file; + else { + spin_lock(&cifs_file_list_lock); + list_move_tail(&inv_file->flist, + &cifs_inode->openFileList); + spin_unlock(&cifs_file_list_lock); + cifsFileInfo_put(inv_file); + spin_lock(&cifs_file_list_lock); + ++refind; + goto refind_writable; + } + } + return NULL; }