From: Greg KH <[email protected]> 3.5-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jeff Layton <[email protected]> commit 764a1b1acecedfe204cb2e80d8e2cc7c6df1b0b8 upstream. The readpages bug is a regression that was introduced in 6993f74a5. This also fixes a couple of similar bugs in the uncached read and write codepaths. Also, prevent this sort of thing in the future by having cifsFileInfo_get take the spinlock itself, and adding a _locked variant for use in places that are already holding the lock. The _put code has always done that so this makes for a less confusing interface. Reviewed-by: Pavel Shilovsky <[email protected]> Signed-off-by: Jeff Layton <[email protected]> Signed-off-by: Steve French <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/cifs/cifsglob.h | 6 +++--- fs/cifs/file.c | 17 ++++++++++++----- 2 files changed, 15 insertions(+), 8 deletions(-) --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -657,13 +657,13 @@ struct cifs_io_parms { * Take a reference on the file private data. Must be called with * cifs_file_list_lock held. */ -static inline -struct cifsFileInfo *cifsFileInfo_get(struct cifsFileInfo *cifs_file) +static inline void +cifsFileInfo_get_locked(struct cifsFileInfo *cifs_file) { ++cifs_file->count; - return cifs_file; } +struct cifsFileInfo *cifsFileInfo_get(struct cifsFileInfo *cifs_file); void cifsFileInfo_put(struct cifsFileInfo *cifs_file); /* --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -284,6 +284,15 @@ cifs_new_fileinfo(__u16 fileHandle, stru static void cifs_del_lock_waiters(struct cifsLockInfo *lock); +struct cifsFileInfo * +cifsFileInfo_get(struct cifsFileInfo *cifs_file) +{ + spin_lock(&cifs_file_list_lock); + cifsFileInfo_get_locked(cifs_file); + spin_unlock(&cifs_file_list_lock); + return cifs_file; +} + /* * Release a reference on the file private data. This may involve closing * the filehandle out on the server. Must be called without holding @@ -1563,7 +1572,7 @@ struct cifsFileInfo *find_readable_file( if (!open_file->invalidHandle) { /* found a good file */ /* lock it so it will not be closed on us */ - cifsFileInfo_get(open_file); + cifsFileInfo_get_locked(open_file); spin_unlock(&cifs_file_list_lock); return open_file; } /* else might as well continue, and look for @@ -1615,7 +1624,7 @@ refind_writable: if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { if (!open_file->invalidHandle) { /* found a good writable file */ - cifsFileInfo_get(open_file); + cifsFileInfo_get_locked(open_file); spin_unlock(&cifs_file_list_lock); return open_file; } else { @@ -1632,7 +1641,7 @@ refind_writable: if (inv_file) { any_available = false; - cifsFileInfo_get(inv_file); + cifsFileInfo_get_locked(inv_file); } spin_unlock(&cifs_file_list_lock); @@ -3082,8 +3091,6 @@ static int cifs_readpages(struct file *f break; } - spin_lock(&cifs_file_list_lock); - spin_unlock(&cifs_file_list_lock); rdata->cfile = cifsFileInfo_get(open_file); rdata->mapping = mapping; rdata->offset = offset; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
