On Wed, 26 Dec 2012 19:53:54 +0400
Pavel Shilovsky <piastry@xxxxxxxxxxx> wrote:
> If we have mandatory byte-range locks on a file we can't cache reads
> because pagereading may have conflicts with these locks on the server.
> That's why we should allow level2 oplocks for files without mandatory
> locks only.
>
> Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
> ---
> fs/cifs/cifsglob.h | 1 +
> fs/cifs/file.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
> fs/cifs/smb1ops.c | 1 +
> fs/cifs/smb2ops.c | 3 +++
> 4 files changed, 58 insertions(+), 2 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index dfab450..e6899ce 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -386,6 +386,7 @@ struct smb_version_values {
> unsigned int cap_unix;
> unsigned int cap_nt_find;
> unsigned int cap_large_files;
> + unsigned int oplock_read;
> };
>
> #define HEADER_SIZE(server) (server->vals->header_size)
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 22c3725..8ea6ca5 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -238,6 +238,23 @@ out:
> return rc;
> }
>
> +static bool
> +cifs_has_mand_locks(struct cifsInodeInfo *cinode)
> +{
> + struct cifs_fid_locks *cur;
> + bool has_locks = false;
> +
> + down_read(&cinode->lock_sem);
> + list_for_each_entry(cur, &cinode->llist, llist) {
> + if (!list_empty(&cur->locks)) {
> + has_locks = true;
> + break;
> + }
> + }
> + up_read(&cinode->lock_sem);
> + return has_locks;
> +}
> +
> struct cifsFileInfo *
> cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
> struct tcon_link *tlink, __u32 oplock)
> @@ -248,6 +265,7 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
> struct cifsFileInfo *cfile;
> struct cifs_fid_locks *fdlocks;
> struct cifs_tcon *tcon = tlink_tcon(tlink);
> + struct TCP_Server_Info *server = tcon->ses->server;
>
> cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
> if (cfile == NULL)
> @@ -276,12 +294,22 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
> INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
> mutex_init(&cfile->fh_mutex);
>
> + /*
> + * If the server returned a read oplock and we have mandatory brlocks,
> + * set oplock level to None.
> + */
> + if (oplock == server->vals->oplock_read &&
> + cifs_has_mand_locks(cinode)) {
> + cFYI(1, "Reset oplock val from read to None due to mand locks");
> + oplock = 0;
> + }
> +
> spin_lock(&cifs_file_list_lock);
> - if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE)
> + if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
> oplock = fid->pending_open->oplock;
> list_del(&fid->pending_open->olist);
>
> - tlink_tcon(tlink)->ses->server->ops->set_fid(cfile, fid, oplock);
> + server->ops->set_fid(cfile, fid, oplock);
>
> list_add(&cfile->tlist, &tcon->openFileList);
> /* if readable file instance put first in list*/
> @@ -1422,6 +1450,7 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
> struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
> struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
> struct TCP_Server_Info *server = tcon->ses->server;
> + struct inode *inode = cfile->dentry->d_inode;
>
> if (posix_lck) {
> int posix_lock_type;
> @@ -1459,6 +1488,21 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
> if (!rc)
> goto out;
>
> + /*
> + * Windows 7 server can delay breaking lease from read to None
> + * if we set a byte-range lock on a file - break it explicitly
> + * before sending the lock to the server to be sure the next
> + * read won't conflict with non-overlapted locks due to
> + * pagereading.
> + */
> + if (!CIFS_I(inode)->clientCanCacheAll &&
> + CIFS_I(inode)->clientCanCacheRead) {
> + cifs_invalidate_mapping(inode);
> + cFYI(1, "Set no oplock for inode=%p due to mand locks",
> + inode);
> + CIFS_I(inode)->clientCanCacheRead = false;
> + }
> +
> rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
> type, 1, 0, wait_flag);
> if (rc) {
> @@ -3537,6 +3581,13 @@ void cifs_oplock_break(struct work_struct *work)
> struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
> int rc = 0;
>
> + if (!cinode->clientCanCacheAll && cinode->clientCanCacheRead &&
> + cifs_has_mand_locks(cinode)) {
> + cFYI(1, "Reset oplock to None for inode=%p due to mand locks",
> + inode);
> + cinode->clientCanCacheRead = false;
> + }
> +
> if (inode && S_ISREG(inode->i_mode)) {
> if (cinode->clientCanCacheRead)
> break_lease(inode, O_RDONLY);
> diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
> index a5d234c..a1de86c 100644
> --- a/fs/cifs/smb1ops.c
> +++ b/fs/cifs/smb1ops.c
> @@ -952,4 +952,5 @@ struct smb_version_values smb1_values = {
> .cap_unix = CAP_UNIX,
> .cap_nt_find = CAP_NT_SMBS | CAP_NT_FIND,
> .cap_large_files = CAP_LARGE_FILES,
> + .oplock_read = OPLOCK_READ,
> };
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index d79de7b..bceffe7 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -708,6 +708,7 @@ struct smb_version_values smb20_values = {
> .cap_unix = 0,
> .cap_nt_find = SMB2_NT_FIND,
> .cap_large_files = SMB2_LARGE_FILES,
> + .oplock_read = SMB2_OPLOCK_LEVEL_II,
> };
>
> struct smb_version_values smb21_values = {
> @@ -725,6 +726,7 @@ struct smb_version_values smb21_values = {
> .cap_unix = 0,
> .cap_nt_find = SMB2_NT_FIND,
> .cap_large_files = SMB2_LARGE_FILES,
> + .oplock_read = SMB2_OPLOCK_LEVEL_II,
> };
>
> struct smb_version_values smb30_values = {
> @@ -742,4 +744,5 @@ struct smb_version_values smb30_values = {
> .cap_unix = 0,
> .cap_nt_find = SMB2_NT_FIND,
> .cap_large_files = SMB2_LARGE_FILES,
> + .oplock_read = SMB2_OPLOCK_LEVEL_II,
> };
Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
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