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CIFS: Don't let read only caching for mandatory byte-range locked files 

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@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Pavel Shilovsky 2012-12-24 14:41:19 +04:00 committed by Steve French
parent 88cf75aaaf
commit 63b7d3a41c
4 changed files with 57 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
fs/cifs/cifsglob.h
View File

@ -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)

55
fs/cifs/file.c
View File

@ -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);

1
fs/cifs/smb1ops.c
View File

@ -959,4 +959,5 @@ 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,
};

2
fs/cifs/smb2ops.c
View File

@ -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 = {