Messages in this thread | | | Date | Mon, 23 Feb 2009 08:33:28 -0800 | From | Jeff Layton <> | Subject | Re: [linux-cifs-client] Re: [PATCH] fs/cifs: send SMB_COM_FLUSH in cifs_fsync |
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On Sun, 22 Feb 2009 22:07:05 -0600 Steve French <smfrench@gmail.com> wrote:
> diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES > index d43e0fe..b33c841 100644 > --- a/fs/cifs/CHANGES > +++ b/fs/cifs/CHANGES > @@ -8,7 +8,9 @@ user's smb session. This fix allows cifs to mount multiple times to the > same server with different userids without risking invalidating earlier > established security contexts. fsync now sends SMB Flush operation > to better ensure that we wait for server to write all of the data to > -server disk (not just write it over the network). > +server disk (not just write it over the network). Add new mount > +parameter to allow user to disable sending the (slow) SMB flush on > +fsync if desired (fsync still flushes all cached write data to the server). > > Version 1.56 > ------------ > diff --git a/fs/cifs/README b/fs/cifs/README > index da4515e..6436966 100644 > --- a/fs/cifs/README > +++ b/fs/cifs/README > @@ -472,6 +472,19 @@ A partial list of the supported mount options follows: > even if the cifs server would support posix advisory locks. > "forcemand" is accepted as a shorter form of this mount > option. > + nostrictsync If this mount option is set, when an application does an > + fsync call then the cifs client does not send an SMB Flush > + to the server (to force the server to write all dirty data > + for this file immediately to disk), although cifs still sends > + all dirty (cached) file data to the server and waits for the > + server to respond to the write write. Since SMB Flush can be > + very slow, and some servers may be reliable enough (to risk > + delaying slightly flushing the data to disk on the server), > + turning on this option may be useful to improve performance for > + applications that fsync too much, at a small risk of server > + crash. If this mount option is not set, by default cifs will > + send an SMB flush request (and wait for a response) on every > + fsync call. > nodfs Disable DFS (global name space support) even if the > server claims to support it. This can help work around > a problem with parsing of DFS paths with Samba server > diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h > index c4c306f..e9f177b 100644 > --- a/fs/cifs/cifs_fs_sb.h > +++ b/fs/cifs/cifs_fs_sb.h > @@ -32,6 +32,7 @@ > #define CIFS_MOUNT_OVERR_GID 0x800 /* override gid returned from server */ > #define CIFS_MOUNT_DYNPERM 0x1000 /* allow in-memory only mode setting */ > #define CIFS_MOUNT_NOPOSIXBRL 0x2000 /* mandatory not posix byte range lock */ > +#define CIFS_MOUNT_NO_SSYNC 0x4000 /* don't do slow SMBflush on every sync*/ > > struct cifs_sb_info { > struct cifsTconInfo *tcon; /* primary mount */ > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index da0f4ff..18e84a4 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -95,6 +95,7 @@ struct smb_vol { > bool local_lease:1; /* check leases only on local system, not remote */ > bool noblocksnd:1; > bool noautotune:1; > + bool nostrictsync:1; /* do not force expensive SMBflush on every sync */ > unsigned int rsize; > unsigned int wsize; > unsigned int sockopt; > @@ -1274,6 +1275,10 @@ cifs_parse_mount_options(char *options, const char *devname, > vol->intr = 0; > } else if (strnicmp(data, "intr", 4) == 0) { > vol->intr = 1; > + } else if (strnicmp(data, "nostrictsync", 12) == 0) { > + vol->nostrictsync = 1; > + } else if (strnicmp(data, "strictsync", 10) == 0) { > + vol->nostrictsync = 0; > } else if (strnicmp(data, "serverino", 7) == 0) { > vol->server_ino = 1; > } else if (strnicmp(data, "noserverino", 9) == 0) { > @@ -2160,6 +2165,8 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_UNX_EMUL; > if (pvolume_info->nobrl) > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_BRL; > + if (pvolume_info->nostrictsync) > + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_SSYNC; > if (pvolume_info->mand_lock) > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOPOSIXBRL; > if (pvolume_info->cifs_acl) > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 83b4741..6411f5f 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -1538,7 +1538,8 @@ int cifs_fsync(struct file *file, struct dentry *dentry, int datasync) > rc = CIFS_I(inode)->write_behind_rc; > CIFS_I(inode)->write_behind_rc = 0; > tcon = CIFS_SB(inode->i_sb)->tcon; > - if (!rc && tcon && smbfile) > + if (!rc && tcon && smbfile && > + !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_SSYNC)) ^^^^^^^ This doesn't compile as there is no cifs_sb defined in this function...
> rc = CIFSSMBFlush(xid, tcon, smbfile->netfid); > } >
-- Jeff Layton <jlayton@redhat.com>
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