From: Pavel Shilovsky Date: Thu, 26 May 2011 19:35:47 +0000 (+0400) Subject: CIFS: Migrate to shared superblock model X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=25c7f41e9234f60af30e086278f1de7974f8816f;p=linux-beck.git CIFS: Migrate to shared superblock model Add cifs_match_super to use in sget to share superblock between mounts that have the same //server/sharename, credentials and mount options. It helps us to improve performance on work with future SMB2.1 leases. Reviewed-by: Jeff Layton Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 46fdd55cf427..360fe2ec2a19 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -630,6 +630,7 @@ cifs_do_mount(struct file_system_type *fs_type, struct super_block *sb; struct cifs_sb_info *cifs_sb; struct smb_vol *volume_info; + struct cifs_mnt_data mnt_data; struct dentry *root; cFYI(1, "Devname: %s flags: %d ", dev_name, flags); @@ -646,12 +647,21 @@ cifs_do_mount(struct file_system_type *fs_type, cifs_setup_cifs_sb(volume_info, cifs_sb); - sb = sget(fs_type, NULL, set_anon_super, NULL); + mnt_data.vol = volume_info; + mnt_data.cifs_sb = cifs_sb; + mnt_data.flags = flags; + + sb = sget(fs_type, cifs_match_super, set_anon_super, &mnt_data); if (IS_ERR(sb)) { root = ERR_CAST(sb); goto out_cifs_sb; } + if (sb->s_fs_info) { + cFYI(1, "Use existing superblock"); + goto out_shared; + } + /* * Copy mount params for use in submounts. Better to do * the copy here and deal with the error before cleanup gets @@ -680,9 +690,16 @@ cifs_do_mount(struct file_system_type *fs_type, root = cifs_get_root(volume_info, sb); if (root == NULL) goto out_super; + cFYI(1, "dentry root is: %p", root); goto out; +out_shared: + root = cifs_get_root(volume_info, sb); + if (root) + cFYI(1, "dentry root is: %p", root); + goto out; + out_super: kfree(cifs_sb->mountdata); deactivate_locked_super(sb); diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 68ec457f8476..ca0c3789206e 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -210,6 +210,25 @@ struct smb_vol { struct nls_table *local_nls; }; +#define CIFS_MOUNT_MASK (CIFS_MOUNT_NO_PERM | CIFS_MOUNT_SET_UID | \ + CIFS_MOUNT_SERVER_INUM | CIFS_MOUNT_DIRECT_IO | \ + CIFS_MOUNT_NO_XATTR | CIFS_MOUNT_MAP_SPECIAL_CHR | \ + CIFS_MOUNT_UNX_EMUL | CIFS_MOUNT_NO_BRL | \ + CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_OVERR_UID | \ + CIFS_MOUNT_OVERR_GID | CIFS_MOUNT_DYNPERM | \ + CIFS_MOUNT_NOPOSIXBRL | CIFS_MOUNT_NOSSYNC | \ + CIFS_MOUNT_FSCACHE | CIFS_MOUNT_MF_SYMLINKS | \ + CIFS_MOUNT_MULTIUSER | CIFS_MOUNT_STRICT_IO) + +#define CIFS_MS_MASK (MS_RDONLY | MS_MANDLOCK | MS_NOEXEC | MS_NOSUID | \ + MS_NODEV | MS_SYNCHRONOUS) + +struct cifs_mnt_data { + struct cifs_sb_info *cifs_sb; + struct smb_vol *vol; + int flags; +}; + struct TCP_Server_Info { struct list_head tcp_ses_list; struct list_head smb_ses_list; diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 495688115988..261ca81d5e49 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2146,6 +2146,100 @@ cifs_put_tlink(struct tcon_link *tlink) return; } +static inline struct tcon_link * +cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb); + +static int +compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data) +{ + struct cifs_sb_info *old = CIFS_SB(sb); + struct cifs_sb_info *new = mnt_data->cifs_sb; + + if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK)) + return 0; + + if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) != + (new->mnt_cifs_flags & CIFS_MOUNT_MASK)) + return 0; + + if (old->rsize != new->rsize) + return 0; + + /* + * We want to share sb only if we don't specify wsize or specified wsize + * is greater or equal than existing one. + */ + if (new->wsize && new->wsize < old->wsize) + return 0; + + if (old->mnt_uid != new->mnt_uid || old->mnt_gid != new->mnt_gid) + return 0; + + if (old->mnt_file_mode != new->mnt_file_mode || + old->mnt_dir_mode != new->mnt_dir_mode) + return 0; + + if (strcmp(old->local_nls->charset, new->local_nls->charset)) + return 0; + + if (old->actimeo != new->actimeo) + return 0; + + return 1; +} + +int +cifs_match_super(struct super_block *sb, void *data) +{ + struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data; + struct smb_vol *volume_info; + struct cifs_sb_info *cifs_sb; + struct TCP_Server_Info *tcp_srv; + struct cifsSesInfo *ses; + struct cifsTconInfo *tcon; + struct tcon_link *tlink; + struct sockaddr_storage addr; + int rc = 0; + + memset(&addr, 0, sizeof(struct sockaddr_storage)); + + spin_lock(&cifs_tcp_ses_lock); + cifs_sb = CIFS_SB(sb); + tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb)); + if (IS_ERR(tlink)) { + spin_unlock(&cifs_tcp_ses_lock); + return rc; + } + tcon = tlink_tcon(tlink); + ses = tcon->ses; + tcp_srv = ses->server; + + volume_info = mnt_data->vol; + + if (!volume_info->UNCip || !volume_info->UNC) + goto out; + + rc = cifs_fill_sockaddr((struct sockaddr *)&addr, + volume_info->UNCip, + strlen(volume_info->UNCip), + volume_info->port); + if (!rc) + goto out; + + if (!match_server(tcp_srv, (struct sockaddr *)&addr, volume_info) || + !match_session(ses, volume_info) || + !match_tcon(tcon, volume_info->UNC)) { + rc = 0; + goto out; + } + + rc = compare_mount_options(sb, mnt_data); +out: + cifs_put_tlink(tlink); + spin_unlock(&cifs_tcp_ses_lock); + return rc; +} + int get_dfs_path(int xid, struct cifsSesInfo *pSesInfo, const char *old_path, const struct nls_table *nls_codepage, unsigned int *pnum_referrals, @@ -2578,6 +2672,14 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, /* Windows ME may prefer this */ cFYI(1, "readsize set to minimum: 2048"); } + + /* + * Temporarily set wsize for matching superblock. If we end up using + * new sb then cifs_negotiate_wsize will later negotiate it downward + * if needed. + */ + cifs_sb->wsize = pvolume_info->wsize; + cifs_sb->mnt_uid = pvolume_info->linux_uid; cifs_sb->mnt_gid = pvolume_info->linux_gid; cifs_sb->mnt_file_mode = pvolume_info->file_mode;