From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:29908 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751596AbaESRAx (ORCPT ); Mon, 19 May 2014 13:00:53 -0400 Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s4JH0qOB003928 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 19 May 2014 17:00:53 GMT Received: from aserz7022.oracle.com (aserz7022.oracle.com [141.146.126.231]) by acsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s4JH0pTD002391 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 19 May 2014 17:00:52 GMT Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserz7022.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s4JH0pMJ013391 for ; Mon, 19 May 2014 17:00:51 GMT From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH 3/4 RESEND] btrfs: add framework to read fs info from btrfs-control Date: Tue, 20 May 2014 01:03:41 +0800 Message-Id: <1400519022-5540-3-git-send-email-anand.jain@oracle.com> In-Reply-To: <1400519022-5540-1-git-send-email-anand.jain@oracle.com> References: <1400519022-5540-1-git-send-email-anand.jain@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: This adds ioctl BTRFS_IOC_GET_FSIDS which reads the fs info through the btrfs-control, needed to optimize heavily used btrfs-progs function check_mounted() plus few other minor uses. Signed-off-by: Anand Jain --- fs/btrfs/super.c | 66 +++++++++++++++++++++++++++++++++++++++++----- fs/btrfs/volumes.c | 39 +++++++++++++++++++++++++++ fs/btrfs/volumes.h | 2 ++ include/uapi/linux/btrfs.h | 19 +++++++++++++ 4 files changed, 120 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index d4878dd..b42cd50 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1717,38 +1717,92 @@ static struct file_system_type btrfs_fs_type = { }; MODULE_ALIAS_FS("btrfs"); +static int btrfs_ioc_get_fslist(void __user *arg) +{ + int ret = 0; + u64 sz_fslist_arg; + u64 sz_fslist; + u64 sz_out; + struct btrfs_ioctl_fslist_args *fslist_arg; + struct btrfs_ioctl_fslist_args *fslist_arg_tmp; + struct btrfs_ioctl_fslist *fslist; + + u64 cnt = 0, ucnt; + + sz_fslist_arg = sizeof(*fslist_arg); + sz_fslist = sizeof(*fslist); + if (copy_from_user(&ucnt, + (struct btrfs_ioctl_fslist_args __user *)(arg + + offsetof(struct btrfs_ioctl_fslist_args, count)), + sizeof(ucnt))) + return -EFAULT; + + cnt = btrfs_get_fslist_cnt(); + + if (cnt > ucnt) { + if (copy_to_user(arg + + offsetof(struct btrfs_ioctl_fslist_args, count), + &cnt, sizeof(cnt))) + return -EFAULT; + return 1; + } + + sz_out = sz_fslist_arg + sz_fslist * cnt; + fslist_arg_tmp = fslist_arg = memdup_user(arg, sz_out); + if (IS_ERR(fslist_arg)) + return PTR_ERR(fslist_arg); + fslist = (struct btrfs_ioctl_fslist *) (++fslist_arg_tmp); + cnt = btrfs_get_fslist(fslist, cnt); + fslist_arg->count = cnt; + if (copy_to_user(arg, fslist_arg, sz_out)) { + ret = -EFAULT; + goto out; + } + ret = 0; +out: + kfree(fslist_arg); + return ret; +} + /* * used by btrfsctl to scan devices when no FS is mounted */ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct btrfs_ioctl_vol_args *vol; + struct btrfs_ioctl_vol_args *vol = NULL; struct btrfs_fs_devices *fs_devices; int ret = -ENOTTY; + void __user *argp = (void __user *)arg; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - vol = memdup_user((void __user *)arg, sizeof(*vol)); - if (IS_ERR(vol)) - return PTR_ERR(vol); - switch (cmd) { case BTRFS_IOC_SCAN_DEV: + vol = memdup_user((void __user *)arg, sizeof(*vol)); + if (IS_ERR(vol)) + return PTR_ERR(vol); ret = btrfs_scan_one_device(vol->name, FMODE_READ, &btrfs_fs_type, &fs_devices); + kfree(vol); break; case BTRFS_IOC_DEVICES_READY: + vol = memdup_user((void __user *)arg, sizeof(*vol)); + if (IS_ERR(vol)) + return PTR_ERR(vol); ret = btrfs_scan_one_device(vol->name, FMODE_READ, &btrfs_fs_type, &fs_devices); + kfree(vol); if (ret) break; ret = !(fs_devices->num_devices == fs_devices->total_devices); break; + case BTRFS_IOC_GET_FSLIST: + ret = btrfs_ioc_get_fslist(argp); + break; } - kfree(vol); return ret; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 1567439..e22ac22 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6341,3 +6341,42 @@ int btrfs_scratch_superblock(struct btrfs_device *device) return 0; } + +int btrfs_get_fslist_cnt(void) +{ + int cnt = 0; + struct btrfs_fs_devices *fs_devices; + + mutex_lock(&uuid_mutex); + list_for_each_entry(fs_devices, &fs_uuids, list) + cnt++; + mutex_unlock(&uuid_mutex); + + return cnt; +} + +u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt) +{ + u64 cnt = 0; + struct btrfs_fs_devices *fs_devices; + + mutex_lock(&uuid_mutex); + list_for_each_entry(fs_devices, &fs_uuids, list) { + if (!(cnt < ucnt)) + break; + memcpy(fslist->fsid, fs_devices->fsid, + BTRFS_FSID_SIZE); + fslist->num_devices = fs_devices->num_devices; + fslist->missing_devices = fs_devices->missing_devices; + fslist->total_devices = fs_devices->total_devices; + + if (fs_devices->opened) + fslist->flags = BTRFS_FS_MOUNTED; + + fslist++; + cnt++; + } + mutex_unlock(&uuid_mutex); + + return cnt; +} diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 80754f9..0b97fcf 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -391,4 +391,6 @@ static inline void btrfs_dev_stat_reset(struct btrfs_device *dev, { btrfs_dev_stat_set(dev, index, 0); } +int btrfs_get_fslist_cnt(void); +u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt); #endif diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index b4d6909..76b91d6 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -518,6 +518,23 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) } } +/* fs flags */ +#define BTRFS_FS_MOUNTED (1LLU << 0) + +struct btrfs_ioctl_fslist { + __u64 self_sz; /* in/out */ + __u8 fsid[BTRFS_FSID_SIZE]; /* out */ + __u64 num_devices; + __u64 missing_devices; + __u64 total_devices; + __u64 flags; +}; + +struct btrfs_ioctl_fslist_args { + __u64 self_sz; /* in/out */ + __u64 count; /* out */ +}; + #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ struct btrfs_ioctl_vol_args) #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \ @@ -612,6 +629,8 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) struct btrfs_ioctl_dev_replace_args) #define BTRFS_IOC_FILE_EXTENT_SAME _IOWR(BTRFS_IOCTL_MAGIC, 54, \ struct btrfs_ioctl_same_args) +#define BTRFS_IOC_GET_FSLIST _IOWR(BTRFS_IOCTL_MAGIC, 56, \ + struct btrfs_ioctl_fslist_args) #define BTRFS_IOC_GET_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \ struct btrfs_ioctl_feature_flags) #define BTRFS_IOC_SET_FEATURES _IOW(BTRFS_IOCTL_MAGIC, 57, \ -- 1.8.5.3