* [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system @ 2012-12-28 3:42 Jeff Liu 2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu 2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu 0 siblings, 2 replies; 6+ messages in thread From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw) To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba Hello, Here is the updated version of introduce get/set_or_change label upon a mounted filesystem. v8->v7: btrfs_ioc_fs_getlabel(): - Examine the label length with strnlen(). - Tweak up warn() info if the label is not NUL terminated according to Goffredo's suggestions. The old versions can be found at: v7: http://www.spinics.net/lists/linux-btrfs/msg20994.html v6: http://www.spinics.net/lists/linux-btrfs/msg20922.html v5: http://www.spinics.net/lists/linux-btrfs/msg20888.html v4: http://permalink.gmane.org/gmane.comp.file-systems.btrfs/21618 v3: https://patchwork.kernel.org/patch/1124642/ v2: http://permalink.gmane.org/gmane.comp.file-systems.btrfs/12877 v1: http://permalink.gmane.org/gmane.comp.file-systems.btrfs/12872 Thanks, -Jeff ^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the label of a mounted file system 2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu @ 2012-12-28 3:42 ` Jeff Liu 2012-12-28 11:51 ` David Sterba 2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu 1 sibling, 1 reply; 6+ messages in thread From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw) To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba Add a new ioctl(2) BTRFS_IOC_GET_FSLABLE, so that we can get the label upon a mounted file system. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Cc: Goffredo Baroncelli <kreijack@inwind.it> Cc: David Sterba <dsterba@suse.cz> --- fs/btrfs/ioctl.c | 22 ++++++++++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 24 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8fcf9a5..4be5d15 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3699,6 +3699,26 @@ out: return ret; } +static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + const char *label = root->fs_info->super_copy->label; + size_t len = strnlen(label, BTRFS_LABEL_SIZE); + int ret; + + if (len == BTRFS_LABEL_SIZE) { + len--; + WARN(1, "btrfs: device label is not zero terminated, " + "it will be truncated to %zu bytes.\n", len); + } + + mutex_lock(&root->fs_info->volume_mutex); + ret = copy_to_user(arg, label, len); + mutex_unlock(&root->fs_info->volume_mutex); + + return ret ? -EFAULT : 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3797,6 +3817,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_create(root, argp); case BTRFS_IOC_QGROUP_LIMIT: return btrfs_ioctl_qgroup_limit(root, argp); + case BTRFS_IOC_GET_FSLABEL: + return btrfs_ioctl_get_fslabel(file, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 731e287..5b2cbef 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -451,6 +451,8 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_create_args) #define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \ struct btrfs_ioctl_qgroup_limit_args) +#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \ + char[BTRFS_LABEL_SIZE]) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) #endif -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the label of a mounted file system 2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu @ 2012-12-28 11:51 ` David Sterba 0 siblings, 0 replies; 6+ messages in thread From: David Sterba @ 2012-12-28 11:51 UTC (permalink / raw) To: Jeff Liu; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli, dsterba On Fri, Dec 28, 2012 at 11:42:36AM +0800, Jeff Liu wrote: > +static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) > +{ > + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; > + const char *label = root->fs_info->super_copy->label; > + size_t len = strnlen(label, BTRFS_LABEL_SIZE); > + int ret; > + > + if (len == BTRFS_LABEL_SIZE) { > + len--; > + WARN(1, "btrfs: device label is not zero terminated, " > + "it will be truncated to %zu bytes.\n", len); This will print a stacktrace, it's not needed in this context, the warning is enough. printk(KERN_WARNING "..."); > + } > + > + mutex_lock(&root->fs_info->volume_mutex); > + ret = copy_to_user(arg, label, len); > + mutex_unlock(&root->fs_info->volume_mutex); > + > + return ret ? -EFAULT : 0; > +} ^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system 2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu 2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu @ 2012-12-28 3:42 ` Jeff Liu 2012-12-28 12:03 ` David Sterba 1 sibling, 1 reply; 6+ messages in thread From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw) To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba With this new ioctl(2) BTRFS_IOC_SET_FSLABEL, we can set/change the label of a mounted file system. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: Goffredo Baroncelli <kreijack@inwind.it> Reviewed-by: David Sterba <dsterba@suse.cz> --- fs/btrfs/ioctl.c | 39 +++++++++++++++++++++++++++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 41 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 4be5d15..7383f49 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3719,6 +3719,43 @@ static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) return ret ? -EFAULT : 0; } +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + struct btrfs_super_block *super_block = root->fs_info->super_copy; + struct btrfs_trans_handle *trans; + char label[BTRFS_LABEL_SIZE]; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (copy_from_user(label, arg, sizeof(label))) + return -EFAULT; + + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) + return -EINVAL; + + ret = mnt_want_write_file(file); + if (ret) + return ret; + + mutex_lock(&root->fs_info->volume_mutex); + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_unlock; + } + + strcpy(super_block->label, label); + ret = btrfs_end_transaction(trans, root); + +out_unlock: + mutex_unlock(&root->fs_info->volume_mutex); + mnt_drop_write_file(file); + return ret; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3819,6 +3856,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_limit(root, argp); case BTRFS_IOC_GET_FSLABEL: return btrfs_ioctl_get_fslabel(file, argp); + case BTRFS_IOC_SET_FSLABEL: + return btrfs_ioctl_set_fslabel(file, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 5b2cbef..2abe239 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -453,6 +453,8 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_limit_args) #define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \ char[BTRFS_LABEL_SIZE]) +#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 50, \ + char[BTRFS_LABEL_SIZE]) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) #endif -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system 2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu @ 2012-12-28 12:03 ` David Sterba 2012-12-31 10:23 ` Jeff Liu 0 siblings, 1 reply; 6+ messages in thread From: David Sterba @ 2012-12-28 12:03 UTC (permalink / raw) To: Jeff Liu; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli, dsterba On Fri, Dec 28, 2012 at 11:42:40AM +0800, Jeff Liu wrote: > +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) > +{ > + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; > + struct btrfs_super_block *super_block = root->fs_info->super_copy; > + struct btrfs_trans_handle *trans; > + char label[BTRFS_LABEL_SIZE]; > + int ret; > + > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > + if (copy_from_user(label, arg, sizeof(label))) > + return -EFAULT; > + > + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) I would expect a message if this happens, similar to the 'get_fslabel' one, otherwise it's difficult to find out the reason. > + return -EINVAL; > + > + ret = mnt_want_write_file(file); > + if (ret) > + return ret; > + > + mutex_lock(&root->fs_info->volume_mutex); > + trans = btrfs_start_transaction(root, 1); Do we need to reserve 1 unit here? This does not touch any non-superblock metadata, modifies superblock in place. This could lead to an ENOSPC (changing label on a full fs), altghouh it need not happen. > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + goto out_unlock; > + } > + > + strcpy(super_block->label, label); > + ret = btrfs_end_transaction(trans, root); > + > +out_unlock: > + mutex_unlock(&root->fs_info->volume_mutex); > + mnt_drop_write_file(file); > + return ret; > +} ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system 2012-12-28 12:03 ` David Sterba @ 2012-12-31 10:23 ` Jeff Liu 0 siblings, 0 replies; 6+ messages in thread From: Jeff Liu @ 2012-12-31 10:23 UTC (permalink / raw) To: dsterba; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli On 12/28/2012 08:03 PM, David Sterba wrote: > On Fri, Dec 28, 2012 at 11:42:40AM +0800, Jeff Liu wrote: >> +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) >> +{ >> + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; >> + struct btrfs_super_block *super_block = root->fs_info->super_copy; >> + struct btrfs_trans_handle *trans; >> + char label[BTRFS_LABEL_SIZE]; >> + int ret; >> + >> + if (!capable(CAP_SYS_ADMIN)) >> + return -EPERM; >> + >> + if (copy_from_user(label, arg, sizeof(label))) >> + return -EFAULT; >> + >> + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) > > I would expect a message if this happens, similar to the 'get_fslabel' > one, otherwise it's difficult to find out the reason. That's sounds make sense. > >> + return -EINVAL; >> + >> + ret = mnt_want_write_file(file); >> + if (ret) >> + return ret; >> + >> + mutex_lock(&root->fs_info->volume_mutex); >> + trans = btrfs_start_transaction(root, 1); > > Do we need to reserve 1 unit here? This does not touch any > non-superblock metadata, modifies superblock in place. This could lead > to an ENOSPC (changing label on a full fs), altghouh it need not happen. Don't need, I can not recalled why I did that before, will fix it. Thanks, -Jeff > >> + if (IS_ERR(trans)) { >> + ret = PTR_ERR(trans); >> + goto out_unlock; >> + } >> + >> + strcpy(super_block->label, label); >> + ret = btrfs_end_transaction(trans, root); >> + >> +out_unlock: >> + mutex_unlock(&root->fs_info->volume_mutex); >> + mnt_drop_write_file(file); >> + return ret; >> +} ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-12-31 10:24 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu 2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu 2012-12-28 11:51 ` David Sterba 2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu 2012-12-28 12:03 ` David Sterba 2012-12-31 10:23 ` Jeff Liu
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