| Message ID | 1394207319-13252-2-git-send-email-Anand.Jain@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Anand, I agree we can export @total_devices to fix 'btrfs file show' problem. This patch addressed two problem, it is better to split it into two patches. Could you please resend the patch, at least we should fix 'btrfs file show' problem firstly. Thanks, Wang On 03/07/2014 11:48 PM, Anand Jain wrote: > ioctl(BTRFS_IOC_FS_INFO) returns num_devices which does not > count seed device. num_devices is used to calculate > the number of slots during the ioctl(BTRFS_IOC_DEV_INFO) > but ioctl(BTRFS_IOC_DEV_INFO) would count seed devices as well. > Due to this miss match btrfs_progs get_fs_info() hits the bug.. > get_fs_info() > :: > BUG_ON(ndevs >= fi_args->num_devices); > > what I notice is total_devices should be returned by the > ioctl(BTRFS_IOC_FS_INFO)), however total_devices does not > count (transient) replacing device but num_devices does. > > first, num_devices which appears to be a subset of > total_devices helps to count the number of devices > under a FSID which excludes the seed devices but > includes the transient replacing device. > > total_devices which includes seed devices is as of > now does not count the tansient replacing device, > which IMO is a bug or the implementation details > are not clear enough to state the role of num_devices > and total_devices. > > The user land on the otherhand would want to know > all the devices that would come out of probe > against a FSID > > As of now in this patch I am making the ioctl.c local > changes (instead of asking replace thread to update > total_devices) to include replacing device. > > Signed-off-by: Anand Jain <Anand.Jain@oracle.com> > --- > fs/btrfs/ioctl.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 5036f9d..ec7d5c6 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -2510,6 +2510,7 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) > struct btrfs_device *next; > struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; > int ret = 0; > + int dev_replace_running = 0; > > if (!capable(CAP_SYS_ADMIN)) > return -EPERM; > @@ -2518,8 +2519,18 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) > if (!fi_args) > return -ENOMEM; > > + btrfs_dev_replace_lock(&root->fs_info->dev_replace); > + if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) > + dev_replace_running = 1; > + > + btrfs_dev_replace_unlock(&root->fs_info->dev_replace); > + > mutex_lock(&fs_devices->device_list_mutex); > - fi_args->num_devices = fs_devices->num_devices; > + if (dev_replace_running) > + fi_args->num_devices = fs_devices->total_devices + 1; > + else > + fi_args->num_devices = fs_devices->total_devices; > + > memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); > > list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello Wang, sure will do. Thanks for the comments. Anand On 13/05/14 17:17, Wang Shilong wrote: > Hello Anand, > > I agree we can export @total_devices to fix 'btrfs file show' problem. > This patch addressed two problem, it is better to split it into two > patches. > > Could you please resend the patch, at least we should fix 'btrfs file show' > problem firstly. > > Thanks, > Wang > > On 03/07/2014 11:48 PM, Anand Jain wrote: >> ioctl(BTRFS_IOC_FS_INFO) returns num_devices which does not >> count seed device. num_devices is used to calculate >> the number of slots during the ioctl(BTRFS_IOC_DEV_INFO) >> but ioctl(BTRFS_IOC_DEV_INFO) would count seed devices as well. >> Due to this miss match btrfs_progs get_fs_info() hits the bug.. >> get_fs_info() >> :: >> BUG_ON(ndevs >= fi_args->num_devices); >> >> what I notice is total_devices should be returned by the >> ioctl(BTRFS_IOC_FS_INFO)), however total_devices does not >> count (transient) replacing device but num_devices does. >> >> first, num_devices which appears to be a subset of >> total_devices helps to count the number of devices >> under a FSID which excludes the seed devices but >> includes the transient replacing device. >> >> total_devices which includes seed devices is as of >> now does not count the tansient replacing device, >> which IMO is a bug or the implementation details >> are not clear enough to state the role of num_devices >> and total_devices. >> >> The user land on the otherhand would want to know >> all the devices that would come out of probe >> against a FSID >> >> As of now in this patch I am making the ioctl.c local >> changes (instead of asking replace thread to update >> total_devices) to include replacing device. >> >> Signed-off-by: Anand Jain <Anand.Jain@oracle.com> >> --- >> fs/btrfs/ioctl.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c >> index 5036f9d..ec7d5c6 100644 >> --- a/fs/btrfs/ioctl.c >> +++ b/fs/btrfs/ioctl.c >> @@ -2510,6 +2510,7 @@ static long btrfs_ioctl_fs_info(struct >> btrfs_root *root, void __user *arg) >> struct btrfs_device *next; >> struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; >> int ret = 0; >> + int dev_replace_running = 0; >> if (!capable(CAP_SYS_ADMIN)) >> return -EPERM; >> @@ -2518,8 +2519,18 @@ static long btrfs_ioctl_fs_info(struct >> btrfs_root *root, void __user *arg) >> if (!fi_args) >> return -ENOMEM; >> + btrfs_dev_replace_lock(&root->fs_info->dev_replace); >> + if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) >> + dev_replace_running = 1; >> + >> + btrfs_dev_replace_unlock(&root->fs_info->dev_replace); >> + >> mutex_lock(&fs_devices->device_list_mutex); >> - fi_args->num_devices = fs_devices->num_devices; >> + if (dev_replace_running) >> + fi_args->num_devices = fs_devices->total_devices + 1; >> + else >> + fi_args->num_devices = fs_devices->total_devices; >> + >> memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); >> list_for_each_entry_safe(device, next, &fs_devices->devices, >> dev_list) { > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Wang, After a much of investigation on this, I think I found a better approach to fix this. Can you kindly comment on patch [PATCH] btrfs: ioctl BTRFS_IOC_FS_INFO and BTRFS_IOC_DEV_INFO miss-matched with slots Thanks, Anand On 14/05/14 16:30, Anand Jain wrote: > > Hello Wang, > > sure will do. Thanks for the comments. > > Anand > > On 13/05/14 17:17, Wang Shilong wrote: >> Hello Anand, >> >> I agree we can export @total_devices to fix 'btrfs file show' problem. >> This patch addressed two problem, it is better to split it into two >> patches. >> >> Could you please resend the patch, at least we should fix 'btrfs file >> show' >> problem firstly. >> >> Thanks, >> Wang >> >> On 03/07/2014 11:48 PM, Anand Jain wrote: >>> ioctl(BTRFS_IOC_FS_INFO) returns num_devices which does not >>> count seed device. num_devices is used to calculate >>> the number of slots during the ioctl(BTRFS_IOC_DEV_INFO) >>> but ioctl(BTRFS_IOC_DEV_INFO) would count seed devices as well. >>> Due to this miss match btrfs_progs get_fs_info() hits the bug.. >>> get_fs_info() >>> :: >>> BUG_ON(ndevs >= fi_args->num_devices); >>> >>> what I notice is total_devices should be returned by the >>> ioctl(BTRFS_IOC_FS_INFO)), however total_devices does not >>> count (transient) replacing device but num_devices does. >>> >>> first, num_devices which appears to be a subset of >>> total_devices helps to count the number of devices >>> under a FSID which excludes the seed devices but >>> includes the transient replacing device. >>> >>> total_devices which includes seed devices is as of >>> now does not count the tansient replacing device, >>> which IMO is a bug or the implementation details >>> are not clear enough to state the role of num_devices >>> and total_devices. >>> >>> The user land on the otherhand would want to know >>> all the devices that would come out of probe >>> against a FSID >>> >>> As of now in this patch I am making the ioctl.c local >>> changes (instead of asking replace thread to update >>> total_devices) to include replacing device. >>> >>> Signed-off-by: Anand Jain <Anand.Jain@oracle.com> >>> --- >>> fs/btrfs/ioctl.c | 13 ++++++++++++- >>> 1 file changed, 12 insertions(+), 1 deletion(-) >>> >>> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c >>> index 5036f9d..ec7d5c6 100644 >>> --- a/fs/btrfs/ioctl.c >>> +++ b/fs/btrfs/ioctl.c >>> @@ -2510,6 +2510,7 @@ static long btrfs_ioctl_fs_info(struct >>> btrfs_root *root, void __user *arg) >>> struct btrfs_device *next; >>> struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; >>> int ret = 0; >>> + int dev_replace_running = 0; >>> if (!capable(CAP_SYS_ADMIN)) >>> return -EPERM; >>> @@ -2518,8 +2519,18 @@ static long btrfs_ioctl_fs_info(struct >>> btrfs_root *root, void __user *arg) >>> if (!fi_args) >>> return -ENOMEM; >>> + btrfs_dev_replace_lock(&root->fs_info->dev_replace); >>> + if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) >>> + dev_replace_running = 1; >>> + >>> + btrfs_dev_replace_unlock(&root->fs_info->dev_replace); >>> + >>> mutex_lock(&fs_devices->device_list_mutex); >>> - fi_args->num_devices = fs_devices->num_devices; >>> + if (dev_replace_running) >>> + fi_args->num_devices = fs_devices->total_devices + 1; >>> + else >>> + fi_args->num_devices = fs_devices->total_devices; >>> + >>> memcpy(&fi_args->fsid, root->fs_info->fsid, >>> sizeof(fi_args->fsid)); >>> list_for_each_entry_safe(device, next, &fs_devices->devices, >>> dev_list) { >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 5036f9d..ec7d5c6 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2510,6 +2510,7 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) struct btrfs_device *next; struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; int ret = 0; + int dev_replace_running = 0; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -2518,8 +2519,18 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) if (!fi_args) return -ENOMEM; + btrfs_dev_replace_lock(&root->fs_info->dev_replace); + if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) + dev_replace_running = 1; + + btrfs_dev_replace_unlock(&root->fs_info->dev_replace); + mutex_lock(&fs_devices->device_list_mutex); - fi_args->num_devices = fs_devices->num_devices; + if (dev_replace_running) + fi_args->num_devices = fs_devices->total_devices + 1; + else + fi_args->num_devices = fs_devices->total_devices; + memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
ioctl(BTRFS_IOC_FS_INFO) returns num_devices which does not count seed device. num_devices is used to calculate the number of slots during the ioctl(BTRFS_IOC_DEV_INFO) but ioctl(BTRFS_IOC_DEV_INFO) would count seed devices as well. Due to this miss match btrfs_progs get_fs_info() hits the bug.. get_fs_info() :: BUG_ON(ndevs >= fi_args->num_devices); what I notice is total_devices should be returned by the ioctl(BTRFS_IOC_FS_INFO)), however total_devices does not count (transient) replacing device but num_devices does. first, num_devices which appears to be a subset of total_devices helps to count the number of devices under a FSID which excludes the seed devices but includes the transient replacing device. total_devices which includes seed devices is as of now does not count the tansient replacing device, which IMO is a bug or the implementation details are not clear enough to state the role of num_devices and total_devices. The user land on the otherhand would want to know all the devices that would come out of probe against a FSID As of now in this patch I am making the ioctl.c local changes (instead of asking replace thread to update total_devices) to include replacing device. Signed-off-by: Anand Jain <Anand.Jain@oracle.com> --- fs/btrfs/ioctl.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)