| Message ID | 1b8c4b9c49deb956e9d065b0677bfeaf17c968d2.1386442053.git.plageat90@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Dec 8, 2013 at 2:59 AM, Mikhail Campos Guadamuz <plageat90@gmail.com> wrote: > For http://tracker.ceph.com/issues/4386 > > It determines situation, when a user is trying to mount CephFS > with no MDS present. Return ECOMM from > open_root_dentry which can be analyzed then by ceph.mount > > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> > --- > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- > fs/ceph/super.c | 10 +++++++++- > include/linux/ceph/mdsmap.h | 1 + > 3 files changed, 26 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c > index 132b64e..3a6ba8a 100644 > --- a/fs/ceph/mdsmap.c > +++ b/fs/ceph/mdsmap.c > @@ -12,6 +12,20 @@ > > #include "super.h" > > +/* > + * count active mds's > + */ > +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) > +{ > + int n = 0; > + int i; > + > + for(i = 0; i < m->m_max_mds; ++i) > + if(m->m_info[i].state > 0) > + ++n; > + > + return n; > +} > > /* > * choose a random mds that is "up" (i.e. has a state > 0), or -1. > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) > return 0; > > /* count */ > - for (i = 0; i < m->m_max_mds; i++) > - if (m->m_info[i].state > 0) > - n++; > + n = ceph_mdsmap_active_mds_count(m); > + > if (n == 0) > return -1; > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index 6627b26..4d33d68 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, > struct ceph_mds_request *req = NULL; > int err; > struct dentry *root; > - > + > + /* check for mds*/ > + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) > + { > + pr_info("active mds not found, possible not exist\n"); > + root = ERR_PTR( -ECOMM ); > + return root; > + } I think we should return error immediately only if there is no mds (mdsmap->m_max_mds == 0). If there is inactive mds, we should stick to current behavior (wait until timeout). Furthermore please don't use uncommon error code ECOMM, use common error code such as EINVAL. Regards Yan, Zheng > + > /* open dir */ > dout("open_root_inode opening '%s'\n", path); > req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); > diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h > index 87ed09f..4d7d502 100644 > --- a/include/linux/ceph/mdsmap.h > +++ b/include/linux/ceph/mdsmap.h > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) > return false; > } > > +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); > extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" 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 ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 2013-12-07 at 21:59 +0800, Yan, Zheng wrote: > On Sun, Dec 8, 2013 at 2:59 AM, Mikhail Campos Guadamuz > <plageat90@gmail.com> wrote: > > For http://tracker.ceph.com/issues/4386 > > > > It determines situation, when a user is trying to mount CephFS > > with no MDS present. Return ECOMM from > > open_root_dentry which can be analyzed then by ceph.mount > > > > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> > > --- > > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- > > fs/ceph/super.c | 10 +++++++++- > > include/linux/ceph/mdsmap.h | 1 + > > 3 files changed, 26 insertions(+), 4 deletions(-) > > > > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c > > index 132b64e..3a6ba8a 100644 > > --- a/fs/ceph/mdsmap.c > > +++ b/fs/ceph/mdsmap.c > > @@ -12,6 +12,20 @@ > > > > #include "super.h" > > > > +/* > > + * count active mds's > > + */ > > +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) > > +{ > > + int n = 0; > > + int i; > > + > > + for(i = 0; i < m->m_max_mds; ++i) > > + if(m->m_info[i].state > 0) > > + ++n; > > + > > + return n; > > +} > > > > /* > > * choose a random mds that is "up" (i.e. has a state > 0), or -1. > > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) > > return 0; > > > > /* count */ > > - for (i = 0; i < m->m_max_mds; i++) > > - if (m->m_info[i].state > 0) > > - n++; > > + n = ceph_mdsmap_active_mds_count(m); > > + > > if (n == 0) > > return -1; > > > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > > index 6627b26..4d33d68 100644 > > --- a/fs/ceph/super.c > > +++ b/fs/ceph/super.c > > @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, > > struct ceph_mds_request *req = NULL; > > int err; > > struct dentry *root; > > - > > + > > + /* check for mds*/ > > + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) > > + { > > + pr_info("active mds not found, possible not exist\n"); > > + root = ERR_PTR( -ECOMM ); > > + return root; > > + } > > I think we should return error immediately only if there is no mds > (mdsmap->m_max_mds == 0). If there is inactive mds, we should stick > to current behavior (wait until timeout). Furthermore please don't use > uncommon error code ECOMM, use common error code such as EINVAL. > > Regards > Yan, Zheng > > > > + > > /* open dir */ > > dout("open_root_inode opening '%s'\n", path); > > req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); > > diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h > > index 87ed09f..4d7d502 100644 > > --- a/include/linux/ceph/mdsmap.h > > +++ b/include/linux/ceph/mdsmap.h > > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) > > return false; > > } > > > > +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); > > extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); > > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); > > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); > > -- > > 1.8.3.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" 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 ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html I think we can't check mds presence by (mdsmap->m_max_mds == 0) statement, because max_mds value does not strictly represent the number of mds. For example, we have max_mds = 1 (by default) no matter have we one mds or haven't. Is this a expected behavior? -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Dec 9, 2013 at 8:02 PM, Dzianis Huznou <dzianis_huznou@epam.com> wrote: > On Sat, 2013-12-07 at 21:59 +0800, Yan, Zheng wrote: >> On Sun, Dec 8, 2013 at 2:59 AM, Mikhail Campos Guadamuz >> <plageat90@gmail.com> wrote: >> > For http://tracker.ceph.com/issues/4386 >> > >> > It determines situation, when a user is trying to mount CephFS >> > with no MDS present. Return ECOMM from >> > open_root_dentry which can be analyzed then by ceph.mount >> > >> > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> >> > --- >> > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- >> > fs/ceph/super.c | 10 +++++++++- >> > include/linux/ceph/mdsmap.h | 1 + >> > 3 files changed, 26 insertions(+), 4 deletions(-) >> > >> > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c >> > index 132b64e..3a6ba8a 100644 >> > --- a/fs/ceph/mdsmap.c >> > +++ b/fs/ceph/mdsmap.c >> > @@ -12,6 +12,20 @@ >> > >> > #include "super.h" >> > >> > +/* >> > + * count active mds's >> > + */ >> > +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) >> > +{ >> > + int n = 0; >> > + int i; >> > + >> > + for(i = 0; i < m->m_max_mds; ++i) >> > + if(m->m_info[i].state > 0) >> > + ++n; >> > + >> > + return n; >> > +} >> > >> > /* >> > * choose a random mds that is "up" (i.e. has a state > 0), or -1. >> > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) >> > return 0; >> > >> > /* count */ >> > - for (i = 0; i < m->m_max_mds; i++) >> > - if (m->m_info[i].state > 0) >> > - n++; >> > + n = ceph_mdsmap_active_mds_count(m); >> > + >> > if (n == 0) >> > return -1; >> > >> > diff --git a/fs/ceph/super.c b/fs/ceph/super.c >> > index 6627b26..4d33d68 100644 >> > --- a/fs/ceph/super.c >> > +++ b/fs/ceph/super.c >> > @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, >> > struct ceph_mds_request *req = NULL; >> > int err; >> > struct dentry *root; >> > - >> > + >> > + /* check for mds*/ >> > + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) >> > + { >> > + pr_info("active mds not found, possible not exist\n"); >> > + root = ERR_PTR( -ECOMM ); >> > + return root; >> > + } >> >> I think we should return error immediately only if there is no mds >> (mdsmap->m_max_mds == 0). If there is inactive mds, we should stick >> to current behavior (wait until timeout). Furthermore please don't use >> uncommon error code ECOMM, use common error code such as EINVAL. >> >> Regards >> Yan, Zheng >> >> >> > + >> > /* open dir */ >> > dout("open_root_inode opening '%s'\n", path); >> > req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); >> > diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h >> > index 87ed09f..4d7d502 100644 >> > --- a/include/linux/ceph/mdsmap.h >> > +++ b/include/linux/ceph/mdsmap.h >> > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) >> > return false; >> > } >> > >> > +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); >> > extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); >> > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); >> > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); >> > -- >> > 1.8.3.1 >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe ceph-devel" 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 ceph-devel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > I think we can't check mds presence by (mdsmap->m_max_mds == 0) > statement, because max_mds value does not strictly represent the number > of mds. For example, we have max_mds = 1 (by default) no matter have we > one mds or haven't. Is this a expected behavior? > I think so. mds may start later, so we should wait until timeout. nfs has the similar behavior. Regards Yan, Zheng -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Personally, I don't think there is issue for current implementation, either. If no ACTIVE mds, the mount process put to wait, until updated MDS map received and with active mds present indicated in the map, it will be waked up and go on the mount process, otherwise, EIO returned if timeout. If it is boring to hang for a long time, you can specify a shorter mount timeout. On 2013/12/8 2:59, Mikhail Campos Guadamuz wrote: > For http://tracker.ceph.com/issues/4386 > > It determines situation, when a user is trying to mount CephFS > with no MDS present. Return ECOMM from > open_root_dentry which can be analyzed then by ceph.mount > > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> > --- > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- > fs/ceph/super.c | 10 +++++++++- > include/linux/ceph/mdsmap.h | 1 + > 3 files changed, 26 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c > index 132b64e..3a6ba8a 100644 > --- a/fs/ceph/mdsmap.c > +++ b/fs/ceph/mdsmap.c > @@ -12,6 +12,20 @@ > > #include "super.h" > > +/* > + * count active mds's > + */ > +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) > +{ > + int n = 0; > + int i; > + > + for(i = 0; i < m->m_max_mds; ++i) > + if(m->m_info[i].state > 0) > + ++n; > + > + return n; > +} > > /* > * choose a random mds that is "up" (i.e. has a state > 0), or -1. > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) > return 0; > > /* count */ > - for (i = 0; i < m->m_max_mds; i++) > - if (m->m_info[i].state > 0) > - n++; > + n = ceph_mdsmap_active_mds_count(m); > + > if (n == 0) > return -1; > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index 6627b26..4d33d68 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, > struct ceph_mds_request *req = NULL; > int err; > struct dentry *root; > - > + > + /* check for mds*/ > + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) > + { > + pr_info("active mds not found, possible not exist\n"); > + root = ERR_PTR( -ECOMM ); > + return root; > + } > + > /* open dir */ > dout("open_root_inode opening '%s'\n", path); > req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); > diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h > index 87ed09f..4d7d502 100644 > --- a/include/linux/ceph/mdsmap.h > +++ b/include/linux/ceph/mdsmap.h > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) > return false; > } > > +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); > extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Well, after double-checking the code, it seems the wait process will be unconditionally waked up if new MDS map received. Is there a situation that the client is pushed a new MDS map, but still no mds active. If so, maybe worth a little bit optimization such as calling check_new_map() to avoid the client be uselessly waked up ... On 2013/12/9 22:26, Li Wang wrote: > Personally, I don't think there is issue for current implementation, > either. If no ACTIVE mds, the mount process put to wait, until updated > MDS map received and with active mds present indicated in the map, it > will be waked up and go on the mount process, otherwise, EIO returned if > timeout. If it is boring to hang for a long time, you can specify a > shorter mount timeout. > > On 2013/12/8 2:59, Mikhail Campos Guadamuz wrote: >> For http://tracker.ceph.com/issues/4386 >> >> It determines situation, when a user is trying to mount CephFS >> with no MDS present. Return ECOMM from >> open_root_dentry which can be analyzed then by ceph.mount >> >> Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> >> --- >> fs/ceph/mdsmap.c | 19 ++++++++++++++++--- >> fs/ceph/super.c | 10 +++++++++- >> include/linux/ceph/mdsmap.h | 1 + >> 3 files changed, 26 insertions(+), 4 deletions(-) >> >> diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c >> index 132b64e..3a6ba8a 100644 >> --- a/fs/ceph/mdsmap.c >> +++ b/fs/ceph/mdsmap.c >> @@ -12,6 +12,20 @@ >> >> #include "super.h" >> >> +/* >> + * count active mds's >> + */ >> +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) >> +{ >> + int n = 0; >> + int i; >> + >> + for(i = 0; i < m->m_max_mds; ++i) >> + if(m->m_info[i].state > 0) >> + ++n; >> + >> + return n; >> +} >> >> /* >> * choose a random mds that is "up" (i.e. has a state > 0), or -1. >> @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) >> return 0; >> >> /* count */ >> - for (i = 0; i < m->m_max_mds; i++) >> - if (m->m_info[i].state > 0) >> - n++; >> + n = ceph_mdsmap_active_mds_count(m); >> + >> if (n == 0) >> return -1; >> >> diff --git a/fs/ceph/super.c b/fs/ceph/super.c >> index 6627b26..4d33d68 100644 >> --- a/fs/ceph/super.c >> +++ b/fs/ceph/super.c >> @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct >> ceph_fs_client *fsc, >> struct ceph_mds_request *req = NULL; >> int err; >> struct dentry *root; >> - >> + >> + /* check for mds*/ >> + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) >> + { >> + pr_info("active mds not found, possible not exist\n"); >> + root = ERR_PTR( -ECOMM ); >> + return root; >> + } >> + >> /* open dir */ >> dout("open_root_inode opening '%s'\n", path); >> req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, >> USE_ANY_MDS); >> diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h >> index 87ed09f..4d7d502 100644 >> --- a/include/linux/ceph/mdsmap.h >> +++ b/include/linux/ceph/mdsmap.h >> @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct >> ceph_mdsmap *m, int w) >> return false; >> } >> >> +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); >> extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); >> extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); >> extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); >> -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Then we have to make a choice between immediately returning with error and patiently waiting for mds joining. My suggestion is (1) Leave an error message from the kernel using 'printk(KERN_WARN"no active mds")' something in __choose_mds() (2) Add a return value 'E_WAITING_FOR_MAP' to __choose_mds(), and capture it in ceph_mdsc_do_request(), if the user feel boring to CRTL+C to kill the mount process (user should at least know how to interrupt the mount :) ), then ceph_mdsc_do_request() know that it is interrupted while waiting for new map, then return good error message to user. On 2013/12/9 22:50, ?????? ?????? wrote: > I agree with some points. But this patches originally created to fix > "confusing for new users for hard-understandable return messages" (based > on http://tracker.ceph.com/issues/4386). The idea was to return a > different error code, which can be than handled by ceph.mount client for > printing simple message about "what's going on". > > > 2013/12/9 Li Wang <liwang@ubuntukylin.com <mailto:liwang@ubuntukylin.com>> > > Personally, I don't think there is issue for current implementation, > either. If no ACTIVE mds, the mount process put to wait, until > updated MDS map received and with active mds present indicated in > the map, it will be waked up and go on the mount process, otherwise, > EIO returned if timeout. If it is boring to hang for a long time, > you can specify a shorter mount timeout. > > > On 2013/12/8 2:59, Mikhail Campos Guadamuz wrote: > > For http://tracker.ceph.com/__issues/4386 > <http://tracker.ceph.com/issues/4386> > > It determines situation, when a user is trying to mount CephFS > with no MDS present. Return ECOMM from > open_root_dentry which can be analyzed then by ceph.mount > > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com > <mailto:plageat90@gmail.com>> > --- > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- > fs/ceph/super.c | 10 +++++++++- > include/linux/ceph/mdsmap.h | 1 + > 3 files changed, 26 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c > index 132b64e..3a6ba8a 100644 > --- a/fs/ceph/mdsmap.c > +++ b/fs/ceph/mdsmap.c > @@ -12,6 +12,20 @@ > > #include "super.h" > > +/* > + * count active mds's > + */ > +int ceph_mdsmap_active_mds_count(__struct ceph_mdsmap *m) > +{ > + int n = 0; > + int i; > + > + for(i = 0; i < m->m_max_mds; ++i) > + if(m->m_info[i].state > 0) > + ++n; > + > + return n; > +} > > /* > * choose a random mds that is "up" (i.e. has a state > 0), > or -1. > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(__struct > ceph_mdsmap *m) > return 0; > > /* count */ > - for (i = 0; i < m->m_max_mds; i++) > - if (m->m_info[i].state > 0) > - n++; > + n = ceph_mdsmap_active_mds_count(__m); > + > if (n == 0) > return -1; > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index 6627b26..4d33d68 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -674,7 +674,15 @@ static struct dentry > *open_root_dentry(struct ceph_fs_client *fsc, > struct ceph_mds_request *req = NULL; > int err; > struct dentry *root; > - > + > + /* check for mds*/ > + if( 0 == ceph_mdsmap_active_mds_count(__mdsc->mdsmap) ) > + { > + pr_info("active mds not found, possible not exist\n"); > + root = ERR_PTR( -ECOMM ); > + return root; > + } > + > /* open dir */ > dout("open_root_inode opening '%s'\n", path); > req = ceph_mdsc_create_request(mdsc, > CEPH_MDS_OP_GETATTR, USE_ANY_MDS); > diff --git a/include/linux/ceph/mdsmap.h > b/include/linux/ceph/mdsmap.h > index 87ed09f..4d7d502 100644 > --- a/include/linux/ceph/mdsmap.h > +++ b/include/linux/ceph/mdsmap.h > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct > ceph_mdsmap *m, int w) > return false; > } > > +extern int ceph_mdsmap_active_mds_count(__struct ceph_mdsmap *m); > extern int ceph_mdsmap_get_random_mds(__struct ceph_mdsmap *m); > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void > *end); > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/10/2013 04:25 AM, Li Wang wrote: > Then we have to make a choice between immediately returning with error > and patiently waiting for mds joining. My suggestion is > (1) Leave an error message from the kernel using 'printk(KERN_WARN"no > active mds")' something in __choose_mds() > (2) Add a return value 'E_WAITING_FOR_MAP' to __choose_mds(), and > capture it in ceph_mdsc_do_request(), if the user feel boring to > CRTL+C to kill the mount process (user should at least know how to > interrupt the mount :) ), then ceph_mdsc_do_request() know that it is > interrupted while waiting for new map, then return good error message > to user. > > On 2013/12/9 22:50, ?????? ?????? wrote: >> I agree with some points. But this patches originally created to fix >> "confusing for new users for hard-understandable return messages" (based >> on http://tracker.ceph.com/issues/4386). The idea was to return a >> different error code, which can be than handled by ceph.mount client for >> printing simple message about "what's going on". >> >> >> 2013/12/9 Li Wang <liwang@ubuntukylin.com >> <mailto:liwang@ubuntukylin.com>> >> >> Personally, I don't think there is issue for current implementation, >> either. If no ACTIVE mds, the mount process put to wait, until >> updated MDS map received and with active mds present indicated in >> the map, it will be waked up and go on the mount process, otherwise, >> EIO returned if timeout. If it is boring to hang for a long time, >> you can specify a shorter mount timeout. >> >> >> On 2013/12/8 2:59, Mikhail Campos Guadamuz wrote: >> >> For http://tracker.ceph.com/__issues/4386 >> <http://tracker.ceph.com/issues/4386> >> >> It determines situation, when a user is trying to mount CephFS >> with no MDS present. Return ECOMM from >> open_root_dentry which can be analyzed then by ceph.mount >> >> Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com >> <mailto:plageat90@gmail.com>> >> --- >> fs/ceph/mdsmap.c | 19 ++++++++++++++++--- >> fs/ceph/super.c | 10 +++++++++- >> include/linux/ceph/mdsmap.h | 1 + >> 3 files changed, 26 insertions(+), 4 deletions(-) >> >> diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c >> index 132b64e..3a6ba8a 100644 >> --- a/fs/ceph/mdsmap.c >> +++ b/fs/ceph/mdsmap.c >> @@ -12,6 +12,20 @@ >> >> #include "super.h" >> >> +/* >> + * count active mds's >> + */ >> +int ceph_mdsmap_active_mds_count(__struct ceph_mdsmap *m) >> +{ >> + int n = 0; >> + int i; >> + >> + for(i = 0; i < m->m_max_mds; ++i) >> + if(m->m_info[i].state > 0) >> + ++n; >> + >> + return n; >> +} >> >> /* >> * choose a random mds that is "up" (i.e. has a state > 0), >> or -1. >> @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(__struct >> ceph_mdsmap *m) >> return 0; >> >> /* count */ >> - for (i = 0; i < m->m_max_mds; i++) >> - if (m->m_info[i].state > 0) >> - n++; >> + n = ceph_mdsmap_active_mds_count(__m); >> + >> if (n == 0) >> return -1; >> >> diff --git a/fs/ceph/super.c b/fs/ceph/super.c >> index 6627b26..4d33d68 100644 >> --- a/fs/ceph/super.c >> +++ b/fs/ceph/super.c >> @@ -674,7 +674,15 @@ static struct dentry >> *open_root_dentry(struct ceph_fs_client *fsc, >> struct ceph_mds_request *req = NULL; >> int err; >> struct dentry *root; >> - >> + >> + /* check for mds*/ >> + if( 0 == ceph_mdsmap_active_mds_count(__mdsc->mdsmap) ) >> + { >> + pr_info("active mds not found, possible not >> exist\n"); >> + root = ERR_PTR( -ECOMM ); >> + return root; >> + } >> + >> /* open dir */ >> dout("open_root_inode opening '%s'\n", path); >> req = ceph_mdsc_create_request(mdsc, >> CEPH_MDS_OP_GETATTR, USE_ANY_MDS); >> diff --git a/include/linux/ceph/mdsmap.h >> b/include/linux/ceph/mdsmap.h >> index 87ed09f..4d7d502 100644 >> --- a/include/linux/ceph/mdsmap.h >> +++ b/include/linux/ceph/mdsmap.h >> @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct >> ceph_mdsmap *m, int w) >> return false; >> } >> >> +extern int ceph_mdsmap_active_mds_count(__struct ceph_mdsmap >> *m); >> extern int ceph_mdsmap_get_random_mds(__struct ceph_mdsmap >> *m); >> extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void >> *end); >> extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); >> >> > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Thanks for suggestion. But I cannot understand one thing. We need to print message to console about no active mds. Since we can not print messages to console from kernel client, we need to return unique external error from kernel mount, which can be handled then by ceph.mount (and printed to console). All suitable errors are already in use (EIO, EINVAL etc.) for other error notification. Can you explain, which suitable "common errors" can we use for this purpose? Is there another solution for printing error to console? -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Just a one question. If you are saying about "common error", what exactly do you mean? Do you mean some error number range that we can only use? Which unique(!) error can we return from ceph kernel client if no mds found? On Sat, 2013-12-07 at 21:59 +0800, Yan, Zheng wrote: > On Sun, Dec 8, 2013 at 2:59 AM, Mikhail Campos Guadamuz > <plageat90@gmail.com> wrote: > > For http://tracker.ceph.com/issues/4386 > > > > It determines situation, when a user is trying to mount CephFS > > with no MDS present. Return ECOMM from > > open_root_dentry which can be analyzed then by ceph.mount > > > > Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> > > --- > > fs/ceph/mdsmap.c | 19 ++++++++++++++++--- > > fs/ceph/super.c | 10 +++++++++- > > include/linux/ceph/mdsmap.h | 1 + > > 3 files changed, 26 insertions(+), 4 deletions(-) > > > > diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c > > index 132b64e..3a6ba8a 100644 > > --- a/fs/ceph/mdsmap.c > > +++ b/fs/ceph/mdsmap.c > > @@ -12,6 +12,20 @@ > > > > #include "super.h" > > > > +/* > > + * count active mds's > > + */ > > +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) > > +{ > > + int n = 0; > > + int i; > > + > > + for(i = 0; i < m->m_max_mds; ++i) > > + if(m->m_info[i].state > 0) > > + ++n; > > + > > + return n; > > +} > > > > /* > > * choose a random mds that is "up" (i.e. has a state > 0), or -1. > > @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) > > return 0; > > > > /* count */ > > - for (i = 0; i < m->m_max_mds; i++) > > - if (m->m_info[i].state > 0) > > - n++; > > + n = ceph_mdsmap_active_mds_count(m); > > + > > if (n == 0) > > return -1; > > > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > > index 6627b26..4d33d68 100644 > > --- a/fs/ceph/super.c > > +++ b/fs/ceph/super.c > > @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, > > struct ceph_mds_request *req = NULL; > > int err; > > struct dentry *root; > > - > > + > > + /* check for mds*/ > > + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) > > + { > > + pr_info("active mds not found, possible not exist\n"); > > + root = ERR_PTR( -ECOMM ); > > + return root; > > + } > > I think we should return error immediately only if there is no mds > (mdsmap->m_max_mds == 0). If there is inactive mds, we should stick > to current behavior (wait until timeout). Furthermore please don't use > uncommon error code ECOMM, use common error code such as EINVAL. > > Regards > Yan, Zheng > > > > + > > /* open dir */ > > dout("open_root_inode opening '%s'\n", path); > > req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); > > diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h > > index 87ed09f..4d7d502 100644 > > --- a/include/linux/ceph/mdsmap.h > > +++ b/include/linux/ceph/mdsmap.h > > @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) > > return false; > > } > > > > +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); > > extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); > > extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); > > extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m); > > -- > > 1.8.3.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" 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 ceph-devel" 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 ceph-devel" 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/ceph/mdsmap.c b/fs/ceph/mdsmap.c index 132b64e..3a6ba8a 100644 --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -12,6 +12,20 @@ #include "super.h" +/* + * count active mds's + */ +int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m) +{ + int n = 0; + int i; + + for(i = 0; i < m->m_max_mds; ++i) + if(m->m_info[i].state > 0) + ++n; + + return n; +} /* * choose a random mds that is "up" (i.e. has a state > 0), or -1. @@ -26,9 +40,8 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) return 0; /* count */ - for (i = 0; i < m->m_max_mds; i++) - if (m->m_info[i].state > 0) - n++; + n = ceph_mdsmap_active_mds_count(m); + if (n == 0) return -1; diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 6627b26..4d33d68 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -674,7 +674,15 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, struct ceph_mds_request *req = NULL; int err; struct dentry *root; - + + /* check for mds*/ + if( 0 == ceph_mdsmap_active_mds_count(mdsc->mdsmap) ) + { + pr_info("active mds not found, possible not exist\n"); + root = ERR_PTR( -ECOMM ); + return root; + } + /* open dir */ dout("open_root_inode opening '%s'\n", path); req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS); diff --git a/include/linux/ceph/mdsmap.h b/include/linux/ceph/mdsmap.h index 87ed09f..4d7d502 100644 --- a/include/linux/ceph/mdsmap.h +++ b/include/linux/ceph/mdsmap.h @@ -56,6 +56,7 @@ static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w) return false; } +extern int ceph_mdsmap_active_mds_count(struct ceph_mdsmap *m); extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m); extern struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end); extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m);
For http://tracker.ceph.com/issues/4386 It determines situation, when a user is trying to mount CephFS with no MDS present. Return ECOMM from open_root_dentry which can be analyzed then by ceph.mount Signed-off-by: Mikhail Campos Guadamuz <plageat90@gmail.com> --- fs/ceph/mdsmap.c | 19 ++++++++++++++++--- fs/ceph/super.c | 10 +++++++++- include/linux/ceph/mdsmap.h | 1 + 3 files changed, 26 insertions(+), 4 deletions(-)