| Message ID | 20220708054216.825004-1-ruansy.fnst@fujitsu.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,v5] mm, pmem, xfs: Introduce MF_MEM_REMOVE for unbind | expand |
On Fri, Jul 08, 2022 at 05:42:22AM +0000, ruansy.fnst@fujitsu.com wrote: > This patch is inspired by Dan's "mm, dax, pmem: Introduce > dev_pagemap_failure()"[1]. With the help of dax_holder and > ->notify_failure() mechanism, the pmem driver is able to ask filesystem > (or mapped device) on it to unmap all files in use and notify processes > who are using those files. > > Call trace: > trigger unbind > -> unbind_store() > -> ... (skip) > -> devres_release_all() # was pmem driver ->remove() in v1 > -> kill_dax() > -> dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_REMOVE) > -> xfs_dax_notify_failure() > > Introduce MF_MEM_REMOVE to let filesystem know this is a remove event. > So do not shutdown filesystem directly if something not supported, or if > failure range includes metadata area. Make sure all files and processes > are handled correctly. > > == > Changes since v4: > 1. sync_filesystem() at the beginning when MF_MEM_REMOVE > 2. Rebased on next-20220706 > > Changes since v3: > 1. Flush dirty files and logs when pmem is about to be removed. > 2. Rebased on next-20220701 > > Changes since v2: > 1. Rebased on next-20220615 > > Changes since v1: > 1. Drop the needless change of moving {kill,put}_dax() > 2. Rebased on '[PATCHSETS] v14 fsdax-rmap + v11 fsdax-reflink'[2] > > [1]: https://lore.kernel.org/linux-mm/161604050314.1463742.14151665140035795571.stgit@dwillia2-desk3.amr.corp.intel.com/ > [2]: https://lore.kernel.org/linux-xfs/20220508143620.1775214-1-ruansy.fnst@fujitsu.com/ > > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> > --- > drivers/dax/super.c | 2 +- > fs/xfs/xfs_notify_failure.c | 16 ++++++++++++++++ > include/linux/mm.h | 1 + > 3 files changed, 18 insertions(+), 1 deletion(-) > > diff --git a/drivers/dax/super.c b/drivers/dax/super.c > index 9b5e2a5eb0ae..d4bc83159d46 100644 > --- a/drivers/dax/super.c > +++ b/drivers/dax/super.c > @@ -323,7 +323,7 @@ void kill_dax(struct dax_device *dax_dev) > return; > > if (dax_dev->holder_data != NULL) > - dax_holder_notify_failure(dax_dev, 0, U64_MAX, 0); > + dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_REMOVE); > > clear_bit(DAXDEV_ALIVE, &dax_dev->flags); > synchronize_srcu(&dax_srcu); > diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c > index aa8dc27c599c..728b0c1d0ddf 100644 > --- a/fs/xfs/xfs_notify_failure.c > +++ b/fs/xfs/xfs_notify_failure.c > @@ -18,6 +18,7 @@ > #include "xfs_rmap_btree.h" > #include "xfs_rtalloc.h" > #include "xfs_trans.h" > +#include "xfs_log.h" > > #include <linux/mm.h> > #include <linux/dax.h> > @@ -75,6 +76,10 @@ xfs_dax_failure_fn( > > if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) || > (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) { > + /* Do not shutdown so early when device is to be removed */ > + if (notify->mf_flags & MF_MEM_REMOVE) { > + return 0; > + } Nit: no curly braces needed here. > xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); > return -EFSCORRUPTED; > } > @@ -168,6 +173,14 @@ xfs_dax_notify_failure( > struct xfs_mount *mp = dax_holder(dax_dev); > u64 ddev_start; > u64 ddev_end; > + int error; > + > + if (mf_flags & MF_MEM_REMOVE) { > + xfs_info(mp, "device is about to be removed!"); > + error = sync_filesystem(mp->m_super); sync_filesystem requires callers to hold s_umount. Does the dax media failure code take that lock for us, or is this missing a lock? Also, I'm not sure it's a good idea to sync_filesystem() before checking if SB_BORN has been set. > + if (error) > + return error; > + } > > if (!(mp->m_sb.sb_flags & SB_BORN)) { > xfs_warn(mp, "filesystem is not ready for notify_failure()!"); > @@ -182,6 +195,9 @@ xfs_dax_notify_failure( > > if (mp->m_logdev_targp && mp->m_logdev_targp->bt_daxdev == dax_dev && > mp->m_logdev_targp != mp->m_ddev_targp) { > + if (mf_flags & MF_MEM_REMOVE) { > + return 0; > + } Same nit about not needing curly braces. > xfs_err(mp, "ondisk log corrupt, shutting down fs!"); > xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); > return -EFSCORRUPTED; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 794ad19b57f8..3eab2d7ba884 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3240,6 +3240,7 @@ enum mf_flags { > MF_UNPOISON = 1 << 4, > MF_SW_SIMULATED = 1 << 5, > MF_NO_RETRY = 1 << 6, > + MF_MEM_REMOVE = 1 << 7, This is more of a pre-removal notification, right? I think the flag value ought to be named that way too (MF_MEM_PRE_REMOVE). --D > }; > int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, > unsigned long count, int mf_flags); > -- > 2.37.0
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 9b5e2a5eb0ae..d4bc83159d46 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -323,7 +323,7 @@ void kill_dax(struct dax_device *dax_dev) return; if (dax_dev->holder_data != NULL) - dax_holder_notify_failure(dax_dev, 0, U64_MAX, 0); + dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_REMOVE); clear_bit(DAXDEV_ALIVE, &dax_dev->flags); synchronize_srcu(&dax_srcu); diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c index aa8dc27c599c..728b0c1d0ddf 100644 --- a/fs/xfs/xfs_notify_failure.c +++ b/fs/xfs/xfs_notify_failure.c @@ -18,6 +18,7 @@ #include "xfs_rmap_btree.h" #include "xfs_rtalloc.h" #include "xfs_trans.h" +#include "xfs_log.h" #include <linux/mm.h> #include <linux/dax.h> @@ -75,6 +76,10 @@ xfs_dax_failure_fn( if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) || (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) { + /* Do not shutdown so early when device is to be removed */ + if (notify->mf_flags & MF_MEM_REMOVE) { + return 0; + } xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); return -EFSCORRUPTED; } @@ -168,6 +173,14 @@ xfs_dax_notify_failure( struct xfs_mount *mp = dax_holder(dax_dev); u64 ddev_start; u64 ddev_end; + int error; + + if (mf_flags & MF_MEM_REMOVE) { + xfs_info(mp, "device is about to be removed!"); + error = sync_filesystem(mp->m_super); + if (error) + return error; + } if (!(mp->m_sb.sb_flags & SB_BORN)) { xfs_warn(mp, "filesystem is not ready for notify_failure()!"); @@ -182,6 +195,9 @@ xfs_dax_notify_failure( if (mp->m_logdev_targp && mp->m_logdev_targp->bt_daxdev == dax_dev && mp->m_logdev_targp != mp->m_ddev_targp) { + if (mf_flags & MF_MEM_REMOVE) { + return 0; + } xfs_err(mp, "ondisk log corrupt, shutting down fs!"); xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); return -EFSCORRUPTED; diff --git a/include/linux/mm.h b/include/linux/mm.h index 794ad19b57f8..3eab2d7ba884 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3240,6 +3240,7 @@ enum mf_flags { MF_UNPOISON = 1 << 4, MF_SW_SIMULATED = 1 << 5, MF_NO_RETRY = 1 << 6, + MF_MEM_REMOVE = 1 << 7, }; int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, unsigned long count, int mf_flags);
This patch is inspired by Dan's "mm, dax, pmem: Introduce dev_pagemap_failure()"[1]. With the help of dax_holder and ->notify_failure() mechanism, the pmem driver is able to ask filesystem (or mapped device) on it to unmap all files in use and notify processes who are using those files. Call trace: trigger unbind -> unbind_store() -> ... (skip) -> devres_release_all() # was pmem driver ->remove() in v1 -> kill_dax() -> dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_REMOVE) -> xfs_dax_notify_failure() Introduce MF_MEM_REMOVE to let filesystem know this is a remove event. So do not shutdown filesystem directly if something not supported, or if failure range includes metadata area. Make sure all files and processes are handled correctly. == Changes since v4: 1. sync_filesystem() at the beginning when MF_MEM_REMOVE 2. Rebased on next-20220706 Changes since v3: 1. Flush dirty files and logs when pmem is about to be removed. 2. Rebased on next-20220701 Changes since v2: 1. Rebased on next-20220615 Changes since v1: 1. Drop the needless change of moving {kill,put}_dax() 2. Rebased on '[PATCHSETS] v14 fsdax-rmap + v11 fsdax-reflink'[2] [1]: https://lore.kernel.org/linux-mm/161604050314.1463742.14151665140035795571.stgit@dwillia2-desk3.amr.corp.intel.com/ [2]: https://lore.kernel.org/linux-xfs/20220508143620.1775214-1-ruansy.fnst@fujitsu.com/ Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> --- drivers/dax/super.c | 2 +- fs/xfs/xfs_notify_failure.c | 16 ++++++++++++++++ include/linux/mm.h | 1 + 3 files changed, 18 insertions(+), 1 deletion(-)