| Message ID | 20230213202346.291008-1-jlayton@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nfsd: allow reaping files that are still under writeback | expand |
> On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> wrote: > > There's no reason to delay reaping an nfsd_file just because its > underlying inode is still under writeback. nfsd just relies on client > activity or the local flusher threads to do writeback. > > Holding the file open does nothing to facilitate that, nor does it help > with tracking errors. Just allow it to close and let the kernel do > writeback as it normally would. > > Signed-off-by: Jeff Layton <jlayton@kernel.org> Thanks! Applied to topic-filecache-cleanups. > --- > fs/nfsd/filecache.c | 22 ---------------------- > 1 file changed, 22 deletions(-) > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > index e6617431df7c..3b9a10378c83 100644 > --- a/fs/nfsd/filecache.c > +++ b/fs/nfsd/filecache.c > @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) > call_rcu(&nf->nf_rcu, nfsd_file_slab_free); > } > > -static bool > -nfsd_file_check_writeback(struct nfsd_file *nf) > -{ > - struct file *file = nf->nf_file; > - struct address_space *mapping; > - > - if (!file || !(file->f_mode & FMODE_WRITE)) > - return false; > - mapping = file->f_mapping; > - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || > - mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); > -} > - > static bool nfsd_file_lru_add(struct nfsd_file *nf) > { > set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); > @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, > /* We should only be dealing with GC entries here */ > WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); > > - /* > - * Don't throw out files that are still undergoing I/O or > - * that have uncleared errors pending. > - */ > - if (nfsd_file_check_writeback(nf)) { > - trace_nfsd_file_gc_writeback(nf); > - return LRU_SKIP; > - } > - > /* If it was recently added to the list, skip it */ > if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) { > trace_nfsd_file_gc_referenced(nf); > -- > 2.39.1 > -- Chuck Lever
On Tue, 2023-02-14 at 14:48 +0000, Chuck Lever III wrote: > > > > On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> > > wrote: > > > > There's no reason to delay reaping an nfsd_file just because its > > underlying inode is still under writeback. nfsd just relies on > > client > > activity or the local flusher threads to do writeback. > > > > Holding the file open does nothing to facilitate that, nor does it > > help > > with tracking errors. Just allow it to close and let the kernel do > > writeback as it normally would. > > > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > > Thanks! Applied to topic-filecache-cleanups. > > > > --- > > fs/nfsd/filecache.c | 22 ---------------------- > > 1 file changed, 22 deletions(-) > > > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > > index e6617431df7c..3b9a10378c83 100644 > > --- a/fs/nfsd/filecache.c > > +++ b/fs/nfsd/filecache.c > > @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) > > call_rcu(&nf->nf_rcu, nfsd_file_slab_free); > > } > > > > -static bool > > -nfsd_file_check_writeback(struct nfsd_file *nf) > > -{ > > - struct file *file = nf->nf_file; > > - struct address_space *mapping; > > - > > - if (!file || !(file->f_mode & FMODE_WRITE)) > > - return false; > > - mapping = file->f_mapping; > > - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || > > - mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); > > -} > > - > > static bool nfsd_file_lru_add(struct nfsd_file *nf) > > { > > set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); > > @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, > > struct list_lru_one *lru, > > /* We should only be dealing with GC entries here */ > > WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); > > > > - /* > > - * Don't throw out files that are still undergoing I/O or > > - * that have uncleared errors pending. > > - */ > > - if (nfsd_file_check_writeback(nf)) { > > - trace_nfsd_file_gc_writeback(nf); > > - return LRU_SKIP; > > - } > > - > > /* If it was recently added to the list, skip it */ > > if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf- > > >nf_flags)) { > > trace_nfsd_file_gc_referenced(nf); > > -- > > 2.39.1 > > > > -- > Chuck Lever > > > Wait... There is a good reason for wanting to do this in the case of NFS re-exports, since close() is a very expensive operation if the file has dirty data.
> On Feb 14, 2023, at 10:00 AM, Trond Myklebust <trondmy@kernel.org> wrote: > > On Tue, 2023-02-14 at 14:48 +0000, Chuck Lever III wrote: >> >> >>> On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> >>> wrote: >>> >>> There's no reason to delay reaping an nfsd_file just because its >>> underlying inode is still under writeback. nfsd just relies on >>> client >>> activity or the local flusher threads to do writeback. >>> >>> Holding the file open does nothing to facilitate that, nor does it >>> help >>> with tracking errors. Just allow it to close and let the kernel do >>> writeback as it normally would. >>> >>> Signed-off-by: Jeff Layton <jlayton@kernel.org> >> >> Thanks! Applied to topic-filecache-cleanups. >> >> >>> --- >>> fs/nfsd/filecache.c | 22 ---------------------- >>> 1 file changed, 22 deletions(-) >>> >>> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c >>> index e6617431df7c..3b9a10378c83 100644 >>> --- a/fs/nfsd/filecache.c >>> +++ b/fs/nfsd/filecache.c >>> @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) >>> call_rcu(&nf->nf_rcu, nfsd_file_slab_free); >>> } >>> >>> -static bool >>> -nfsd_file_check_writeback(struct nfsd_file *nf) >>> -{ >>> - struct file *file = nf->nf_file; >>> - struct address_space *mapping; >>> - >>> - if (!file || !(file->f_mode & FMODE_WRITE)) >>> - return false; >>> - mapping = file->f_mapping; >>> - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || >>> - mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); >>> -} >>> - >>> static bool nfsd_file_lru_add(struct nfsd_file *nf) >>> { >>> set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); >>> @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, >>> struct list_lru_one *lru, >>> /* We should only be dealing with GC entries here */ >>> WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); >>> >>> - /* >>> - * Don't throw out files that are still undergoing I/O or >>> - * that have uncleared errors pending. >>> - */ >>> - if (nfsd_file_check_writeback(nf)) { >>> - trace_nfsd_file_gc_writeback(nf); >>> - return LRU_SKIP; >>> - } >>> - >>> /* If it was recently added to the list, skip it */ >>> if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf- >>>> nf_flags)) { >>> trace_nfsd_file_gc_referenced(nf); >>> -- >>> 2.39.1 >>> >> >> -- >> Chuck Lever >> >> >> > > Wait... There is a good reason for wanting to do this in the case of > NFS re-exports, since close() is a very expensive operation if the file > has dirty data. Then perhaps skipping these files can be gated on an EXPORT_OP flag? -- Chuck Lever
On Tue, 2023-02-14 at 15:05 +0000, Chuck Lever III wrote: > > > > On Feb 14, 2023, at 10:00 AM, Trond Myklebust <trondmy@kernel.org> > > wrote: > > > > On Tue, 2023-02-14 at 14:48 +0000, Chuck Lever III wrote: > > > > > > > > > > On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> > > > > wrote: > > > > > > > > There's no reason to delay reaping an nfsd_file just because > > > > its > > > > underlying inode is still under writeback. nfsd just relies on > > > > client > > > > activity or the local flusher threads to do writeback. > > > > > > > > Holding the file open does nothing to facilitate that, nor does > > > > it > > > > help > > > > with tracking errors. Just allow it to close and let the kernel > > > > do > > > > writeback as it normally would. > > > > > > > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > > > > > > Thanks! Applied to topic-filecache-cleanups. > > > > > > > > > > --- > > > > fs/nfsd/filecache.c | 22 ---------------------- > > > > 1 file changed, 22 deletions(-) > > > > > > > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > > > > index e6617431df7c..3b9a10378c83 100644 > > > > --- a/fs/nfsd/filecache.c > > > > +++ b/fs/nfsd/filecache.c > > > > @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) > > > > call_rcu(&nf->nf_rcu, nfsd_file_slab_free); > > > > } > > > > > > > > -static bool > > > > -nfsd_file_check_writeback(struct nfsd_file *nf) > > > > -{ > > > > - struct file *file = nf->nf_file; > > > > - struct address_space *mapping; > > > > - > > > > - if (!file || !(file->f_mode & FMODE_WRITE)) > > > > - return false; > > > > - mapping = file->f_mapping; > > > > - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || > > > > - mapping_tagged(mapping, > > > > PAGECACHE_TAG_WRITEBACK); > > > > -} > > > > - > > > > static bool nfsd_file_lru_add(struct nfsd_file *nf) > > > > { > > > > set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); > > > > @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, > > > > struct list_lru_one *lru, > > > > /* We should only be dealing with GC entries here */ > > > > WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); > > > > > > > > - /* > > > > - * Don't throw out files that are still undergoing I/O > > > > or > > > > - * that have uncleared errors pending. > > > > - */ > > > > - if (nfsd_file_check_writeback(nf)) { > > > > - trace_nfsd_file_gc_writeback(nf); > > > > - return LRU_SKIP; > > > > - } > > > > - > > > > /* If it was recently added to the list, skip it */ > > > > if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf- > > > > > nf_flags)) { > > > > trace_nfsd_file_gc_referenced(nf); > > > > -- > > > > 2.39.1 > > > > > > > > > > -- > > > Chuck Lever > > > > > > > > > > > > > Wait... There is a good reason for wanting to do this in the case > > of > > NFS re-exports, since close() is a very expensive operation if the > > file > > has dirty data. > > Then perhaps skipping these files can be gated on an EXPORT_OP flag? That would work.
On Tue, 2023-02-14 at 10:00 -0500, Trond Myklebust wrote: > On Tue, 2023-02-14 at 14:48 +0000, Chuck Lever III wrote: > > > > > > > On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> > > > wrote: > > > > > > There's no reason to delay reaping an nfsd_file just because its > > > underlying inode is still under writeback. nfsd just relies on > > > client > > > activity or the local flusher threads to do writeback. > > > > > > Holding the file open does nothing to facilitate that, nor does it > > > help > > > with tracking errors. Just allow it to close and let the kernel do > > > writeback as it normally would. > > > > > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > > > > Thanks! Applied to topic-filecache-cleanups. > > > > > > > --- > > > fs/nfsd/filecache.c | 22 ---------------------- > > > 1 file changed, 22 deletions(-) > > > > > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > > > index e6617431df7c..3b9a10378c83 100644 > > > --- a/fs/nfsd/filecache.c > > > +++ b/fs/nfsd/filecache.c > > > @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) > > > call_rcu(&nf->nf_rcu, nfsd_file_slab_free); > > > } > > > > > > -static bool > > > -nfsd_file_check_writeback(struct nfsd_file *nf) > > > -{ > > > - struct file *file = nf->nf_file; > > > - struct address_space *mapping; > > > - > > > - if (!file || !(file->f_mode & FMODE_WRITE)) > > > - return false; > > > - mapping = file->f_mapping; > > > - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || > > > - mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); > > > -} > > > - > > > static bool nfsd_file_lru_add(struct nfsd_file *nf) > > > { > > > set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); > > > @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, > > > struct list_lru_one *lru, > > > /* We should only be dealing with GC entries here */ > > > WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); > > > > > > - /* > > > - * Don't throw out files that are still undergoing I/O or > > > - * that have uncleared errors pending. > > > - */ > > > - if (nfsd_file_check_writeback(nf)) { > > > - trace_nfsd_file_gc_writeback(nf); > > > - return LRU_SKIP; > > > - } > > > - > > > /* If it was recently added to the list, skip it */ > > > if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf- > > > > nf_flags)) { > > > trace_nfsd_file_gc_referenced(nf); > > > -- > > > 2.39.1 > > > > > > > -- > > Chuck Lever > > > > > > > > Wait... There is a good reason for wanting to do this in the case of > NFS re-exports, since close() is a very expensive operation if the file > has dirty data. > Fair enough. What if we added a new EXPORT_OP_FLUSH_ON_CLOSE flag that filesystems could set in the export_operations? Then we could make this behavior conditional on that being set?
On Tue, 2023-02-14 at 10:16 -0500, Jeff Layton wrote: > On Tue, 2023-02-14 at 10:00 -0500, Trond Myklebust wrote: > > On Tue, 2023-02-14 at 14:48 +0000, Chuck Lever III wrote: > > > > > > > > > > On Feb 13, 2023, at 3:23 PM, Jeff Layton <jlayton@kernel.org> > > > > wrote: > > > > > > > > There's no reason to delay reaping an nfsd_file just because > > > > its > > > > underlying inode is still under writeback. nfsd just relies on > > > > client > > > > activity or the local flusher threads to do writeback. > > > > > > > > Holding the file open does nothing to facilitate that, nor does > > > > it > > > > help > > > > with tracking errors. Just allow it to close and let the kernel > > > > do > > > > writeback as it normally would. > > > > > > > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > > > > > > Thanks! Applied to topic-filecache-cleanups. > > > > > > > > > > --- > > > > fs/nfsd/filecache.c | 22 ---------------------- > > > > 1 file changed, 22 deletions(-) > > > > > > > > diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c > > > > index e6617431df7c..3b9a10378c83 100644 > > > > --- a/fs/nfsd/filecache.c > > > > +++ b/fs/nfsd/filecache.c > > > > @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) > > > > call_rcu(&nf->nf_rcu, nfsd_file_slab_free); > > > > } > > > > > > > > -static bool > > > > -nfsd_file_check_writeback(struct nfsd_file *nf) > > > > -{ > > > > - struct file *file = nf->nf_file; > > > > - struct address_space *mapping; > > > > - > > > > - if (!file || !(file->f_mode & FMODE_WRITE)) > > > > - return false; > > > > - mapping = file->f_mapping; > > > > - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || > > > > - mapping_tagged(mapping, > > > > PAGECACHE_TAG_WRITEBACK); > > > > -} > > > > - > > > > static bool nfsd_file_lru_add(struct nfsd_file *nf) > > > > { > > > > set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); > > > > @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, > > > > struct list_lru_one *lru, > > > > /* We should only be dealing with GC entries here */ > > > > WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); > > > > > > > > - /* > > > > - * Don't throw out files that are still undergoing I/O > > > > or > > > > - * that have uncleared errors pending. > > > > - */ > > > > - if (nfsd_file_check_writeback(nf)) { > > > > - trace_nfsd_file_gc_writeback(nf); > > > > - return LRU_SKIP; > > > > - } > > > > - > > > > /* If it was recently added to the list, skip it */ > > > > if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf- > > > > > nf_flags)) { > > > > trace_nfsd_file_gc_referenced(nf); > > > > -- > > > > 2.39.1 > > > > > > > > > > -- > > > Chuck Lever > > > > > > > > > > > > > Wait... There is a good reason for wanting to do this in the case > > of > > NFS re-exports, since close() is a very expensive operation if the > > file > > has dirty data. > > > > Fair enough. What if we added a new EXPORT_OP_FLUSH_ON_CLOSE flag > that > filesystems could set in the export_operations? Then we could make > this > behavior conditional on that being set? Sure.
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index e6617431df7c..3b9a10378c83 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -296,19 +296,6 @@ nfsd_file_free(struct nfsd_file *nf) call_rcu(&nf->nf_rcu, nfsd_file_slab_free); } -static bool -nfsd_file_check_writeback(struct nfsd_file *nf) -{ - struct file *file = nf->nf_file; - struct address_space *mapping; - - if (!file || !(file->f_mode & FMODE_WRITE)) - return false; - mapping = file->f_mapping; - return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || - mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); -} - static bool nfsd_file_lru_add(struct nfsd_file *nf) { set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); @@ -438,15 +425,6 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, /* We should only be dealing with GC entries here */ WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); - /* - * Don't throw out files that are still undergoing I/O or - * that have uncleared errors pending. - */ - if (nfsd_file_check_writeback(nf)) { - trace_nfsd_file_gc_writeback(nf); - return LRU_SKIP; - } - /* If it was recently added to the list, skip it */ if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) { trace_nfsd_file_gc_referenced(nf);
There's no reason to delay reaping an nfsd_file just because its underlying inode is still under writeback. nfsd just relies on client activity or the local flusher threads to do writeback. Holding the file open does nothing to facilitate that, nor does it help with tracking errors. Just allow it to close and let the kernel do writeback as it normally would. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/nfsd/filecache.c | 22 ---------------------- 1 file changed, 22 deletions(-)