| Message ID | 20231213152350.431591-7-dhowells@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | netfs, afs, 9p: Delegate high-level I/O to netfslib | expand |
On Wed, 2023-12-13 at 15:23 +0000, David Howells wrote: > Add a procfile, /proc/fs/netfs/requests, to list in-progress netfslib I/O > requests. > This should probably be in debugfs. I could see us wanting to improve this interface over time. That's harder with procfs but with debugfs we'd have carte blanche to do so. > Signed-off-by: David Howells <dhowells@redhat.com> > cc: Jeff Layton <jlayton@kernel.org> > cc: linux-cachefs@redhat.com > cc: linux-fsdevel@vger.kernel.org > cc: linux-mm@kvack.org > --- > fs/netfs/internal.h | 22 ++++++++++++++ > fs/netfs/main.c | 69 ++++++++++++++++++++++++++++++++++++++++++- > fs/netfs/objects.c | 4 ++- > include/linux/netfs.h | 6 +++- > 4 files changed, 98 insertions(+), 3 deletions(-) > > diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h > index a15fe67e1db7..937d9a22f178 100644 > --- a/fs/netfs/internal.h > +++ b/fs/netfs/internal.h > @@ -33,6 +33,28 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync); > * main.c > */ > extern unsigned int netfs_debug; > +extern struct list_head netfs_io_requests; > +extern spinlock_t netfs_proc_lock; > + > +#ifdef CONFIG_PROC_FS > +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) > +{ > + spin_lock(&netfs_proc_lock); > + list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests); > + spin_unlock(&netfs_proc_lock); > +} > +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) > +{ > + if (!list_empty(&rreq->proc_link)) { > + spin_lock(&netfs_proc_lock); > + list_del_rcu(&rreq->proc_link); > + spin_unlock(&netfs_proc_lock); > + } > +} > +#else > +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {} > +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} > +#endif > > /* > * objects.c > diff --git a/fs/netfs/main.c b/fs/netfs/main.c > index c9af6e0896d3..97ce1436615b 100644 > --- a/fs/netfs/main.c > +++ b/fs/netfs/main.c > @@ -21,13 +21,80 @@ unsigned netfs_debug; > module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); > MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); > > +#ifdef CONFIG_PROC_FS > +LIST_HEAD(netfs_io_requests); > +DEFINE_SPINLOCK(netfs_proc_lock); > + > +static const char *netfs_origins[] = { > + [NETFS_READAHEAD] = "RA", > + [NETFS_READPAGE] = "RP", > + [NETFS_READ_FOR_WRITE] = "RW", > +}; > + > +/* > + * Generate a list of I/O requests in /proc/fs/netfs/requests > + */ > +static int netfs_requests_seq_show(struct seq_file *m, void *v) > +{ > + struct netfs_io_request *rreq; > + > + if (v == &netfs_io_requests) { > + seq_puts(m, > + "REQUEST OR REF FL ERR OPS COVERAGE\n" > + "======== == === == ==== === =========\n" > + ); > + return 0; > + } > + > + rreq = list_entry(v, struct netfs_io_request, proc_link); > + seq_printf(m, > + "%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx", > + rreq->debug_id, > + netfs_origins[rreq->origin], > + refcount_read(&rreq->ref), > + rreq->flags, > + rreq->error, > + atomic_read(&rreq->nr_outstanding), > + rreq->start, rreq->submitted, rreq->len); > + seq_putc(m, '\n'); > + return 0; > +} > + > +static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) > + __acquires(rcu) > +{ > + rcu_read_lock(); > + return seq_list_start_head(&netfs_io_requests, *_pos); > +} > + > +static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) > +{ > + return seq_list_next(v, &netfs_io_requests, _pos); > +} > + > +static void netfs_requests_seq_stop(struct seq_file *m, void *v) > + __releases(rcu) > +{ > + rcu_read_unlock(); > +} > + > +static const struct seq_operations netfs_requests_seq_ops = { > + .start = netfs_requests_seq_start, > + .next = netfs_requests_seq_next, > + .stop = netfs_requests_seq_stop, > + .show = netfs_requests_seq_show, > +}; > +#endif /* CONFIG_PROC_FS */ > + > static int __init netfs_init(void) > { > int ret = -ENOMEM; > > if (!proc_mkdir("fs/netfs", NULL)) > goto error; > - > + if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, > + &netfs_requests_seq_ops)) > + goto error_proc; > #ifdef CONFIG_FSCACHE_STATS > if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, > netfs_stats_show)) > diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c > index e17cdf53f6a7..85f428fc52e6 100644 > --- a/fs/netfs/objects.c > +++ b/fs/netfs/objects.c > @@ -45,6 +45,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, > } > } > > + netfs_proc_add_rreq(rreq); > netfs_stat(&netfs_n_rh_rreq); > return rreq; > } > @@ -76,12 +77,13 @@ static void netfs_free_request(struct work_struct *work) > container_of(work, struct netfs_io_request, work); > > trace_netfs_rreq(rreq, netfs_rreq_trace_free); > + netfs_proc_del_rreq(rreq); > netfs_clear_subrequests(rreq, false); > if (rreq->netfs_ops->free_request) > rreq->netfs_ops->free_request(rreq); > if (rreq->cache_resources.ops) > rreq->cache_resources.ops->end_operation(&rreq->cache_resources); > - kfree(rreq); > + kfree_rcu(rreq, rcu); > netfs_stat_d(&netfs_n_rh_rreq); > } > > diff --git a/include/linux/netfs.h b/include/linux/netfs.h > index 32faf6c89702..7244ddebd974 100644 > --- a/include/linux/netfs.h > +++ b/include/linux/netfs.h > @@ -175,10 +175,14 @@ enum netfs_io_origin { > * operations to a variety of data stores and then stitch the result together. > */ > struct netfs_io_request { > - struct work_struct work; > + union { > + struct work_struct work; > + struct rcu_head rcu; > + }; > struct inode *inode; /* The file being accessed */ > struct address_space *mapping; /* The mapping being accessed */ > struct netfs_cache_resources cache_resources; > + struct list_head proc_link; /* Link in netfs_iorequests */ > struct list_head subrequests; /* Contributory I/O operations */ > void *netfs_priv; /* Private data for the netfs */ > unsigned int debug_id; >
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index a15fe67e1db7..937d9a22f178 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -33,6 +33,28 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync); * main.c */ extern unsigned int netfs_debug; +extern struct list_head netfs_io_requests; +extern spinlock_t netfs_proc_lock; + +#ifdef CONFIG_PROC_FS +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) +{ + spin_lock(&netfs_proc_lock); + list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests); + spin_unlock(&netfs_proc_lock); +} +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) +{ + if (!list_empty(&rreq->proc_link)) { + spin_lock(&netfs_proc_lock); + list_del_rcu(&rreq->proc_link); + spin_unlock(&netfs_proc_lock); + } +} +#else +static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {} +static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} +#endif /* * objects.c diff --git a/fs/netfs/main.c b/fs/netfs/main.c index c9af6e0896d3..97ce1436615b 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -21,13 +21,80 @@ unsigned netfs_debug; module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); +#ifdef CONFIG_PROC_FS +LIST_HEAD(netfs_io_requests); +DEFINE_SPINLOCK(netfs_proc_lock); + +static const char *netfs_origins[] = { + [NETFS_READAHEAD] = "RA", + [NETFS_READPAGE] = "RP", + [NETFS_READ_FOR_WRITE] = "RW", +}; + +/* + * Generate a list of I/O requests in /proc/fs/netfs/requests + */ +static int netfs_requests_seq_show(struct seq_file *m, void *v) +{ + struct netfs_io_request *rreq; + + if (v == &netfs_io_requests) { + seq_puts(m, + "REQUEST OR REF FL ERR OPS COVERAGE\n" + "======== == === == ==== === =========\n" + ); + return 0; + } + + rreq = list_entry(v, struct netfs_io_request, proc_link); + seq_printf(m, + "%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx", + rreq->debug_id, + netfs_origins[rreq->origin], + refcount_read(&rreq->ref), + rreq->flags, + rreq->error, + atomic_read(&rreq->nr_outstanding), + rreq->start, rreq->submitted, rreq->len); + seq_putc(m, '\n'); + return 0; +} + +static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) + __acquires(rcu) +{ + rcu_read_lock(); + return seq_list_start_head(&netfs_io_requests, *_pos); +} + +static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) +{ + return seq_list_next(v, &netfs_io_requests, _pos); +} + +static void netfs_requests_seq_stop(struct seq_file *m, void *v) + __releases(rcu) +{ + rcu_read_unlock(); +} + +static const struct seq_operations netfs_requests_seq_ops = { + .start = netfs_requests_seq_start, + .next = netfs_requests_seq_next, + .stop = netfs_requests_seq_stop, + .show = netfs_requests_seq_show, +}; +#endif /* CONFIG_PROC_FS */ + static int __init netfs_init(void) { int ret = -ENOMEM; if (!proc_mkdir("fs/netfs", NULL)) goto error; - + if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, + &netfs_requests_seq_ops)) + goto error_proc; #ifdef CONFIG_FSCACHE_STATS if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, netfs_stats_show)) diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index e17cdf53f6a7..85f428fc52e6 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -45,6 +45,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, } } + netfs_proc_add_rreq(rreq); netfs_stat(&netfs_n_rh_rreq); return rreq; } @@ -76,12 +77,13 @@ static void netfs_free_request(struct work_struct *work) container_of(work, struct netfs_io_request, work); trace_netfs_rreq(rreq, netfs_rreq_trace_free); + netfs_proc_del_rreq(rreq); netfs_clear_subrequests(rreq, false); if (rreq->netfs_ops->free_request) rreq->netfs_ops->free_request(rreq); if (rreq->cache_resources.ops) rreq->cache_resources.ops->end_operation(&rreq->cache_resources); - kfree(rreq); + kfree_rcu(rreq, rcu); netfs_stat_d(&netfs_n_rh_rreq); } diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 32faf6c89702..7244ddebd974 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -175,10 +175,14 @@ enum netfs_io_origin { * operations to a variety of data stores and then stitch the result together. */ struct netfs_io_request { - struct work_struct work; + union { + struct work_struct work; + struct rcu_head rcu; + }; struct inode *inode; /* The file being accessed */ struct address_space *mapping; /* The mapping being accessed */ struct netfs_cache_resources cache_resources; + struct list_head proc_link; /* Link in netfs_iorequests */ struct list_head subrequests; /* Contributory I/O operations */ void *netfs_priv; /* Private data for the netfs */ unsigned int debug_id;
Add a procfile, /proc/fs/netfs/requests, to list in-progress netfslib I/O requests. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- fs/netfs/internal.h | 22 ++++++++++++++ fs/netfs/main.c | 69 ++++++++++++++++++++++++++++++++++++++++++- fs/netfs/objects.c | 4 ++- include/linux/netfs.h | 6 +++- 4 files changed, 98 insertions(+), 3 deletions(-)