From aa43457799f715d76cb77342baab0615877e2b8a Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Tue, 22 May 2018 10:52:17 -0700 Subject: [PATCH 1/7] block: add ioprio_check_cap function Aio per command iopriority support introduces a second interface between userland and the kernel capable of passing iopriority. The aio interface also needs the ability to verify that the submitting context has sufficient privileges to submit IOPRIO_RT commands. This patch creates the ioprio_check_cap function to be used by the ioprio_set system call and also by the aio interface. Signed-off-by: Adam Manzanares Reviewed-by: Christoph Hellwig Reviewed-by: Jeff Moyer Signed-off-by: Al Viro --- block/ioprio.c | 22 ++++++++++++++++------ include/linux/ioprio.h | 2 ++ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/block/ioprio.c b/block/ioprio.c index 6f5d0b6625e3..f9821080c92c 100644 --- a/block/ioprio.c +++ b/block/ioprio.c @@ -61,15 +61,10 @@ int set_task_ioprio(struct task_struct *task, int ioprio) } EXPORT_SYMBOL_GPL(set_task_ioprio); -SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) +int ioprio_check_cap(int ioprio) { int class = IOPRIO_PRIO_CLASS(ioprio); int data = IOPRIO_PRIO_DATA(ioprio); - struct task_struct *p, *g; - struct user_struct *user; - struct pid *pgrp; - kuid_t uid; - int ret; switch (class) { case IOPRIO_CLASS_RT: @@ -92,6 +87,21 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) return -EINVAL; } + return 0; +} + +SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) +{ + struct task_struct *p, *g; + struct user_struct *user; + struct pid *pgrp; + kuid_t uid; + int ret; + + ret = ioprio_check_cap(ioprio); + if (ret) + return ret; + ret = -ESRCH; rcu_read_lock(); switch (which) { diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index 627efac73e6d..4a28cec49ec3 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -77,4 +77,6 @@ extern int ioprio_best(unsigned short aprio, unsigned short bprio); extern int set_task_ioprio(struct task_struct *task, int ioprio); +extern int ioprio_check_cap(int ioprio); + #endif From fc28724d67c90ff48b976e0687caf79993160bed Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Tue, 22 May 2018 10:52:18 -0700 Subject: [PATCH 2/7] fs: Convert kiocb rw_hint from enum to u16 In order to avoid kiocb bloat for per command iopriority support, rw_hint is converted from enum to a u16. Added a guard around ki_hint assignment. Signed-off-by: Adam Manzanares Signed-off-by: Al Viro --- fs/aio.c | 2 +- include/linux/fs.h | 13 +++++++++++-- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index b850e92ee0d5..33299ece7540 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1434,7 +1434,7 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) req->ki_flags = iocb_flags(req->ki_filp); if (iocb->aio_flags & IOCB_FLAG_RESFD) req->ki_flags |= IOCB_EVENTFD; - req->ki_hint = file_write_hint(req->ki_filp); + req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp)); ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags); if (unlikely(ret)) fput(req->ki_filp); diff --git a/include/linux/fs.h b/include/linux/fs.h index 4b6045ebb2f2..b432fc3feb93 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -299,7 +299,7 @@ struct kiocb { void (*ki_complete)(struct kiocb *iocb, long ret, long ret2); void *private; int ki_flags; - enum rw_hint ki_hint; + u16 ki_hint; } __randomize_layout; static inline bool is_sync_kiocb(struct kiocb *kiocb) @@ -1929,12 +1929,21 @@ static inline enum rw_hint file_write_hint(struct file *file) static inline int iocb_flags(struct file *file); +static inline u16 ki_hint_validate(enum rw_hint hint) +{ + typeof(((struct kiocb *)0)->ki_hint) max_hint = -1; + + if (hint <= max_hint) + return hint; + return 0; +} + static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) { *kiocb = (struct kiocb) { .ki_filp = filp, .ki_flags = iocb_flags(filp), - .ki_hint = file_write_hint(filp), + .ki_hint = ki_hint_validate(file_write_hint(filp)), }; } From d9a08a9e616beeccdbd0e7262b7225ffdfa49e92 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Tue, 22 May 2018 10:52:19 -0700 Subject: [PATCH 3/7] fs: Add aio iopriority support This is the per-I/O equivalent of the ioprio_set system call. When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field. This patch depends on block: add ioprio_check_cap function. Signed-off-by: Adam Manzanares Reviewed-by: Jeff Moyer Reviewed-by: Christoph Hellwig Signed-off-by: Al Viro --- drivers/block/loop.c | 3 +++ fs/aio.c | 16 ++++++++++++++++ include/linux/fs.h | 3 +++ include/uapi/linux/aio_abi.h | 1 + 4 files changed, 23 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 5d4e31655d96..dd98dfd97f5e 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -76,6 +76,8 @@ #include #include #include +#include + #include "loop.h" #include @@ -559,6 +561,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, cmd->iocb.ki_filp = file; cmd->iocb.ki_complete = lo_rw_aio_complete; cmd->iocb.ki_flags = IOCB_DIRECT; + cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); if (cmd->css) kthread_associate_blkcg(cmd->css); diff --git a/fs/aio.c b/fs/aio.c index 33299ece7540..9527ededa669 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1435,6 +1435,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) if (iocb->aio_flags & IOCB_FLAG_RESFD) req->ki_flags |= IOCB_EVENTFD; req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp)); + if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { + /* + * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then + * aio_reqprio is interpreted as an I/O scheduling + * class and priority. + */ + ret = ioprio_check_cap(iocb->aio_reqprio); + if (ret) { + pr_debug("aio ioprio check cap error\n"); + return -EINVAL; + } + + req->ki_ioprio = iocb->aio_reqprio; + } else + req->ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); + ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags); if (unlikely(ret)) fput(req->ki_filp); diff --git a/include/linux/fs.h b/include/linux/fs.h index b432fc3feb93..eef9334b26d1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -300,6 +301,7 @@ struct kiocb { void *private; int ki_flags; u16 ki_hint; + u16 ki_ioprio; /* See linux/ioprio.h */ } __randomize_layout; static inline bool is_sync_kiocb(struct kiocb *kiocb) @@ -1944,6 +1946,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) .ki_filp = filp, .ki_flags = iocb_flags(filp), .ki_hint = ki_hint_validate(file_write_hint(filp)), + .ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0), }; } diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h index ed0185945bb2..75846164290e 100644 --- a/include/uapi/linux/aio_abi.h +++ b/include/uapi/linux/aio_abi.h @@ -53,6 +53,7 @@ enum { * is valid. */ #define IOCB_FLAG_RESFD (1 << 0) +#define IOCB_FLAG_IOPRIO (1 << 1) /* read() from /dev/aio returns these structures. */ struct io_event { From 074111ca5f713e4db9d370d2502c493b8e8568c6 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Tue, 22 May 2018 10:52:20 -0700 Subject: [PATCH 4/7] fs: blkdev set bio prio from kiocb prio Now that kiocb has an ioprio field copy this over to the bio when it is created from the kiocb. Signed-off-by: Adam Manzanares Reviewed-by: Jeff Moyer Signed-off-by: Al Viro --- fs/block_dev.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 7ec920e27065..11ba99e79d2a 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -216,6 +216,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, bio.bi_write_hint = iocb->ki_hint; bio.bi_private = current; bio.bi_end_io = blkdev_bio_end_io_simple; + bio.bi_ioprio = iocb->ki_ioprio; ret = bio_iov_iter_get_pages(&bio, iter); if (unlikely(ret)) @@ -355,6 +356,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) bio->bi_write_hint = iocb->ki_hint; bio->bi_private = dio; bio->bi_end_io = blkdev_bio_end_io; + bio->bi_ioprio = iocb->ki_ioprio; ret = bio_iov_iter_get_pages(bio, iter); if (unlikely(ret)) { From 087e566916ce2cde4f20a148607c9c3591f46f67 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Tue, 22 May 2018 10:52:21 -0700 Subject: [PATCH 5/7] fs: iomap dio set bio prio from kiocb prio Now that kiocb has an ioprio field copy this over to the bio when it is created from the kiocb during direct IO. Signed-off-by: Adam Manzanares Reviewed-by: Jeff Moyer Reviewed-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/iomap.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/iomap.c b/fs/iomap.c index afd163586aa0..65aae194aeca 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -919,6 +919,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, bio->bi_iter.bi_sector = (iomap->addr + pos - iomap->offset) >> 9; bio->bi_write_hint = dio->iocb->ki_hint; + bio->bi_ioprio = dio->iocb->ki_ioprio; bio->bi_private = dio; bio->bi_end_io = iomap_dio_bio_end_io; From b0966e7b894035dba6710aa4e9f18d7a3a3d5b22 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Mon, 4 Jun 2018 10:59:56 -0700 Subject: [PATCH 6/7] fs: aio ioprio add explicit block layer dependence Previously, the ioprio_check_cap function was only defined when CONFIG_BLOCK was set. Make this relationship explicit and add a stub for !CONFIG_BLOCK. Signed-off-by: Adam Manzanares Signed-off-by: Al Viro --- include/linux/ioprio.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index 4a28cec49ec3..9e30ed6443db 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -77,6 +77,13 @@ extern int ioprio_best(unsigned short aprio, unsigned short bprio); extern int set_task_ioprio(struct task_struct *task, int ioprio); +#ifdef CONFIG_BLOCK extern int ioprio_check_cap(int ioprio); +#else +static inline int ioprio_check_cap(int ioprio) +{ + return -ENOTBLK; +} +#endif /* CONFIG_BLOCK */ #endif From 9a6d9a62e0fd4b9927c3124db0f25fc6b4fb6576 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Mon, 4 Jun 2018 10:59:57 -0700 Subject: [PATCH 7/7] fs: aio ioprio use ioprio_check_cap ret val Previously the value was ignored. Signed-off-by: Adam Manzanares Signed-off-by: Al Viro --- fs/aio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 9527ededa669..134e5b635d64 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1443,8 +1443,8 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) */ ret = ioprio_check_cap(iocb->aio_reqprio); if (ret) { - pr_debug("aio ioprio check cap error\n"); - return -EINVAL; + pr_debug("aio ioprio check cap error: %d\n", ret); + return ret; } req->ki_ioprio = iocb->aio_reqprio;