* [PATCH v2 1/3] io_uring/cmd: rename struct uring_cache to io_uring_cmd_data @ 2024-12-13 18:44 Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 2/3] io_uring/cmd: add per-op data to struct io_uring_cmd_data Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() Mark Harmstone 0 siblings, 2 replies; 5+ messages in thread From: Mark Harmstone @ 2024-12-13 18:44 UTC (permalink / raw) To: linux-btrfs, io-uring; +Cc: Jens Axboe From: Jens Axboe <[email protected]> In preparation for making this more generically available for ->uring_cmd() usage that needs stable command data, rename it and move it to io_uring/cmd.h instead. Signed-off-by: Jens Axboe <[email protected]> --- include/linux/io_uring/cmd.h | 4 ++++ io_uring/io_uring.c | 2 +- io_uring/opdef.c | 3 ++- io_uring/uring_cmd.c | 10 +++++----- io_uring/uring_cmd.h | 4 ---- 5 files changed, 12 insertions(+), 11 deletions(-) diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index 0d5448c0b86c..61f97a398e9d 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -18,6 +18,10 @@ struct io_uring_cmd { u8 pdu[32]; /* available inline for free use */ }; +struct io_uring_cmd_data { + struct io_uring_sqe sqes[2]; +}; + static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe) { return sqe->cmd; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 06ff41484e29..8bac014ed631 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -320,7 +320,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) ret |= io_alloc_cache_init(&ctx->rw_cache, IO_ALLOC_CACHE_MAX, sizeof(struct io_async_rw)); ret |= io_alloc_cache_init(&ctx->uring_cache, IO_ALLOC_CACHE_MAX, - sizeof(struct uring_cache)); + sizeof(struct io_uring_cmd_data)); spin_lock_init(&ctx->msg_lock); ret |= io_alloc_cache_init(&ctx->msg_cache, IO_ALLOC_CACHE_MAX, sizeof(struct io_kiocb)); diff --git a/io_uring/opdef.c b/io_uring/opdef.c index 3de75eca1c92..e8baef4e5146 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -7,6 +7,7 @@ #include <linux/fs.h> #include <linux/file.h> #include <linux/io_uring.h> +#include <linux/io_uring/cmd.h> #include "io_uring.h" #include "opdef.h" @@ -414,7 +415,7 @@ const struct io_issue_def io_issue_defs[] = { .plug = 1, .iopoll = 1, .iopoll_queue = 1, - .async_size = 2 * sizeof(struct io_uring_sqe), + .async_size = sizeof(struct io_uring_cmd_data), .prep = io_uring_cmd_prep, .issue = io_uring_cmd, }, diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index af842e9b4eb9..629cb4266da6 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -16,10 +16,10 @@ #include "rsrc.h" #include "uring_cmd.h" -static struct uring_cache *io_uring_async_get(struct io_kiocb *req) +static struct io_uring_cmd_data *io_uring_async_get(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; - struct uring_cache *cache; + struct io_uring_cmd_data *cache; cache = io_alloc_cache_get(&ctx->uring_cache); if (cache) { @@ -35,7 +35,7 @@ static struct uring_cache *io_uring_async_get(struct io_kiocb *req) static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); - struct uring_cache *cache = req->async_data; + struct io_uring_cmd_data *cache = req->async_data; if (issue_flags & IO_URING_F_UNLOCKED) return; @@ -183,7 +183,7 @@ static int io_uring_cmd_prep_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); - struct uring_cache *cache; + struct io_uring_cmd_data *cache; cache = io_uring_async_get(req); if (unlikely(!cache)) @@ -260,7 +260,7 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags) ret = file->f_op->uring_cmd(ioucmd, issue_flags); if (ret == -EAGAIN) { - struct uring_cache *cache = req->async_data; + struct io_uring_cmd_data *cache = req->async_data; if (ioucmd->sqe != (void *) cache) memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx)); diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h index 7dba0f1efc58..f6837ee0955b 100644 --- a/io_uring/uring_cmd.h +++ b/io_uring/uring_cmd.h @@ -1,9 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 -struct uring_cache { - struct io_uring_sqe sqes[2]; -}; - int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags); int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); -- 2.45.2 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/3] io_uring/cmd: add per-op data to struct io_uring_cmd_data 2024-12-13 18:44 [PATCH v2 1/3] io_uring/cmd: rename struct uring_cache to io_uring_cmd_data Mark Harmstone @ 2024-12-13 18:44 ` Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() Mark Harmstone 1 sibling, 0 replies; 5+ messages in thread From: Mark Harmstone @ 2024-12-13 18:44 UTC (permalink / raw) To: linux-btrfs, io-uring; +Cc: Jens Axboe From: Jens Axboe <[email protected]> In case an op handler for ->uring_cmd() needs stable storage for user data, it can allocate io_uring_cmd_data->op_data and use it for the duration of the request. When the request gets cleaned up, uring_cmd will free it automatically. Signed-off-by: Jens Axboe <[email protected]> --- include/linux/io_uring/cmd.h | 1 + io_uring/uring_cmd.c | 13 +++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index 61f97a398e9d..a65c7043078f 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -20,6 +20,7 @@ struct io_uring_cmd { struct io_uring_cmd_data { struct io_uring_sqe sqes[2]; + void *op_data; }; static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe) diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 629cb4266da6..ce7726a04883 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -23,12 +23,16 @@ static struct io_uring_cmd_data *io_uring_async_get(struct io_kiocb *req) cache = io_alloc_cache_get(&ctx->uring_cache); if (cache) { + cache->op_data = NULL; req->flags |= REQ_F_ASYNC_DATA; req->async_data = cache; return cache; } - if (!io_alloc_async_data(req)) - return req->async_data; + if (!io_alloc_async_data(req)) { + cache = req->async_data; + cache->op_data = NULL; + return cache; + } return NULL; } @@ -37,6 +41,11 @@ static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags) struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); struct io_uring_cmd_data *cache = req->async_data; + if (cache->op_data) { + kfree(cache->op_data); + cache->op_data = NULL; + } + if (issue_flags & IO_URING_F_UNLOCKED) return; if (io_alloc_cache_put(&req->ctx->uring_cache, cache)) { -- 2.45.2 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() 2024-12-13 18:44 [PATCH v2 1/3] io_uring/cmd: rename struct uring_cache to io_uring_cmd_data Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 2/3] io_uring/cmd: add per-op data to struct io_uring_cmd_data Mark Harmstone @ 2024-12-13 18:44 ` Mark Harmstone 2024-12-13 19:50 ` Jens Axboe 2024-12-13 21:18 ` Pavel Begunkov 1 sibling, 2 replies; 5+ messages in thread From: Mark Harmstone @ 2024-12-13 18:44 UTC (permalink / raw) To: linux-btrfs, io-uring; +Cc: Mark Harmstone If we return -EAGAIN the first time because we need to block, btrfs_uring_encoded_read() will get called twice. Take a copy of args the first time, to prevent userspace from messing around with it. Signed-off-by: Mark Harmstone <[email protected]> --- Refactored slightly from the first version, in order to eliminate the need_copy variable. fs/btrfs/ioctl.c | 75 +++++++++++++++++++++++++++++++----------------- 1 file changed, 49 insertions(+), 26 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index dc5faa89cdba..684c1541105e 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4882,7 +4882,7 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue { size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args, flags); size_t copy_end; - struct btrfs_ioctl_encoded_io_args args = { 0 }; + struct btrfs_ioctl_encoded_io_args *args; int ret; u64 disk_bytenr, disk_io_size; struct file *file; @@ -4897,6 +4897,8 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue struct extent_state *cached_state = NULL; u64 start, lockend; void __user *sqe_addr; + struct io_kiocb *req = cmd_to_io_kiocb(cmd); + struct io_uring_cmd_data *data = req->async_data; if (!capable(CAP_SYS_ADMIN)) { ret = -EPERM; @@ -4910,32 +4912,53 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue if (issue_flags & IO_URING_F_COMPAT) { #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT) - struct btrfs_ioctl_encoded_io_args_32 args32; - copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32, flags); - if (copy_from_user(&args32, sqe_addr, copy_end)) { - ret = -EFAULT; - goto out_acct; - } - args.iov = compat_ptr(args32.iov); - args.iovcnt = args32.iovcnt; - args.offset = args32.offset; - args.flags = args32.flags; #else return -ENOTTY; #endif } else { copy_end = copy_end_kernel; - if (copy_from_user(&args, sqe_addr, copy_end)) { - ret = -EFAULT; + } + + args = data->op_data; + + if (!args) { + args = kzalloc(sizeof(*args), GFP_NOFS); + if (!args) { + ret = -ENOMEM; goto out_acct; } - } - if (args.flags != 0) - return -EINVAL; + data->op_data = args; - ret = import_iovec(ITER_DEST, args.iov, args.iovcnt, ARRAY_SIZE(iovstack), + if (issue_flags & IO_URING_F_COMPAT) { +#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT) + struct btrfs_ioctl_encoded_io_args_32 args32; + + if (copy_from_user(&args32, sqe_addr, copy_end)) { + ret = -EFAULT; + goto out_acct; + } + + args->iov = compat_ptr(args32.iov); + args->iovcnt = args32.iovcnt; + args->offset = args32.offset; + args->flags = args32.flags; +#endif + } else { + if (copy_from_user(args, sqe_addr, copy_end)) { + ret = -EFAULT; + goto out_acct; + } + } + + if (args->flags != 0) { + ret = -EINVAL; + goto out_acct; + } + } + + ret = import_iovec(ITER_DEST, args->iov, args->iovcnt, ARRAY_SIZE(iovstack), &iov, &iter); if (ret < 0) goto out_acct; @@ -4945,8 +4968,8 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue goto out_free; } - pos = args.offset; - ret = rw_verify_area(READ, file, &pos, args.len); + pos = args->offset; + ret = rw_verify_area(READ, file, &pos, args->len); if (ret < 0) goto out_free; @@ -4959,15 +4982,15 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue start = ALIGN_DOWN(pos, fs_info->sectorsize); lockend = start + BTRFS_MAX_UNCOMPRESSED - 1; - ret = btrfs_encoded_read(&kiocb, &iter, &args, &cached_state, + ret = btrfs_encoded_read(&kiocb, &iter, args, &cached_state, &disk_bytenr, &disk_io_size); if (ret < 0 && ret != -EIOCBQUEUED) goto out_free; file_accessed(file); - if (copy_to_user(sqe_addr + copy_end, (const char *)&args + copy_end_kernel, - sizeof(args) - copy_end_kernel)) { + if (copy_to_user(sqe_addr + copy_end, (const char *)args + copy_end_kernel, + sizeof(*args) - copy_end_kernel)) { if (ret == -EIOCBQUEUED) { unlock_extent(io_tree, start, lockend, &cached_state); btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED); @@ -4984,7 +5007,7 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue * undo this. */ if (!iov) { - iov = kmemdup(iovstack, sizeof(struct iovec) * args.iovcnt, + iov = kmemdup(iovstack, sizeof(struct iovec) * args->iovcnt, GFP_NOFS); if (!iov) { unlock_extent(io_tree, start, lockend, &cached_state); @@ -4997,13 +5020,13 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue count = min_t(u64, iov_iter_count(&iter), disk_io_size); /* Match ioctl by not returning past EOF if uncompressed. */ - if (!args.compression) - count = min_t(u64, count, args.len); + if (!args->compression) + count = min_t(u64, count, args->len); ret = btrfs_uring_read_extent(&kiocb, &iter, start, lockend, cached_state, disk_bytenr, disk_io_size, count, - args.compression, iov, cmd); + args->compression, iov, cmd); goto out_acct; } -- 2.45.2 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() 2024-12-13 18:44 ` [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() Mark Harmstone @ 2024-12-13 19:50 ` Jens Axboe 2024-12-13 21:18 ` Pavel Begunkov 1 sibling, 0 replies; 5+ messages in thread From: Jens Axboe @ 2024-12-13 19:50 UTC (permalink / raw) To: Mark Harmstone, linux-btrfs, io-uring On 12/13/24 11:44 AM, Mark Harmstone wrote: > If we return -EAGAIN the first time because we need to block, > btrfs_uring_encoded_read() will get called twice. Take a copy of args > the first time, to prevent userspace from messing around with it. Looks good to me, however I think you'd want to add: Reported-by: Jens Axboe <[email protected]> Fixes: 34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)") to the tags, but probably whoever applies this can do that. -- Jens Axboe ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() 2024-12-13 18:44 ` [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() Mark Harmstone 2024-12-13 19:50 ` Jens Axboe @ 2024-12-13 21:18 ` Pavel Begunkov 1 sibling, 0 replies; 5+ messages in thread From: Pavel Begunkov @ 2024-12-13 21:18 UTC (permalink / raw) To: Mark Harmstone, linux-btrfs, io-uring On 12/13/24 18:44, Mark Harmstone wrote: > If we return -EAGAIN the first time because we need to block, > btrfs_uring_encoded_read() will get called twice. Take a copy of args > the first time, to prevent userspace from messing around with it. > > Signed-off-by: Mark Harmstone <[email protected]> > --- > Refactored slightly from the first version, in order to eliminate the > need_copy variable. > > fs/btrfs/ioctl.c | 75 +++++++++++++++++++++++++++++++----------------- > 1 file changed, 49 insertions(+), 26 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index dc5faa89cdba..684c1541105e 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -4882,7 +4882,7 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue > { > size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args, flags); > size_t copy_end; > - struct btrfs_ioctl_encoded_io_args args = { 0 }; > + struct btrfs_ioctl_encoded_io_args *args; > int ret; > u64 disk_bytenr, disk_io_size; > struct file *file; > @@ -4897,6 +4897,8 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue > struct extent_state *cached_state = NULL; > u64 start, lockend; > void __user *sqe_addr; > + struct io_kiocb *req = cmd_to_io_kiocb(cmd); Oh no, please don't. In general cmd implementations should never use helpers that are not explicitly given to them in include/linux/io_uring/* > + struct io_uring_cmd_data *data = req->async_data; Just add a helper to io_uring/cmd.h, > > if (!capable(CAP_SYS_ADMIN)) { > ret = -EPERM; ... -- Pavel Begunkov ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-12-13 21:17 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2024-12-13 18:44 [PATCH v2 1/3] io_uring/cmd: rename struct uring_cache to io_uring_cmd_data Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 2/3] io_uring/cmd: add per-op data to struct io_uring_cmd_data Mark Harmstone 2024-12-13 18:44 ` [PATCH v2 3/3] btrfs: don't read from userspace twice in btrfs_uring_encoded_read() Mark Harmstone 2024-12-13 19:50 ` Jens Axboe 2024-12-13 21:18 ` Pavel Begunkov
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox