From c186afb4dbd0050a537b96c7fbee2dba3b57fc38 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 2 Feb 2014 21:16:54 -0500 Subject: switch ->is_partially_uptodate() to saner arguments Signed-off-by: Al Viro --- mm/filemap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index 7a13f6ac5421..46e98019af6c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1148,7 +1148,7 @@ find_page: if (!page->mapping) goto page_not_up_to_date_locked; if (!mapping->a_ops->is_partially_uptodate(page, - desc, offset)) + offset, desc->count)) goto page_not_up_to_date_locked; unlock_page(page); } -- cgit v1.2.3 From 9e8c2af96e0d2d5fe298dd796fb6bc16e888a48d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 2 Feb 2014 22:10:25 -0500 Subject: callers of iov_copy_from_user_atomic() don't need pagecache_disable() ... it does that itself (via kmap_atomic()) Signed-off-by: Al Viro --- fs/btrfs/file.c | 5 ----- fs/fuse/file.c | 2 -- mm/filemap.c | 3 --- 3 files changed, 10 deletions(-) (limited to 'mm') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 0165b8672f09..34e096201da1 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -425,13 +425,8 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, struct page *page = prepared_pages[pg]; /* * Copy data from userspace to the current page - * - * Disable pagefault to avoid recursive lock since - * the pages are already locked */ - pagefault_disable(); copied = iov_iter_copy_from_user_atomic(page, i, offset, count); - pagefault_enable(); /* Flush processor's dcache for this page */ flush_dcache_page(page); diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 77bcc303c3ae..a91d3b4d32f3 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1003,9 +1003,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, if (mapping_writably_mapped(mapping)) flush_dcache_page(page); - pagefault_disable(); tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); - pagefault_enable(); flush_dcache_page(page); mark_page_accessed(page); diff --git a/mm/filemap.c b/mm/filemap.c index 46e98019af6c..bfb7a97d6d0f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1974,7 +1974,6 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, char *kaddr; size_t copied; - BUG_ON(!in_atomic()); kaddr = kmap_atomic(page); if (likely(i->nr_segs == 1)) { int left; @@ -2348,9 +2347,7 @@ again: if (mapping_writably_mapped(mapping)) flush_dcache_page(page); - pagefault_disable(); copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); - pagefault_enable(); flush_dcache_page(page); mark_page_accessed(page); -- cgit v1.2.3 From 8142c184b8f16d213eb8ba06ccb6222259a51cfc Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 2 Feb 2014 22:18:22 -0500 Subject: do_shmem_file_read(): call file_read_actor() directly Signed-off-by: Al Viro --- mm/shmem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index 1f18c9d0d93e..9398e6cd48cb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1462,7 +1462,7 @@ shmem_write_end(struct file *file, struct address_space *mapping, return copied; } -static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) +static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc) { struct inode *inode = file_inode(filp); struct address_space *mapping = inode->i_mapping; @@ -1550,7 +1550,7 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_ * "pos" here (the actor routine has to update the user buffer * pointers and the remaining count). */ - ret = actor(desc, page, offset, nr); + ret = file_read_actor(desc, page, offset, nr); offset += ret; index += offset >> PAGE_CACHE_SHIFT; offset &= ~PAGE_CACHE_MASK; @@ -1588,7 +1588,7 @@ static ssize_t shmem_file_aio_read(struct kiocb *iocb, if (desc.count == 0) continue; desc.error = 0; - do_shmem_file_read(filp, ppos, &desc, file_read_actor); + do_shmem_file_read(filp, ppos, &desc); retval += desc.written; if (desc.error) { retval = retval ?: desc.error; -- cgit v1.2.3 From 6e58e79db8a16222b31fc8da1ca2ac2dccfc4237 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 3 Feb 2014 17:07:03 -0500 Subject: introduce copy_page_to_iter, kill loop over iovec in generic_file_aio_read() generic_file_aio_read() was looping over the target iovec, with loop over (source) pages nested inside that. Just set an iov_iter up and pass *that* to do_generic_file_aio_read(). With copy_page_to_iter() doing all work of mapping and copying a page to iovec and advancing iov_iter. Switch shmem_file_aio_read() to the same and kill file_read_actor(), while we are at it. Signed-off-by: Al Viro --- include/linux/fs.h | 1 - include/linux/uio.h | 2 + mm/filemap.c | 202 ++++++++++++++++++++++++++++------------------------ mm/shmem.c | 77 +++++++------------- 4 files changed, 138 insertions(+), 144 deletions(-) (limited to 'mm') diff --git a/include/linux/fs.h b/include/linux/fs.h index 2261ac8f0534..2a5b1744f80a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2390,7 +2390,6 @@ extern int generic_file_mmap(struct file *, struct vm_area_struct *); extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr, unsigned long size, pgoff_t pgoff); -extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size); int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk); extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t); extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, diff --git a/include/linux/uio.h b/include/linux/uio.h index 347d70ce098e..199bcc34241b 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -67,6 +67,8 @@ size_t iov_iter_copy_from_user(struct page *page, void iov_iter_advance(struct iov_iter *i, size_t bytes); int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); +size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, + struct iov_iter *i); static inline void iov_iter_init(struct iov_iter *i, const struct iovec *iov, unsigned long nr_segs, diff --git a/mm/filemap.c b/mm/filemap.c index bfb7a97d6d0f..a16eb2c4f316 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1085,11 +1085,90 @@ static void shrink_readahead_size_eio(struct file *filp, ra->ra_pages /= 4; } +size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, + struct iov_iter *i) +{ + size_t skip, copy, left, wanted; + const struct iovec *iov; + char __user *buf; + void *kaddr, *from; + + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + wanted = bytes; + iov = i->iov; + skip = i->iov_offset; + buf = iov->iov_base + skip; + copy = min(bytes, iov->iov_len - skip); + + if (!fault_in_pages_writeable(buf, copy)) { + kaddr = kmap_atomic(page); + from = kaddr + offset; + + /* first chunk, usually the only one */ + left = __copy_to_user_inatomic(buf, from, copy); + copy -= left; + skip += copy; + from += copy; + bytes -= copy; + + while (unlikely(!left && bytes)) { + iov++; + buf = iov->iov_base; + copy = min(bytes, iov->iov_len); + left = __copy_to_user_inatomic(buf, from, copy); + copy -= left; + skip = copy; + from += copy; + bytes -= copy; + } + if (likely(!bytes)) { + kunmap_atomic(kaddr); + goto done; + } + offset = from - kaddr; + buf += copy; + kunmap_atomic(kaddr); + copy = min(bytes, iov->iov_len - skip); + } + /* Too bad - revert to non-atomic kmap */ + kaddr = kmap(page); + from = kaddr + offset; + left = __copy_to_user(buf, from, copy); + copy -= left; + skip += copy; + from += copy; + bytes -= copy; + while (unlikely(!left && bytes)) { + iov++; + buf = iov->iov_base; + copy = min(bytes, iov->iov_len); + left = __copy_to_user(buf, from, copy); + copy -= left; + skip = copy; + from += copy; + bytes -= copy; + } + kunmap(page); +done: + i->count -= wanted - bytes; + i->nr_segs -= iov - i->iov; + i->iov = iov; + i->iov_offset = skip; + return wanted - bytes; +} +EXPORT_SYMBOL(copy_page_to_iter); + /** * do_generic_file_read - generic file read routine * @filp: the file to read * @ppos: current file position - * @desc: read_descriptor + * @iter: data destination + * @written: already copied * * This is a generic file read routine, and uses the * mapping->a_ops->readpage() function for the actual low-level stuff. @@ -1097,8 +1176,8 @@ static void shrink_readahead_size_eio(struct file *filp, * This is really ugly. But the goto's actually try to clarify some * of the logic when it comes to error handling etc. */ -static void do_generic_file_read(struct file *filp, loff_t *ppos, - read_descriptor_t *desc) +static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, + struct iov_iter *iter, ssize_t written) { struct address_space *mapping = filp->f_mapping; struct inode *inode = mapping->host; @@ -1108,12 +1187,12 @@ static void do_generic_file_read(struct file *filp, loff_t *ppos, pgoff_t prev_index; unsigned long offset; /* offset into pagecache page */ unsigned int prev_offset; - int error; + int error = 0; index = *ppos >> PAGE_CACHE_SHIFT; prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT; prev_offset = ra->prev_pos & (PAGE_CACHE_SIZE-1); - last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT; + last_index = (*ppos + iter->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT; offset = *ppos & ~PAGE_CACHE_MASK; for (;;) { @@ -1148,7 +1227,7 @@ find_page: if (!page->mapping) goto page_not_up_to_date_locked; if (!mapping->a_ops->is_partially_uptodate(page, - offset, desc->count)) + offset, iter->count)) goto page_not_up_to_date_locked; unlock_page(page); } @@ -1198,24 +1277,23 @@ page_ok: /* * Ok, we have the page, and it's up-to-date, so * now we can copy it to user space... - * - * The file_read_actor routine returns how many bytes were - * actually used.. - * NOTE! This may not be the same as how much of a user buffer - * we filled up (we may be padding etc), so we can only update - * "pos" here (the actor routine has to update the user buffer - * pointers and the remaining count). */ - ret = file_read_actor(desc, page, offset, nr); + + ret = copy_page_to_iter(page, offset, nr, iter); offset += ret; index += offset >> PAGE_CACHE_SHIFT; offset &= ~PAGE_CACHE_MASK; prev_offset = offset; page_cache_release(page); - if (ret == nr && desc->count) - continue; - goto out; + written += ret; + if (!iov_iter_count(iter)) + goto out; + if (ret < nr) { + error = -EFAULT; + goto out; + } + continue; page_not_up_to_date: /* Get exclusive access to the page ... */ @@ -1250,6 +1328,7 @@ readpage: if (unlikely(error)) { if (error == AOP_TRUNCATED_PAGE) { page_cache_release(page); + error = 0; goto find_page; } goto readpage_error; @@ -1280,7 +1359,6 @@ readpage: readpage_error: /* UHHUH! A synchronous read error occurred. Report it */ - desc->error = error; page_cache_release(page); goto out; @@ -1291,16 +1369,17 @@ no_cached_page: */ page = page_cache_alloc_cold(mapping); if (!page) { - desc->error = -ENOMEM; + error = -ENOMEM; goto out; } error = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL); if (error) { page_cache_release(page); - if (error == -EEXIST) + if (error == -EEXIST) { + error = 0; goto find_page; - desc->error = error; + } goto out; } goto readpage; @@ -1313,44 +1392,7 @@ out: *ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset; file_accessed(filp); -} - -int file_read_actor(read_descriptor_t *desc, struct page *page, - unsigned long offset, unsigned long size) -{ - char *kaddr; - unsigned long left, count = desc->count; - - if (size > count) - size = count; - - /* - * Faults on the destination of a read are common, so do it before - * taking the kmap. - */ - if (!fault_in_pages_writeable(desc->arg.buf, size)) { - kaddr = kmap_atomic(page); - left = __copy_to_user_inatomic(desc->arg.buf, - kaddr + offset, size); - kunmap_atomic(kaddr); - if (left == 0) - goto success; - } - - /* Do it the slow way */ - kaddr = kmap(page); - left = __copy_to_user(desc->arg.buf, kaddr + offset, size); - kunmap(page); - - if (left) { - size -= left; - desc->error = -EFAULT; - } -success: - desc->count = count - size; - desc->written += size; - desc->arg.buf += size; - return size; + return written ? written : error; } /* @@ -1408,14 +1450,15 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, { struct file *filp = iocb->ki_filp; ssize_t retval; - unsigned long seg = 0; size_t count; loff_t *ppos = &iocb->ki_pos; + struct iov_iter i; count = 0; retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); if (retval) return retval; + iov_iter_init(&i, iov, nr_segs, count, 0); /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (filp->f_flags & O_DIRECT) { @@ -1437,6 +1480,11 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, if (retval > 0) { *ppos = pos + retval; count -= retval; + /* + * If we did a short DIO read we need to skip the + * section of the iov that we've already read data into. + */ + iov_iter_advance(&i, retval); } /* @@ -1453,39 +1501,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, } } - count = retval; - for (seg = 0; seg < nr_segs; seg++) { - read_descriptor_t desc; - loff_t offset = 0; - - /* - * If we did a short DIO read we need to skip the section of the - * iov that we've already read data into. - */ - if (count) { - if (count > iov[seg].iov_len) { - count -= iov[seg].iov_len; - continue; - } - offset = count; - count = 0; - } - - desc.written = 0; - desc.arg.buf = iov[seg].iov_base + offset; - desc.count = iov[seg].iov_len - offset; - if (desc.count == 0) - continue; - desc.error = 0; - do_generic_file_read(filp, ppos, &desc); - retval += desc.written; - if (desc.error) { - retval = retval ?: desc.error; - break; - } - if (desc.count > 0) - break; - } + retval = do_generic_file_read(filp, ppos, &i, retval); out: return retval; } diff --git a/mm/shmem.c b/mm/shmem.c index 9398e6cd48cb..17d3799d04bd 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1462,13 +1462,25 @@ shmem_write_end(struct file *file, struct address_space *mapping, return copied; } -static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc) +static ssize_t shmem_file_aio_read(struct kiocb *iocb, + const struct iovec *iov, unsigned long nr_segs, loff_t pos) { - struct inode *inode = file_inode(filp); + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); struct address_space *mapping = inode->i_mapping; pgoff_t index; unsigned long offset; enum sgp_type sgp = SGP_READ; + int error; + ssize_t retval; + size_t count; + loff_t *ppos = &iocb->ki_pos; + struct iov_iter iter; + + retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); + if (retval) + return retval; + iov_iter_init(&iter, iov, nr_segs, count, 0); /* * Might this read be for a stacking filesystem? Then when reading @@ -1496,10 +1508,10 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_ break; } - desc->error = shmem_getpage(inode, index, &page, sgp, NULL); - if (desc->error) { - if (desc->error == -EINVAL) - desc->error = 0; + error = shmem_getpage(inode, index, &page, sgp, NULL); + if (error) { + if (error == -EINVAL) + error = 0; break; } if (page) @@ -1543,61 +1555,26 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_ /* * Ok, we have the page, and it's up-to-date, so * now we can copy it to user space... - * - * The actor routine returns how many bytes were actually used.. - * NOTE! This may not be the same as how much of a user buffer - * we filled up (we may be padding etc), so we can only update - * "pos" here (the actor routine has to update the user buffer - * pointers and the remaining count). */ - ret = file_read_actor(desc, page, offset, nr); + ret = copy_page_to_iter(page, offset, nr, &iter); + retval += ret; offset += ret; index += offset >> PAGE_CACHE_SHIFT; offset &= ~PAGE_CACHE_MASK; page_cache_release(page); - if (ret != nr || !desc->count) + if (!iov_iter_count(&iter)) break; - + if (ret < nr) { + error = -EFAULT; + break; + } cond_resched(); } *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset; - file_accessed(filp); -} - -static ssize_t shmem_file_aio_read(struct kiocb *iocb, - const struct iovec *iov, unsigned long nr_segs, loff_t pos) -{ - struct file *filp = iocb->ki_filp; - ssize_t retval; - unsigned long seg; - size_t count; - loff_t *ppos = &iocb->ki_pos; - - retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); - if (retval) - return retval; - - for (seg = 0; seg < nr_segs; seg++) { - read_descriptor_t desc; - - desc.written = 0; - desc.arg.buf = iov[seg].iov_base; - desc.count = iov[seg].iov_len; - if (desc.count == 0) - continue; - desc.error = 0; - do_shmem_file_read(filp, ppos, &desc); - retval += desc.written; - if (desc.error) { - retval = retval ?: desc.error; - break; - } - if (desc.count > 0) - break; - } - return retval; + file_accessed(file); + return retval ? retval : error; } static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, -- cgit v1.2.3 From 480402e18def5514c9dc8cb04e3c0e7482ff2b86 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 10:14:01 -0500 Subject: untangling process_vm_..., part 1 we want to massage it to use of iov_iter. This one is an equivalent transformation - just introduce a local variable mirroring lvec + *lvec_current. Signed-off-by: Al Viro --- mm/process_vm_access.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index fd26d0433509..7b8d63e6c30b 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -60,6 +60,7 @@ static int process_vm_rw_pages(struct task_struct *task, int ret; ssize_t bytes_to_copy; ssize_t rc = 0; + const struct iovec *iov = lvec + *lvec_current; *bytes_copied = 0; @@ -81,8 +82,10 @@ static int process_vm_rw_pages(struct task_struct *task, pgs_copied++) { /* Make sure we have a non zero length iovec */ while (*lvec_current < lvec_cnt - && lvec[*lvec_current].iov_len == 0) + && iov->iov_len == 0) { + iov++; (*lvec_current)++; + } if (*lvec_current == lvec_cnt) break; @@ -94,18 +97,18 @@ static int process_vm_rw_pages(struct task_struct *task, bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset, len - *bytes_copied); bytes_to_copy = min_t(ssize_t, bytes_to_copy, - lvec[*lvec_current].iov_len + iov->iov_len - *lvec_offset); target_kaddr = kmap(process_pages[pgs_copied]) + start_offset; if (vm_write) ret = copy_from_user(target_kaddr, - lvec[*lvec_current].iov_base + iov->iov_base + *lvec_offset, bytes_to_copy); else - ret = copy_to_user(lvec[*lvec_current].iov_base + ret = copy_to_user(iov->iov_base + *lvec_offset, target_kaddr, bytes_to_copy); kunmap(process_pages[pgs_copied]); @@ -117,12 +120,13 @@ static int process_vm_rw_pages(struct task_struct *task, } *bytes_copied += bytes_to_copy; *lvec_offset += bytes_to_copy; - if (*lvec_offset == lvec[*lvec_current].iov_len) { + if (*lvec_offset == iov->iov_len) { /* * Need to copy remaining part of page into the * next iovec if there are any bytes left in page */ (*lvec_current)++; + iov++; *lvec_offset = 0; start_offset = (start_offset + bytes_to_copy) % PAGE_SIZE; -- cgit v1.2.3 From c61c70384fad407bfcb066c3fb9271164d630212 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 10:22:50 -0500 Subject: untangling process_vm_..., part 2 move iov to caller's stack frame; the value we assign to it on the next call of process_vm_rw_pages() is equal to the value it had when the last time we were leaving process_vm_rw_pages(). drop lvec argument of process_vm_rw_pages() - it's not used anymore. Signed-off-by: Al Viro --- mm/process_vm_access.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 7b8d63e6c30b..186ec5db6090 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -45,7 +45,7 @@ static int process_vm_rw_pages(struct task_struct *task, unsigned long pa, unsigned long start_offset, unsigned long len, - const struct iovec *lvec, + const struct iovec **iovp, unsigned long lvec_cnt, unsigned long *lvec_current, size_t *lvec_offset, @@ -60,7 +60,7 @@ static int process_vm_rw_pages(struct task_struct *task, int ret; ssize_t bytes_to_copy; ssize_t rc = 0; - const struct iovec *iov = lvec + *lvec_current; + const struct iovec *iov = *iovp; *bytes_copied = 0; @@ -149,6 +149,7 @@ end: put_page(process_pages[j]); } + *iovp = iov; return rc; } @@ -192,6 +193,7 @@ static int process_vm_rw_single_vec(unsigned long addr, unsigned long nr_pages_to_copy; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); + const struct iovec *iov = lvec + *lvec_current; *bytes_copied = 0; @@ -206,7 +208,7 @@ static int process_vm_rw_single_vec(unsigned long addr, rc = process_vm_rw_pages(task, mm, process_pages, pa, start_offset, len, - lvec, lvec_cnt, + &iov, lvec_cnt, lvec_current, lvec_offset, vm_write, nr_pages_to_copy, &bytes_copied_loop); -- cgit v1.2.3 From 12e3004e464f554e0d57ddd0b4185060275e1f12 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 10:28:58 -0500 Subject: untangling process_vm_..., part 3 lift iov one more level out - from process_vm_rw_single_vec to process_vm_rw_core(). Same story as with the previous commit. Signed-off-by: Al Viro --- mm/process_vm_access.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 186ec5db6090..40dfb396e8ab 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -174,7 +174,7 @@ end: */ static int process_vm_rw_single_vec(unsigned long addr, unsigned long len, - const struct iovec *lvec, + const struct iovec **iovp, unsigned long lvec_cnt, unsigned long *lvec_current, size_t *lvec_offset, @@ -193,7 +193,6 @@ static int process_vm_rw_single_vec(unsigned long addr, unsigned long nr_pages_to_copy; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); - const struct iovec *iov = lvec + *lvec_current; *bytes_copied = 0; @@ -208,7 +207,7 @@ static int process_vm_rw_single_vec(unsigned long addr, rc = process_vm_rw_pages(task, mm, process_pages, pa, start_offset, len, - &iov, lvec_cnt, + iovp, lvec_cnt, lvec_current, lvec_offset, vm_write, nr_pages_to_copy, &bytes_copied_loop); @@ -319,7 +318,7 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) { rc = process_vm_rw_single_vec( (unsigned long)rvec[i].iov_base, rvec[i].iov_len, - lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset, + &lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset, process_pages, mm, task, vm_write, &bytes_copied_loop); bytes_copied += bytes_copied_loop; if (rc != 0) { -- cgit v1.2.3 From 1291afc18115885cf3ff265a5dc836393060e820 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 10:40:15 -0500 Subject: untangling process_vm_..., part 4 instead of passing vector size (by value) and index (by reference), pass the number of elements remaining. That's all we care about in these functions by that point. Signed-off-by: Al Viro --- mm/process_vm_access.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 40dfb396e8ab..4bbd495fcedd 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -46,8 +46,7 @@ static int process_vm_rw_pages(struct task_struct *task, unsigned long start_offset, unsigned long len, const struct iovec **iovp, - unsigned long lvec_cnt, - unsigned long *lvec_current, + unsigned long *left, size_t *lvec_offset, int vm_write, unsigned int nr_pages_to_copy, @@ -78,15 +77,14 @@ static int process_vm_rw_pages(struct task_struct *task, /* Do the copy for each page */ for (pgs_copied = 0; - (pgs_copied < nr_pages_to_copy) && (*lvec_current < lvec_cnt); + (pgs_copied < nr_pages_to_copy) && *left; pgs_copied++) { /* Make sure we have a non zero length iovec */ - while (*lvec_current < lvec_cnt - && iov->iov_len == 0) { + while (*left && iov->iov_len == 0) { iov++; - (*lvec_current)++; + (*left)--; } - if (*lvec_current == lvec_cnt) + if (!*left) break; /* @@ -125,7 +123,7 @@ static int process_vm_rw_pages(struct task_struct *task, * Need to copy remaining part of page into the * next iovec if there are any bytes left in page */ - (*lvec_current)++; + (*left)--; iov++; *lvec_offset = 0; start_offset = (start_offset + bytes_to_copy) @@ -175,8 +173,7 @@ end: static int process_vm_rw_single_vec(unsigned long addr, unsigned long len, const struct iovec **iovp, - unsigned long lvec_cnt, - unsigned long *lvec_current, + unsigned long *left, size_t *lvec_offset, struct page **process_pages, struct mm_struct *mm, @@ -201,14 +198,14 @@ static int process_vm_rw_single_vec(unsigned long addr, return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - while ((nr_pages_copied < nr_pages) && (*lvec_current < lvec_cnt)) { + while ((nr_pages_copied < nr_pages) && *left) { nr_pages_to_copy = min(nr_pages - nr_pages_copied, max_pages_per_loop); rc = process_vm_rw_pages(task, mm, process_pages, pa, start_offset, len, - iovp, lvec_cnt, - lvec_current, lvec_offset, + iovp, left, + lvec_offset, vm_write, nr_pages_to_copy, &bytes_copied_loop); start_offset = 0; @@ -259,7 +256,7 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, ssize_t bytes_copied = 0; unsigned long nr_pages = 0; unsigned long nr_pages_iov; - unsigned long iov_l_curr_idx = 0; + unsigned long left = liovcnt; size_t iov_l_curr_offset = 0; ssize_t iov_len; @@ -315,10 +312,10 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, goto put_task_struct; } - for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) { + for (i = 0; i < riovcnt && left; i++) { rc = process_vm_rw_single_vec( (unsigned long)rvec[i].iov_base, rvec[i].iov_len, - &lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset, + &lvec, &left, &iov_l_curr_offset, process_pages, mm, task, vm_write, &bytes_copied_loop); bytes_copied += bytes_copied_loop; if (rc != 0) { -- cgit v1.2.3 From 9f78bdfabf0de0bc8d3cc97d06908651b577a567 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 11:51:53 -0500 Subject: process_vm_access: switch to iov_iter instead of keeping its pieces in separate variables and passing pointers to all of them... Signed-off-by: Al Viro --- mm/process_vm_access.c | 62 +++++++++++++++++++++++--------------------------- 1 file changed, 28 insertions(+), 34 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 4bbd495fcedd..1e3c81103b2c 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -45,9 +45,7 @@ static int process_vm_rw_pages(struct task_struct *task, unsigned long pa, unsigned long start_offset, unsigned long len, - const struct iovec **iovp, - unsigned long *left, - size_t *lvec_offset, + struct iov_iter *iter, int vm_write, unsigned int nr_pages_to_copy, ssize_t *bytes_copied) @@ -59,7 +57,7 @@ static int process_vm_rw_pages(struct task_struct *task, int ret; ssize_t bytes_to_copy; ssize_t rc = 0; - const struct iovec *iov = *iovp; + const struct iovec *iov = iter->iov; *bytes_copied = 0; @@ -77,14 +75,14 @@ static int process_vm_rw_pages(struct task_struct *task, /* Do the copy for each page */ for (pgs_copied = 0; - (pgs_copied < nr_pages_to_copy) && *left; + (pgs_copied < nr_pages_to_copy) && iter->nr_segs; pgs_copied++) { /* Make sure we have a non zero length iovec */ - while (*left && iov->iov_len == 0) { + while (iter->nr_segs && iov->iov_len == 0) { iov++; - (*left)--; + iter->nr_segs--; } - if (!*left) + if (!iter->nr_segs) break; /* @@ -96,18 +94,18 @@ static int process_vm_rw_pages(struct task_struct *task, len - *bytes_copied); bytes_to_copy = min_t(ssize_t, bytes_to_copy, iov->iov_len - - *lvec_offset); + - iter->iov_offset); target_kaddr = kmap(process_pages[pgs_copied]) + start_offset; if (vm_write) ret = copy_from_user(target_kaddr, iov->iov_base - + *lvec_offset, + + iter->iov_offset, bytes_to_copy); else ret = copy_to_user(iov->iov_base - + *lvec_offset, + + iter->iov_offset, target_kaddr, bytes_to_copy); kunmap(process_pages[pgs_copied]); if (ret) { @@ -117,15 +115,15 @@ static int process_vm_rw_pages(struct task_struct *task, goto end; } *bytes_copied += bytes_to_copy; - *lvec_offset += bytes_to_copy; - if (*lvec_offset == iov->iov_len) { + iter->iov_offset += bytes_to_copy; + if (iter->iov_offset == iov->iov_len) { /* * Need to copy remaining part of page into the * next iovec if there are any bytes left in page */ - (*left)--; + iter->nr_segs--; iov++; - *lvec_offset = 0; + iter->iov_offset = 0; start_offset = (start_offset + bytes_to_copy) % PAGE_SIZE; if (start_offset) @@ -147,7 +145,7 @@ end: put_page(process_pages[j]); } - *iovp = iov; + iter->iov = iov; return rc; } @@ -172,9 +170,7 @@ end: */ static int process_vm_rw_single_vec(unsigned long addr, unsigned long len, - const struct iovec **iovp, - unsigned long *left, - size_t *lvec_offset, + struct iov_iter *iter, struct page **process_pages, struct mm_struct *mm, struct task_struct *task, @@ -198,14 +194,12 @@ static int process_vm_rw_single_vec(unsigned long addr, return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - while ((nr_pages_copied < nr_pages) && *left) { + while ((nr_pages_copied < nr_pages) && iter->nr_segs) { nr_pages_to_copy = min(nr_pages - nr_pages_copied, max_pages_per_loop); rc = process_vm_rw_pages(task, mm, process_pages, pa, - start_offset, len, - iovp, left, - lvec_offset, + start_offset, len, iter, vm_write, nr_pages_to_copy, &bytes_copied_loop); start_offset = 0; @@ -240,8 +234,7 @@ static int process_vm_rw_single_vec(unsigned long addr, * return less bytes than expected if an error occurs during the copying * process. */ -static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, - unsigned long liovcnt, +static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, const struct iovec *rvec, unsigned long riovcnt, unsigned long flags, int vm_write) @@ -256,8 +249,6 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, ssize_t bytes_copied = 0; unsigned long nr_pages = 0; unsigned long nr_pages_iov; - unsigned long left = liovcnt; - size_t iov_l_curr_offset = 0; ssize_t iov_len; /* @@ -312,11 +303,11 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec, goto put_task_struct; } - for (i = 0; i < riovcnt && left; i++) { + for (i = 0; i < riovcnt && iter->nr_segs; i++) { rc = process_vm_rw_single_vec( (unsigned long)rvec[i].iov_base, rvec[i].iov_len, - &lvec, &left, &iov_l_curr_offset, - process_pages, mm, task, vm_write, &bytes_copied_loop); + iter, process_pages, mm, task, vm_write, + &bytes_copied_loop); bytes_copied += bytes_copied_loop; if (rc != 0) { /* If we have managed to copy any data at all then @@ -365,6 +356,7 @@ static ssize_t process_vm_rw(pid_t pid, struct iovec iovstack_r[UIO_FASTIOV]; struct iovec *iov_l = iovstack_l; struct iovec *iov_r = iovstack_r; + struct iov_iter iter; ssize_t rc; if (flags != 0) @@ -380,13 +372,14 @@ static ssize_t process_vm_rw(pid_t pid, if (rc <= 0) goto free_iovecs; + iov_iter_init(&iter, iov_l, liovcnt, rc, 0); + rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, iovstack_r, &iov_r); if (rc <= 0) goto free_iovecs; - rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags, - vm_write); + rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); free_iovecs: if (iov_r != iovstack_r) @@ -426,6 +419,7 @@ compat_process_vm_rw(compat_pid_t pid, struct iovec iovstack_r[UIO_FASTIOV]; struct iovec *iov_l = iovstack_l; struct iovec *iov_r = iovstack_r; + struct iov_iter iter; ssize_t rc = -EFAULT; if (flags != 0) @@ -441,14 +435,14 @@ compat_process_vm_rw(compat_pid_t pid, &iov_l); if (rc <= 0) goto free_iovecs; + iov_iter_init(&iter, iov_l, liovcnt, rc, 0); rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, iovstack_r, &iov_r); if (rc <= 0) goto free_iovecs; - rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags, - vm_write); + rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write); free_iovecs: if (iov_r != iovstack_r) -- cgit v1.2.3 From 240f3905f513cd5f27cc3f79bf03bf3f88323f41 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 12:14:11 -0500 Subject: process_vm_access: switch to copy_page_to_iter/iov_iter_copy_from_user ... rather than open-coding those. As a side benefit, we get much saner loop calling those; we can just feed entire pages, instead of the "copy would span the iovec boundary, let's do it in two loop iterations" mess. Signed-off-by: Al Viro --- mm/process_vm_access.c | 91 +++++++++++++------------------------------------- 1 file changed, 23 insertions(+), 68 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 1e3c81103b2c..70ec3156f45a 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -51,13 +51,11 @@ static int process_vm_rw_pages(struct task_struct *task, ssize_t *bytes_copied) { int pages_pinned; - void *target_kaddr; int pgs_copied = 0; int j; int ret; ssize_t bytes_to_copy; ssize_t rc = 0; - const struct iovec *iov = iter->iov; *bytes_copied = 0; @@ -75,77 +73,34 @@ static int process_vm_rw_pages(struct task_struct *task, /* Do the copy for each page */ for (pgs_copied = 0; - (pgs_copied < nr_pages_to_copy) && iter->nr_segs; + (pgs_copied < nr_pages_to_copy) && iov_iter_count(iter); pgs_copied++) { - /* Make sure we have a non zero length iovec */ - while (iter->nr_segs && iov->iov_len == 0) { - iov++; - iter->nr_segs--; + struct page *page = process_pages[pgs_copied]; + bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset, len); + + if (vm_write) { + if (bytes_to_copy > iov_iter_count(iter)) + bytes_to_copy = iov_iter_count(iter); + ret = iov_iter_copy_from_user(page, + iter, start_offset, bytes_to_copy); + iov_iter_advance(iter, ret); + set_page_dirty_lock(page); + } else { + ret = copy_page_to_iter(page, start_offset, + bytes_to_copy, iter); } - if (!iter->nr_segs) - break; - - /* - * Will copy smallest of: - * - bytes remaining in page - * - bytes remaining in destination iovec - */ - bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset, - len - *bytes_copied); - bytes_to_copy = min_t(ssize_t, bytes_to_copy, - iov->iov_len - - iter->iov_offset); - - target_kaddr = kmap(process_pages[pgs_copied]) + start_offset; - - if (vm_write) - ret = copy_from_user(target_kaddr, - iov->iov_base - + iter->iov_offset, - bytes_to_copy); - else - ret = copy_to_user(iov->iov_base - + iter->iov_offset, - target_kaddr, bytes_to_copy); - kunmap(process_pages[pgs_copied]); - if (ret) { - *bytes_copied += bytes_to_copy - ret; - pgs_copied++; + *bytes_copied += ret; + len -= ret; + if (ret < bytes_to_copy && iov_iter_count(iter)) { rc = -EFAULT; - goto end; - } - *bytes_copied += bytes_to_copy; - iter->iov_offset += bytes_to_copy; - if (iter->iov_offset == iov->iov_len) { - /* - * Need to copy remaining part of page into the - * next iovec if there are any bytes left in page - */ - iter->nr_segs--; - iov++; - iter->iov_offset = 0; - start_offset = (start_offset + bytes_to_copy) - % PAGE_SIZE; - if (start_offset) - pgs_copied--; - } else { - start_offset = 0; + break; } + start_offset = 0; } end: - if (vm_write) { - for (j = 0; j < pages_pinned; j++) { - if (j < pgs_copied) - set_page_dirty_lock(process_pages[j]); - put_page(process_pages[j]); - } - } else { - for (j = 0; j < pages_pinned; j++) - put_page(process_pages[j]); - } - - iter->iov = iov; + for (j = 0; j < pages_pinned; j++) + put_page(process_pages[j]); return rc; } @@ -194,7 +149,7 @@ static int process_vm_rw_single_vec(unsigned long addr, return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - while ((nr_pages_copied < nr_pages) && iter->nr_segs) { + while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) { nr_pages_to_copy = min(nr_pages - nr_pages_copied, max_pages_per_loop); @@ -303,7 +258,7 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, goto put_task_struct; } - for (i = 0; i < riovcnt && iter->nr_segs; i++) { + for (i = 0; i < riovcnt && iov_iter_count(iter); i++) { rc = process_vm_rw_single_vec( (unsigned long)rvec[i].iov_base, rvec[i].iov_len, iter, process_pages, mm, task, vm_write, -- cgit v1.2.3 From 70eca12d80a8b51800b4ebfbc629e0ee34166779 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 12:44:24 -0500 Subject: process_vm_access: take get_user_pages/put_pages one level up ... and trim the fuck out of process_vm_rw_pages() argument list. Signed-off-by: Al Viro --- mm/process_vm_access.c | 97 ++++++++++++++++++++------------------------------ 1 file changed, 39 insertions(+), 58 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 70ec3156f45a..c2a1916bacbf 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -39,69 +39,39 @@ * @bytes_copied: returns number of bytes successfully copied * Returns 0 on success, error code otherwise */ -static int process_vm_rw_pages(struct task_struct *task, - struct mm_struct *mm, - struct page **process_pages, - unsigned long pa, - unsigned long start_offset, +static int process_vm_rw_pages(struct page **pages, + unsigned offset, unsigned long len, struct iov_iter *iter, int vm_write, unsigned int nr_pages_to_copy, ssize_t *bytes_copied) { - int pages_pinned; - int pgs_copied = 0; - int j; - int ret; - ssize_t bytes_to_copy; - ssize_t rc = 0; - *bytes_copied = 0; - /* Get the pages we're interested in */ - down_read(&mm->mmap_sem); - pages_pinned = get_user_pages(task, mm, pa, - nr_pages_to_copy, - vm_write, 0, process_pages, NULL); - up_read(&mm->mmap_sem); - - if (pages_pinned != nr_pages_to_copy) { - rc = -EFAULT; - goto end; - } - /* Do the copy for each page */ - for (pgs_copied = 0; - (pgs_copied < nr_pages_to_copy) && iov_iter_count(iter); - pgs_copied++) { - struct page *page = process_pages[pgs_copied]; - bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset, len); + while (iov_iter_count(iter) && nr_pages_to_copy--) { + struct page *page = *pages++; + size_t copy = min_t(ssize_t, PAGE_SIZE - offset, len); + size_t copied; if (vm_write) { - if (bytes_to_copy > iov_iter_count(iter)) - bytes_to_copy = iov_iter_count(iter); - ret = iov_iter_copy_from_user(page, - iter, start_offset, bytes_to_copy); - iov_iter_advance(iter, ret); + if (copy > iov_iter_count(iter)) + copy = iov_iter_count(iter); + copied = iov_iter_copy_from_user(page, iter, + offset, copy); + iov_iter_advance(iter, copied); set_page_dirty_lock(page); } else { - ret = copy_page_to_iter(page, start_offset, - bytes_to_copy, iter); - } - *bytes_copied += ret; - len -= ret; - if (ret < bytes_to_copy && iov_iter_count(iter)) { - rc = -EFAULT; - break; + copied = copy_page_to_iter(page, offset, copy, iter); } - start_offset = 0; + *bytes_copied += copied; + len -= copied; + if (copied < copy && iov_iter_count(iter)) + return -EFAULT; + offset = 0; } - -end: - for (j = 0; j < pages_pinned; j++) - put_page(process_pages[j]); - return rc; + return 0; } /* Maximum number of pages kmalloc'd to hold struct page's during copy */ @@ -138,7 +108,6 @@ static int process_vm_rw_single_vec(unsigned long addr, ssize_t bytes_copied_loop; ssize_t rc = 0; unsigned long nr_pages_copied = 0; - unsigned long nr_pages_to_copy; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); @@ -150,23 +119,35 @@ static int process_vm_rw_single_vec(unsigned long addr, nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) { + int nr_pages_to_copy; + int pages_pinned; nr_pages_to_copy = min(nr_pages - nr_pages_copied, max_pages_per_loop); - rc = process_vm_rw_pages(task, mm, process_pages, pa, + /* Get the pages we're interested in */ + down_read(&mm->mmap_sem); + pages_pinned = get_user_pages(task, mm, pa, + nr_pages_to_copy, + vm_write, 0, process_pages, NULL); + up_read(&mm->mmap_sem); + + if (pages_pinned <= 0) + return -EFAULT; + + rc = process_vm_rw_pages(process_pages, start_offset, len, iter, - vm_write, nr_pages_to_copy, + vm_write, pages_pinned, &bytes_copied_loop); start_offset = 0; *bytes_copied += bytes_copied_loop; + len -= bytes_copied_loop; + nr_pages_copied += pages_pinned; + pa += pages_pinned * PAGE_SIZE; + while (pages_pinned) + put_page(process_pages[--pages_pinned]); - if (rc < 0) { - return rc; - } else { - len -= bytes_copied_loop; - nr_pages_copied += nr_pages_to_copy; - pa += nr_pages_to_copy * PAGE_SIZE; - } + if (rc < 0) + break; } return rc; -- cgit v1.2.3 From e21345f9c3f8a806604910cae886e471a860ab86 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 12:55:11 -0500 Subject: process_vm_rw_pages(): pass accurate amount of bytes ... makes passing the amount of pages unnecessary Signed-off-by: Al Viro --- mm/process_vm_access.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index c2a1916bacbf..83252d783482 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -41,20 +41,22 @@ */ static int process_vm_rw_pages(struct page **pages, unsigned offset, - unsigned long len, + size_t len, struct iov_iter *iter, int vm_write, - unsigned int nr_pages_to_copy, ssize_t *bytes_copied) { *bytes_copied = 0; /* Do the copy for each page */ - while (iov_iter_count(iter) && nr_pages_to_copy--) { + while (iov_iter_count(iter) && len) { struct page *page = *pages++; - size_t copy = min_t(ssize_t, PAGE_SIZE - offset, len); + size_t copy = PAGE_SIZE - offset; size_t copied; + if (copy > len) + copy = len; + if (vm_write) { if (copy > iov_iter_count(iter)) copy = iov_iter_count(iter); @@ -121,6 +123,7 @@ static int process_vm_rw_single_vec(unsigned long addr, while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) { int nr_pages_to_copy; int pages_pinned; + size_t n; nr_pages_to_copy = min(nr_pages - nr_pages_copied, max_pages_per_loop); @@ -134,18 +137,21 @@ static int process_vm_rw_single_vec(unsigned long addr, if (pages_pinned <= 0) return -EFAULT; + n = pages_pinned * PAGE_SIZE - start_offset; + if (n > len) + n = len; + rc = process_vm_rw_pages(process_pages, - start_offset, len, iter, - vm_write, pages_pinned, + start_offset, n, iter, + vm_write, &bytes_copied_loop); + len -= n; start_offset = 0; *bytes_copied += bytes_copied_loop; - len -= bytes_copied_loop; nr_pages_copied += pages_pinned; pa += pages_pinned * PAGE_SIZE; while (pages_pinned) put_page(process_pages[--pages_pinned]); - if (rc < 0) break; } -- cgit v1.2.3 From 9acc1a0f9af244826de0eea2c38b78410eb0df6d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 13:15:28 -0500 Subject: process_vm_access: don't bother with returning the amounts of bytes copied we can calculate that in the caller just fine, TYVM Signed-off-by: Al Viro --- mm/process_vm_access.c | 47 ++++++++++++++++------------------------------- 1 file changed, 16 insertions(+), 31 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 83252d783482..15e4c2f312e8 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -43,13 +43,10 @@ static int process_vm_rw_pages(struct page **pages, unsigned offset, size_t len, struct iov_iter *iter, - int vm_write, - ssize_t *bytes_copied) + int vm_write) { - *bytes_copied = 0; - /* Do the copy for each page */ - while (iov_iter_count(iter) && len) { + while (len && iov_iter_count(iter)) { struct page *page = *pages++; size_t copy = PAGE_SIZE - offset; size_t copied; @@ -67,7 +64,6 @@ static int process_vm_rw_pages(struct page **pages, } else { copied = copy_page_to_iter(page, offset, copy, iter); } - *bytes_copied += copied; len -= copied; if (copied < copy && iov_iter_count(iter)) return -EFAULT; @@ -101,20 +97,16 @@ static int process_vm_rw_single_vec(unsigned long addr, struct page **process_pages, struct mm_struct *mm, struct task_struct *task, - int vm_write, - ssize_t *bytes_copied) + int vm_write) { unsigned long pa = addr & PAGE_MASK; unsigned long start_offset = addr - pa; unsigned long nr_pages; - ssize_t bytes_copied_loop; ssize_t rc = 0; unsigned long nr_pages_copied = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); - *bytes_copied = 0; - /* Work out address and page range required */ if (len == 0) return 0; @@ -143,11 +135,9 @@ static int process_vm_rw_single_vec(unsigned long addr, rc = process_vm_rw_pages(process_pages, start_offset, n, iter, - vm_write, - &bytes_copied_loop); + vm_write); len -= n; start_offset = 0; - *bytes_copied += bytes_copied_loop; nr_pages_copied += pages_pinned; pa += pages_pinned * PAGE_SIZE; while (pages_pinned) @@ -187,11 +177,10 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, struct mm_struct *mm; unsigned long i; ssize_t rc = 0; - ssize_t bytes_copied_loop; - ssize_t bytes_copied = 0; unsigned long nr_pages = 0; unsigned long nr_pages_iov; ssize_t iov_len; + size_t total_len = iov_iter_count(iter); /* * Work out how many pages of struct pages we're going to need @@ -245,24 +234,20 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, goto put_task_struct; } - for (i = 0; i < riovcnt && iov_iter_count(iter); i++) { + for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++) rc = process_vm_rw_single_vec( (unsigned long)rvec[i].iov_base, rvec[i].iov_len, - iter, process_pages, mm, task, vm_write, - &bytes_copied_loop); - bytes_copied += bytes_copied_loop; - if (rc != 0) { - /* If we have managed to copy any data at all then - we return the number of bytes copied. Otherwise - we return the error code */ - if (bytes_copied) - rc = bytes_copied; - goto put_mm; - } - } + iter, process_pages, mm, task, vm_write); + + /* copied = space before - space after */ + total_len -= iov_iter_count(iter); + + /* If we have managed to copy any data at all then + we return the number of bytes copied. Otherwise + we return the error code */ + if (total_len) + rc = total_len; - rc = bytes_copied; -put_mm: mmput(mm); put_task_struct: -- cgit v1.2.3 From 4bafbec7bf60ed56ccbb36a96091bdbd162f075d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 13:25:32 -0500 Subject: process_vm_access: tidy up a bit saner variable names, update linuxdoc comments, etc. Signed-off-by: Al Viro --- mm/process_vm_access.c | 59 ++++++++++++++++---------------------------------- 1 file changed, 19 insertions(+), 40 deletions(-) (limited to 'mm') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 15e4c2f312e8..d6bd3fdd6925 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -23,20 +23,11 @@ /** * process_vm_rw_pages - read/write pages from task specified - * @task: task to read/write from - * @mm: mm for task - * @process_pages: struct pages area that can store at least - * nr_pages_to_copy struct page pointers - * @pa: address of page in task to start copying from/to + * @pages: array of pointers to pages we want to copy * @start_offset: offset in page to start copying from/to * @len: number of bytes to copy - * @lvec: iovec array specifying where to copy to/from - * @lvec_cnt: number of elements in iovec array - * @lvec_current: index in iovec array we are up to - * @lvec_offset: offset in bytes from current iovec iov_base we are up to + * @iter: where to copy to/from locally * @vm_write: 0 means copy from, 1 means copy to - * @nr_pages_to_copy: number of pages to copy - * @bytes_copied: returns number of bytes successfully copied * Returns 0 on success, error code otherwise */ static int process_vm_rw_pages(struct page **pages, @@ -79,16 +70,12 @@ static int process_vm_rw_pages(struct page **pages, * process_vm_rw_single_vec - read/write pages from task specified * @addr: start memory address of target process * @len: size of area to copy to/from - * @lvec: iovec array specifying where to copy to/from locally - * @lvec_cnt: number of elements in iovec array - * @lvec_current: index in iovec array we are up to - * @lvec_offset: offset in bytes from current iovec iov_base we are up to + * @iter: where to copy to/from locally * @process_pages: struct pages area that can store at least * nr_pages_to_copy struct page pointers * @mm: mm for task * @task: task to read/write from * @vm_write: 0 means copy from, 1 means copy to - * @bytes_copied: returns number of bytes successfully copied * Returns 0 on success or on failure error code */ static int process_vm_rw_single_vec(unsigned long addr, @@ -103,7 +90,6 @@ static int process_vm_rw_single_vec(unsigned long addr, unsigned long start_offset = addr - pa; unsigned long nr_pages; ssize_t rc = 0; - unsigned long nr_pages_copied = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); @@ -112,38 +98,32 @@ static int process_vm_rw_single_vec(unsigned long addr, return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; - while ((nr_pages_copied < nr_pages) && iov_iter_count(iter)) { - int nr_pages_to_copy; - int pages_pinned; - size_t n; - nr_pages_to_copy = min(nr_pages - nr_pages_copied, - max_pages_per_loop); + while (!rc && nr_pages && iov_iter_count(iter)) { + int pages = min(nr_pages, max_pages_per_loop); + size_t bytes; /* Get the pages we're interested in */ down_read(&mm->mmap_sem); - pages_pinned = get_user_pages(task, mm, pa, - nr_pages_to_copy, - vm_write, 0, process_pages, NULL); + pages = get_user_pages(task, mm, pa, pages, + vm_write, 0, process_pages, NULL); up_read(&mm->mmap_sem); - if (pages_pinned <= 0) + if (pages <= 0) return -EFAULT; - n = pages_pinned * PAGE_SIZE - start_offset; - if (n > len) - n = len; + bytes = pages * PAGE_SIZE - start_offset; + if (bytes > len) + bytes = len; rc = process_vm_rw_pages(process_pages, - start_offset, n, iter, + start_offset, bytes, iter, vm_write); - len -= n; + len -= bytes; start_offset = 0; - nr_pages_copied += pages_pinned; - pa += pages_pinned * PAGE_SIZE; - while (pages_pinned) - put_page(process_pages[--pages_pinned]); - if (rc < 0) - break; + nr_pages -= pages; + pa += pages * PAGE_SIZE; + while (pages) + put_page(process_pages[--pages]); } return rc; @@ -156,8 +136,7 @@ static int process_vm_rw_single_vec(unsigned long addr, /** * process_vm_rw_core - core of reading/writing pages from task specified * @pid: PID of process to read/write from/to - * @lvec: iovec array specifying where to copy to/from locally - * @liovcnt: size of lvec array + * @iter: where to copy to/from locally * @rvec: iovec array specifying where to copy to/from in the other process * @riovcnt: size of rvec array * @flags: currently unused -- cgit v1.2.3 From 4f18cd317a118c28482f97303600a2fe2ada6c79 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Feb 2014 19:11:33 -0500 Subject: take iov_iter stuff to mm/iov_iter.c Signed-off-by: Al Viro --- mm/Makefile | 2 +- mm/filemap.c | 221 --------------------------------------------------------- mm/iov_iter.c | 224 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 225 insertions(+), 222 deletions(-) create mode 100644 mm/iov_iter.c (limited to 'mm') diff --git a/mm/Makefile b/mm/Makefile index 310c90a09264..178a43406b0c 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -17,7 +17,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ util.o mmzone.o vmstat.o backing-dev.o \ mm_init.o mmu_context.o percpu.o slab_common.o \ compaction.o balloon_compaction.o \ - interval_tree.o list_lru.o $(mmu-y) + interval_tree.o list_lru.o iov_iter.o $(mmu-y) obj-y += init-mm.o diff --git a/mm/filemap.c b/mm/filemap.c index a16eb2c4f316..c4730efa5d9e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1085,84 +1085,6 @@ static void shrink_readahead_size_eio(struct file *filp, ra->ra_pages /= 4; } -size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, - struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - void *kaddr, *from; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - if (!fault_in_pages_writeable(buf, copy)) { - kaddr = kmap_atomic(page); - from = kaddr + offset; - - /* first chunk, usually the only one */ - left = __copy_to_user_inatomic(buf, from, copy); - copy -= left; - skip += copy; - from += copy; - bytes -= copy; - - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_to_user_inatomic(buf, from, copy); - copy -= left; - skip = copy; - from += copy; - bytes -= copy; - } - if (likely(!bytes)) { - kunmap_atomic(kaddr); - goto done; - } - offset = from - kaddr; - buf += copy; - kunmap_atomic(kaddr); - copy = min(bytes, iov->iov_len - skip); - } - /* Too bad - revert to non-atomic kmap */ - kaddr = kmap(page); - from = kaddr + offset; - left = __copy_to_user(buf, from, copy); - copy -= left; - skip += copy; - from += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_to_user(buf, from, copy); - copy -= left; - skip = copy; - from += copy; - bytes -= copy; - } - kunmap(page); -done: - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} -EXPORT_SYMBOL(copy_page_to_iter); - /** * do_generic_file_read - generic file read routine * @filp: the file to read @@ -1957,149 +1879,6 @@ struct page *read_cache_page(struct address_space *mapping, } EXPORT_SYMBOL(read_cache_page); -static size_t __iovec_copy_from_user_inatomic(char *vaddr, - const struct iovec *iov, size_t base, size_t bytes) -{ - size_t copied = 0, left = 0; - - while (bytes) { - char __user *buf = iov->iov_base + base; - int copy = min(bytes, iov->iov_len - base); - - base = 0; - left = __copy_from_user_inatomic(vaddr, buf, copy); - copied += copy; - bytes -= copy; - vaddr += copy; - iov++; - - if (unlikely(left)) - break; - } - return copied - left; -} - -/* - * Copy as much as we can into the page and return the number of bytes which - * were successfully copied. If a fault is encountered then return the number of - * bytes which were copied. - */ -size_t iov_iter_copy_from_user_atomic(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) -{ - char *kaddr; - size_t copied; - - kaddr = kmap_atomic(page); - if (likely(i->nr_segs == 1)) { - int left; - char __user *buf = i->iov->iov_base + i->iov_offset; - left = __copy_from_user_inatomic(kaddr + offset, buf, bytes); - copied = bytes - left; - } else { - copied = __iovec_copy_from_user_inatomic(kaddr + offset, - i->iov, i->iov_offset, bytes); - } - kunmap_atomic(kaddr); - - return copied; -} -EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); - -/* - * This has the same sideeffects and return value as - * iov_iter_copy_from_user_atomic(). - * The difference is that it attempts to resolve faults. - * Page must not be locked. - */ -size_t iov_iter_copy_from_user(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) -{ - char *kaddr; - size_t copied; - - kaddr = kmap(page); - if (likely(i->nr_segs == 1)) { - int left; - char __user *buf = i->iov->iov_base + i->iov_offset; - left = __copy_from_user(kaddr + offset, buf, bytes); - copied = bytes - left; - } else { - copied = __iovec_copy_from_user_inatomic(kaddr + offset, - i->iov, i->iov_offset, bytes); - } - kunmap(page); - return copied; -} -EXPORT_SYMBOL(iov_iter_copy_from_user); - -void iov_iter_advance(struct iov_iter *i, size_t bytes) -{ - BUG_ON(i->count < bytes); - - if (likely(i->nr_segs == 1)) { - i->iov_offset += bytes; - i->count -= bytes; - } else { - const struct iovec *iov = i->iov; - size_t base = i->iov_offset; - unsigned long nr_segs = i->nr_segs; - - /* - * The !iov->iov_len check ensures we skip over unlikely - * zero-length segments (without overruning the iovec). - */ - while (bytes || unlikely(i->count && !iov->iov_len)) { - int copy; - - copy = min(bytes, iov->iov_len - base); - BUG_ON(!i->count || i->count < copy); - i->count -= copy; - bytes -= copy; - base += copy; - if (iov->iov_len == base) { - iov++; - nr_segs--; - base = 0; - } - } - i->iov = iov; - i->iov_offset = base; - i->nr_segs = nr_segs; - } -} -EXPORT_SYMBOL(iov_iter_advance); - -/* - * Fault in the first iovec of the given iov_iter, to a maximum length - * of bytes. Returns 0 on success, or non-zero if the memory could not be - * accessed (ie. because it is an invalid address). - * - * writev-intensive code may want this to prefault several iovecs -- that - * would be possible (callers must not rely on the fact that _only_ the - * first iovec will be faulted with the current implementation). - */ -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) -{ - char __user *buf = i->iov->iov_base + i->iov_offset; - bytes = min(bytes, i->iov->iov_len - i->iov_offset); - return fault_in_pages_readable(buf, bytes); -} -EXPORT_SYMBOL(iov_iter_fault_in_readable); - -/* - * Return the count of just the current iov_iter segment. - */ -size_t iov_iter_single_seg_count(const struct iov_iter *i) -{ - const struct iovec *iov = i->iov; - if (i->nr_segs == 1) - return i->count; - else - return min(i->count, iov->iov_len - i->iov_offset); -} -EXPORT_SYMBOL(iov_iter_single_seg_count); - /* * Performs necessary checks before doing a write * diff --git a/mm/iov_iter.c b/mm/iov_iter.c new file mode 100644 index 000000000000..10e46cd721de --- /dev/null +++ b/mm/iov_iter.c @@ -0,0 +1,224 @@ +#include +#include +#include + +size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, + struct iov_iter *i) +{ + size_t skip, copy, left, wanted; + const struct iovec *iov; + char __user *buf; + void *kaddr, *from; + + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + wanted = bytes; + iov = i->iov; + skip = i->iov_offset; + buf = iov->iov_base + skip; + copy = min(bytes, iov->iov_len - skip); + + if (!fault_in_pages_writeable(buf, copy)) { + kaddr = kmap_atomic(page); + from = kaddr + offset; + + /* first chunk, usually the only one */ + left = __copy_to_user_inatomic(buf, from, copy); + copy -= left; + skip += copy; + from += copy; + bytes -= copy; + + while (unlikely(!left && bytes)) { + iov++; + buf = iov->iov_base; + copy = min(bytes, iov->iov_len); + left = __copy_to_user_inatomic(buf, from, copy); + copy -= left; + skip = copy; + from += copy; + bytes -= copy; + } + if (likely(!bytes)) { + kunmap_atomic(kaddr); + goto done; + } + offset = from - kaddr; + buf += copy; + kunmap_atomic(kaddr); + copy = min(bytes, iov->iov_len - skip); + } + /* Too bad - revert to non-atomic kmap */ + kaddr = kmap(page); + from = kaddr + offset; + left = __copy_to_user(buf, from, copy); + copy -= left; + skip += copy; + from += copy; + bytes -= copy; + while (unlikely(!left && bytes)) { + iov++; + buf = iov->iov_base; + copy = min(bytes, iov->iov_len); + left = __copy_to_user(buf, from, copy); + copy -= left; + skip = copy; + from += copy; + bytes -= copy; + } + kunmap(page); +done: + i->count -= wanted - bytes; + i->nr_segs -= iov - i->iov; + i->iov = iov; + i->iov_offset = skip; + return wanted - bytes; +} +EXPORT_SYMBOL(copy_page_to_iter); + +static size_t __iovec_copy_from_user_inatomic(char *vaddr, + const struct iovec *iov, size_t base, size_t bytes) +{ + size_t copied = 0, left = 0; + + while (bytes) { + char __user *buf = iov->iov_base + base; + int copy = min(bytes, iov->iov_len - base); + + base = 0; + left = __copy_from_user_inatomic(vaddr, buf, copy); + copied += copy; + bytes -= copy; + vaddr += copy; + iov++; + + if (unlikely(left)) + break; + } + return copied - left; +} + +/* + * Copy as much as we can into the page and return the number of bytes which + * were successfully copied. If a fault is encountered then return the number of + * bytes which were copied. + */ +size_t iov_iter_copy_from_user_atomic(struct page *page, + struct iov_iter *i, unsigned long offset, size_t bytes) +{ + char *kaddr; + size_t copied; + + kaddr = kmap_atomic(page); + if (likely(i->nr_segs == 1)) { + int left; + char __user *buf = i->iov->iov_base + i->iov_offset; + left = __copy_from_user_inatomic(kaddr + offset, buf, bytes); + copied = bytes - left; + } else { + copied = __iovec_copy_from_user_inatomic(kaddr + offset, + i->iov, i->iov_offset, bytes); + } + kunmap_atomic(kaddr); + + return copied; +} +EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); + +/* + * This has the same sideeffects and return value as + * iov_iter_copy_from_user_atomic(). + * The difference is that it attempts to resolve faults. + * Page must not be locked. + */ +size_t iov_iter_copy_from_user(struct page *page, + struct iov_iter *i, unsigned long offset, size_t bytes) +{ + char *kaddr; + size_t copied; + + kaddr = kmap(page); + if (likely(i->nr_segs == 1)) { + int left; + char __user *buf = i->iov->iov_base + i->iov_offset; + left = __copy_from_user(kaddr + offset, buf, bytes); + copied = bytes - left; + } else { + copied = __iovec_copy_from_user_inatomic(kaddr + offset, + i->iov, i->iov_offset, bytes); + } + kunmap(page); + return copied; +} +EXPORT_SYMBOL(iov_iter_copy_from_user); + +void iov_iter_advance(struct iov_iter *i, size_t bytes) +{ + BUG_ON(i->count < bytes); + + if (likely(i->nr_segs == 1)) { + i->iov_offset += bytes; + i->count -= bytes; + } else { + const struct iovec *iov = i->iov; + size_t base = i->iov_offset; + unsigned long nr_segs = i->nr_segs; + + /* + * The !iov->iov_len check ensures we skip over unlikely + * zero-length segments (without overruning the iovec). + */ + while (bytes || unlikely(i->count && !iov->iov_len)) { + int copy; + + copy = min(bytes, iov->iov_len - base); + BUG_ON(!i->count || i->count < copy); + i->count -= copy; + bytes -= copy; + base += copy; + if (iov->iov_len == base) { + iov++; + nr_segs--; + base = 0; + } + } + i->iov = iov; + i->iov_offset = base; + i->nr_segs = nr_segs; + } +} +EXPORT_SYMBOL(iov_iter_advance); + +/* + * Fault in the first iovec of the given iov_iter, to a maximum length + * of bytes. Returns 0 on success, or non-zero if the memory could not be + * accessed (ie. because it is an invalid address). + * + * writev-intensive code may want this to prefault several iovecs -- that + * would be possible (callers must not rely on the fact that _only_ the + * first iovec will be faulted with the current implementation). + */ +int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) +{ + char __user *buf = i->iov->iov_base + i->iov_offset; + bytes = min(bytes, i->iov->iov_len - i->iov_offset); + return fault_in_pages_readable(buf, bytes); +} +EXPORT_SYMBOL(iov_iter_fault_in_readable); + +/* + * Return the count of just the current iov_iter segment. + */ +size_t iov_iter_single_seg_count(const struct iov_iter *i) +{ + const struct iovec *iov = i->iov; + if (i->nr_segs == 1) + return i->count; + else + return min(i->count, iov->iov_len - i->iov_offset); +} +EXPORT_SYMBOL(iov_iter_single_seg_count); -- cgit v1.2.3 From 41fc56d573c35a212688b12b48af8c303f9bb6d2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 9 Feb 2014 12:58:52 -0500 Subject: kill the 4th argument of __generic_file_aio_write() It's always equal to &iocb->ki_pos, where iocb is the value of the 1st argument. Signed-off-by: Al Viro --- fs/block_dev.c | 2 +- fs/ext4/file.c | 2 +- fs/udf/file.c | 2 +- include/linux/fs.h | 3 +-- mm/filemap.c | 13 ++++++------- 5 files changed, 10 insertions(+), 12 deletions(-) (limited to 'mm') diff --git a/fs/block_dev.c b/fs/block_dev.c index 1e86823a9cbd..764bd3b8d2fa 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1518,7 +1518,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, BUG_ON(iocb->ki_pos != pos); blk_start_plug(&plug); - ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); + ret = __generic_file_aio_write(iocb, iov, nr_segs); if (ret > 0) { ssize_t err; diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 1a5073959f32..d564bcfb23c5 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -146,7 +146,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov, overwrite = 1; } - ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); + ret = __generic_file_aio_write(iocb, iov, nr_segs); mutex_unlock(&inode->i_mutex); if (ret > 0) { diff --git a/fs/udf/file.c b/fs/udf/file.c index 1037637957c7..d2c170f8b035 100644 --- a/fs/udf/file.c +++ b/fs/udf/file.c @@ -171,7 +171,7 @@ static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov, } else up_write(&iinfo->i_data_sem); - retval = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); + retval = __generic_file_aio_write(iocb, iov, nr_segs); mutex_unlock(&inode->i_mutex); if (retval > 0) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 2a5b1744f80a..e677d1e1189f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2392,8 +2392,7 @@ extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr, unsigned long size, pgoff_t pgoff); int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk); extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t); -extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, - loff_t *); +extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long); extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t); extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, unsigned long *, loff_t, loff_t *, size_t, size_t); diff --git a/mm/filemap.c b/mm/filemap.c index c4730efa5d9e..ce2246dd90de 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2222,14 +2222,14 @@ EXPORT_SYMBOL(generic_file_buffered_write); * avoid syncing under i_mutex. */ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t *ppos) + unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct address_space * mapping = file->f_mapping; size_t ocount; /* original count */ size_t count; /* after file limit checks */ struct inode *inode = mapping->host; - loff_t pos; + loff_t pos = iocb->ki_pos; ssize_t written; ssize_t err; @@ -2239,7 +2239,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, return err; count = ocount; - pos = *ppos; /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; @@ -2266,7 +2265,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, ssize_t written_buffered; written = generic_file_direct_write(iocb, iov, &nr_segs, pos, - ppos, count, ocount); + &iocb->ki_pos, count, ocount); if (written < 0 || written == count) goto out; /* @@ -2276,7 +2275,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, pos += written; count -= written; written_buffered = generic_file_buffered_write(iocb, iov, - nr_segs, pos, ppos, count, + nr_segs, pos, &iocb->ki_pos, count, written); /* * If generic_file_buffered_write() retuned a synchronous error @@ -2310,7 +2309,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, } } else { written = generic_file_buffered_write(iocb, iov, nr_segs, - pos, ppos, count, written); + pos, &iocb->ki_pos, count, written); } out: current->backing_dev_info = NULL; @@ -2339,7 +2338,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, BUG_ON(iocb->ki_pos != pos); mutex_lock(&inode->i_mutex); - ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); + ret = __generic_file_aio_write(iocb, iov, nr_segs); mutex_unlock(&inode->i_mutex); if (ret > 0) { -- cgit v1.2.3 From fcacafd269adc88f41b68cb77a3f957a66563428 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 9 Feb 2014 13:37:49 -0500 Subject: kill the 5th argument of generic_file_buffered_write() same story - it's &iocb->ki_pos in all cases Signed-off-by: Al Viro --- fs/ceph/file.c | 3 +-- fs/ocfs2/file.c | 2 +- fs/xfs/xfs_file.c | 2 +- include/linux/fs.h | 2 +- mm/filemap.c | 9 ++++----- 5 files changed, 8 insertions(+), 10 deletions(-) (limited to 'mm') diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 09c7afe32e49..a798db5e5e39 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -978,8 +978,7 @@ retry_snap: * can not run at the same time */ written = generic_file_buffered_write(iocb, iov, nr_segs, - pos, &iocb->ki_pos, - count, 0); + pos, count, 0); mutex_unlock(&inode->i_mutex); } diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 51632c40e896..89099cce14fe 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2383,7 +2383,7 @@ relock: } else { current->backing_dev_info = file->f_mapping->backing_dev_info; written = generic_file_buffered_write(iocb, iov, nr_segs, *ppos, - ppos, count, 0); + count, 0); current->backing_dev_info = NULL; } diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 64b48eade91d..175ce58fbfa3 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -738,7 +738,7 @@ xfs_file_buffered_aio_write( write_retry: trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0); ret = generic_file_buffered_write(iocb, iovp, nr_segs, - pos, &iocb->ki_pos, count, 0); + pos, count, 0); /* * If we just got an ENOSPC, try to write back all dirty inodes to diff --git a/include/linux/fs.h b/include/linux/fs.h index e677d1e1189f..830e37420f5e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2397,7 +2397,7 @@ extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsi extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, unsigned long *, loff_t, loff_t *, size_t, size_t); extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, - unsigned long, loff_t, loff_t *, size_t, ssize_t); + unsigned long, loff_t, size_t, ssize_t); extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); extern int generic_segment_checks(const struct iovec *iov, diff --git a/mm/filemap.c b/mm/filemap.c index ce2246dd90de..9d515a1a2372 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2183,7 +2183,7 @@ again: ssize_t generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos, loff_t *ppos, + unsigned long nr_segs, loff_t pos, size_t count, ssize_t written) { struct file *file = iocb->ki_filp; @@ -2195,7 +2195,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, if (likely(status >= 0)) { written += status; - *ppos = pos + status; + iocb->ki_pos = pos + status; } return written ? written : status; @@ -2275,8 +2275,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, pos += written; count -= written; written_buffered = generic_file_buffered_write(iocb, iov, - nr_segs, pos, &iocb->ki_pos, count, - written); + nr_segs, pos, count, written); /* * If generic_file_buffered_write() retuned a synchronous error * then we want to return the number of bytes which were @@ -2309,7 +2308,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, } } else { written = generic_file_buffered_write(iocb, iov, nr_segs, - pos, &iocb->ki_pos, count, written); + pos, count, written); } out: current->backing_dev_info = NULL; -- cgit v1.2.3 From 5cb6c6c7eb1ed24744b41fad47d9a25b72207098 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 11 Feb 2014 20:58:20 -0500 Subject: generic_file_direct_write(): get rid of ppos argument always equal to &iocb->ki_pos. Signed-off-by: Al Viro --- fs/btrfs/file.c | 2 +- fs/fuse/file.c | 3 +-- fs/ocfs2/file.c | 2 +- fs/xfs/xfs_file.c | 2 +- include/linux/fs.h | 2 +- mm/filemap.c | 6 +++--- 6 files changed, 8 insertions(+), 9 deletions(-) (limited to 'mm') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f6032a2bfab9..8ed4b165abbd 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1640,7 +1640,7 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb, loff_t endbyte; int err; - written = generic_file_direct_write(iocb, iov, &nr_segs, pos, &iocb->ki_pos, + written = generic_file_direct_write(iocb, iov, &nr_segs, pos, count, ocount); if (written < 0 || written == count) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index a91d3b4d32f3..fd06d1ebc2eb 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1143,8 +1143,7 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, goto out; if (file->f_flags & O_DIRECT) { - written = generic_file_direct_write(iocb, iov, &nr_segs, - pos, &iocb->ki_pos, + written = generic_file_direct_write(iocb, iov, &nr_segs, pos, count, ocount); if (written < 0 || written == count) goto out; diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 89099cce14fe..77b8a742866f 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2375,7 +2375,7 @@ relock: if (direct_io) { written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos, - ppos, count, ocount); + count, ocount); if (written < 0) { ret = written; goto out_dio; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 175ce58fbfa3..e593554ce65e 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -699,7 +699,7 @@ xfs_file_dio_aio_write( trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); ret = generic_file_direct_write(iocb, iovp, - &nr_segs, pos, &iocb->ki_pos, count, ocount); + &nr_segs, pos, count, ocount); out: xfs_rw_iunlock(ip, iolock); diff --git a/include/linux/fs.h b/include/linux/fs.h index 830e37420f5e..9dfd7c7ff8e3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2395,7 +2395,7 @@ extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsig extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long); extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t); extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, - unsigned long *, loff_t, loff_t *, size_t, size_t); + unsigned long *, loff_t, size_t, size_t); extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, unsigned long, loff_t, size_t, ssize_t); extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); diff --git a/mm/filemap.c b/mm/filemap.c index 9d515a1a2372..93e9cf576452 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1985,7 +1985,7 @@ EXPORT_SYMBOL(pagecache_write_end); ssize_t generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long *nr_segs, loff_t pos, loff_t *ppos, + unsigned long *nr_segs, loff_t pos, size_t count, size_t ocount) { struct file *file = iocb->ki_filp; @@ -2046,7 +2046,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, i_size_write(inode, pos); mark_inode_dirty(inode); } - *ppos = pos; + iocb->ki_pos = pos; } out: return written; @@ -2265,7 +2265,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, ssize_t written_buffered; written = generic_file_direct_write(iocb, iov, &nr_segs, pos, - &iocb->ki_pos, count, ocount); + count, ocount); if (written < 0 || written == count) goto out; /* -- cgit v1.2.3 From 3b93f911d55cf8b3540f82fac4eeddfee7b5de0c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 11 Feb 2014 21:34:08 -0500 Subject: export generic_perform_write(), start getting rid of generic_file_buffer_write() Signed-off-by: Al Viro --- include/linux/fs.h | 2 ++ mm/filemap.c | 37 +++++++++++++++++++++---------------- 2 files changed, 23 insertions(+), 16 deletions(-) (limited to 'mm') diff --git a/include/linux/fs.h b/include/linux/fs.h index 9dfd7c7ff8e3..87be51aff9d7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -48,6 +48,7 @@ struct cred; struct swap_info_struct; struct seq_file; struct workqueue_struct; +struct iov_iter; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -2396,6 +2397,7 @@ extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, un extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t); extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, unsigned long *, loff_t, size_t, size_t); +extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t); extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, unsigned long, loff_t, size_t, ssize_t); extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); diff --git a/mm/filemap.c b/mm/filemap.c index 93e9cf576452..09bfc9b3bb51 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2092,7 +2092,7 @@ found: } EXPORT_SYMBOL(grab_cache_page_write_begin); -static ssize_t generic_perform_write(struct file *file, +ssize_t generic_perform_write(struct file *file, struct iov_iter *i, loff_t pos) { struct address_space *mapping = file->f_mapping; @@ -2180,6 +2180,7 @@ again: return written ? written : status; } +EXPORT_SYMBOL(generic_perform_write); ssize_t generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, @@ -2230,8 +2231,10 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, size_t count; /* after file limit checks */ struct inode *inode = mapping->host; loff_t pos = iocb->ki_pos; - ssize_t written; + ssize_t written = 0; ssize_t err; + ssize_t status; + struct iov_iter from; ocount = 0; err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); @@ -2242,8 +2245,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; - written = 0; - err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); if (err) goto out; @@ -2259,44 +2260,47 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (err) goto out; + iov_iter_init(&from, iov, nr_segs, count, 0); + /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (unlikely(file->f_flags & O_DIRECT)) { loff_t endbyte; - ssize_t written_buffered; - written = generic_file_direct_write(iocb, iov, &nr_segs, pos, + written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos, count, ocount); if (written < 0 || written == count) goto out; + iov_iter_advance(&from, written); + /* * direct-io write to a hole: fall through to buffered I/O * for completing the rest of the request. */ pos += written; count -= written; - written_buffered = generic_file_buffered_write(iocb, iov, - nr_segs, pos, count, written); + + status = generic_perform_write(file, &from, pos); /* - * If generic_file_buffered_write() retuned a synchronous error + * If generic_perform_write() returned a synchronous error * then we want to return the number of bytes which were * direct-written, or the error code if that was zero. Note * that this differs from normal direct-io semantics, which * will return -EFOO even if some bytes were written. */ - if (written_buffered < 0) { - err = written_buffered; + if (unlikely(status < 0) && !written) { + err = status; goto out; } - + iocb->ki_pos = pos + status; /* * We need to ensure that the page cache pages are written to * disk and invalidated to preserve the expected O_DIRECT * semantics. */ - endbyte = pos + written_buffered - written - 1; + endbyte = pos + status - 1; err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); if (err == 0) { - written = written_buffered; + written += status; invalidate_mapping_pages(mapping, pos >> PAGE_CACHE_SHIFT, endbyte >> PAGE_CACHE_SHIFT); @@ -2307,8 +2311,9 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, */ } } else { - written = generic_file_buffered_write(iocb, iov, nr_segs, - pos, count, written); + written = generic_perform_write(file, &from, pos); + if (likely(written >= 0)) + iocb->ki_pos = pos + written; } out: current->backing_dev_info = NULL; -- cgit v1.2.3 From ccad2365668f12336dd497d9039e8584af836070 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 11 Feb 2014 22:36:48 -0500 Subject: kill generic_file_buffered_write() Signed-off-by: Al Viro --- include/linux/fs.h | 2 -- mm/filemap.c | 23 +---------------------- 2 files changed, 1 insertion(+), 24 deletions(-) (limited to 'mm') diff --git a/include/linux/fs.h b/include/linux/fs.h index 87be51aff9d7..c309b7a0da2d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2398,8 +2398,6 @@ extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsi extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, unsigned long *, loff_t, size_t, size_t); extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t); -extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, - unsigned long, loff_t, size_t, ssize_t); extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); extern int generic_segment_checks(const struct iovec *iov, diff --git a/mm/filemap.c b/mm/filemap.c index 09bfc9b3bb51..1a455142784d 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -76,7 +76,7 @@ * ->mmap_sem * ->lock_page (access_process_vm) * - * ->i_mutex (generic_file_buffered_write) + * ->i_mutex (generic_perform_write) * ->mmap_sem (fault_in_pages_readable->do_page_fault) * * bdi->wb.list_lock @@ -2182,27 +2182,6 @@ again: } EXPORT_SYMBOL(generic_perform_write); -ssize_t -generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos, - size_t count, ssize_t written) -{ - struct file *file = iocb->ki_filp; - ssize_t status; - struct iov_iter i; - - iov_iter_init(&i, iov, nr_segs, count, written); - status = generic_perform_write(file, &i, pos); - - if (likely(status >= 0)) { - written += status; - iocb->ki_pos = pos + status; - } - - return written ? written : status; -} -EXPORT_SYMBOL(generic_file_buffered_write); - /** * __generic_file_aio_write - write data to a file * @iocb: IO state structure (file, offset, etc.) -- cgit v1.2.3 From a786c06d9f2719203c00b3d97b21f9a96980d0b5 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 11 Apr 2014 12:01:03 -0400 Subject: missing bits of "splice: fix racy pipe->buffers uses" that commit has fixed only the parts of that mess in fs/splice.c itself; there had been more in several other ->splice_read() instances... Signed-off-by: Al Viro --- kernel/relay.c | 2 +- kernel/trace/trace.c | 4 ++-- mm/shmem.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'mm') diff --git a/kernel/relay.c b/kernel/relay.c index 98833f664fb6..7d38607649a3 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -1251,7 +1251,7 @@ static ssize_t subbuf_splice_actor(struct file *in, subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; pidx = (read_start / PAGE_SIZE) % subbuf_pages; poff = read_start & ~PAGE_MASK; - nr_pages = min_t(unsigned int, subbuf_pages, pipe->buffers); + nr_pages = min_t(unsigned int, subbuf_pages, spd.nr_pages_max); for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) { unsigned int this_len, this_end, private; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7511de35257f..27924caaa124 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4410,7 +4410,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, trace_access_lock(iter->cpu_file); /* Fill as many pages as possible. */ - for (i = 0, rem = len; i < pipe->buffers && rem; i++) { + for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) { spd.pages[i] = alloc_page(GFP_KERNEL); if (!spd.pages[i]) break; @@ -5267,7 +5267,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, trace_access_lock(iter->cpu_file); entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); - for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { + for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) { struct page *page; int r; diff --git a/mm/shmem.c b/mm/shmem.c index 17d3799d04bd..37400a148f29 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1613,7 +1613,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, index = *ppos >> PAGE_CACHE_SHIFT; loff = *ppos & ~PAGE_CACHE_MASK; req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - nr_pages = min(req_pages, pipe->buffers); + nr_pages = min(req_pages, spd.nr_pages_max); spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages); -- cgit v1.2.3