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author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-30 10:26:41 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-10 11:45:14 -0400 |
commit | f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454 (patch) | |
tree | 05ad20f84ee097a534132fa9b2df9feae6d4a7d2 /fs | |
parent | e4f8df86798aea60aff6cfff40252b709431f850 (diff) | |
download | linux-stable-f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454.tar.gz linux-stable-f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454.tar.bz2 linux-stable-f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454.zip |
iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the
callers do *not* need to do iov_iter_advance() after it. In case when they end
up consuming less than they'd been given they need to do iov_iter_revert() on
everything they had not consumed. That, however, needs to be done only on slow
paths.
All in-tree callers converted. And that kills the last user of iterate_all_kinds()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/file.c | 23 | ||||
-rw-r--r-- | fs/fuse/file.c | 3 | ||||
-rw-r--r-- | fs/iomap/buffered-io.c | 14 | ||||
-rw-r--r-- | fs/ntfs/file.c | 4 |
4 files changed, 20 insertions, 24 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 864c08d08a35..78cb8f9eaa6b 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -398,7 +398,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, /* * Copy data from userspace to the current page */ - copied = iov_iter_copy_from_user_atomic(page, i, offset, count); + copied = copy_page_from_iter_atomic(page, offset, count, i); /* Flush processor's dcache for this page */ flush_dcache_page(page); @@ -412,20 +412,19 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, * The rest of the btrfs_file_write code will fall * back to page at a time copies after we return 0. */ - if (!PageUptodate(page) && copied < count) - copied = 0; + if (unlikely(copied < count)) { + if (!PageUptodate(page)) { + iov_iter_revert(i, copied); + copied = 0; + } + if (!copied) + break; + } - iov_iter_advance(i, copied); write_bytes -= copied; total_copied += copied; - - /* Return to btrfs_file_write_iter to fault page */ - if (unlikely(copied == 0)) - break; - - if (copied < PAGE_SIZE - offset) { - offset += copied; - } else { + offset += copied; + if (offset == PAGE_SIZE) { pg++; offset = 0; } diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 44bd301fa4fb..4722fa31a185 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1171,10 +1171,9 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia, if (mapping_writably_mapped(mapping)) flush_dcache_page(page); - tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); + tmp = copy_page_from_iter_atomic(page, offset, bytes, ii); flush_dcache_page(page); - iov_iter_advance(ii, tmp); if (!tmp) { unlock_page(page); put_page(page); diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 354b41d20e5d..c5ff13e0e7cf 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -785,13 +785,15 @@ again: if (mapping_writably_mapped(inode->i_mapping)) flush_dcache_page(page); - copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); + copied = copy_page_from_iter_atomic(page, offset, bytes, i); status = iomap_write_end(inode, pos, bytes, copied, page, iomap, srcmap); - cond_resched(); + if (unlikely(copied != status)) + iov_iter_revert(i, copied - status); + cond_resched(); if (unlikely(status == 0)) { /* * A short copy made iomap_write_end() reject the @@ -803,11 +805,9 @@ again: bytes = copied; goto again; } - copied = status; - iov_iter_advance(i, copied); - pos += copied; - written += copied; - length -= copied; + pos += status; + written += status; + length -= status; balance_dirty_pages_ratelimited(inode->i_mapping); } while (iov_iter_count(i) && length); diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index 0666d4578137..ab4f3362466d 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1690,9 +1690,7 @@ static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages, len = PAGE_SIZE - ofs; if (len > bytes) len = bytes; - copied = iov_iter_copy_from_user_atomic(*pages, i, ofs, - len); - iov_iter_advance(i, copied); + copied = copy_page_from_iter_atomic(*pages, ofs, len, i); total += copied; bytes -= copied; if (!bytes) |