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-rw-r--r--mm/filemap.c117
1 files changed, 51 insertions, 66 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 65d9d9e2b755..6343f3c841b7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -42,9 +42,6 @@
42 42
43#include <asm/mman.h> 43#include <asm/mman.h>
44 44
45static ssize_t
46generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
47 loff_t offset, unsigned long nr_segs);
48 45
49/* 46/*
50 * Shared mappings implemented 30.11.1994. It's not fully working yet, 47 * Shared mappings implemented 30.11.1994. It's not fully working yet,
@@ -1205,8 +1202,11 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
1205 goto out; /* skip atime */ 1202 goto out; /* skip atime */
1206 size = i_size_read(inode); 1203 size = i_size_read(inode);
1207 if (pos < size) { 1204 if (pos < size) {
1208 retval = generic_file_direct_IO(READ, iocb, 1205 retval = filemap_write_and_wait(mapping);
1209 iov, pos, nr_segs); 1206 if (!retval) {
1207 retval = mapping->a_ops->direct_IO(READ, iocb,
1208 iov, pos, nr_segs);
1209 }
1210 if (retval > 0) 1210 if (retval > 0)
1211 *ppos = pos + retval; 1211 *ppos = pos + retval;
1212 } 1212 }
@@ -2004,11 +2004,55 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
2004 struct address_space *mapping = file->f_mapping; 2004 struct address_space *mapping = file->f_mapping;
2005 struct inode *inode = mapping->host; 2005 struct inode *inode = mapping->host;
2006 ssize_t written; 2006 ssize_t written;
2007 size_t write_len;
2008 pgoff_t end;
2007 2009
2008 if (count != ocount) 2010 if (count != ocount)
2009 *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count); 2011 *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
2010 2012
2011 written = generic_file_direct_IO(WRITE, iocb, iov, pos, *nr_segs); 2013 /*
2014 * Unmap all mmappings of the file up-front.
2015 *
2016 * This will cause any pte dirty bits to be propagated into the
2017 * pageframes for the subsequent filemap_write_and_wait().
2018 */
2019 write_len = iov_length(iov, *nr_segs);
2020 end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
2021 if (mapping_mapped(mapping))
2022 unmap_mapping_range(mapping, pos, write_len, 0);
2023
2024 written = filemap_write_and_wait(mapping);
2025 if (written)
2026 goto out;
2027
2028 /*
2029 * After a write we want buffered reads to be sure to go to disk to get
2030 * the new data. We invalidate clean cached page from the region we're
2031 * about to write. We do this *before* the write so that we can return
2032 * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().
2033 */
2034 if (mapping->nrpages) {
2035 written = invalidate_inode_pages2_range(mapping,
2036 pos >> PAGE_CACHE_SHIFT, end);
2037 if (written)
2038 goto out;
2039 }
2040
2041 written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
2042
2043 /*
2044 * Finally, try again to invalidate clean pages which might have been
2045 * cached by non-direct readahead, or faulted in by get_user_pages()
2046 * if the source of the write was an mmap'ed region of the file
2047 * we're writing. Either one is a pretty crazy thing to do,
2048 * so we don't support it 100%. If this invalidation
2049 * fails, tough, the write still worked...
2050 */
2051 if (mapping->nrpages) {
2052 invalidate_inode_pages2_range(mapping,
2053 pos >> PAGE_CACHE_SHIFT, end);
2054 }
2055
2012 if (written > 0) { 2056 if (written > 0) {
2013 loff_t end = pos + written; 2057 loff_t end = pos + written;
2014 if (end > i_size_read(inode) && !S_ISBLK(inode->i_mode)) { 2058 if (end > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
@@ -2024,6 +2068,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
2024 * i_mutex is held, which protects generic_osync_inode() from 2068 * i_mutex is held, which protects generic_osync_inode() from
2025 * livelocking. AIO O_DIRECT ops attempt to sync metadata here. 2069 * livelocking. AIO O_DIRECT ops attempt to sync metadata here.
2026 */ 2070 */
2071out:
2027 if ((written >= 0 || written == -EIOCBQUEUED) && 2072 if ((written >= 0 || written == -EIOCBQUEUED) &&
2028 ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { 2073 ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
2029 int err = generic_osync_inode(inode, mapping, OSYNC_METADATA); 2074 int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
@@ -2511,66 +2556,6 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
2511} 2556}
2512EXPORT_SYMBOL(generic_file_aio_write); 2557EXPORT_SYMBOL(generic_file_aio_write);
2513 2558
2514/*
2515 * Called under i_mutex for writes to S_ISREG files. Returns -EIO if something
2516 * went wrong during pagecache shootdown.
2517 */
2518static ssize_t
2519generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
2520 loff_t offset, unsigned long nr_segs)
2521{
2522 struct file *file = iocb->ki_filp;
2523 struct address_space *mapping = file->f_mapping;
2524 ssize_t retval;
2525 size_t write_len;
2526 pgoff_t end = 0; /* silence gcc */
2527
2528 /*
2529 * If it's a write, unmap all mmappings of the file up-front. This
2530 * will cause any pte dirty bits to be propagated into the pageframes
2531 * for the subsequent filemap_write_and_wait().
2532 */
2533 if (rw == WRITE) {
2534 write_len = iov_length(iov, nr_segs);
2535 end = (offset + write_len - 1) >> PAGE_CACHE_SHIFT;
2536 if (mapping_mapped(mapping))
2537 unmap_mapping_range(mapping, offset, write_len, 0);
2538 }
2539
2540 retval = filemap_write_and_wait(mapping);
2541 if (retval)
2542 goto out;
2543
2544 /*
2545 * After a write we want buffered reads to be sure to go to disk to get
2546 * the new data. We invalidate clean cached page from the region we're
2547 * about to write. We do this *before* the write so that we can return
2548 * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().
2549 */
2550 if (rw == WRITE && mapping->nrpages) {
2551 retval = invalidate_inode_pages2_range(mapping,
2552 offset >> PAGE_CACHE_SHIFT, end);
2553 if (retval)
2554 goto out;
2555 }
2556
2557 retval = mapping->a_ops->direct_IO(rw, iocb, iov, offset, nr_segs);
2558
2559 /*
2560 * Finally, try again to invalidate clean pages which might have been
2561 * cached by non-direct readahead, or faulted in by get_user_pages()
2562 * if the source of the write was an mmap'ed region of the file
2563 * we're writing. Either one is a pretty crazy thing to do,
2564 * so we don't support it 100%. If this invalidation
2565 * fails, tough, the write still worked...
2566 */
2567 if (rw == WRITE && mapping->nrpages) {
2568 invalidate_inode_pages2_range(mapping, offset >> PAGE_CACHE_SHIFT, end);
2569 }
2570out:
2571 return retval;
2572}
2573
2574/** 2559/**
2575 * try_to_release_page() - release old fs-specific metadata on a page 2560 * try_to_release_page() - release old fs-specific metadata on a page
2576 * 2561 *