swap: rename SWP_FS to SWAP_FS_OPS to avoid ambiguity

SWP_FS is used to make swap_{read,write}page() go through the filesystem,
and it's only used for swap files over NFS for now.  Otherwise it will
directly submit IO to blockdev according to swapfile extents reported by
filesystems in advance.

As Matthew pointed out [1], SWP_FS naming is somewhat confusing, so let's
rename to SWP_FS_OPS.

[1] https://lore.kernel.org/r/20200820113448.GM17456@casper.infradead.org

Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200822113019.11319-1-hsiangkao@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 23c6e43a956ded3ae83ca45c4f447aa19b4ed90d..7bd5b4aac049e70f8c4d9aa79a0865de1c759f2a 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -170,7 +170,7 @@ enum {
        SWP_CONTINUED   = (1 << 5),     /* swap_map has count continuation */
        SWP_BLKDEV      = (1 << 6),     /* its a block device */
        SWP_ACTIVATED   = (1 << 7),     /* set after swap_activate success */
-       SWP_FS          = (1 << 8),     /* swap file goes through fs */
+       SWP_FS_OPS      = (1 << 8),     /* swapfile operations go through fs */
        SWP_AREA_DISCARD = (1 << 9),    /* single-time swap area discards */
        SWP_PAGE_DISCARD = (1 << 10),   /* freed swap page-cluster discards */
        SWP_STABLE_WRITES = (1 << 11),  /* no overwrite PG_writeback pages */

diff --git a/mm/page_io.c b/mm/page_io.c
index f9e9267f296f57ffa15e37b54137bf1381063a5d..2ffe4c4a6d975d3b3c0b0297591ae41ae284e0bf 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -312,7 +312,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
        struct swap_info_struct *sis = page_swap_info(page);
 
        VM_BUG_ON_PAGE(!PageSwapCache(page), page);
-       if (data_race(sis->flags & SWP_FS)) {
+       if (data_race(sis->flags & SWP_FS_OPS)) {
                struct kiocb kiocb;
                struct file *swap_file = sis->swap_file;
                struct address_space *mapping = swap_file->f_mapping;
@@ -403,7 +403,7 @@ int swap_readpage(struct page *page, bool synchronous)
                goto out;
        }
 
-       if (data_race(sis->flags & SWP_FS)) {
+       if (data_race(sis->flags & SWP_FS_OPS)) {
                struct file *swap_file = sis->swap_file;
                struct address_space *mapping = swap_file->f_mapping;
 
@@ -467,7 +467,7 @@ int swap_set_page_dirty(struct page *page)
 {
        struct swap_info_struct *sis = page_swap_info(page);
 
-       if (data_race(sis->flags & SWP_FS)) {
+       if (data_race(sis->flags & SWP_FS_OPS)) {
                struct address_space *mapping = sis->swap_file->f_mapping;
 
                VM_BUG_ON_PAGE(!PageSwapCache(page), page);

diff --git a/mm/swap_state.c b/mm/swap_state.c
index f24f2cea4238e1fe2c3b6f2937ee0c22e00b8b73..aa40e706604cd4cdb32c0baedb60167fb32a8dd7 100644 (file)
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -665,7 +665,7 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
                goto skip;
 
        /* Test swap type to make sure the dereference is safe */
-       if (likely(si->flags & (SWP_BLKDEV | SWP_FS))) {
+       if (likely(si->flags & (SWP_BLKDEV | SWP_FS_OPS))) {
                struct inode *inode = si->swap_file->f_mapping->host;
                if (inode_read_congested(inode))
                        goto skip;

diff --git a/mm/swapfile.c b/mm/swapfile.c
index ced4635d924cfad7cc829cba0ec38636a6a39a45..183b87bc87ccbc5dc717b3ec2449ebd82dc01bf6 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2437,7 +2437,7 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
                if (ret >= 0)
                        sis->flags |= SWP_ACTIVATED;
                if (!ret) {
-                       sis->flags |= SWP_FS;
+                       sis->flags |= SWP_FS_OPS;
                        ret = add_swap_extent(sis, 0, sis->max, 0);
                        *span = sis->pages;
                }