On Tue, May 12, 2026 at 07:35:17AM +0200, Christoph Hellwig wrote: > Always use si->max which is updated setup_swap_extents instead of copying
"...updated in setup_swap_extents..." > into and out of maxpages. > > Signed-off-by: Christoph Hellwig <[email protected]> But yes, it's much harder to track the data flows if we keep copying the value in and out of local variables. Reviewed-by: "Darrick J. Wong" <[email protected]> --D > --- > mm/swapfile.c | 27 +++++++++++---------------- > 1 file changed, 11 insertions(+), 16 deletions(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 9174f1eeffb0..f7ebd97e28a3 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -3350,10 +3350,9 @@ static unsigned long read_swap_header(struct > swap_info_struct *si, > } > > static int setup_swap_clusters_info(struct swap_info_struct *si, > - union swap_header *swap_header, > - unsigned long maxpages) > + union swap_header *swap_header) > { > - unsigned long nr_clusters = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER); > + unsigned long nr_clusters = DIV_ROUND_UP(si->max, SWAPFILE_CLUSTER); > struct swap_cluster_info *cluster_info; > int err = -ENOMEM; > unsigned long i; > @@ -3395,7 +3394,7 @@ static int setup_swap_clusters_info(struct > swap_info_struct *si, > if (err) > goto err; > } > - for (i = maxpages; i < round_up(maxpages, SWAPFILE_CLUSTER); i++) { > + for (i = si->max; i < round_up(si->max, SWAPFILE_CLUSTER); i++) { > err = swap_cluster_setup_bad_slot(si, cluster_info, i, true); > if (err) > goto err; > @@ -3425,7 +3424,7 @@ static int setup_swap_clusters_info(struct > swap_info_struct *si, > si->cluster_info = cluster_info; > return 0; > err: > - free_swap_cluster_info(cluster_info, maxpages); > + free_swap_cluster_info(cluster_info, si->max); > return err; > } > > @@ -3440,7 +3439,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, > specialfile, int, swap_flags) > union swap_header *swap_header; > int nr_extents; > sector_t span; > - unsigned long maxpages; > struct folio *folio = NULL; > struct inode *inode = NULL; > bool inced_nr_rotate_swap = false; > @@ -3512,14 +3510,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, > specialfile, int, swap_flags) > } > swap_header = kmap_local_folio(folio, 0); > > - maxpages = read_swap_header(si, swap_header, inode); > - if (unlikely(!maxpages)) { > + si->max = read_swap_header(si, swap_header, inode); > + if (unlikely(!si->max)) { > error = -EINVAL; > goto bad_swap_unlock_inode; > } > > - si->max = maxpages; > - si->pages = maxpages - 1; > + si->pages = si->max - 1; > nr_extents = setup_swap_extents(si, swap_file, &span); > if (nr_extents < 0) { > error = nr_extents; > @@ -3531,14 +3528,12 @@ SYSCALL_DEFINE2(swapon, const char __user *, > specialfile, int, swap_flags) > goto bad_swap_unlock_inode; > } > > - maxpages = si->max; > - > /* Set up the swap cluster info */ > - error = setup_swap_clusters_info(si, swap_header, maxpages); > + error = setup_swap_clusters_info(si, swap_header); > if (error) > goto bad_swap_unlock_inode; > > - error = swap_cgroup_swapon(si->type, maxpages); > + error = swap_cgroup_swapon(si->type, si->max); > if (error) > goto bad_swap_unlock_inode; > > @@ -3546,7 +3541,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, > specialfile, int, swap_flags) > * Use kvmalloc_array instead of bitmap_zalloc as the allocation order > might > * be above MAX_PAGE_ORDER incase of a large swap file. > */ > - si->zeromap = kvmalloc_array(BITS_TO_LONGS(maxpages), sizeof(long), > + si->zeromap = kvmalloc_array(BITS_TO_LONGS(si->max), sizeof(long), > GFP_KERNEL | __GFP_ZERO); > if (!si->zeromap) { > error = -ENOMEM; > @@ -3597,7 +3592,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, > specialfile, int, swap_flags) > } > } > > - error = zswap_swapon(si->type, maxpages); > + error = zswap_swapon(si->type, si->max); > if (error) > goto bad_swap_unlock_inode; > > -- > 2.53.0 > > _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
