diff options
author | Jan Kara <jack@suse.cz> | 2019-08-29 09:04:11 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 15:12:34 +0200 |
commit | 46b4c5d9df6d94c45de2b42d264b848884ee25a6 (patch) | |
tree | 6f460a9958de8caf705ed562bed07930159b5ea6 /mm/madvise.c | |
parent | fbe7950a17c7786130d1e2bb0fa91a5256f7e186 (diff) | |
download | linux-stable-46b4c5d9df6d94c45de2b42d264b848884ee25a6.tar.gz linux-stable-46b4c5d9df6d94c45de2b42d264b848884ee25a6.tar.bz2 linux-stable-46b4c5d9df6d94c45de2b42d264b848884ee25a6.zip |
mm: Handle MADV_WILLNEED through vfs_fadvise()
commit 692fe62433d4ca47605b39f7c416efd6679ba694 upstream.
Currently handling of MADV_WILLNEED hint calls directly into readahead
code. Handle it by calling vfs_fadvise() instead so that filesystem can
use its ->fadvise() callback to acquire necessary locks or otherwise
prepare for the request.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Boaz Harrosh <boazh@netapp.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/madvise.c')
-rw-r--r-- | mm/madvise.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index 968df3aa069f..bac973b9f2cc 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -14,6 +14,7 @@ #include <linux/userfaultfd_k.h> #include <linux/hugetlb.h> #include <linux/falloc.h> +#include <linux/fadvise.h> #include <linux/sched.h> #include <linux/ksm.h> #include <linux/fs.h> @@ -275,6 +276,7 @@ static long madvise_willneed(struct vm_area_struct *vma, unsigned long start, unsigned long end) { struct file *file = vma->vm_file; + loff_t offset; *prev = vma; #ifdef CONFIG_SWAP @@ -298,12 +300,20 @@ static long madvise_willneed(struct vm_area_struct *vma, return 0; } - start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - if (end > vma->vm_end) - end = vma->vm_end; - end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - - force_page_cache_readahead(file->f_mapping, file, start, end - start); + /* + * Filesystem's fadvise may need to take various locks. We need to + * explicitly grab a reference because the vma (and hence the + * vma's reference to the file) can go away as soon as we drop + * mmap_sem. + */ + *prev = NULL; /* tell sys_madvise we drop mmap_sem */ + get_file(file); + up_read(¤t->mm->mmap_sem); + offset = (loff_t)(start - vma->vm_start) + + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); + vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); + fput(file); + down_read(¤t->mm->mmap_sem); return 0; } |