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authorAmir Goldstein <amir73il@gmail.com>2018-08-27 15:56:02 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2018-08-30 18:08:35 +0300
commit45cd0faae3715e305bc46e23b34c5ed4d185ceb8 (patch)
treebe01e26c488ebd3cb7943136a0805563e311d117 /mm/fadvise.c
parent17ef445f9befdc5c9adac270b18240ad24ee50ec (diff)
downloadlinux-45cd0faae3715e305bc46e23b34c5ed4d185ceb8.tar.xz
vfs: add the fadvise() file operation
This is going to be used by overlayfs and possibly useful for other filesystems. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'mm/fadvise.c')
-rw-r--r--mm/fadvise.c78
1 files changed, 45 insertions, 33 deletions
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 2d8376e3c640..2f59bac1cb77 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -27,9 +27,9 @@
* deactivate the pages and clear PG_Referenced.
*/
-int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
+static int generic_fadvise(struct file *file, loff_t offset, loff_t len,
+ int advice)
{
- struct fd f = fdget(fd);
struct inode *inode;
struct address_space *mapping;
struct backing_dev_info *bdi;
@@ -37,22 +37,14 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
pgoff_t start_index;
pgoff_t end_index;
unsigned long nrpages;
- int ret = 0;
- if (!f.file)
- return -EBADF;
+ inode = file_inode(file);
+ if (S_ISFIFO(inode->i_mode))
+ return -ESPIPE;
- inode = file_inode(f.file);
- if (S_ISFIFO(inode->i_mode)) {
- ret = -ESPIPE;
- goto out;
- }
-
- mapping = f.file->f_mapping;
- if (!mapping || len < 0) {
- ret = -EINVAL;
- goto out;
- }
+ mapping = file->f_mapping;
+ if (!mapping || len < 0)
+ return -EINVAL;
bdi = inode_to_bdi(mapping->host);
@@ -67,9 +59,9 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
/* no bad return value, but ignore advice */
break;
default:
- ret = -EINVAL;
+ return -EINVAL;
}
- goto out;
+ return 0;
}
/*
@@ -85,21 +77,21 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
switch (advice) {
case POSIX_FADV_NORMAL:
- f.file->f_ra.ra_pages = bdi->ra_pages;
- spin_lock(&f.file->f_lock);
- f.file->f_mode &= ~FMODE_RANDOM;
- spin_unlock(&f.file->f_lock);
+ file->f_ra.ra_pages = bdi->ra_pages;
+ spin_lock(&file->f_lock);
+ file->f_mode &= ~FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
break;
case POSIX_FADV_RANDOM:
- spin_lock(&f.file->f_lock);
- f.file->f_mode |= FMODE_RANDOM;
- spin_unlock(&f.file->f_lock);
+ spin_lock(&file->f_lock);
+ file->f_mode |= FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
break;
case POSIX_FADV_SEQUENTIAL:
- f.file->f_ra.ra_pages = bdi->ra_pages * 2;
- spin_lock(&f.file->f_lock);
- f.file->f_mode &= ~FMODE_RANDOM;
- spin_unlock(&f.file->f_lock);
+ file->f_ra.ra_pages = bdi->ra_pages * 2;
+ spin_lock(&file->f_lock);
+ file->f_mode &= ~FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
break;
case POSIX_FADV_WILLNEED:
/* First and last PARTIAL page! */
@@ -115,8 +107,7 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
* Ignore return value because fadvise() shall return
* success even if filesystem can't retrieve a hint,
*/
- force_page_cache_readahead(mapping, f.file, start_index,
- nrpages);
+ force_page_cache_readahead(mapping, file, start_index, nrpages);
break;
case POSIX_FADV_NOREUSE:
break;
@@ -183,9 +174,30 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
}
break;
default:
- ret = -EINVAL;
+ return -EINVAL;
}
-out:
+ return 0;
+}
+
+int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
+{
+ if (file->f_op->fadvise)
+ return file->f_op->fadvise(file, offset, len, advice);
+
+ return generic_fadvise(file, offset, len, advice);
+}
+EXPORT_SYMBOL(vfs_fadvise);
+
+int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
+{
+ struct fd f = fdget(fd);
+ int ret;
+
+ if (!f.file)
+ return -EBADF;
+
+ ret = vfs_fadvise(f.file, offset, len, advice);
+
fdput(f);
return ret;
}