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-rw-r--r--mm/Makefile3
-rw-r--r--mm/fadvise.c3
-rw-r--r--mm/readahead.c45
3 files changed, 21 insertions, 30 deletions
diff --git a/mm/Makefile b/mm/Makefile
index 8716bdabe1e6..26ef77a3883b 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -32,7 +32,7 @@ ifdef CONFIG_CROSS_MEMORY_ATTACH
mmu-$(CONFIG_MMU) += process_vm_access.o
endif
-obj-y := filemap.o mempool.o oom_kill.o \
+obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
util.o mmzone.o vmstat.o backing-dev.o \
@@ -49,7 +49,6 @@ else
obj-y += bootmem.o
endif
-obj-$(CONFIG_ADVISE_SYSCALLS) += fadvise.o
ifdef CONFIG_MMU
obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o
endif
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 2f59bac1cb77..467bcd032037 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -188,6 +188,8 @@ int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
}
EXPORT_SYMBOL(vfs_fadvise);
+#ifdef CONFIG_ADVISE_SYSCALLS
+
int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
{
struct fd f = fdget(fd);
@@ -215,3 +217,4 @@ SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
}
#endif
+#endif
diff --git a/mm/readahead.c b/mm/readahead.c
index a59ea70527b9..4e630143a0ba 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -20,6 +20,7 @@
#include <linux/file.h>
#include <linux/mm_inline.h>
#include <linux/blk-cgroup.h>
+#include <linux/fadvise.h>
#include "internal.h"
@@ -575,24 +576,6 @@ page_cache_async_readahead(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);
-static ssize_t
-do_readahead(struct address_space *mapping, struct file *filp,
- pgoff_t index, unsigned long nr)
-{
- if (!mapping || !mapping->a_ops)
- return -EINVAL;
-
- /*
- * Readahead doesn't make sense for DAX inodes, but we don't want it
- * to report a failure either. Instead, we just return success and
- * don't do any work.
- */
- if (dax_mapping(mapping))
- return 0;
-
- return force_page_cache_readahead(mapping, filp, index, nr);
-}
-
ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
{
ssize_t ret;
@@ -600,16 +583,22 @@ ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
ret = -EBADF;
f = fdget(fd);
- if (f.file) {
- if (f.file->f_mode & FMODE_READ) {
- struct address_space *mapping = f.file->f_mapping;
- pgoff_t start = offset >> PAGE_SHIFT;
- pgoff_t end = (offset + count - 1) >> PAGE_SHIFT;
- unsigned long len = end - start + 1;
- ret = do_readahead(mapping, f.file, start, len);
- }
- fdput(f);
- }
+ if (!f.file || !(f.file->f_mode & FMODE_READ))
+ goto out;
+
+ /*
+ * The readahead() syscall is intended to run only on files
+ * that can execute readahead. If readahead is not possible
+ * on this file, then we must return -EINVAL.
+ */
+ ret = -EINVAL;
+ if (!f.file->f_mapping || !f.file->f_mapping->a_ops ||
+ !S_ISREG(file_inode(f.file)->i_mode))
+ goto out;
+
+ ret = vfs_fadvise(f.file, offset, count, POSIX_FADV_WILLNEED);
+out:
+ fdput(f);
return ret;
}