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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /fs/hugetlbfs/inode.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'fs/hugetlbfs/inode.c')
-rw-r--r--fs/hugetlbfs/inode.c190
1 files changed, 87 insertions, 103 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 595ebdb41..e1f465a38 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -4,11 +4,11 @@
* Nadia Yvette Chambers, 2002
*
* Copyright (C) 2002 Linus Torvalds.
+ * License: GPL
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/module.h>
#include <linux/thread_info.h>
#include <asm/current.h>
#include <linux/sched.h> /* remove ASAP */
@@ -141,7 +141,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
vma_len = (loff_t)(vma->vm_end - vma->vm_start);
- mutex_lock(&inode->i_mutex);
+ inode_lock(inode);
file_accessed(file);
ret = -ENOMEM;
@@ -157,7 +157,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
if (vma->vm_flags & VM_WRITE && inode->i_size < len)
inode->i_size = len;
out:
- mutex_unlock(&inode->i_mutex);
+ inode_unlock(inode);
return ret;
}
@@ -324,11 +324,48 @@ static void remove_huge_page(struct page *page)
delete_from_page_cache(page);
}
+static void
+hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end)
+{
+ struct vm_area_struct *vma;
+
+ /*
+ * end == 0 indicates that the entire range after
+ * start should be unmapped.
+ */
+ vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) {
+ unsigned long v_offset;
+ unsigned long v_end;
+
+ /*
+ * Can the expression below overflow on 32-bit arches?
+ * No, because the interval tree returns us only those vmas
+ * which overlap the truncated area starting at pgoff,
+ * and no vma on a 32-bit arch can span beyond the 4GB.
+ */
+ if (vma->vm_pgoff < start)
+ v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
+ else
+ v_offset = 0;
+
+ if (!end)
+ v_end = vma->vm_end;
+ else {
+ v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT)
+ + vma->vm_start;
+ if (v_end > vma->vm_end)
+ v_end = vma->vm_end;
+ }
+
+ unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end,
+ NULL);
+ }
+}
/*
* remove_inode_hugepages handles two distinct cases: truncation and hole
* punch. There are subtle differences in operation for each case.
-
+ *
* truncation is indicated by end of range being LLONG_MAX
* In this case, we first scan the range and release found pages.
* After releasing pages, hugetlb_unreserve_pages cleans up region/reserv
@@ -379,6 +416,7 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
for (i = 0; i < pagevec_count(&pvec); ++i) {
struct page *page = pvec.pages[i];
+ bool rsv_on_error;
u32 hash;
/*
@@ -395,37 +433,43 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
mapping, next, 0);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
- lock_page(page);
- if (likely(!page_mapped(page))) {
- bool rsv_on_error = !PagePrivate(page);
- /*
- * We must free the huge page and remove
- * from page cache (remove_huge_page) BEFORE
- * removing the region/reserve map
- * (hugetlb_unreserve_pages). In rare out
- * of memory conditions, removal of the
- * region/reserve map could fail. Before
- * free'ing the page, note PagePrivate which
- * is used in case of error.
- */
- remove_huge_page(page);
- freed++;
- if (!truncate_op) {
- if (unlikely(hugetlb_unreserve_pages(
- inode, next,
- next + 1, 1)))
- hugetlb_fix_reserve_counts(
- inode, rsv_on_error);
- }
- } else {
- /*
- * If page is mapped, it was faulted in after
- * being unmapped. It indicates a race between
- * hole punch and page fault. Do nothing in
- * this case. Getting here in a truncate
- * operation is a bug.
- */
+ /*
+ * If page is mapped, it was faulted in after being
+ * unmapped in caller. Unmap (again) now after taking
+ * the fault mutex. The mutex will prevent faults
+ * until we finish removing the page.
+ *
+ * This race can only happen in the hole punch case.
+ * Getting here in a truncate operation is a bug.
+ */
+ if (unlikely(page_mapped(page))) {
BUG_ON(truncate_op);
+
+ i_mmap_lock_write(mapping);
+ hugetlb_vmdelete_list(&mapping->i_mmap,
+ next * pages_per_huge_page(h),
+ (next + 1) * pages_per_huge_page(h));
+ i_mmap_unlock_write(mapping);
+ }
+
+ lock_page(page);
+ /*
+ * We must free the huge page and remove from page
+ * cache (remove_huge_page) BEFORE removing the
+ * region/reserve map (hugetlb_unreserve_pages). In
+ * rare out of memory conditions, removal of the
+ * region/reserve map could fail. Before free'ing
+ * the page, note PagePrivate which is used in case
+ * of error.
+ */
+ rsv_on_error = !PagePrivate(page);
+ remove_huge_page(page);
+ freed++;
+ if (!truncate_op) {
+ if (unlikely(hugetlb_unreserve_pages(inode,
+ next, next + 1, 1)))
+ hugetlb_fix_reserve_counts(inode,
+ rsv_on_error);
}
unlock_page(page);
@@ -452,44 +496,6 @@ static void hugetlbfs_evict_inode(struct inode *inode)
clear_inode(inode);
}
-static inline void
-hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end)
-{
- struct vm_area_struct *vma;
-
- /*
- * end == 0 indicates that the entire range after
- * start should be unmapped.
- */
- vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) {
- unsigned long v_offset;
- unsigned long v_end;
-
- /*
- * Can the expression below overflow on 32-bit arches?
- * No, because the interval tree returns us only those vmas
- * which overlap the truncated area starting at pgoff,
- * and no vma on a 32-bit arch can span beyond the 4GB.
- */
- if (vma->vm_pgoff < start)
- v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
- else
- v_offset = 0;
-
- if (!end)
- v_end = vma->vm_end;
- else {
- v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT)
- + vma->vm_start;
- if (v_end > vma->vm_end)
- v_end = vma->vm_end;
- }
-
- unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end,
- NULL);
- }
-}
-
static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
{
pgoff_t pgoff;
@@ -524,7 +530,7 @@ static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
if (hole_end > hole_start) {
struct address_space *mapping = inode->i_mapping;
- mutex_lock(&inode->i_mutex);
+ inode_lock(inode);
i_mmap_lock_write(mapping);
if (!RB_EMPTY_ROOT(&mapping->i_mmap))
hugetlb_vmdelete_list(&mapping->i_mmap,
@@ -532,7 +538,7 @@ static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
hole_end >> PAGE_SHIFT);
i_mmap_unlock_write(mapping);
remove_inode_hugepages(inode, hole_start, hole_end);
- mutex_unlock(&inode->i_mutex);
+ inode_unlock(inode);
}
return 0;
@@ -566,7 +572,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
start = offset >> hpage_shift;
end = (offset + len + hpage_size - 1) >> hpage_shift;
- mutex_lock(&inode->i_mutex);
+ inode_lock(inode);
/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
error = inode_newsize_ok(inode, offset + len);
@@ -653,7 +659,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
i_size_write(inode, offset + len);
inode->i_ctime = CURRENT_TIME;
out:
- mutex_unlock(&inode->i_mutex);
+ inode_unlock(inode);
return error;
}
@@ -711,7 +717,7 @@ static struct inode *hugetlbfs_get_root(struct super_block *sb,
/*
* Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never
* be taken from reclaim -- unlike regular filesystems. This needs an
- * annotation because huge_pmd_share() does an allocation under
+ * annotation because huge_pmd_share() does an allocation under hugetlb's
* i_mmap_rwsem.
*/
static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
@@ -741,7 +747,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
/*
* The policy is initialized here even if we are creating a
* private inode because initialization simply creates an
- * an empty rb tree and calls spin_lock_init(), later when we
+ * an empty rb tree and calls rwlock_init(), later when we
* call mpol_free_shared_policy() it will just return because
* the rb tree will still be empty.
*/
@@ -763,6 +769,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
break;
}
lockdep_annotate_inode_mutex_key(inode);
@@ -1204,7 +1211,6 @@ static struct file_system_type hugetlbfs_fs_type = {
.mount = hugetlbfs_mount,
.kill_sb = kill_litter_super,
};
-MODULE_ALIAS_FS("hugetlbfs");
static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
@@ -1324,7 +1330,7 @@ static int __init init_hugetlbfs_fs(void)
error = -ENOMEM;
hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
sizeof(struct hugetlbfs_inode_info),
- 0, 0, init_once);
+ 0, SLAB_ACCOUNT, init_once);
if (hugetlbfs_inode_cachep == NULL)
goto out2;
@@ -1358,26 +1364,4 @@ static int __init init_hugetlbfs_fs(void)
out2:
return error;
}
-
-static void __exit exit_hugetlbfs_fs(void)
-{
- struct hstate *h;
- int i;
-
-
- /*
- * Make sure all delayed rcu free inodes are flushed before we
- * destroy cache.
- */
- rcu_barrier();
- kmem_cache_destroy(hugetlbfs_inode_cachep);
- i = 0;
- for_each_hstate(h)
- kern_unmount(hugetlbfs_vfsmount[i++]);
- unregister_filesystem(&hugetlbfs_fs_type);
-}
-
-module_init(init_hugetlbfs_fs)
-module_exit(exit_hugetlbfs_fs)
-
-MODULE_LICENSE("GPL");
+fs_initcall(init_hugetlbfs_fs)