This patch is concerned with the changes to be done in kernel space code for
turning FS_IOC_FIEMAPFS present in the earlier version of xfs_spaceman
into an XFS specific ioctl called XFS_IOC_FIEMAPFS, which uses all existing
fiemap insfrastructure.
By introducing XFS_IOC_FIMEAPFS ioctl, it can be seperated from file based
fiemap commands and allows us to review it and push it as we need, making the
process much simpler.
----------------------------------------------------------------------------------------
Signed-off-by: Dhruvesh Rathore <dhruvesh_r@xxxxxxxxxxx>
Signed-off-by: Amey Ruikar <ameyruikar@xxxxxxxxx>
Signed-off-by: Somdeep Dey <somdeepdey10@xxxxxxxxx>
---
fs/ioctl.c | 3 ++-
include/linux/fs.h | 6 ++++++
fs/xfs/xfs_ioctl.c | 55 +++++++++++++
fs/xfs/xfs_fs.h | 1 +
4 files changed, 64 insertions(+), 1 deletion(-)
--- a/fs/ioctl.c 2015-01-29 18:08:19.608874677 +0530
+++ b/fs/ioctl.c 2015-01-29 18:07:39.624876178 +0530
@@ -175,7 +175,7 @@
}
EXPORT_SYMBOL(fiemapfs_check_flags);
-static int fiemap_check_ranges(struct super_block *sb,
+int fiemap_check_ranges(struct super_block *sb,
u64 start, u64 len, u64 *new_len)
{
u64 maxbytes = (u64) sb->s_maxbytes;
@@ -196,6 +196,7 @@
return 0;
}
+EXPORT_SYMBOL(fiemap_check_ranges);
static int ioctl_fiemap(struct file *filp, unsigned long arg)
{
----------------------------------------------------------------------------------------
--- a/include/linux/fs.h 2015-01-29 18:00:44.716891762 +0530
+++ b/include/linux/fs.h 2015-01-29 17:59:34.532894398 +0530
@@ -1435,6 +1435,9 @@
* VFS FS_IOC_FIEMAP helper definitions.
*/
+/* So that the fiemap access checks can't overflow on 32 bit machines. */
+#define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
+
struct fiemap_extent_info {
unsigned int fi_flags; /* Flags as passed from user */
unsigned int fi_extents_mapped; /* Number of mapped extents */
@@ -1447,6 +1450,9 @@
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
int fiemapfs_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
+int fiemap_check_ranges(struct super_block *sb,
+ u64 start, u64 len, u64 *new_len);
+
/*
* File types
*
----------------------------------------------------------------------------------------
--- a/fs/xfs/xfs_ioctl.c 2015-01-29 17:55:05.452904504 +0530
+++ b/fs/xfs/xfs_ioctl.c 2015-01-29 17:50:40.852914441 +0530
@@ -1509,6 +1509,58 @@
return error;
}
+/*
+ * Mostly similar to ioctl_fiemap() function present
+ * in fs/ioctl.c
+ */
+static int
+xfs_ioctl_fiemapfs(
+ struct xfs_mount *mp,
+ void __user *arg)
+{
+ struct fiemap fiemap;
+ u64 len;
+ int error;
+
+ struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
+ struct fiemap_extent_info fieinfo = { 0, };
+
+ if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
+ return -EFAULT;
+
+ if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
+ return -EINVAL;
+
+ error = fiemap_check_ranges(mp->m_super, fiemap.fm_start, fiemap.fm_length,
+ &len);
+ if (error)
+ return error;
+
+ fieinfo.fi_flags = fiemap.fm_flags;
+ fieinfo.fi_extents_max = fiemap.fm_extent_count;
+ fieinfo.fi_extents_start = ufiemap->fm_extents;
+
+ if (fiemap.fm_extent_count != 0 &&
+ !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
+ fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
+ return -EFAULT;
+
+ if (fiemap.fm_extent_count != 0 &&
+ (fiemap.fm_flags & FIEMAPFS_FLAG_FREESP_SIZE_HINT) &&
+ !access_ok(VERIFY_READ, fieinfo.fi_extents_start,
+ sizeof(struct fiemap_extent)))
+ return -EFAULT;
+
+ error = mp->m_super->s_op->fiemapfs(mp->m_super, &fieinfo, fiemap.fm_start,
+ len);
+
+ fiemap.fm_flags = fieinfo.fi_flags;
+ fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
+ if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
+ error = -EFAULT;
+
+ return error;
+}
/*
* Note: some of the ioctl's return positive numbers as a
@@ -1566,6 +1618,9 @@
return 0;
}
+ case XFS_IOC_FIEMAPFS:
+ return xfs_ioctl_fiemapfs(mp, arg);
+
case XFS_IOC_FSBULKSTAT_SINGLE:
case XFS_IOC_FSBULKSTAT:
case XFS_IOC_FSINUMBERS:
----------------------------------------------------------------------------------------
--- a/fs/xfs/xfs_fs.h 2015-01-29 15:26:46.954401773 +0530
+++ b/fs/xfs/xfs_fs.h 2015-01-29 11:29:54.531652554 +0530
@@ -505,6 +505,7 @@
#define XFS_IOC_DIOINFO _IOR ('X', 30, struct dioattr)
#define XFS_IOC_FSGETXATTR _IOR ('X', 31, struct fsxattr)
#define XFS_IOC_FSSETXATTR _IOW ('X', 32, struct fsxattr)
+#define XFS_IOC_FIEMAPFS _IOWR('X', 33, struct fiemap)
#define XFS_IOC_ALLOCSP64 _IOW ('X', 36, struct xfs_flock64)
#define XFS_IOC_FREESP64 _IOW ('X', 37, struct xfs_flock64)
#define XFS_IOC_GETBMAP _IOWR('X', 38, struct getbmap)
----------------------------------------------------------------------------------------
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