Add a flags field to help glibc implementing statvfs(3) efficiently.
We copy the flag values from glibc, and add a new ST_VALID flag to
denote that f_flags is implemented.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6/arch/mips/include/asm/statfs.h
===================================================================
--- linux-2.6.orig/arch/mips/include/asm/statfs.h 2010-06-26 09:26:56.000000000 +0200
+++ linux-2.6/arch/mips/include/asm/statfs.h 2010-06-26 10:00:33.864004297 +0200
@@ -33,7 +33,8 @@ struct statfs {
/* Linux specials */
__kernel_fsid_t f_fsid;
long f_namelen;
- long f_spare[6];
+ long f_flags;
+ long f_spare[5];
};
#if (_MIPS_SIM == _MIPS_SIM_ABI32) || (_MIPS_SIM == _MIPS_SIM_NABI32)
@@ -53,7 +54,8 @@ struct statfs64 {
__u64 f_bavail;
__kernel_fsid_t f_fsid;
__u32 f_namelen;
- __u32 f_spare[6];
+ __u32 f_flags;
+ __u32 f_spare[5];
};
#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
@@ -73,7 +75,8 @@ struct statfs64 { /* Same as struct st
/* Linux specials */
__kernel_fsid_t f_fsid;
long f_namelen;
- long f_spare[6];
+ long f_flags;
+ long f_spare[5];
};
struct compat_statfs64 {
@@ -88,7 +91,8 @@ struct compat_statfs64 {
__u64 f_bavail;
__kernel_fsid_t f_fsid;
__u32 f_namelen;
- __u32 f_spare[6];
+ __u32 f_flags;
+ __u32 f_spare[5];
};
#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
Index: linux-2.6/arch/s390/include/asm/statfs.h
===================================================================
--- linux-2.6.orig/arch/s390/include/asm/statfs.h 2010-06-26 09:26:56.000000000 +0200
+++ linux-2.6/arch/s390/include/asm/statfs.h 2010-06-26 10:00:33.864004297 +0200
@@ -33,7 +33,8 @@ struct statfs {
__kernel_fsid_t f_fsid;
int f_namelen;
int f_frsize;
- int f_spare[5];
+ int f_flags;
+ int f_spare[4];
};
struct statfs64 {
@@ -47,7 +48,8 @@ struct statfs64 {
__kernel_fsid_t f_fsid;
int f_namelen;
int f_frsize;
- int f_spare[5];
+ int f_flags;
+ int f_spare[4];
};
struct compat_statfs64 {
@@ -61,7 +63,8 @@ struct compat_statfs64 {
__kernel_fsid_t f_fsid;
__u32 f_namelen;
__u32 f_frsize;
- __u32 f_spare[5];
+ __u32 f_flags;
+ __u32 f_spare[4];
};
#endif /* __s390x__ */
Index: linux-2.6/include/asm-generic/statfs.h
===================================================================
--- linux-2.6.orig/include/asm-generic/statfs.h 2010-06-26 09:26:56.000000000 +0200
+++ linux-2.6/include/asm-generic/statfs.h 2010-06-26 10:00:33.868047809 +0200
@@ -33,7 +33,8 @@ struct statfs {
__kernel_fsid_t f_fsid;
__statfs_word f_namelen;
__statfs_word f_frsize;
- __statfs_word f_spare[5];
+ __statfs_word f_flags;
+ __statfs_word f_spare[4];
};
/*
@@ -55,7 +56,8 @@ struct statfs64 {
__kernel_fsid_t f_fsid;
__statfs_word f_namelen;
__statfs_word f_frsize;
- __statfs_word f_spare[5];
+ __statfs_word f_flags;
+ __statfs_word f_spare[4];
} ARCH_PACK_STATFS64;
/*
@@ -77,6 +79,7 @@ struct compat_statfs64 {
__kernel_fsid_t f_fsid;
__u32 f_namelen;
__u32 f_frsize;
+ __u32 f_flags[5];
__u32 f_spare[5];
} ARCH_PACK_COMPAT_STATFS64;
Index: linux-2.6/include/linux/statfs.h
===================================================================
--- linux-2.6.orig/include/linux/statfs.h 2010-06-26 09:26:56.000000000 +0200
+++ linux-2.6/include/linux/statfs.h 2010-06-26 10:19:53.609016448 +0200
@@ -2,7 +2,6 @@
#define _LINUX_STATFS_H
#include <linux/types.h>
-
#include <asm/statfs.h>
struct kstatfs {
@@ -16,7 +15,29 @@ struct kstatfs {
__kernel_fsid_t f_fsid;
long f_namelen;
long f_frsize;
- long f_spare[5];
+ long f_flags;
+ long f_spare[4];
};
+/*
+ * Definitions for the flag in f_flag.
+ *
+ * Generally these flags are equivalent to the MS_ flags used in the mount
+ * ABI. The exception is ST_VALID which has the same value as MS_REMOUNT
+ * which doesn't make any sense for statfs.
+ */
+#define ST_RDONLY 0x0001 /* mount read-only */
+#define ST_NOSUID 0x0002 /* ignore suid and sgid bits */
+#define ST_NODEV 0x0004 /* disallow access to device special files */
+#define ST_NOEXEC 0x0008 /* disallow program execution */
+#define ST_SYNCHRONOUS 0x0010 /* writes are synced at once */
+#define ST_VALID 0x0020 /* f_flags support is implemented */
+#define ST_MANDLOCK 0x0040 /* allow mandatory locks on an FS */
+/* 0x0080 used for ST_WRITE in glibc */
+/* 0x0100 used for ST_APPEND in glibc */
+/* 0x0200 used for ST_IMMUTABLE in glibc */
+#define ST_NOATIME 0x0400 /* do not update access times */
+#define ST_NODIRATIME 0x0800 /* do not update directory access times */
+#define ST_RELATIME 0x1000 /* update atime relative to mtime/ctime */
+
#endif
Index: linux-2.6/fs/statfs.c
===================================================================
--- linux-2.6.orig/fs/statfs.c 2010-06-26 09:40:08.000000000 +0200
+++ linux-2.6/fs/statfs.c 2010-06-26 10:24:27.674272979 +0200
@@ -2,11 +2,40 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/file.h>
+#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/uaccess.h>
+static int calculate_f_flags(struct vfsmount *mnt)
+{
+ struct super_block *sb = mnt->mnt_sb;
+ long flags = ST_VALID;
+
+ if (mnt->mnt_flags & MNT_READONLY)
+ flags |= ST_RDONLY;
+ if (mnt->mnt_flags & MNT_NOSUID)
+ flags |= ST_NOSUID;
+ if (mnt->mnt_flags & MNT_NODEV)
+ flags |= ST_NODEV;
+ if (mnt->mnt_flags & MNT_NOEXEC)
+ flags |= ST_NOEXEC;
+ if (mnt->mnt_flags & MNT_NOATIME)
+ flags |= ST_NOATIME;
+ if (mnt->mnt_flags & MNT_NODIRATIME)
+ flags |= ST_NODIRATIME;
+ if (mnt->mnt_flags & MNT_RELATIME)
+ flags |= ST_RELATIME;
+
+ if (sb->s_flags & MS_SYNCHRONOUS)
+ flags |= ST_SYNCHRONOUS;
+ if (sb->s_flags & MS_MANDLOCK)
+ flags |= ST_MANDLOCK;
+
+ return flags;
+}
+
int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
{
int retval;
@@ -26,7 +55,12 @@ int statfs_by_dentry(struct dentry *dent
int vfs_statfs(struct path *path, struct kstatfs *buf)
{
- return statfs_by_dentry(path->dentry, buf);
+ int error;
+
+ error = statfs_by_dentry(path->dentry, buf);
+ if (!error)
+ buf->f_flags = calculate_f_flags(path->mnt);
+ return error;
}
EXPORT_SYMBOL(vfs_statfs);
@@ -69,6 +103,7 @@ static int do_statfs_native(struct path
buf->f_fsid = st.f_fsid;
buf->f_namelen = st.f_namelen;
buf->f_frsize = st.f_frsize;
+ buf->f_flags = st.f_flags;
memset(buf->f_spare, 0, sizeof(buf->f_spare));
}
return 0;
@@ -96,6 +131,7 @@ static int do_statfs64(struct path *path
buf->f_fsid = st.f_fsid;
buf->f_namelen = st.f_namelen;
buf->f_frsize = st.f_frsize;
+ buf->f_flags = st.f_flags;
memset(buf->f_spare, 0, sizeof(buf->f_spare));
}
return 0;
--
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