ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support

This patch adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR ioctl interface
support for ext4. The interface is kept consistent with
XFS_IOC_FSGETXATTR/XFS_IOC_FSGETXATTR.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>

2 files changed, 336 insertions, 87 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 96cc151d5931..1c127213363a 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -381,6 +381,13 @@ struct flex_groups {
 #define EXT4_FL_USER_VISIBLE            0x304BDFFF /* User visible flags */
 #define EXT4_FL_USER_MODIFIABLE         0x204380FF /* User modifiable flags */
 
+#define EXT4_FL_XFLAG_VISIBLE           (EXT4_SYNC_FL | \
+                                         EXT4_IMMUTABLE_FL | \
+                                         EXT4_APPEND_FL | \
+                                         EXT4_NODUMP_FL | \
+                                         EXT4_NOATIME_FL | \
+                                         EXT4_PROJINHERIT_FL)
+
 /* Flags that should be inherited by new inodes from their parent. */
 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
@@ -619,6 +626,46 @@ enum {
 #define EXT4_IOC_GET_ENCRYPTION_PWSALT  _IOW('f', 20, __u8[16])
 #define EXT4_IOC_GET_ENCRYPTION_POLICY  _IOW('f', 21, struct ext4_encryption_policy)
 
+#ifndef FS_IOC_FSGETXATTR
+/* Until the uapi changes get merged for project quota... */
+
+#define FS_IOC_FSGETXATTR               _IOR('X', 31, struct fsxattr)
+#define FS_IOC_FSSETXATTR               _IOW('X', 32, struct fsxattr)
+
+/*
+ * Structure for FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR.
+ */
+struct fsxattr {
+        __u32           fsx_xflags;     /* xflags field value (get/set) */
+        __u32           fsx_extsize;    /* extsize field value (get/set)*/
+        __u32           fsx_nextents;   /* nextents field value (get)   */
+        __u32           fsx_projid;     /* project identifier (get/set) */
+        unsigned char   fsx_pad[12];
+};
+
+/*
+ * Flags for the fsx_xflags field
+ */
+#define FS_XFLAG_REALTIME       0x00000001      /* data in realtime volume */
+#define FS_XFLAG_PREALLOC       0x00000002      /* preallocated file extents */
+#define FS_XFLAG_IMMUTABLE      0x00000008      /* file cannot be modified */
+#define FS_XFLAG_APPEND         0x00000010      /* all writes append */
+#define FS_XFLAG_SYNC           0x00000020      /* all writes synchronous */
+#define FS_XFLAG_NOATIME        0x00000040      /* do not update access time */
+#define FS_XFLAG_NODUMP         0x00000080      /* do not include in backups */
+#define FS_XFLAG_RTINHERIT      0x00000100      /* create with rt bit set */
+#define FS_XFLAG_PROJINHERIT    0x00000200      /* create with parents projid */
+#define FS_XFLAG_NOSYMLINKS     0x00000400      /* disallow symlink creation */
+#define FS_XFLAG_EXTSIZE        0x00000800      /* extent size allocator hint */
+#define FS_XFLAG_EXTSZINHERIT   0x00001000      /* inherit inode extent size */
+#define FS_XFLAG_NODEFRAG       0x00002000      /* do not defragment */
+#define FS_XFLAG_FILESTREAM     0x00004000      /* use filestream allocator */
+#define FS_XFLAG_HASATTR        0x80000000      /* no DIFLAG for this */
+#endif /* !defined(FS_IOC_FSGETXATTR) */
+
+#define EXT4_IOC_FSGETXATTR             FS_IOC_FSGETXATTR
+#define EXT4_IOC_FSSETXATTR             FS_IOC_FSSETXATTR
+
 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 /*
  * ioctl commands in 32 bit emulation
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 5e872fd40e5e..2b0cb84255eb 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -14,6 +14,7 @@
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/random.h>
+#include <linux/quotaops.h>
 #include <asm/uaccess.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"
@@ -202,6 +203,238 @@ static int uuid_is_zero(__u8 u[16])
         return 1;
 }
 
+static int ext4_ioctl_setflags(struct inode *inode,
+                               unsigned int flags)
+{
+        struct ext4_inode_info *ei = EXT4_I(inode);
+        handle_t *handle = NULL;
+        int err = EPERM, migrate = 0;
+        struct ext4_iloc iloc;
+        unsigned int oldflags, mask, i;
+        unsigned int jflag;
+
+        /* Is it quota file? Do not allow user to mess with it */
+        if (IS_NOQUOTA(inode))
+                goto flags_out;
+
+        oldflags = ei->i_flags;
+
+        /* The JOURNAL_DATA flag is modifiable only by root */
+        jflag = flags & EXT4_JOURNAL_DATA_FL;
+
+        /*
+         * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+         * the relevant capability.
+         *
+         * This test looks nicer. Thanks to Pauline Middelink
+         */
+        if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
+                if (!capable(CAP_LINUX_IMMUTABLE))
+                        goto flags_out;
+        }
+
+        /*
+         * The JOURNAL_DATA flag can only be changed by
+         * the relevant capability.
+         */
+        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
+                if (!capable(CAP_SYS_RESOURCE))
+                        goto flags_out;
+        }
+        if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
+                migrate = 1;
+
+        if (flags & EXT4_EOFBLOCKS_FL) {
+                /* we don't support adding EOFBLOCKS flag */
+                if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
+                        err = -EOPNOTSUPP;
+                        goto flags_out;
+                }
+        } else if (oldflags & EXT4_EOFBLOCKS_FL)
+                ext4_truncate(inode);
+
+        handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+        if (IS_ERR(handle)) {
+                err = PTR_ERR(handle);
+                goto flags_out;
+        }
+        if (IS_SYNC(inode))
+                ext4_handle_sync(handle);
+        err = ext4_reserve_inode_write(handle, inode, &iloc);
+        if (err)
+                goto flags_err;
+
+        for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
+                if (!(mask & EXT4_FL_USER_MODIFIABLE))
+                        continue;
+                if (mask & flags)
+                        ext4_set_inode_flag(inode, i);
+                else
+                        ext4_clear_inode_flag(inode, i);
+        }
+
+        ext4_set_inode_flags(inode);
+        inode->i_ctime = ext4_current_time(inode);
+
+        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+flags_err:
+        ext4_journal_stop(handle);
+        if (err)
+                goto flags_out;
+
+        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
+                err = ext4_change_inode_journal_flag(inode, jflag);
+        if (err)
+                goto flags_out;
+        if (migrate) {
+                if (flags & EXT4_EXTENTS_FL)
+                        err = ext4_ext_migrate(inode);
+                else
+                        err = ext4_ind_migrate(inode);
+        }
+
+flags_out:
+        return err;
+}
+
+#ifdef CONFIG_QUOTA
+static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+{
+        struct inode *inode = file_inode(filp);
+        struct super_block *sb = inode->i_sb;
+        struct ext4_inode_info *ei = EXT4_I(inode);
+        int err, rc;
+        handle_t *handle;
+        kprojid_t kprojid;
+        struct ext4_iloc iloc;
+        struct ext4_inode *raw_inode;
+
+        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                        EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+                if (projid != EXT4_DEF_PROJID)
+                        return -EOPNOTSUPP;
+                else
+                        return 0;
+        }
+
+        if (EXT4_INODE_SIZE(sb) <= EXT4_GOOD_OLD_INODE_SIZE)
+                return -EOPNOTSUPP;
+
+        kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
+
+        if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
+                return 0;
+
+        err = mnt_want_write_file(filp);
+        if (err)
+                return err;
+
+        err = -EPERM;
+        mutex_lock(&inode->i_mutex);
+        /* Is it quota file? Do not allow user to mess with it */
+        if (IS_NOQUOTA(inode))
+                goto out_unlock;
+
+        err = ext4_get_inode_loc(inode, &iloc);
+        if (err)
+                goto out_unlock;
+
+        raw_inode = ext4_raw_inode(&iloc);
+        if (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) {
+                err = -EOVERFLOW;
+                brelse(iloc.bh);
+                goto out_unlock;
+        }
+        brelse(iloc.bh);
+
+        dquot_initialize(inode);
+
+        handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
+                EXT4_QUOTA_INIT_BLOCKS(sb) +
+                EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
+        if (IS_ERR(handle)) {
+                err = PTR_ERR(handle);
+                goto out_unlock;
+        }
+
+        err = ext4_reserve_inode_write(handle, inode, &iloc);
+        if (err)
+                goto out_stop;
+
+        if (sb_has_quota_limits_enabled(sb, PRJQUOTA)) {
+                struct dquot *transfer_to[MAXQUOTAS] = { };
+
+                transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
+                if (transfer_to[PRJQUOTA]) {
+                        err = __dquot_transfer(inode, transfer_to);
+                        dqput(transfer_to[PRJQUOTA]);
+                        if (err)
+                                goto out_dirty;
+                }
+        }
+        EXT4_I(inode)->i_projid = kprojid;
+        inode->i_ctime = ext4_current_time(inode);
+out_dirty:
+        rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
+        if (!err)
+                err = rc;
+out_stop:
+        ext4_journal_stop(handle);
+out_unlock:
+        mutex_unlock(&inode->i_mutex);
+        mnt_drop_write_file(filp);
+        return err;
+}
+#else
+static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+{
+        if (projid != EXT4_DEF_PROJID)
+                return -EOPNOTSUPP;
+        return 0;
+}
+#endif
+
+/* Transfer internal flags to xflags */
+static inline __u32 ext4_iflags_to_xflags(unsigned long iflags)
+{
+        __u32 xflags = 0;
+
+        if (iflags & EXT4_SYNC_FL)
+                xflags |= FS_XFLAG_SYNC;
+        if (iflags & EXT4_IMMUTABLE_FL)
+                xflags |= FS_XFLAG_IMMUTABLE;
+        if (iflags & EXT4_APPEND_FL)
+                xflags |= FS_XFLAG_APPEND;
+        if (iflags & EXT4_NODUMP_FL)
+                xflags |= FS_XFLAG_NODUMP;
+        if (iflags & EXT4_NOATIME_FL)
+                xflags |= FS_XFLAG_NOATIME;
+        if (iflags & EXT4_PROJINHERIT_FL)
+                xflags |= FS_XFLAG_PROJINHERIT;
+        return xflags;
+}
+
+/* Transfer xflags flags to internal */
+static inline unsigned long ext4_xflags_to_iflags(__u32 xflags)
+{
+        unsigned long iflags = 0;
+
+        if (xflags & FS_XFLAG_SYNC)
+                iflags |= EXT4_SYNC_FL;
+        if (xflags & FS_XFLAG_IMMUTABLE)
+                iflags |= EXT4_IMMUTABLE_FL;
+        if (xflags & FS_XFLAG_APPEND)
+                iflags |= EXT4_APPEND_FL;
+        if (xflags & FS_XFLAG_NODUMP)
+                iflags |= EXT4_NODUMP_FL;
+        if (xflags & FS_XFLAG_NOATIME)
+                iflags |= EXT4_NOATIME_FL;
+        if (xflags & FS_XFLAG_PROJINHERIT)
+                iflags |= EXT4_PROJINHERIT_FL;
+
+        return iflags;
+}
+
 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
         struct inode *inode = file_inode(filp);
@@ -217,11 +450,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
                 return put_user(flags, (int __user *) arg);
         case EXT4_IOC_SETFLAGS: {
-                handle_t *handle = NULL;
-                int err, migrate = 0;
-                struct ext4_iloc iloc;
-                unsigned int oldflags, mask, i;
-                unsigned int jflag;
+                int err;
 
                 if (!inode_owner_or_capable(inode))
                         return -EACCES;
@@ -235,89 +464,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
                 flags = ext4_mask_flags(inode->i_mode, flags);
 
-                err = -EPERM;
                 mutex_lock(&inode->i_mutex);
-                /* Is it quota file? Do not allow user to mess with it */
-                if (IS_NOQUOTA(inode))
-                        goto flags_out;
-
-                oldflags = ei->i_flags;
-
-                /* The JOURNAL_DATA flag is modifiable only by root */
-                jflag = flags & EXT4_JOURNAL_DATA_FL;
-
-                /*
-                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
-                 * the relevant capability.
-                 *
-                 * This test looks nicer. Thanks to Pauline Middelink
-                 */
-                if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
-                        if (!capable(CAP_LINUX_IMMUTABLE))
-                                goto flags_out;
-                }
-
-                /*
-                 * The JOURNAL_DATA flag can only be changed by
-                 * the relevant capability.
-                 */
-                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
-                        if (!capable(CAP_SYS_RESOURCE))
-                                goto flags_out;
-                }
-                if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
-                        migrate = 1;
-
-                if (flags & EXT4_EOFBLOCKS_FL) {
-                        /* we don't support adding EOFBLOCKS flag */
-                        if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
-                                err = -EOPNOTSUPP;
-                                goto flags_out;
-                        }
-                } else if (oldflags & EXT4_EOFBLOCKS_FL)
-                        ext4_truncate(inode);
-
-                handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
-                if (IS_ERR(handle)) {
-                        err = PTR_ERR(handle);
-                        goto flags_out;
-                }
-                if (IS_SYNC(inode))
-                        ext4_handle_sync(handle);
-                err = ext4_reserve_inode_write(handle, inode, &iloc);
-                if (err)
-                        goto flags_err;
-
-                for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
-                        if (!(mask & EXT4_FL_USER_MODIFIABLE))
-                                continue;
-                        if (mask & flags)
-                                ext4_set_inode_flag(inode, i);
-                        else
-                                ext4_clear_inode_flag(inode, i);
-                }
-
-                ext4_set_inode_flags(inode);
-                inode->i_ctime = ext4_current_time(inode);
-
-                err = ext4_mark_iloc_dirty(handle, inode, &iloc);
-flags_err:
-                ext4_journal_stop(handle);
-                if (err)
-                        goto flags_out;
-
-                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
-                        err = ext4_change_inode_journal_flag(inode, jflag);
-                if (err)
-                        goto flags_out;
-                if (migrate) {
-                        if (flags & EXT4_EXTENTS_FL)
-                                err = ext4_ext_migrate(inode);
-                        else
-                                err = ext4_ind_migrate(inode);
-                }
-
-flags_out:
+                err = ext4_ioctl_setflags(inode, flags);
                 mutex_unlock(&inode->i_mutex);
                 mnt_drop_write_file(filp);
                 return err;
@@ -689,6 +837,60 @@ encryption_policy_out:
                 return -EOPNOTSUPP;
 #endif
         }
+        case EXT4_IOC_FSGETXATTR:
+        {
+                struct fsxattr fa;
+
+                memset(&fa, 0, sizeof(struct fsxattr));
+                ext4_get_inode_flags(ei);
+                fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);
+
+                if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+                                EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+                        fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
+                                EXT4_I(inode)->i_projid);
+                }
+
+                if (copy_to_user((struct fsxattr __user *)arg,
+                                 &fa, sizeof(fa)))
+                        return -EFAULT;
+                return 0;
+        }
+        case EXT4_IOC_FSSETXATTR:
+        {
+                struct fsxattr fa;
+                int err;
+
+                if (copy_from_user(&fa, (struct fsxattr __user *)arg,
+                                   sizeof(fa)))
+                        return -EFAULT;
+
+                /* Make sure caller has proper permission */
+                if (!inode_owner_or_capable(inode))
+                        return -EACCES;
+
+                err = mnt_want_write_file(filp);
+                if (err)
+                        return err;
+
+                flags = ext4_xflags_to_iflags(fa.fsx_xflags);
+                flags = ext4_mask_flags(inode->i_mode, flags);
+
+                mutex_lock(&inode->i_mutex);
+                flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
+                         (flags & EXT4_FL_XFLAG_VISIBLE);
+                err = ext4_ioctl_setflags(inode, flags);
+                mutex_unlock(&inode->i_mutex);
+                mnt_drop_write_file(filp);
+                if (err)
+                        return err;
+
+                err = ext4_ioctl_setproject(filp, fa.fsx_projid);
+                if (err)
+                        return err;
+
+                return 0;
+        }
         default:
                 return -ENOTTY;
         }