Lukas Czerner <lczerner@xxxxxxxxxx> wrote: > Gitweb: http://git.kernel.org/linus/367a51a339020ba4d9edb0ce0f21d65bd50b00c9 > Commit: 367a51a339020ba4d9edb0ce0f21d65bd50b00c9 > Parent: 77ca6cdf0ab8a42f481ec997911bc89e79138723 > Author: Lukas Czerner <lczerner@xxxxxxxxxx> > AuthorDate: Wed Oct 27 21:30:11 2010 -0400 > Committer: Theodore Ts'o <tytso@xxxxxxx> > CommitDate: Wed Oct 27 21:30:11 2010 -0400 > I've just noticed this patch. Was it posted to linux-fsdevel? Sorry for missing it. So I have a comment, and question. --- > fs: Add FITRIM ioctl > > Adds an filesystem independent ioctl to allow implementation of file > system batched discard support. I takes fstrim_range structure as an > argument. fstrim_range is definec in the include/fs.h and its > definition is as follows. > > struct fstrim_range { > start; > len; > minlen; > } > > start - first Byte to trim > len - number of Bytes to trim from start > minlen - minimum extent length to trim, free extents shorter than this > number of Bytes will be ignored. This will be rounded up to fs > block size. > Was the range done so it could be called in parts, and progress displayed? > It is also possible to specify NULL as an argument. In this case the > arguments will set itself as follows: > > start = 0; > len = ULLONG_MAX; > minlen = 0; > > So it will trim the whole file system at one run. > > After the FITRIM is done, the number of actually discarded Bytes is stored > in fstrim_range.len to give the user better insight on how much storage > space has been really released for wear-leveling. > > Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx> > Reviewed-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> > Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> > --- > fs/ioctl.c | 39 +++++++++++++++++++++++++++++++++++++++ > include/linux/fs.h | 8 ++++++++ > 2 files changed, 47 insertions(+), 0 deletions(-) > > diff --git a/fs/ioctl.c b/fs/ioctl.c > index f855ea4..e92fdbb 100644 > --- a/fs/ioctl.c > +++ b/fs/ioctl.c > @@ -530,6 +530,41 @@ static int ioctl_fsthaw(struct file *filp) > return thaw_super(sb); > } > > +static int ioctl_fstrim(struct file *filp, void __user *argp) > +{ > + struct super_block *sb = filp->f_path.dentry->d_inode->i_sb; > + struct fstrim_range range; > + int ret = 0; > + > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > + /* If filesystem doesn't support trim feature, return. */ > + if (sb->s_op->trim_fs == NULL) > + return -EOPNOTSUPP; > + > + /* If a blockdevice-backed filesystem isn't specified, return EINVAL. */ > + if (sb->s_bdev == NULL) > + return -EINVAL; > + What is the point of that? sb->s_bdev is not used anywhere in this code. If an FS published an sb->s_op->trim_fs, it should know what it wants No? Note that the FS in question does not even need to check. It already knows if it's block based or not. Thanks Boaz > + if (argp == NULL) { > + range.start = 0; > + range.len = ULLONG_MAX; > + range.minlen = 0; > + } else if (copy_from_user(&range, argp, sizeof(range))) > + return -EFAULT; > + > + ret = sb->s_op->trim_fs(sb, &range); > + if (ret < 0) > + return ret; > + > + if ((argp != NULL) && > + (copy_to_user(argp, &range, sizeof(range)))) > + return -EFAULT; > + > + return 0; > +} > + > /* > * When you add any new common ioctls to the switches above and below > * please update compat_sys_ioctl() too. > @@ -580,6 +615,10 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, > error = ioctl_fsthaw(filp); > break; > > + case FITRIM: > + error = ioctl_fstrim(filp, argp); > + break; > + > case FS_IOC_FIEMAP: > return ioctl_fiemap(filp, arg); > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 63d069b..7008268 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -32,6 +32,12 @@ > #define SEEK_END 2 /* seek relative to end of file */ > #define SEEK_MAX SEEK_END > > +struct fstrim_range { > + uint64_t start; > + uint64_t len; > + uint64_t minlen; > +}; > + > /* And dynamically-tunable limits and defaults: */ > struct files_stat_struct { > int nr_files; /* read only */ > @@ -316,6 +322,7 @@ struct inodes_stat_t { > #define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */ > #define FIFREEZE _IOWR('X', 119, int) /* Freeze */ > #define FITHAW _IOWR('X', 120, int) /* Thaw */ > +#define FITRIM _IOWR('X', 121, struct fstrim_range) /* Trim */ > > #define FS_IOC_GETFLAGS _IOR('f', 1, long) > #define FS_IOC_SETFLAGS _IOW('f', 2, long) > @@ -1581,6 +1588,7 @@ struct super_operations { > ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); > #endif > int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); > + int (*trim_fs) (struct super_block *, struct fstrim_range *); > }; > > /* > -- > To unsubscribe from this list: send the line "unsubscribe git-commits-head" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
