Add metadata readahead ioctl in vfs. Filesystem can hook to super_operations.metadata_readahead to handle filesystem specific task. Next patch will give an example how btrfs implements it.
Signed-off-by: Shaohua Li <[email protected]> --- fs/compat_ioctl.c | 1 + fs/ioctl.c | 21 +++++++++++++++++++++ include/linux/fs.h | 8 ++++++++ 3 files changed, 30 insertions(+) Index: linux/fs/ioctl.c =================================================================== --- linux.orig/fs/ioctl.c 2011-01-03 21:15:48.000000000 +0800 +++ linux/fs/ioctl.c 2011-01-03 21:16:06.000000000 +0800 @@ -601,6 +601,24 @@ static int ioctl_metadata_incore(struct return entries; } +static int ioctl_metadata_readahead(struct file *filp, void __user *argp) +{ + struct super_block *sb = filp->f_path.dentry->d_inode->i_sb; + struct metadata_readahead_args args; + + if (!sb->s_op->metadata_readahead) + return -EINVAL; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + + /* readahead in page unit */ + if ((args.offset & ~PAGE_CACHE_MASK) || (args.size & ~PAGE_CACHE_MASK)) + return -EINVAL; + + return sb->s_op->metadata_readahead(sb, args.offset, args.size); +} + /* * When you add any new common ioctls to the switches above and below * please update compat_sys_ioctl() too. @@ -664,6 +682,9 @@ int do_vfs_ioctl(struct file *filp, unsi case FIMETADATA_INCORE: return ioctl_metadata_incore(filp, argp); + case FIMETADATA_READAHEAD: + return ioctl_metadata_readahead(filp, argp); + default: if (S_ISREG(filp->f_path.dentry->d_inode->i_mode)) error = file_ioctl(filp, cmd, arg); Index: linux/include/linux/fs.h =================================================================== --- linux.orig/include/linux/fs.h 2011-01-03 21:15:48.000000000 +0800 +++ linux/include/linux/fs.h 2011-01-03 21:16:06.000000000 +0800 @@ -65,6 +65,11 @@ struct metadata_incore_args { __u32 unused; }; +struct metadata_readahead_args { + __u64 offset; + __u64 size; +}; + #define NR_FILE 8192 /* this can well be larger on a larger system */ #define MAY_EXEC 1 @@ -338,6 +343,7 @@ struct metadata_incore_args { #define FITHAW _IOWR('X', 120, int) /* Thaw */ #define FITRIM _IOWR('X', 121, struct fstrim_range) /* Trim */ #define FIMETADATA_INCORE _IOWR('X', 122, struct metadata_incore_args) +#define FIMETADATA_READAHEAD _IOR('X', 123, struct metadata_readahead_args) #define FS_IOC_GETFLAGS _IOR('f', 1, long) #define FS_IOC_SETFLAGS _IOW('f', 2, long) @@ -1628,6 +1634,8 @@ struct super_operations { int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); int (*metadata_incore)(struct super_block*, loff_t *offset, ssize_t *size); + int (*metadata_readahead)(struct super_block*, loff_t offset, + ssize_t size); }; /* Index: linux/fs/compat_ioctl.c =================================================================== --- linux.orig/fs/compat_ioctl.c 2011-01-03 21:15:48.000000000 +0800 +++ linux/fs/compat_ioctl.c 2011-01-03 21:16:06.000000000 +0800 @@ -883,6 +883,7 @@ COMPATIBLE_IOCTL(FIGETBSZ) COMPATIBLE_IOCTL(FIFREEZE) COMPATIBLE_IOCTL(FITHAW) COMPATIBLE_IOCTL(FIMETADATA_INCORE) +COMPATIBLE_IOCTL(FIMETADATA_READAHEAD) COMPATIBLE_IOCTL(KDGETKEYCODE) COMPATIBLE_IOCTL(KDSETKEYCODE) COMPATIBLE_IOCTL(KDGKBTYPE) -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
