This flag was not accepted when fiemap was proposed [2] due to lack of in-kernel users. Btrfs has compression for a long time and we'd like to see that an extent is compressed in the output of 'filefrag' utility once it's taught about it. For that purpose, a reserved field from fiemap_extent is used to let the filesystem store along the physcial extent length when the flag is set. This keeps compatibility with applications that use FIEMAP. In order to minimize changes to current ->fiemap users that do not understand the compressed flag, a new filesystem helper is introduced, fiemap_fill_next_extent_full. This is supposed to take parameters matching all valid fiemap_extent fields, fe_phys_length in this case. [1] http://article.gmane.org/gmane.comp.file-systems.ext4/8871 [2] http://thread.gmane.org/gmane.comp.file-systems.ext4/8870 [3] http://thread.gmane.org/gmane.linux.file-systems/77632 (v1) CC: Andreas Dilger <adilger@xxxxxxxxx> CC: Christoph Hellwig <hch@xxxxxxxxxxxxx> CC: Mark Fasheh <mfasheh@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxx> --- fs/ioctl.c | 42 ++++++++++++++++++++++++++++++++++++++---- include/linux/fs.h | 2 ++ include/uapi/linux/fiemap.h | 6 +++++- 3 files changed, 45 insertions(+), 5 deletions(-) diff --git a/fs/ioctl.c b/fs/ioctl.c index fd507fb460f8..29db45020874 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -65,25 +65,30 @@ static int ioctl_fibmap(struct file *filp, int __user *p) } /** - * fiemap_fill_next_extent - Fiemap helper function + * fiemap_fill_next_extent_full - Fiemap helper function (extended argument list) * @fieinfo: Fiemap context passed into ->fiemap * @logical: Extent logical start offset, in bytes * @phys: Extent physical start offset, in bytes * @len: Extent length, in bytes + * @phys_len: Physical extent length in bytes * @flags: FIEMAP_EXTENT flags that describe this extent * * Called from file system ->fiemap callback. Will populate extent * info as passed in via arguments and copy to user memory. On * success, extent count on fieinfo is incremented. * + * This is an extended version of fiemap_fill_next_extent that fills all valid + * fiemap_extent fields. + * * Returns 0 on success, -errno on error, 1 if this was the last * extent that will fit in user array. */ #define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC) -#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED) +#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED | \ + FIEMAP_EXTENT_DATA_COMPRESSED) #define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE) -int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, - u64 phys, u64 len, u32 flags) +int fiemap_fill_next_extent_full(struct fiemap_extent_info *fieinfo, + u64 logical, u64 phys, u64 len, u64 phys_len, u32 flags) { struct fiemap_extent extent; struct fiemap_extent __user *dest = fieinfo->fi_extents_start; @@ -110,6 +115,9 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, extent.fe_length = len; extent.fe_flags = flags; + if (flags & FIEMAP_EXTENT_DATA_COMPRESSED) + extent.fe_phys_length = phys_len; + dest += fieinfo->fi_extents_mapped; if (copy_to_user(dest, &extent, sizeof(extent))) return -EFAULT; @@ -119,6 +127,32 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, return 1; return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0; } +EXPORT_SYMBOL(fiemap_fill_next_extent_full); + +/** + * fiemap_fill_next_extent - Fiemap helper function + * @fieinfo: Fiemap context passed into ->fiemap + * @logical: Extent logical start offset, in bytes + * @phys: Extent physical start offset, in bytes + * @len: Extent length, in bytes + * @flags: FIEMAP_EXTENT flags that describe this extent + * + * Called from file system ->fiemap callback. Will populate extent + * info as passed in via arguments and copy to user memory. On + * success, extent count on fieinfo is incremented. + * + * Returns 0 on success, -errno on error, 1 if this was the last + * extent that will fit in user array. + */ +int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, + u64 phys, u64 len, u32 flags) +{ + /* + * Use fiemap_fill_next_extent_full if you see this + */ + WARN_ON_ONCE(flags & FIEMAP_EXTENT_DATA_COMPRESSED); + return fiemap_fill_next_extent_full(fieinfo, logical, phys, len, 0, flags); +} EXPORT_SYMBOL(fiemap_fill_next_extent); /** diff --git a/include/linux/fs.h b/include/linux/fs.h index 3f40547ba191..40f6b59c910b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1485,6 +1485,8 @@ struct fiemap_extent_info { }; int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, u64 phys, u64 len, u32 flags); +int fiemap_fill_next_extent_full(struct fiemap_extent_info *info, u64 logical, + u64 phys, u64 len, u64 phys_len, u32 flags); int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); /* diff --git a/include/uapi/linux/fiemap.h b/include/uapi/linux/fiemap.h index 93abfcd9ac47..0e32caeccedd 100644 --- a/include/uapi/linux/fiemap.h +++ b/include/uapi/linux/fiemap.h @@ -19,7 +19,9 @@ struct fiemap_extent { __u64 fe_physical; /* physical offset in bytes for the start * of the extent from the beginning of the disk */ __u64 fe_length; /* length in bytes for this extent */ - __u64 fe_reserved64[2]; + __u64 fe_phys_length; /* physical length in bytes, undefined if + * DATA_COMPRESSED not set */ + __u64 fe_reserved64; __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */ __u32 fe_reserved[3]; }; @@ -50,6 +52,8 @@ struct fiemap { * Sets EXTENT_UNKNOWN. */ #define FIEMAP_EXTENT_ENCODED 0x00000008 /* Data can not be read * while fs is unmounted */ +#define FIEMAP_EXTENT_DATA_COMPRESSED 0x00000040 /* Data is compressed by fs. + * Sets EXTENT_ENCODED */ #define FIEMAP_EXTENT_DATA_ENCRYPTED 0x00000080 /* Data is encrypted by fs. * Sets EXTENT_ENCODED */ #define FIEMAP_EXTENT_NOT_ALIGNED 0x00000100 /* Extent offsets may not be -- 1.8.3.1 -- 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
