Re: [PATCH 6/7] xfs: Extend data extent counter to 47 bits

[Chandan Babu R <chandanrlinux@gmail.com>]

On Monday 8 June 2020 10:44:10 PM IST Darrick J. Wong wrote:
> On Sat, Jun 06, 2020 at 01:57:44PM +0530, Chandan Babu R wrote:
> > This commit extends the per-inode data extent counter to 47 bits. The
> > length of 47-bits was chosen because,
> > Maximum file size = 2^63.
> > Maximum extent count when using 64k block size = 2^63 / 2^16 = 2^47.
> > 
> > The following changes are made to accomplish this,
> > 1. A new ro-compat superblock flag to prevent older kernels from
> >    mounting the filesystem in read-write mode. This flag is set for the
> >    first time when an inode would end up having more than 2^31 extents.
> > 3. Carve out a new 32-bit field from xfs_dinode->di_pad2[]. This field
> >    holds the most significant 15 bits of the data extent counter.
> 
> On a 1k block V5 fs, the maximum extent count is 2^(63-10) = 2^53.
> 
> If you're going to allocate 32 bits of space from di_pad2 to expand the
> data fork's nextents, let's use the entire bitspace.

But 2^53 extents will be beyond the limit of number of extents possible for a
64k blocksized filesystem?

> 
> > 2. A new inode->di_flags2 flag to indicate that the newly added field
> >    contains valid data. This flag is set when one of the following two
> >    conditions are met,
> >    - When the inode is about to have more than 2^31 extents.
> >    - When flushing the incore inode (See xfs_iflush_int()), if
> >      the superblock ro-compat flag is already set.
> > 
> > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> > ---
> >  fs/xfs/libxfs/xfs_bmap.c        | 40 ++++++++--------
> >  fs/xfs/libxfs/xfs_format.h      | 30 ++++++++----
> >  fs/xfs/libxfs/xfs_inode_buf.c   | 46 +++++++++++++++---
> >  fs/xfs/libxfs/xfs_inode_buf.h   |  2 +
> >  fs/xfs/libxfs/xfs_inode_fork.c  | 84 ++++++++++++++++++++++++++-------
> >  fs/xfs/libxfs/xfs_inode_fork.h  |  3 +-
> >  fs/xfs/libxfs/xfs_log_format.h  |  5 +-
> >  fs/xfs/libxfs/xfs_types.h       |  5 +-
> >  fs/xfs/scrub/inode.c            |  9 ++--
> >  fs/xfs/xfs_inode.c              |  6 ++-
> >  fs/xfs/xfs_inode_item.c         |  5 +-
> >  fs/xfs/xfs_inode_item_recover.c | 16 +++++--
> >  12 files changed, 184 insertions(+), 67 deletions(-)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> > index f75b70ae7b1f..73e552678adc 100644
> > --- a/fs/xfs/libxfs/xfs_bmap.c
> > +++ b/fs/xfs/libxfs/xfs_bmap.c
> > @@ -53,9 +53,9 @@ xfs_bmap_compute_maxlevels(
> >  	int		whichfork,	/* data or attr fork */
> >  	int		dir_bmbt)	/* Dir or non-dir data fork */
> >  {
> > +	uint64_t	maxleafents;	/* max leaf entries possible */
> >  	int		level;		/* btree level */
> >  	uint		maxblocks;	/* max blocks at this level */
> > -	uint		maxleafents;	/* max leaf entries possible */
> >  	int		maxrootrecs;	/* max records in root block */
> >  	int		minleafrecs;	/* min records in leaf block */
> >  	int		minnoderecs;	/* min records in node block */
> > @@ -477,7 +477,7 @@ xfs_bmap_check_leaf_extents(
> >  	if (bp_release)
> >  		xfs_trans_brelse(NULL, bp);
> >  error_norelse:
> > -	xfs_warn(mp, "%s: BAD after btree leaves for %d extents",
> > +	xfs_warn(mp, "%s: BAD after btree leaves for %llu extents",
> >  		__func__, i);
> >  	xfs_err(mp, "%s: CORRUPTED BTREE OR SOMETHING", __func__);
> >  	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
> > @@ -918,7 +918,7 @@ xfs_bmap_local_to_extents(
> >  	xfs_iext_first(ifp, &icur);
> >  	xfs_iext_insert(ip, &icur, &rec, 0);
> >  
> > -	error = xfs_next_set(ip, whichfork, 1);
> > +	error = xfs_next_set(tp, ip, whichfork, 1);
> >  	if (error)
> >  		goto done;
> >  
> > @@ -1610,7 +1610,7 @@ xfs_bmap_add_extent_delay_real(
> >  		xfs_iext_prev(ifp, &bma->icur);
> >  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
> >  
> > -		error = xfs_next_set(bma->ip, whichfork, -1);
> > +		error = xfs_next_set(bma->tp, bma->ip, whichfork, -1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -1717,7 +1717,7 @@ xfs_bmap_add_extent_delay_real(
> >  		PREV.br_state = new->br_state;
> >  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
> >  
> > -		error = xfs_next_set(bma->ip, whichfork, 1);
> > +		error = xfs_next_set(bma->tp, bma->ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -1786,7 +1786,7 @@ xfs_bmap_add_extent_delay_real(
> >  		 */
> >  		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
> >  
> > -		error = xfs_next_set(bma->ip, whichfork, 1);
> > +		error = xfs_next_set(bma->tp, bma->ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -1876,7 +1876,7 @@ xfs_bmap_add_extent_delay_real(
> >  		 */
> >  		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
> >  
> > -		error = xfs_next_set(bma->ip, whichfork, 1);
> > +		error = xfs_next_set(bma->tp, bma->ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -1965,7 +1965,7 @@ xfs_bmap_add_extent_delay_real(
> >  		xfs_iext_insert(bma->ip, &bma->icur, &RIGHT, state);
> >  		xfs_iext_insert(bma->ip, &bma->icur, &LEFT, state);
> >  
> > -		error = xfs_next_set(bma->ip, whichfork, 1);
> > +		error = xfs_next_set(bma->tp, bma->ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2172,7 +2172,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_prev(ifp, icur);
> >  		xfs_iext_update_extent(ip, state, icur, &LEFT);
> >  
> > -		error = xfs_next_set(ip, whichfork, -2);
> > +		error = xfs_next_set(tp, ip, whichfork, -2);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2228,7 +2228,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_prev(ifp, icur);
> >  		xfs_iext_update_extent(ip, state, icur, &LEFT);
> >  
> > -		error = xfs_next_set(ip, whichfork, -1);
> > +		error = xfs_next_set(tp, ip, whichfork, -1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2274,7 +2274,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_prev(ifp, icur);
> >  		xfs_iext_update_extent(ip, state, icur, &PREV);
> >  
> > -		error = xfs_next_set(ip, whichfork, -1);
> > +		error = xfs_next_set(tp, ip, whichfork, -1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2385,7 +2385,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_update_extent(ip, state, icur, &PREV);
> >  		xfs_iext_insert(ip, icur, new, state);
> >  
> > -		error = xfs_next_set(ip, whichfork, 1);
> > +		error = xfs_next_set(tp, ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2464,7 +2464,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_next(ifp, icur);
> >  		xfs_iext_insert(ip, icur, new, state);
> >  
> > -		error = xfs_next_set(ip, whichfork, 1);
> > +		error = xfs_next_set(tp, ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2519,7 +2519,7 @@ xfs_bmap_add_extent_unwritten_real(
> >  		xfs_iext_insert(ip, icur, &r[1], state);
> >  		xfs_iext_insert(ip, icur, &r[0], state);
> >  
> > -		error = xfs_next_set(ip, whichfork, 2);
> > +		error = xfs_next_set(tp, ip, whichfork, 2);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2838,7 +2838,7 @@ xfs_bmap_add_extent_hole_real(
> >  		xfs_iext_prev(ifp, icur);
> >  		xfs_iext_update_extent(ip, state, icur, &left);
> >  
> > -		error = xfs_next_set(ip, whichfork, -1);
> > +		error = xfs_next_set(tp, ip, whichfork, -1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -2940,7 +2940,7 @@ xfs_bmap_add_extent_hole_real(
> >  		 */
> >  		xfs_iext_insert(ip, icur, new, state);
> >  
> > -		error = xfs_next_set(ip, whichfork, 1);
> > +		error = xfs_next_set(tp, ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -5140,7 +5140,7 @@ xfs_bmap_del_extent_real(
> >  		xfs_iext_remove(ip, icur, state);
> >  		xfs_iext_prev(ifp, icur);
> >  
> > -		error = xfs_next_set(ip, whichfork, -1);
> > +		error = xfs_next_set(tp, ip, whichfork, -1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -5252,7 +5252,7 @@ xfs_bmap_del_extent_real(
> >  		} else
> >  			flags |= xfs_ilog_fext(whichfork);
> >  
> > -		error = xfs_next_set(ip, whichfork, 1);
> > +		error = xfs_next_set(tp, ip, whichfork, 1);
> >  		if (error)
> >  			goto done;
> >  
> > @@ -5722,7 +5722,7 @@ xfs_bmse_merge(
> >  	 * Update the on-disk extent count, the btree if necessary and log the
> >  	 * inode.
> >  	 */
> > -	error = xfs_next_set(ip, whichfork, -1);
> > +	error = xfs_next_set(tp, ip, whichfork, -1);
> >  	if (error)
> >  		goto done;
> >  
> > @@ -6113,7 +6113,7 @@ xfs_bmap_split_extent(
> >  	xfs_iext_next(ifp, &icur);
> >  	xfs_iext_insert(ip, &icur, &new, 0);
> >  
> > -	error = xfs_next_set(ip, whichfork, 1);
> > +	error = xfs_next_set(tp, ip, whichfork, 1);
> >  	if (error)
> >  		goto del_cursor;
> >  
> > diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> > index b42a52bfa1e9..91bee33aa988 100644
> > --- a/fs/xfs/libxfs/xfs_format.h
> > +++ b/fs/xfs/libxfs/xfs_format.h
> > @@ -449,10 +449,12 @@ xfs_sb_has_compat_feature(
> >  #define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)		/* free inode btree */
> >  #define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)		/* reverse map btree */
> >  #define XFS_SB_FEAT_RO_COMPAT_REFLINK  (1 << 2)		/* reflinked files */
> > +#define XFS_SB_FEAT_RO_COMPAT_47BIT_DEXT_CNTR (1 << 3)	/* 47bit data extents */
> 
> I wonder if we could come up with a better name for this...
> 
> DFORK_EXTENTHI
> 
> Hmm...
> 
> BIG_DFORK
> 
> Hmmm...
> 
> ULTRAFRAG
> 
> There we go.  "XFS with UltraFrag, part of this complete g@m3r t00lk1t." ;)
> 
> ...
> 
> (What do you think of the second suggestion?)

I like the name DFORK_EXTENTHI since it signifies that we are now using the
"_HI" field of the extent counter and it can also be used to convey the same
for the attr extent counter as well. Thanks for the suggestions.

> 
> >  #define XFS_SB_FEAT_RO_COMPAT_ALL \
> >  		(XFS_SB_FEAT_RO_COMPAT_FINOBT | \
> >  		 XFS_SB_FEAT_RO_COMPAT_RMAPBT | \
> > -		 XFS_SB_FEAT_RO_COMPAT_REFLINK)
> > +		 XFS_SB_FEAT_RO_COMPAT_REFLINK | \
> > +		 XFS_SB_FEAT_RO_COMPAT_47BIT_DEXT_CNTR)
> >  #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN	~XFS_SB_FEAT_RO_COMPAT_ALL
> >  static inline bool
> >  xfs_sb_has_ro_compat_feature(
> > @@ -563,6 +565,18 @@ static inline bool xfs_sb_version_hasreflink(struct xfs_sb *sbp)
> >  		(sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK);
> >  }
> >  
> > +static inline bool xfs_sb_version_has47bitext(struct xfs_sb *sbp)
> > +{
> > +	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
> > +		(sbp->sb_features_ro_compat &
> > +			XFS_SB_FEAT_RO_COMPAT_47BIT_DEXT_CNTR);
> > +}
> > +
> > +static inline void xfs_sb_version_add47bitext(struct xfs_sb *sbp)
> > +{
> > +	sbp->sb_features_ro_compat |= XFS_SB_FEAT_RO_COMPAT_47BIT_DEXT_CNTR;
> > +}
> > +
> >  /*
> >   * end of superblock version macros
> >   */
> > @@ -873,7 +887,7 @@ typedef struct xfs_dinode {
> >  	__be64		di_size;	/* number of bytes in file */
> >  	__be64		di_nblocks;	/* # of direct & btree blocks used */
> >  	__be32		di_extsize;	/* basic/minimum extent size for file */
> > -	__be32		di_nextents;	/* number of extents in data fork */
> > +	__be32		di_nextents_lo;	/* number of extents in data fork */
> >  	__be16		di_anextents;	/* number of extents in attribute fork*/
> >  	__u8		di_forkoff;	/* attr fork offs, <<3 for 64b align */
> >  	__s8		di_aformat;	/* format of attr fork's data */
> > @@ -891,7 +905,8 @@ typedef struct xfs_dinode {
> >  	__be64		di_lsn;		/* flush sequence */
> >  	__be64		di_flags2;	/* more random flags */
> >  	__be32		di_cowextsize;	/* basic cow extent size for file */
> > -	__u8		di_pad2[12];	/* more padding for future expansion */
> > +	__be32		di_nextents_hi;
> > +	__u8		di_pad2[8];	/* more padding for future expansion */
> >  
> >  	/* fields only written to during inode creation */
> >  	xfs_timestamp_t	di_crtime;	/* time created */
> > @@ -992,10 +1007,6 @@ enum xfs_dinode_fmt {
> >  	((w) == XFS_DATA_FORK ? \
> >  		(dip)->di_format : \
> >  		(dip)->di_aformat)
> > -#define XFS_DFORK_NEXTENTS(dip,w) \
> > -	((w) == XFS_DATA_FORK ? \
> > -		be32_to_cpu((dip)->di_nextents) : \
> > -		be16_to_cpu((dip)->di_anextents))
> >  
> >  /*
> >   * For block and character special files the 32bit dev_t is stored at the
> > @@ -1061,12 +1072,15 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
> >  #define XFS_DIFLAG2_DAX_BIT	0	/* use DAX for this inode */
> >  #define XFS_DIFLAG2_REFLINK_BIT	1	/* file's blocks may be shared */
> >  #define XFS_DIFLAG2_COWEXTSIZE_BIT   2  /* copy on write extent size hint */
> > +#define XFS_DIFLAG2_47BIT_NEXTENTS_BIT 3 /* Uses di_nextents_hi field */
> >  #define XFS_DIFLAG2_DAX		(1 << XFS_DIFLAG2_DAX_BIT)
> >  #define XFS_DIFLAG2_REFLINK     (1 << XFS_DIFLAG2_REFLINK_BIT)
> >  #define XFS_DIFLAG2_COWEXTSIZE  (1 << XFS_DIFLAG2_COWEXTSIZE_BIT)
> > +#define XFS_DIFLAG2_47BIT_NEXTENTS (1 << XFS_DIFLAG2_47BIT_NEXTENTS_BIT)
> >  
> >  #define XFS_DIFLAG2_ANY \
> > -	(XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)
> > +	(XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
> > +	 XFS_DIFLAG2_47BIT_NEXTENTS)
> >  
> >  /*
> >   * Inode number format:
> > diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
> > index 6f84ea85fdd8..8b89fe080f70 100644
> > --- a/fs/xfs/libxfs/xfs_inode_buf.c
> > +++ b/fs/xfs/libxfs/xfs_inode_buf.c
> > @@ -307,7 +307,8 @@ xfs_inode_to_disk(
> >  	to->di_size = cpu_to_be64(from->di_size);
> >  	to->di_nblocks = cpu_to_be64(from->di_nblocks);
> >  	to->di_extsize = cpu_to_be32(from->di_extsize);
> > -	to->di_nextents = cpu_to_be32(xfs_ifork_nextents(&ip->i_df));
> > +	to->di_nextents_lo = cpu_to_be32(xfs_ifork_nextents(&ip->i_df) &
> > +					0xffffffffU);
> >  	to->di_anextents = cpu_to_be16(xfs_ifork_nextents(ip->i_afp));
> >  	to->di_forkoff = from->di_forkoff;
> >  	to->di_aformat = xfs_ifork_format(ip->i_afp);
> > @@ -322,6 +323,10 @@ xfs_inode_to_disk(
> >  		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.tv_nsec);
> >  		to->di_flags2 = cpu_to_be64(from->di_flags2);
> >  		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
> > +		if (from->di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +			to->di_nextents_hi
> > +				= cpu_to_be32(xfs_ifork_nextents(&ip->i_df)
> > +					>> 32);
> 
> /me kinda hates the indentation here, would a convenience variable
> reduce the amount of linewrapping here?

I will use a variable here as you have suggested.

> 
> Oh, right, we're in a new epoch now; just go past 80 columns.
> 
> >  		to->di_ino = cpu_to_be64(ip->i_ino);
> >  		to->di_lsn = cpu_to_be64(lsn);
> >  		memset(to->di_pad2, 0, sizeof(to->di_pad2));
> > @@ -360,7 +365,7 @@ xfs_log_dinode_to_disk(
> >  	to->di_size = cpu_to_be64(from->di_size);
> >  	to->di_nblocks = cpu_to_be64(from->di_nblocks);
> >  	to->di_extsize = cpu_to_be32(from->di_extsize);
> > -	to->di_nextents = cpu_to_be32(from->di_nextents);
> > +	to->di_nextents_lo = cpu_to_be32(from->di_nextents_lo);
> >  	to->di_anextents = cpu_to_be16(from->di_anextents);
> >  	to->di_forkoff = from->di_forkoff;
> >  	to->di_aformat = from->di_aformat;
> > @@ -375,6 +380,9 @@ xfs_log_dinode_to_disk(
> >  		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.t_nsec);
> >  		to->di_flags2 = cpu_to_be64(from->di_flags2);
> >  		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
> > +		if (from->di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +			to->di_nextents_hi =
> > +				cpu_to_be32(from->di_nextents_hi);
> >  		to->di_ino = cpu_to_be64(from->di_ino);
> >  		to->di_lsn = cpu_to_be64(from->di_lsn);
> >  		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
> > @@ -391,7 +399,9 @@ xfs_dinode_verify_fork(
> >  	struct xfs_mount	*mp,
> >  	int			whichfork)
> >  {
> > -	uint32_t		di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
> > +	xfs_extnum_t		di_nextents;
> > +
> > +	di_nextents = xfs_dfork_nextents(&mp->m_sb, dip, whichfork);
> >  
> >  	switch (XFS_DFORK_FORMAT(dip, whichfork)) {
> >  	case XFS_DINODE_FMT_LOCAL:
> > @@ -462,6 +472,8 @@ xfs_dinode_verify(
> >  	uint16_t		flags;
> >  	uint64_t		flags2;
> >  	uint64_t		di_size;
> > +	xfs_extnum_t		nextents;
> > +	int64_t			nblocks;
> >  
> >  	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
> >  		return __this_address;
> > @@ -492,10 +504,12 @@ xfs_dinode_verify(
> >  	if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0)
> >  		return __this_address;
> >  
> > +	nextents = xfs_dfork_nextents(&mp->m_sb, dip, XFS_DATA_FORK);
> > +	nextents += xfs_dfork_nextents(&mp->m_sb, dip, XFS_ATTR_FORK);
> > +	nblocks = be64_to_cpu(dip->di_nblocks);
> > +
> >  	/* Fork checks carried over from xfs_iformat_fork */
> > -	if (mode &&
> > -	    be32_to_cpu(dip->di_nextents) + be16_to_cpu(dip->di_anextents) >
> > -			be64_to_cpu(dip->di_nblocks))
> > +	if (mode && nextents > nblocks)
> >  		return __this_address;
> >  
> >  	if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize)
> > @@ -716,3 +730,23 @@ xfs_inode_validate_cowextsize(
> >  
> >  	return NULL;
> >  }
> > +
> > +xfs_extnum_t
> > +xfs_dfork_nextents(
> > +	struct xfs_sb		*sbp,
> > +	struct xfs_dinode	*dip,
> > +	int			whichfork)
> > +{
> > +	xfs_extnum_t		nextents;
> > +
> > +	if (whichfork == XFS_DATA_FORK) {
> > +		nextents = be32_to_cpu(dip->di_nextents_lo);
> > +		if (xfs_sb_version_has_v3inode(sbp)
> > +			&& (dip->di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS))
> 
> Please don't align the second line of the if test with the if body.
> 
> Or maybe just create a "xfs_inode_has_big_dfork" helper to encapsulate
> this, like we do for reflink/hascow/realtime inodes.

Ok. I will follow the style used for reflink inodes.

> 
> > +			nextents |= (u64)(be32_to_cpu(dip->di_nextents_hi))
> > +				<< 32;
> > +		return nextents;
> > +	} else {
> > +		return be16_to_cpu(dip->di_anextents);
> 
> I suspect you could reduce the indenting here by inverting the logic,
> e.g.
> 
> 	if (attr fork)
> 		return be16_to_cpu(anextents);
> 
> 	nextents = be32_to_cpu(nextents_lo);
> 	if (xfs_inode_has_big_dfork())
> 		nextents += be32_to_cpu(nextents_hi);
> 	return nextents;
>

The "else" part (i.e. attr fork) gets expanded in the next
patch to contain code similar to the data fork. I will have to introduce the
"if/else" branch logic once again in that patch.

> > +	}
> > +}
> > diff --git a/fs/xfs/libxfs/xfs_inode_buf.h b/fs/xfs/libxfs/xfs_inode_buf.h
> > index 865ac493c72a..4583db53b933 100644
> > --- a/fs/xfs/libxfs/xfs_inode_buf.h
> > +++ b/fs/xfs/libxfs/xfs_inode_buf.h
> > @@ -65,5 +65,7 @@ xfs_failaddr_t xfs_inode_validate_extsize(struct xfs_mount *mp,
> >  xfs_failaddr_t xfs_inode_validate_cowextsize(struct xfs_mount *mp,
> >  		uint32_t cowextsize, uint16_t mode, uint16_t flags,
> >  		uint64_t flags2);
> > +xfs_extnum_t xfs_dfork_nextents(struct xfs_sb *sbp, struct xfs_dinode *dip,
> > +		int whichfork);
> >  
> >  #endif	/* __XFS_INODE_BUF_H__ */
> > diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
> > index 3bf5a2c391bd..ec682e2d5bcb 100644
> > --- a/fs/xfs/libxfs/xfs_inode_fork.c
> > +++ b/fs/xfs/libxfs/xfs_inode_fork.c
> > @@ -10,6 +10,7 @@
> >  #include "xfs_format.h"
> >  #include "xfs_log_format.h"
> >  #include "xfs_trans_resv.h"
> > +#include "xfs_sb.h"
> >  #include "xfs_mount.h"
> >  #include "xfs_inode.h"
> >  #include "xfs_trans.h"
> > @@ -103,21 +104,22 @@ xfs_iformat_extents(
> >  	int			whichfork)
> >  {
> >  	struct xfs_mount	*mp = ip->i_mount;
> > +	struct xfs_sb		*sb = &mp->m_sb;
> >  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
> > +	xfs_extnum_t		nex = xfs_dfork_nextents(sb, dip, whichfork);
> >  	int			state = xfs_bmap_fork_to_state(whichfork);
> > -	int			nex = XFS_DFORK_NEXTENTS(dip, whichfork);
> >  	int			size = nex * sizeof(xfs_bmbt_rec_t);
> >  	struct xfs_iext_cursor	icur;
> >  	struct xfs_bmbt_rec	*dp;
> >  	struct xfs_bmbt_irec	new;
> > -	int			i;
> > +	xfs_extnum_t		i;
> >  
> >  	/*
> >  	 * If the number of extents is unreasonable, then something is wrong and
> >  	 * we just bail out rather than crash in kmem_alloc() or memcpy() below.
> >  	 */
> >  	if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
> > -		xfs_warn(ip->i_mount, "corrupt inode %Lu ((a)extents = %d).",
> > +		xfs_warn(ip->i_mount, "corrupt inode %Lu ((a)extents = %llu).",
> >  			(unsigned long long) ip->i_ino, nex);
> >  		xfs_inode_verifier_error(ip, -EFSCORRUPTED,
> >  				"xfs_iformat_extents(1)", dip, sizeof(*dip),
> > @@ -233,7 +235,11 @@ xfs_iformat_data_fork(
> >  	 * depend on it.
> >  	 */
> >  	ip->i_df.if_format = dip->di_format;
> > -	ip->i_df.if_nextents = be32_to_cpu(dip->di_nextents);
> > +	ip->i_df.if_nextents = be32_to_cpu(dip->di_nextents_lo);
> > +	if (ip->i_d.di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +		ip->i_df.if_nextents |=
> > +			((u64)(be32_to_cpu(dip->di_nextents_hi)) << 32);
> > +
> >  
> >  	switch (inode->i_mode & S_IFMT) {
> >  	case S_IFIFO:
> > @@ -729,31 +735,73 @@ xfs_ifork_verify_local_attr(
> >  	return 0;
> >  }
> >  
> > +static int
> > +xfs_next_set_data(
> > +	struct xfs_trans	*tp,
> > +	struct xfs_inode	*ip,
> > +	struct xfs_ifork	*ifp,
> > +	int			delta)
> > +{
> > +	struct xfs_mount	*mp = ip->i_mount;
> > +	xfs_extnum_t		nr_exts;
> > +
> > +	nr_exts = ifp->if_nextents + delta;
> > +
> > +	if ((delta > 0 && nr_exts > MAXEXTNUM)
> > +		|| (delta < 0 && nr_exts > ifp->if_nextents))
> > +		return -EOVERFLOW;
> > +
> > +	if (ifp->if_nextents <= MAXEXTNUM31BIT &&
> > +		nr_exts > MAXEXTNUM31BIT &&
> > +		!(ip->i_d.di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS) &&
> > +		xfs_sb_version_has_v3inode(&mp->m_sb)) {
> > +		if (!xfs_sb_version_has47bitext(&mp->m_sb)) {
> 
> Urk.  Again, don't indent the if test logic and the if body statements
> to the same level.

I am sorry. I will fixup the indentation issues.

> 
> > +			bool log_sb = false;
> > +
> > +			spin_lock(&mp->m_sb_lock);
> > +			if (!xfs_sb_version_has47bitext(&mp->m_sb)) {
> > +				xfs_sb_version_add47bitext(&mp->m_sb);
> > +				log_sb = true;
> > +			}
> > +			spin_unlock(&mp->m_sb_lock);
> > +
> > +			if (log_sb)
> > +				xfs_log_sb(tp);
> > +		}
> 
> Hm, dynamic filesystem upgrade.  This probably ought to log something to
> dmesg about the upgrade.  It might also be a better to make this a
> separate helper so that it's not triply-indented.

Ok. I will implement that.

> 
> > +
> > +		ip->i_d.di_flags2 |= XFS_DIFLAG2_47BIT_NEXTENTS;
> > +	}
> > +
> > +	ifp->if_nextents = nr_exts;
> > +
> > +	return 0;
> > +}
> > +
> >  int
> >  xfs_next_set(
> > +	struct xfs_trans	*tp,
> >  	struct xfs_inode	*ip,
> >  	int			whichfork,
> >  	int			delta)
> >  {
> >  	struct xfs_ifork	*ifp;
> >  	int64_t			nr_exts;
> > -	int64_t			max_exts;
> > +	int			error = 0;
> >  
> >  	ifp = XFS_IFORK_PTR(ip, whichfork);
> >  
> > -	if (whichfork == XFS_DATA_FORK || whichfork == XFS_COW_FORK)
> > -		max_exts = MAXEXTNUM;
> > -	else if (whichfork == XFS_ATTR_FORK)
> > -		max_exts = MAXAEXTNUM;
> > -	else
> > -		ASSERT(0);
> > -
> > -	nr_exts = ifp->if_nextents + delta;
> > -	if ((delta > 0 && nr_exts > max_exts)
> > -		|| (delta < 0 && nr_exts < 0))
> > -		return -EOVERFLOW;
> > +	if (whichfork == XFS_DATA_FORK || whichfork == XFS_COW_FORK) {
> > +		error = xfs_next_set_data(tp, ip, ifp, delta);
> > +	} else if (whichfork == XFS_ATTR_FORK) {
> > +		nr_exts = ifp->if_nextents + delta;
> > +		if ((delta > 0 && nr_exts > MAXAEXTNUM)
> > +			|| (delta < 0 && nr_exts < 0))
> > +			return -EOVERFLOW;
> >  
> > -	ifp->if_nextents = nr_exts;
> > +		ifp->if_nextents = nr_exts;
> > +	} else {
> > +		ASSERT(0);
> > +	}
> >  
> > -	return 0;
> > +	return error;
> >  }
> > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
> > index a84ae42ace79..c74fa6371cc8 100644
> > --- a/fs/xfs/libxfs/xfs_inode_fork.h
> > +++ b/fs/xfs/libxfs/xfs_inode_fork.h
> > @@ -173,5 +173,6 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip);
> >  int xfs_ifork_verify_local_data(struct xfs_inode *ip);
> >  int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
> >  
> > -int xfs_next_set(struct xfs_inode *ip, int whichfork, int delta);
> > +int xfs_next_set(struct xfs_trans *tp, struct xfs_inode *ip, int whichfork,
> > +		int delta);
> >  #endif	/* __XFS_INODE_FORK_H__ */
> > diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
> > index e3400c9c71cd..879aadff7692 100644
> > --- a/fs/xfs/libxfs/xfs_log_format.h
> > +++ b/fs/xfs/libxfs/xfs_log_format.h
> > @@ -396,7 +396,7 @@ struct xfs_log_dinode {
> >  	xfs_fsize_t	di_size;	/* number of bytes in file */
> >  	xfs_rfsblock_t	di_nblocks;	/* # of direct & btree blocks used */
> >  	xfs_extlen_t	di_extsize;	/* basic/minimum extent size for file */
> > -	xfs_extnum_t	di_nextents;	/* number of extents in data fork */
> > +	uint32_t	di_nextents_lo;	/* number of extents in data fork */
> >  	xfs_aextnum_t	di_anextents;	/* number of extents in attribute fork*/
> >  	uint8_t		di_forkoff;	/* attr fork offs, <<3 for 64b align */
> >  	int8_t		di_aformat;	/* format of attr fork's data */
> > @@ -414,7 +414,8 @@ struct xfs_log_dinode {
> >  	xfs_lsn_t	di_lsn;		/* flush sequence */
> >  	uint64_t	di_flags2;	/* more random flags */
> >  	uint32_t	di_cowextsize;	/* basic cow extent size for file */
> > -	uint8_t		di_pad2[12];	/* more padding for future expansion */
> > +	uint32_t	di_nextents_hi;
> > +	uint8_t		di_pad2[8];	/* more padding for future expansion */
> >  
> >  	/* fields only written to during inode creation */
> >  	xfs_ictimestamp_t di_crtime;	/* time created */
> > diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
> > index 0a3041ad5bec..c68ff2178976 100644
> > --- a/fs/xfs/libxfs/xfs_types.h
> > +++ b/fs/xfs/libxfs/xfs_types.h
> > @@ -12,7 +12,7 @@ typedef uint32_t	xfs_agblock_t;	/* blockno in alloc. group */
> >  typedef uint32_t	xfs_agino_t;	/* inode # within allocation grp */
> >  typedef uint32_t	xfs_extlen_t;	/* extent length in blocks */
> >  typedef uint32_t	xfs_agnumber_t;	/* allocation group number */
> > -typedef int32_t		xfs_extnum_t;	/* # of extents in a file */
> > +typedef uint64_t	xfs_extnum_t;	/* # of extents in a file */
> >  typedef int16_t		xfs_aextnum_t;	/* # extents in an attribute fork */
> >  typedef int64_t		xfs_fsize_t;	/* bytes in a file */
> >  typedef uint64_t	xfs_ufsize_t;	/* unsigned bytes in a file */
> > @@ -59,7 +59,8 @@ typedef void *		xfs_failaddr_t;
> >   * Max values for extlen, extnum, aextnum.
> >   */
> >  #define	MAXEXTLEN	((xfs_extlen_t)0x001fffff)	/* 21 bits */
> > -#define	MAXEXTNUM	((xfs_extnum_t)0x7fffffff)	/* signed int */
> > +#define	MAXEXTNUM31BIT	((xfs_extnum_t)0x7fffffff)	/* 31 bits */
> > +#define	MAXEXTNUM	((xfs_extnum_t)0x7fffffffffff)	/* 47 bits */
> >  #define	MAXDIREXTNUM	((xfs_extnum_t)0x7ffffff)	/* 27 bits */
> >  #define	MAXAEXTNUM	((xfs_aextnum_t)0x7fff)		/* signed short */
> >  
> > diff --git a/fs/xfs/scrub/inode.c b/fs/xfs/scrub/inode.c
> > index 6d483ab29e63..be41fd242ff2 100644
> > --- a/fs/xfs/scrub/inode.c
> > +++ b/fs/xfs/scrub/inode.c
> > @@ -205,8 +205,8 @@ xchk_dinode(
> >  	struct xfs_mount	*mp = sc->mp;
> >  	size_t			fork_recs;
> >  	unsigned long long	isize;
> > +	xfs_extnum_t		nextents;
> >  	uint64_t		flags2;
> > -	uint32_t		nextents;
> >  	uint16_t		flags;
> >  	uint16_t		mode;
> >  
> > @@ -354,7 +354,7 @@ xchk_dinode(
> >  	xchk_inode_extsize(sc, dip, ino, mode, flags);
> >  
> >  	/* di_nextents */
> > -	nextents = be32_to_cpu(dip->di_nextents);
> > +	nextents = xfs_dfork_nextents(&mp->m_sb, dip, XFS_DATA_FORK);
> >  	fork_recs =  XFS_DFORK_DSIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
> >  	switch (dip->di_format) {
> >  	case XFS_DINODE_FMT_EXTENTS:
> > @@ -464,6 +464,7 @@ xchk_inode_xref_bmap(
> >  	struct xfs_scrub	*sc,
> >  	struct xfs_dinode	*dip)
> >  {
> > +	xfs_mount_t		*mp = sc->mp;
> 
> struct xfs_mount.  The structure typedefs usages are deprecated and
> we're trying to get rid of them (slowly).

Yes, I missed out on this one. I will fix this up.

> 
> --D
> 
> >  	xfs_extnum_t		nextents;
> >  	xfs_filblks_t		count;
> >  	xfs_filblks_t		acount;
> > @@ -477,14 +478,14 @@ xchk_inode_xref_bmap(
> >  			&nextents, &count);
> >  	if (!xchk_should_check_xref(sc, &error, NULL))
> >  		return;
> > -	if (nextents < be32_to_cpu(dip->di_nextents))
> > +	if (nextents < xfs_dfork_nextents(&mp->m_sb, dip, XFS_DATA_FORK))
> >  		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
> >  
> >  	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_ATTR_FORK,
> >  			&nextents, &acount);
> >  	if (!xchk_should_check_xref(sc, &error, NULL))
> >  		return;
> > -	if (nextents != be16_to_cpu(dip->di_anextents))
> > +	if (nextents != xfs_dfork_nextents(&mp->m_sb, dip, XFS_ATTR_FORK))
> >  		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
> >  
> >  	/* Check nblocks against the inode. */
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index 64f5f9a440ae..4418a66cf6d6 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -3748,7 +3748,7 @@ xfs_iflush_int(
> >  				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
> >  		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
> >  			"%s: detected corrupt incore inode %Lu, "
> > -			"total extents = %d, nblocks = %Ld, ptr "PTR_FMT,
> > +			"total extents = %llu, nblocks = %Ld, ptr "PTR_FMT,
> >  			__func__, ip->i_ino,
> >  			ip->i_df.if_nextents + xfs_ifork_nextents(ip->i_afp),
> >  			ip->i_d.di_nblocks, ip);
> > @@ -3785,6 +3785,10 @@ xfs_iflush_int(
> >  	    xfs_ifork_verify_local_attr(ip))
> >  		goto flush_out;
> >  
> > +	if (!(ip->i_d.di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +		&& xfs_sb_version_has47bitext(&mp->m_sb))
> > +		ip->i_d.di_flags2 |= XFS_DIFLAG2_47BIT_NEXTENTS;
> > +
> >  	/*
> >  	 * Copy the dirty parts of the inode into the on-disk inode.  We always
> >  	 * copy out the core of the inode, because if the inode is dirty at all
> > diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> > index ba47bf65b772..6f27ac7c8631 100644
> > --- a/fs/xfs/xfs_inode_item.c
> > +++ b/fs/xfs/xfs_inode_item.c
> > @@ -326,7 +326,7 @@ xfs_inode_to_log_dinode(
> >  	to->di_size = from->di_size;
> >  	to->di_nblocks = from->di_nblocks;
> >  	to->di_extsize = from->di_extsize;
> > -	to->di_nextents = xfs_ifork_nextents(&ip->i_df);
> > +	to->di_nextents_lo = xfs_ifork_nextents(&ip->i_df) & 0xffffffffU;
> >  	to->di_anextents = xfs_ifork_nextents(ip->i_afp);
> >  	to->di_forkoff = from->di_forkoff;
> >  	to->di_aformat = xfs_ifork_format(ip->i_afp);
> > @@ -344,6 +344,9 @@ xfs_inode_to_log_dinode(
> >  		to->di_crtime.t_nsec = from->di_crtime.tv_nsec;
> >  		to->di_flags2 = from->di_flags2;
> >  		to->di_cowextsize = from->di_cowextsize;
> > +		if (from->di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +			to->di_nextents_hi =
> > +				xfs_ifork_nextents(&ip->i_df) >> 32;
> >  		to->di_ino = ip->i_ino;
> >  		to->di_lsn = lsn;
> >  		memset(to->di_pad2, 0, sizeof(to->di_pad2));
> > diff --git a/fs/xfs/xfs_inode_item_recover.c b/fs/xfs/xfs_inode_item_recover.c
> > index 10ef5ddf5429..8d64b861fb66 100644
> > --- a/fs/xfs/xfs_inode_item_recover.c
> > +++ b/fs/xfs/xfs_inode_item_recover.c
> > @@ -134,6 +134,7 @@ xlog_recover_inode_commit_pass2(
> >  	struct xfs_log_dinode		*ldip;
> >  	uint				isize;
> >  	int				need_free = 0;
> > +	xfs_extnum_t			nextents;
> >  
> >  	if (item->ri_buf[0].i_len == sizeof(struct xfs_inode_log_format)) {
> >  		in_f = item->ri_buf[0].i_addr;
> > @@ -255,16 +256,23 @@ xlog_recover_inode_commit_pass2(
> >  			goto out_release;
> >  		}
> >  	}
> > -	if (unlikely(ldip->di_nextents + ldip->di_anextents > ldip->di_nblocks)){
> > +
> > +	nextents = ldip->di_nextents_lo;
> > +	if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
> > +		ldip->di_flags2 & XFS_DIFLAG2_47BIT_NEXTENTS)
> > +		nextents |= ((u64)(ldip->di_nextents_hi) << 32);
> > +
> > +	nextents += ldip->di_anextents;
> > +
> > +	if (unlikely(nextents > ldip->di_nblocks)) {
> >  		XFS_CORRUPTION_ERROR("xlog_recover_inode_pass2(5)",
> >  				     XFS_ERRLEVEL_LOW, mp, ldip,
> >  				     sizeof(*ldip));
> >  		xfs_alert(mp,
> >  	"%s: Bad inode log record, rec ptr "PTR_FMT", dino ptr "PTR_FMT", "
> > -	"dino bp "PTR_FMT", ino %Ld, total extents = %d, nblocks = %Ld",
> > +	"dino bp "PTR_FMT", ino %Ld, total extents = %llu, nblocks = %Ld",
> >  			__func__, item, dip, bp, in_f->ilf_ino,
> > -			ldip->di_nextents + ldip->di_anextents,
> > -			ldip->di_nblocks);
> > +			nextents, ldip->di_nblocks);
> >  		error = -EFSCORRUPTED;
> >  		goto out_release;
> >  	}
> 

-- 
chandan