From: Christoph Hellwig Date: Sun, 18 Sep 2011 20:40:53 +0000 (+0000) Subject: xfs: introduce xfs_bmap_last_extent X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=27a3f8f;p=linux-beck.git xfs: introduce xfs_bmap_last_extent Add a common helper for finding the last extent in a file. Largely based on a patch from Dave Chinner. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 595cc6311937..d9de5ae1fd5c 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -203,19 +203,6 @@ xfs_bmap_search_extents( xfs_bmbt_irec_t *gotp, /* out: extent entry found */ xfs_bmbt_irec_t *prevp); /* out: previous extent entry found */ -/* - * Check the last inode extent to determine whether this allocation will result - * in blocks being allocated at the end of the file. When we allocate new data - * blocks at the end of the file which do not start at the previous data block, - * we will try to align the new blocks at stripe unit boundaries. - */ -STATIC int /* error */ -xfs_bmap_isaeof( - xfs_inode_t *ip, /* incore inode pointer */ - xfs_fileoff_t off, /* file offset in fsblocks */ - int whichfork, /* data or attribute fork */ - char *aeof); /* return value */ - /* * Compute the worst-case number of indirect blocks that will be used * for ip's delayed extent of length "len". @@ -3924,42 +3911,122 @@ xfs_bmap_last_before( return 0; } +STATIC int +xfs_bmap_last_extent( + struct xfs_trans *tp, + struct xfs_inode *ip, + int whichfork, + struct xfs_bmbt_irec *rec, + int *is_empty) +{ + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); + int error; + int nextents; + + if (!(ifp->if_flags & XFS_IFEXTENTS)) { + error = xfs_iread_extents(tp, ip, whichfork); + if (error) + return error; + } + + nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t); + if (nextents == 0) { + *is_empty = 1; + return 0; + } + + xfs_bmbt_get_all(xfs_iext_get_ext(ifp, nextents - 1), rec); + *is_empty = 0; + return 0; +} + +/* + * Check the last inode extent to determine whether this allocation will result + * in blocks being allocated at the end of the file. When we allocate new data + * blocks at the end of the file which do not start at the previous data block, + * we will try to align the new blocks at stripe unit boundaries. + * + * Returns 0 in *aeof if the file (fork) is empty as any new write will be at, + * or past the EOF. + */ +STATIC int +xfs_bmap_isaeof( + struct xfs_inode *ip, + xfs_fileoff_t off, + int whichfork, + char *aeof) +{ + struct xfs_bmbt_irec rec; + int is_empty; + int error; + + *aeof = 0; + error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty); + if (error || is_empty) + return error; + + /* + * Check if we are allocation or past the last extent, or at least into + * the last delayed allocated extent. + */ + *aeof = off >= rec.br_startoff + rec.br_blockcount || + (off >= rec.br_startoff && isnullstartblock(rec.br_startblock)); + return 0; +} + +/* + * Check if the endoff is outside the last extent. If so the caller will grow + * the allocation to a stripe unit boundary. All offsets are considered outside + * the end of file for an empty fork, so 1 is returned in *eof in that case. + */ +int +xfs_bmap_eof( + struct xfs_inode *ip, + xfs_fileoff_t endoff, + int whichfork, + int *eof) +{ + struct xfs_bmbt_irec rec; + int error; + + error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, eof); + if (error || *eof) + return error; + + *eof = endoff >= rec.br_startoff + rec.br_blockcount; + return 0; +} + /* * Returns the file-relative block number of the first block past eof in * the file. This is not based on i_size, it is based on the extent records. * Returns 0 for local files, as they do not have extent records. */ -int /* error */ +int xfs_bmap_last_offset( - xfs_trans_t *tp, /* transaction pointer */ - xfs_inode_t *ip, /* incore inode */ - xfs_fileoff_t *last_block, /* last block */ - int whichfork) /* data or attr fork */ + struct xfs_trans *tp, + struct xfs_inode *ip, + xfs_fileoff_t *last_block, + int whichfork) { - xfs_bmbt_rec_host_t *ep; /* pointer to last extent */ - int error; /* error return value */ - xfs_ifork_t *ifp; /* inode fork pointer */ - xfs_extnum_t nextents; /* number of extent entries */ + struct xfs_bmbt_irec rec; + int is_empty; + int error; + + *last_block = 0; + + if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) + return 0; if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE && - XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS && - XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL) + XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS) return XFS_ERROR(EIO); - if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) { - *last_block = 0; - return 0; - } - ifp = XFS_IFORK_PTR(ip, whichfork); - if (!(ifp->if_flags & XFS_IFEXTENTS) && - (error = xfs_iread_extents(tp, ip, whichfork))) + + error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty); + if (error || is_empty) return error; - nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); - if (!nextents) { - *last_block = 0; - return 0; - } - ep = xfs_iext_get_ext(ifp, nextents - 1); - *last_block = xfs_bmbt_get_startoff(ep) + xfs_bmbt_get_blockcount(ep); + + *last_block = rec.br_startoff + rec.br_blockcount; return 0; } @@ -5687,89 +5754,6 @@ xfs_getbmap( return error; } -/* - * Check the last inode extent to determine whether this allocation will result - * in blocks being allocated at the end of the file. When we allocate new data - * blocks at the end of the file which do not start at the previous data block, - * we will try to align the new blocks at stripe unit boundaries. - */ -STATIC int /* error */ -xfs_bmap_isaeof( - xfs_inode_t *ip, /* incore inode pointer */ - xfs_fileoff_t off, /* file offset in fsblocks */ - int whichfork, /* data or attribute fork */ - char *aeof) /* return value */ -{ - int error; /* error return value */ - xfs_ifork_t *ifp; /* inode fork pointer */ - xfs_bmbt_rec_host_t *lastrec; /* extent record pointer */ - xfs_extnum_t nextents; /* number of file extents */ - xfs_bmbt_irec_t s; /* expanded extent record */ - - ASSERT(whichfork == XFS_DATA_FORK); - ifp = XFS_IFORK_PTR(ip, whichfork); - if (!(ifp->if_flags & XFS_IFEXTENTS) && - (error = xfs_iread_extents(NULL, ip, whichfork))) - return error; - nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); - if (nextents == 0) { - *aeof = 1; - return 0; - } - /* - * Go to the last extent - */ - lastrec = xfs_iext_get_ext(ifp, nextents - 1); - xfs_bmbt_get_all(lastrec, &s); - /* - * Check we are allocating in the last extent (for delayed allocations) - * or past the last extent for non-delayed allocations. - */ - *aeof = (off >= s.br_startoff && - off < s.br_startoff + s.br_blockcount && - isnullstartblock(s.br_startblock)) || - off >= s.br_startoff + s.br_blockcount; - return 0; -} - -/* - * Check if the endoff is outside the last extent. If so the caller will grow - * the allocation to a stripe unit boundary. - */ -int /* error */ -xfs_bmap_eof( - xfs_inode_t *ip, /* incore inode pointer */ - xfs_fileoff_t endoff, /* file offset in fsblocks */ - int whichfork, /* data or attribute fork */ - int *eof) /* result value */ -{ - xfs_fsblock_t blockcount; /* extent block count */ - int error; /* error return value */ - xfs_ifork_t *ifp; /* inode fork pointer */ - xfs_bmbt_rec_host_t *lastrec; /* extent record pointer */ - xfs_extnum_t nextents; /* number of file extents */ - xfs_fileoff_t startoff; /* extent starting file offset */ - - ASSERT(whichfork == XFS_DATA_FORK); - ifp = XFS_IFORK_PTR(ip, whichfork); - if (!(ifp->if_flags & XFS_IFEXTENTS) && - (error = xfs_iread_extents(NULL, ip, whichfork))) - return error; - nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); - if (nextents == 0) { - *eof = 1; - return 0; - } - /* - * Go to the last extent - */ - lastrec = xfs_iext_get_ext(ifp, nextents - 1); - startoff = xfs_bmbt_get_startoff(lastrec); - blockcount = xfs_bmbt_get_blockcount(lastrec); - *eof = endoff >= startoff + blockcount; - return 0; -} - #ifdef DEBUG STATIC struct xfs_buf * xfs_bmap_get_bp(