diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_file.c | 10 | ||||
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 255 | ||||
| -rw-r--r-- | fs/xfs/xfs_reflink.h | 4 |
3 files changed, 267 insertions, 2 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 39fde9f51303..07f951dd2685 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -848,7 +848,7 @@ buffered: #define XFS_FALLOC_FL_SUPPORTED \ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \ - FALLOC_FL_INSERT_RANGE) + FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE) STATIC long xfs_file_fallocate( @@ -938,9 +938,15 @@ xfs_file_fallocate( if (mode & FALLOC_FL_ZERO_RANGE) error = xfs_zero_file_space(ip, offset, len); - else + else { + if (mode & FALLOC_FL_UNSHARE_RANGE) { + error = xfs_reflink_unshare(ip, offset, len); + if (error) + goto out_unlock; + } error = xfs_alloc_file_space(ip, offset, len, XFS_BMAPI_PREALLOC); + } if (error) goto out_unlock; } diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 6b22669421b2..d4707e627a74 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1345,3 +1345,258 @@ out_error: trace_xfs_reflink_remap_range_error(dest, error, _RET_IP_); return error; } + +/* + * The user wants to preemptively CoW all shared blocks in this file, + * which enables us to turn off the reflink flag. Iterate all + * extents which are not prealloc/delalloc to see which ranges are + * mentioned in the refcount tree, then read those blocks into the + * pagecache, dirty them, fsync them back out, and then we can update + * the inode flag. What happens if we run out of memory? :) + */ +STATIC int +xfs_reflink_dirty_extents( + struct xfs_inode *ip, + xfs_fileoff_t fbno, + xfs_filblks_t end, + xfs_off_t isize) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_agnumber_t agno; + xfs_agblock_t agbno; + xfs_extlen_t aglen; + xfs_agblock_t rbno; + xfs_extlen_t rlen; + xfs_off_t fpos; + xfs_off_t flen; + struct xfs_bmbt_irec map[2]; + int nmaps; + int error; + + while (end - fbno > 0) { + nmaps = 1; + /* + * Look for extents in the file. Skip holes, delalloc, or + * unwritten extents; they can't be reflinked. + */ + error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); + if (error) + goto out; + if (nmaps == 0) + break; + if (map[0].br_startblock == HOLESTARTBLOCK || + map[0].br_startblock == DELAYSTARTBLOCK || + ISUNWRITTEN(&map[0])) + goto next; + + map[1] = map[0]; + while (map[1].br_blockcount) { + agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); + agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); + aglen = map[1].br_blockcount; + + error = xfs_reflink_find_shared(mp, agno, agbno, aglen, + &rbno, &rlen, true); + if (error) + goto out; + if (rbno == NULLAGBLOCK) + break; + + /* Dirty the pages */ + xfs_iunlock(ip, XFS_ILOCK_EXCL); + fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + + (rbno - agbno)); + flen = XFS_FSB_TO_B(mp, rlen); + if (fpos + flen > isize) + flen = isize - fpos; + error = iomap_file_dirty(VFS_I(ip), fpos, flen, + &xfs_iomap_ops); + xfs_ilock(ip, XFS_ILOCK_EXCL); + if (error) + goto out; + + map[1].br_blockcount -= (rbno - agbno + rlen); + map[1].br_startoff += (rbno - agbno + rlen); + map[1].br_startblock += (rbno - agbno + rlen); + } + +next: + fbno = map[0].br_startoff + map[0].br_blockcount; + } +out: + return error; +} + +/* Clear the inode reflink flag if there are no shared extents. */ +int +xfs_reflink_clear_inode_flag( + struct xfs_inode *ip, + struct xfs_trans **tpp) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t fbno; + xfs_filblks_t end; + xfs_agnumber_t agno; + xfs_agblock_t agbno; + xfs_extlen_t aglen; + xfs_agblock_t rbno; + xfs_extlen_t rlen; + struct xfs_bmbt_irec map[2]; + int nmaps; + int error = 0; + + if (!(ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) + return 0; + + fbno = 0; + end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip))); + while (end - fbno > 0) { + nmaps = 1; + /* + * Look for extents in the file. Skip holes, delalloc, or + * unwritten extents; they can't be reflinked. + */ + error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); + if (error) + return error; + if (nmaps == 0) + break; + if (map[0].br_startblock == HOLESTARTBLOCK || + map[0].br_startblock == DELAYSTARTBLOCK || + ISUNWRITTEN(&map[0])) + goto next; + + map[1] = map[0]; + while (map[1].br_blockcount) { + agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); + agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); + aglen = map[1].br_blockcount; + + error = xfs_reflink_find_shared(mp, agno, agbno, aglen, + &rbno, &rlen, false); + if (error) + return error; + /* Is there still a shared block here? */ + if (rbno != NULLAGBLOCK) + return 0; + + map[1].br_blockcount -= aglen; + map[1].br_startoff += aglen; + map[1].br_startblock += aglen; + } + +next: + fbno = map[0].br_startoff + map[0].br_blockcount; + } + + /* + * We didn't find any shared blocks so turn off the reflink flag. + * First, get rid of any leftover CoW mappings. + */ + error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF); + if (error) + return error; + + /* Clear the inode flag. */ + trace_xfs_reflink_unset_inode_flag(ip); + ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; + xfs_trans_ijoin(*tpp, ip, 0); + xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); + + return error; +} + +/* + * Clear the inode reflink flag if there are no shared extents and the size + * hasn't changed. + */ +STATIC int +xfs_reflink_try_clear_inode_flag( + struct xfs_inode *ip, + xfs_off_t old_isize) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + int error = 0; + + /* Start a rolling transaction to remove the mappings */ + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); + if (error) + return error; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + if (old_isize != i_size_read(VFS_I(ip))) + goto cancel; + + error = xfs_reflink_clear_inode_flag(ip, &tp); + if (error) + goto cancel; + + error = xfs_trans_commit(tp); + if (error) + goto out; + + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return 0; +cancel: + xfs_trans_cancel(tp); +out: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +/* + * Pre-COW all shared blocks within a given byte range of a file and turn off + * the reflink flag if we unshare all of the file's blocks. + */ +int +xfs_reflink_unshare( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t fbno; + xfs_filblks_t end; + xfs_off_t isize; + int error; + + if (!xfs_is_reflink_inode(ip)) + return 0; + + trace_xfs_reflink_unshare(ip, offset, len); + + inode_dio_wait(VFS_I(ip)); + + /* Try to CoW the selected ranges */ + xfs_ilock(ip, XFS_ILOCK_EXCL); + fbno = XFS_B_TO_FSB(mp, offset); + isize = i_size_read(VFS_I(ip)); + end = XFS_B_TO_FSB(mp, offset + len); + error = xfs_reflink_dirty_extents(ip, fbno, end, isize); + if (error) + goto out_unlock; + xfs_iunlock(ip, XFS_ILOCK_EXCL); + + /* Wait for the IO to finish */ + error = filemap_write_and_wait(VFS_I(ip)->i_mapping); + if (error) + goto out; + + /* Turn off the reflink flag if we unshared the whole file */ + if (offset == 0 && len == isize) { + error = xfs_reflink_try_clear_inode_flag(ip, isize); + if (error) + goto out; + } + + return 0; + +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); +out: + trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); + return error; +} diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h index df82b2049187..bade5a61f3b0 100644 --- a/fs/xfs/xfs_reflink.h +++ b/fs/xfs/xfs_reflink.h @@ -48,5 +48,9 @@ extern int xfs_reflink_recover_cow(struct xfs_mount *mp); extern int xfs_reflink_remap_range(struct xfs_inode *src, xfs_off_t srcoff, struct xfs_inode *dest, xfs_off_t destoff, xfs_off_t len, unsigned int flags); +extern int xfs_reflink_clear_inode_flag(struct xfs_inode *ip, + struct xfs_trans **tpp); +extern int xfs_reflink_unshare(struct xfs_inode *ip, xfs_off_t offset, + xfs_off_t len); #endif /* __XFS_REFLINK_H */ |