From 92dfe8d266eaf35a50607a0e0dcf525e1d367c80 Mon Sep 17 00:00:00 2001 From: David Chinner Date: Thu, 24 May 2007 15:22:19 +1000 Subject: [PATCH] [XFS] Make hole punching at EOF atomic. If hole punching at EOF is done as two steps (i.e. truncate then extend) the file is in a transient state between the two steps where an application can see the incorrect file size. Punching a hole to EOF needs to be treated in teh same way as all other hole punching cases so that the file size is never seen to change. SGI-PV: 962012 SGI-Modid: xfs-linux-melb:xfs-kern:28641a Signed-off-by: David Chinner Signed-off-by: Vlad Apostolov Signed-off-by: Tim Shimmin --- fs/xfs/xfs_rw.h | 14 +++++++++++--- fs/xfs/xfs_vnodeops.c | 28 ++++++++++++++++++---------- 2 files changed, 29 insertions(+), 13 deletions(-) diff --git a/fs/xfs/xfs_rw.h b/fs/xfs/xfs_rw.h index 188b296ff5..ba74000931 100644 --- a/fs/xfs/xfs_rw.h +++ b/fs/xfs/xfs_rw.h @@ -71,6 +71,12 @@ xfs_fsb_to_db_io(struct xfs_iocore *io, xfs_fsblock_t fsb) XFS_FSB_TO_DADDR((io)->io_mount, (fsb))); } +/* + * Flags for xfs_free_eofblocks + */ +#define XFS_FREE_EOF_LOCK (1<<0) +#define XFS_FREE_EOF_NOLOCK (1<<1) + /* * Prototypes for functions in xfs_rw.c. */ @@ -91,10 +97,12 @@ extern void xfs_ioerror_alert(char *func, struct xfs_mount *mp, extern int xfs_rwlock(bhv_desc_t *bdp, bhv_vrwlock_t write_lock); extern void xfs_rwunlock(bhv_desc_t *bdp, bhv_vrwlock_t write_lock); extern int xfs_setattr(bhv_desc_t *, bhv_vattr_t *vap, int flags, - cred_t *credp); + cred_t *credp); extern int xfs_change_file_space(bhv_desc_t *bdp, int cmd, xfs_flock64_t *bf, - xfs_off_t offset, cred_t *credp, int flags); + xfs_off_t offset, cred_t *credp, int flags); extern int xfs_set_dmattrs(bhv_desc_t *bdp, u_int evmask, u_int16_t state, - cred_t *credp); + cred_t *credp); +extern int xfs_free_eofblocks(struct xfs_mount *mp, struct xfs_inode *ip, + int flags); #endif /* __XFS_RW_H__ */ diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c index 70bc82f653..6420ca8df5 100644 --- a/fs/xfs/xfs_vnodeops.c +++ b/fs/xfs/xfs_vnodeops.c @@ -1201,13 +1201,15 @@ xfs_fsync( } /* - * This is called by xfs_inactive to free any blocks beyond eof, - * when the link count isn't zero. + * This is called by xfs_inactive to free any blocks beyond eof + * when the link count isn't zero and by xfs_dm_punch_hole() when + * punching a hole to EOF. */ -STATIC int -xfs_inactive_free_eofblocks( +int +xfs_free_eofblocks( xfs_mount_t *mp, - xfs_inode_t *ip) + xfs_inode_t *ip, + int flags) { xfs_trans_t *tp; int error; @@ -1216,6 +1218,7 @@ xfs_inactive_free_eofblocks( xfs_filblks_t map_len; int nimaps; xfs_bmbt_irec_t imap; + int use_iolock = (flags & XFS_FREE_EOF_LOCK); /* * Figure out if there are any blocks beyond the end @@ -1256,11 +1259,13 @@ xfs_inactive_free_eofblocks( * cache and we can't * do that within a transaction. */ - xfs_ilock(ip, XFS_IOLOCK_EXCL); + if (use_iolock) + xfs_ilock(ip, XFS_IOLOCK_EXCL); error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, ip->i_size); if (error) { - xfs_iunlock(ip, XFS_IOLOCK_EXCL); + if (use_iolock) + xfs_iunlock(ip, XFS_IOLOCK_EXCL); return error; } @@ -1297,7 +1302,8 @@ xfs_inactive_free_eofblocks( error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); } - xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL); + xfs_iunlock(ip, (use_iolock ? (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL) + : XFS_ILOCK_EXCL)); } return error; } @@ -1573,7 +1579,8 @@ xfs_release( (ip->i_df.if_flags & XFS_IFEXTENTS)) && (!(ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))) { - if ((error = xfs_inactive_free_eofblocks(mp, ip))) + error = xfs_free_eofblocks(mp, ip, XFS_FREE_EOF_LOCK); + if (error) return error; /* Update linux inode block count after free above */ vn_to_inode(vp)->i_blocks = XFS_FSB_TO_BB(mp, @@ -1654,7 +1661,8 @@ xfs_inactive( (!(ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) || (ip->i_delayed_blks != 0)))) { - if ((error = xfs_inactive_free_eofblocks(mp, ip))) + error = xfs_free_eofblocks(mp, ip, XFS_FREE_EOF_LOCK); + if (error) return VN_INACTIVE_CACHE; /* Update linux inode block count after free above */ vn_to_inode(vp)->i_blocks = XFS_FSB_TO_BB(mp, -- 2.39.5