From def6b3ba56b637d58126ef67fc19bab57945fcc4 Mon Sep 17 00:00:00 2001 From: Lachlan McIlroy Date: Thu, 23 Apr 2009 22:18:00 -0400 Subject: xfs_file_last_byte() needs to acquire ilock We had some systems crash with this stack: [] ia64_leave_kernel+0x0/0x280 [] xfs_bmbt_get_startoff+0x0/0x20 [xfs] [] xfs_bmap_last_offset+0x210/0x280 [xfs] [] xfs_file_last_byte+0x70/0x1a0 [xfs] [] xfs_itruncate_start+0xc0/0x1a0 [xfs] [] xfs_inactive_free_eofblocks+0x290/0x460 [xfs] [] xfs_release+0x1b0/0x240 [xfs] [] xfs_file_release+0x70/0xa0 [xfs] [] __fput+0x1a0/0x420 [] fput+0x40/0x60 The problem here is that xfs_file_last_byte() does not acquire the inode lock and can therefore race with another thread that is modifying the extext list. While xfs_bmap_last_offset() is trying to lookup what was the last extent some extents were merged and the extent list shrunk so the index we lookup is now beyond the end of the extent list and potentially in a freed buffer. Signed-off-by: Lachlan McIlroy Reviewed-by: Christoph Hellwig Reviewed-by: Felix Blyakher Signed-off-by: Felix Blyakher --- fs/xfs/xfs_inode.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index e7ae08d1df4..123b20c8cbf 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -1258,8 +1258,10 @@ xfs_file_last_byte( * necessary. */ if (ip->i_df.if_flags & XFS_IFEXTENTS) { + xfs_ilock(ip, XFS_ILOCK_SHARED); error = xfs_bmap_last_offset(NULL, ip, &last_block, XFS_DATA_FORK); + xfs_iunlock(ip, XFS_ILOCK_SHARED); if (error) { last_block = 0; } -- cgit v1.2.3 From b9ec9068d79e039507a247ebc5bc9c0ce53654ce Mon Sep 17 00:00:00 2001 From: Olaf Weber Date: Fri, 17 Apr 2009 16:12:45 -0500 Subject: xfs: add more checks to superblock validation There had been reports where xfs filesystem was randomly corrupted with fsfuzzer, and xfs failed to handle it gracefully. This patch fixes couple of reported problem by providing additional checks in the superblock validation routine. Signed-off-by: Olaf Weber Reviewed-by: Josef 'Jeff' Sipek Reviewed-by: Christoph Hellwig Signed-off-by: Felix Blyakher --- fs/xfs/xfs_mount.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs') diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index b101990df02..65a99725d0c 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -291,14 +291,17 @@ xfs_mount_validate_sb( sbp->sb_sectsize > XFS_MAX_SECTORSIZE || sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG || sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG || + sbp->sb_sectsize != (1 << sbp->sb_sectlog) || sbp->sb_blocksize < XFS_MIN_BLOCKSIZE || sbp->sb_blocksize > XFS_MAX_BLOCKSIZE || sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG || sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG || + sbp->sb_blocksize != (1 << sbp->sb_blocklog) || sbp->sb_inodesize < XFS_DINODE_MIN_SIZE || sbp->sb_inodesize > XFS_DINODE_MAX_SIZE || sbp->sb_inodelog < XFS_DINODE_MIN_LOG || sbp->sb_inodelog > XFS_DINODE_MAX_LOG || + sbp->sb_inodesize != (1 << sbp->sb_inodelog) || (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) || (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) || (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) || -- cgit v1.2.3 From 5f79ed685fc6122018c4b5826e2e5bdb7bc6f109 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 29 Apr 2009 10:50:48 -0400 Subject: xfs: a couple getbmap cleanups - reshuffle various conditionals for data vs attr fork to make the code more readable - do fine-grainded goto-based error handling - exit early from conditionals instead of keeping a long else branch around - allow kmem_alloc to fail Signed-off-by: Christoph Hellwig Reviewed-by: Eric Sandeen Reviewed-by: Felix Blyakher Signed-off-by: Felix Blyakher --- fs/xfs/xfs_bmap.c | 162 ++++++++++++++++++++++++++---------------------------- 1 file changed, 79 insertions(+), 83 deletions(-) (limited to 'fs') diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 3a6ed426327..abe42448b1c 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -5880,7 +5880,7 @@ xfs_getbmap( void *arg) /* formatter arg */ { __int64_t bmvend; /* last block requested */ - int error; /* return value */ + int error = 0; /* return value */ __int64_t fixlen; /* length for -1 case */ int i; /* extent number */ int lock; /* lock state */ @@ -5899,30 +5899,8 @@ xfs_getbmap( mp = ip->i_mount; iflags = bmv->bmv_iflags; - whichfork = iflags & BMV_IF_ATTRFORK ? XFS_ATTR_FORK : XFS_DATA_FORK; - /* If the BMV_IF_NO_DMAPI_READ interface bit specified, do not - * generate a DMAPI read event. Otherwise, if the DM_EVENT_READ - * bit is set for the file, generate a read event in order - * that the DMAPI application may do its thing before we return - * the extents. Usually this means restoring user file data to - * regions of the file that look like holes. - * - * The "old behavior" (from XFS_IOC_GETBMAP) is to not specify - * BMV_IF_NO_DMAPI_READ so that read events are generated. - * If this were not true, callers of ioctl( XFS_IOC_GETBMAP ) - * could misinterpret holes in a DMAPI file as true holes, - * when in fact they may represent offline user data. - */ - if ((iflags & BMV_IF_NO_DMAPI_READ) == 0 && - DM_EVENT_ENABLED(ip, DM_EVENT_READ) && - whichfork == XFS_DATA_FORK) { - error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, 0, 0, 0, NULL); - if (error) - return XFS_ERROR(error); - } - if (whichfork == XFS_ATTR_FORK) { if (XFS_IFORK_Q(ip)) { if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS && @@ -5936,11 +5914,37 @@ xfs_getbmap( ip->i_mount); return XFS_ERROR(EFSCORRUPTED); } - } else if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS && - ip->i_d.di_format != XFS_DINODE_FMT_BTREE && - ip->i_d.di_format != XFS_DINODE_FMT_LOCAL) - return XFS_ERROR(EINVAL); - if (whichfork == XFS_DATA_FORK) { + + prealloced = 0; + fixlen = 1LL << 32; + } else { + /* + * If the BMV_IF_NO_DMAPI_READ interface bit specified, do + * not generate a DMAPI read event. Otherwise, if the + * DM_EVENT_READ bit is set for the file, generate a read + * event in order that the DMAPI application may do its thing + * before we return the extents. Usually this means restoring + * user file data to regions of the file that look like holes. + * + * The "old behavior" (from XFS_IOC_GETBMAP) is to not specify + * BMV_IF_NO_DMAPI_READ so that read events are generated. + * If this were not true, callers of ioctl(XFS_IOC_GETBMAP) + * could misinterpret holes in a DMAPI file as true holes, + * when in fact they may represent offline user data. + */ + if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && + !(iflags & BMV_IF_NO_DMAPI_READ)) { + error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, + 0, 0, 0, NULL); + if (error) + return XFS_ERROR(error); + } + + if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS && + ip->i_d.di_format != XFS_DINODE_FMT_BTREE && + ip->i_d.di_format != XFS_DINODE_FMT_LOCAL) + return XFS_ERROR(EINVAL); + if (xfs_get_extsz_hint(ip) || ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){ prealloced = 1; @@ -5949,42 +5953,34 @@ xfs_getbmap( prealloced = 0; fixlen = ip->i_size; } - } else { - prealloced = 0; - fixlen = 1LL << 32; } if (bmv->bmv_length == -1) { fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen)); - bmv->bmv_length = MAX( (__int64_t)(fixlen - bmv->bmv_offset), - (__int64_t)0); - } else if (bmv->bmv_length < 0) - return XFS_ERROR(EINVAL); - if (bmv->bmv_length == 0) { + bmv->bmv_length = + max_t(__int64_t, fixlen - bmv->bmv_offset, 0); + } else if (bmv->bmv_length == 0) { bmv->bmv_entries = 0; return 0; + } else if (bmv->bmv_length < 0) { + return XFS_ERROR(EINVAL); } + nex = bmv->bmv_count - 1; if (nex <= 0) return XFS_ERROR(EINVAL); bmvend = bmv->bmv_offset + bmv->bmv_length; xfs_ilock(ip, XFS_IOLOCK_SHARED); - - if (((iflags & BMV_IF_DELALLOC) == 0) && - (whichfork == XFS_DATA_FORK) && - (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size)) { - /* xfs_fsize_t last_byte = xfs_file_last_byte(ip); */ - error = xfs_flush_pages(ip, (xfs_off_t)0, - -1, 0, FI_REMAPF); - if (error) { - xfs_iunlock(ip, XFS_IOLOCK_SHARED); - return error; + if (whichfork == XFS_DATA_FORK && !(iflags & BMV_IF_DELALLOC)) { + if (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size) { + error = xfs_flush_pages(ip, 0, -1, 0, FI_REMAPF); + if (error) + goto out_unlock_iolock; } - } - ASSERT(whichfork == XFS_ATTR_FORK || (iflags & BMV_IF_DELALLOC) || - ip->i_delayed_blks == 0); + ASSERT(ip->i_delayed_blks == 0); + } lock = xfs_ilock_map_shared(ip); @@ -5995,23 +5991,25 @@ xfs_getbmap( if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1) nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1; - bmapi_flags = xfs_bmapi_aflag(whichfork) | - ((iflags & BMV_IF_PREALLOC) ? 0 : XFS_BMAPI_IGSTATE); + bmapi_flags = xfs_bmapi_aflag(whichfork); + if (!(iflags & BMV_IF_PREALLOC)) + bmapi_flags |= XFS_BMAPI_IGSTATE; /* * Allocate enough space to handle "subnex" maps at a time. */ + error = ENOMEM; subnex = 16; - map = kmem_alloc(subnex * sizeof(*map), KM_SLEEP); + map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL); + if (!map) + goto out_unlock_ilock; bmv->bmv_entries = 0; - if ((XFS_IFORK_NEXTENTS(ip, whichfork) == 0)) { - if (((iflags & BMV_IF_DELALLOC) == 0) || - whichfork == XFS_ATTR_FORK) { - error = 0; - goto unlock_and_return; - } + if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 && + (whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) { + error = 0; + goto out_free_map; } nexleft = nex; @@ -6023,10 +6021,12 @@ xfs_getbmap( bmapi_flags, NULL, 0, map, &nmap, NULL, NULL); if (error) - goto unlock_and_return; + goto out_free_map; ASSERT(nmap <= subnex); for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) { + int full = 0; /* user array is full */ + out.bmv_oflags = 0; if (map[i].br_state == XFS_EXT_UNWRITTEN) out.bmv_oflags |= BMV_OF_PREALLOC; @@ -6041,36 +6041,32 @@ xfs_getbmap( whichfork == XFS_ATTR_FORK) { /* came to the end of attribute fork */ out.bmv_oflags |= BMV_OF_LAST; - goto unlock_and_return; - } else { - int full = 0; /* user array is full */ - - if (!xfs_getbmapx_fix_eof_hole(ip, &out, - prealloced, bmvend, - map[i].br_startblock)) { - goto unlock_and_return; - } - - /* format results & advance arg */ - error = formatter(&arg, &out, &full); - if (error || full) - goto unlock_and_return; - nexleft--; - bmv->bmv_offset = - out.bmv_offset + out.bmv_length; - bmv->bmv_length = MAX((__int64_t)0, - (__int64_t)(bmvend - bmv->bmv_offset)); - bmv->bmv_entries++; + goto out_free_map; } + + if (!xfs_getbmapx_fix_eof_hole(ip, &out, prealloced, + bmvend, map[i].br_startblock)) + goto out_free_map; + + /* format results & advance arg */ + error = formatter(&arg, &out, &full); + if (error || full) + goto out_free_map; + nexleft--; + bmv->bmv_offset = + out.bmv_offset + out.bmv_length; + bmv->bmv_length = + max_t(__int64_t, 0, bmvend - bmv->bmv_offset); + bmv->bmv_entries++; } } while (nmap && nexleft && bmv->bmv_length); -unlock_and_return: + out_free_map: + kmem_free(map); + out_unlock_ilock: xfs_iunlock_map_shared(ip, lock); + out_unlock_iolock: xfs_iunlock(ip, XFS_IOLOCK_SHARED); - - kmem_free(map); - return error; } -- cgit v1.2.3 From 28e211700a81b0a934b6c7a4b8e7dda843634d2f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 24 Feb 2009 08:39:02 -0500 Subject: xfs: fix getbmap vs mmap deadlock xfs_getbmap (or rather the formatters called by it) copy out the getbmap structures under the ilock, which can deadlock against mmap. This has been reported via bugzilla a while ago (#717) and has recently also shown up via lockdep. So allocate a temporary buffer to format the kernel getbmap structures into and then copy them out after dropping the locks. A little problem with this is that we limit the number of extents we can copy out by the maximum allocation size, but I see no real way around that. Signed-off-by: Christoph Hellwig Reviewed-by: Eric Sandeen Reviewed-by: Felix Blyakher Signed-off-by: Felix Blyakher --- fs/xfs/xfs_bmap.c | 52 +++++++++++++++++++++++++++++++++++----------------- 1 file changed, 35 insertions(+), 17 deletions(-) (limited to 'fs') diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index abe42448b1c..ca7c6005a48 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -5890,12 +5890,13 @@ xfs_getbmap( int nexleft; /* # of user extents left */ int subnex; /* # of bmapi's can do */ int nmap; /* number of map entries */ - struct getbmapx out; /* output structure */ + struct getbmapx *out; /* output structure */ int whichfork; /* data or attr fork */ int prealloced; /* this is a file with * preallocated data space */ int iflags; /* interface flags */ int bmapi_flags; /* flags for xfs_bmapi */ + int cur_ext = 0; mp = ip->i_mount; iflags = bmv->bmv_iflags; @@ -5971,6 +5972,13 @@ xfs_getbmap( return XFS_ERROR(EINVAL); bmvend = bmv->bmv_offset + bmv->bmv_length; + + if (bmv->bmv_count > ULONG_MAX / sizeof(struct getbmapx)) + return XFS_ERROR(ENOMEM); + out = kmem_zalloc(bmv->bmv_count * sizeof(struct getbmapx), KM_MAYFAIL); + if (!out) + return XFS_ERROR(ENOMEM); + xfs_ilock(ip, XFS_IOLOCK_SHARED); if (whichfork == XFS_DATA_FORK && !(iflags & BMV_IF_DELALLOC)) { if (ip->i_delayed_blks || ip->i_size > ip->i_d.di_size) { @@ -6025,39 +6033,39 @@ xfs_getbmap( ASSERT(nmap <= subnex); for (i = 0; i < nmap && nexleft && bmv->bmv_length; i++) { - int full = 0; /* user array is full */ - - out.bmv_oflags = 0; + out[cur_ext].bmv_oflags = 0; if (map[i].br_state == XFS_EXT_UNWRITTEN) - out.bmv_oflags |= BMV_OF_PREALLOC; + out[cur_ext].bmv_oflags |= BMV_OF_PREALLOC; else if (map[i].br_startblock == DELAYSTARTBLOCK) - out.bmv_oflags |= BMV_OF_DELALLOC; - out.bmv_offset = XFS_FSB_TO_BB(mp, map[i].br_startoff); - out.bmv_length = XFS_FSB_TO_BB(mp, map[i].br_blockcount); - out.bmv_unused1 = out.bmv_unused2 = 0; + out[cur_ext].bmv_oflags |= BMV_OF_DELALLOC; + out[cur_ext].bmv_offset = + XFS_FSB_TO_BB(mp, map[i].br_startoff); + out[cur_ext].bmv_length = + XFS_FSB_TO_BB(mp, map[i].br_blockcount); + out[cur_ext].bmv_unused1 = 0; + out[cur_ext].bmv_unused2 = 0; ASSERT(((iflags & BMV_IF_DELALLOC) != 0) || (map[i].br_startblock != DELAYSTARTBLOCK)); if (map[i].br_startblock == HOLESTARTBLOCK && whichfork == XFS_ATTR_FORK) { /* came to the end of attribute fork */ - out.bmv_oflags |= BMV_OF_LAST; + out[cur_ext].bmv_oflags |= BMV_OF_LAST; goto out_free_map; } - if (!xfs_getbmapx_fix_eof_hole(ip, &out, prealloced, - bmvend, map[i].br_startblock)) + if (!xfs_getbmapx_fix_eof_hole(ip, &out[cur_ext], + prealloced, bmvend, + map[i].br_startblock)) goto out_free_map; - /* format results & advance arg */ - error = formatter(&arg, &out, &full); - if (error || full) - goto out_free_map; nexleft--; bmv->bmv_offset = - out.bmv_offset + out.bmv_length; + out[cur_ext].bmv_offset + + out[cur_ext].bmv_length; bmv->bmv_length = max_t(__int64_t, 0, bmvend - bmv->bmv_offset); bmv->bmv_entries++; + cur_ext++; } } while (nmap && nexleft && bmv->bmv_length); @@ -6067,6 +6075,16 @@ xfs_getbmap( xfs_iunlock_map_shared(ip, lock); out_unlock_iolock: xfs_iunlock(ip, XFS_IOLOCK_SHARED); + + for (i = 0; i < cur_ext; i++) { + int full = 0; /* user array is full */ + + /* format results & advance arg */ + error = formatter(&arg, &out[i], &full); + if (error || full) + break; + } + return error; } -- cgit v1.2.3