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[XFS] Fix speculative allocation beyond eof

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Speculative allocation beyond eof doesn't work properly.  It was
broken some time ago after a code cleanup that moved what is now
xfs_iomap_eof_align_last_fsb() and xfs_iomap_eof_want_preallocate()
out of xfs_iomap_write_delay() into separate functions.  The code
used to use the current file size in various checks but got changed
to be max(file_size, i_new_size).  Since i_new_size is the result
of 'offset + count' then in xfs_iomap_eof_want_preallocate() the
check for '(offset + count) <= isize' will always be true.

ie if 'offset + count' is > ip->i_size then isize will be i_new_size
and equal to 'offset + count'.

This change fixes all the places that used to use the current file
size.

Reviewed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
This commit is contained in:
Lachlan McIlroy 2008-12-22 17:56:49 +11:00
parent 4fdc778179
commit 9f6c92b9cc
1 changed files with 7 additions and 21 deletions
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28
fs/xfs/xfs_iomap.c
View File

@ -290,7 +290,6 @@ STATIC int
xfs_iomap_eof_align_last_fsb(
xfs_mount_t *mp,
xfs_inode_t *ip,
xfs_fsize_t isize,
xfs_extlen_t extsize,
xfs_fileoff_t *last_fsb)
{
@ -306,14 +305,14 @@ xfs_iomap_eof_align_last_fsb(
* stripe width and we are allocating past the allocation eof.
*/
else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
(isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
(ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth)))
new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
/*
* Roundup the allocation request to a stripe unit (m_dalign) boundary
* if the file size is >= stripe unit size, and we are allocating past
* the allocation eof.
*/
else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign)))
new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
/*
@ -403,7 +402,6 @@ xfs_iomap_write_direct(
xfs_filblks_t count_fsb, resaligned;
xfs_fsblock_t firstfsb;
xfs_extlen_t extsz, temp;
xfs_fsize_t isize;
int nimaps;
int bmapi_flag;
int quota_flag;
@ -426,15 +424,10 @@ xfs_iomap_write_direct(
rt = XFS_IS_REALTIME_INODE(ip);
extsz = xfs_get_extsz_hint(ip);
isize = ip->i_size;
if (ip->i_new_size > isize)
isize = ip->i_new_size;
offset_fsb = XFS_B_TO_FSBT(mp, offset);
last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
if ((offset + count) > isize) {
error = xfs_iomap_eof_align_last_fsb(mp, ip, isize, extsz,
&last_fsb);
if ((offset + count) > ip->i_size) {
error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
if (error)
goto error_out;
} else {
@ -559,7 +552,6 @@ STATIC int
xfs_iomap_eof_want_preallocate(
xfs_mount_t *mp,
xfs_inode_t *ip,
xfs_fsize_t isize,
xfs_off_t offset,
size_t count,
int ioflag,
@ -573,7 +565,7 @@ xfs_iomap_eof_want_preallocate(
int n, error, imaps;
*prealloc = 0;
if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
if ((ioflag & BMAPI_SYNC) || (offset + count) <= ip->i_size)
return 0;
/*
@ -617,7 +609,6 @@ xfs_iomap_write_delay(
xfs_fileoff_t ioalign;
xfs_fsblock_t firstblock;
xfs_extlen_t extsz;
xfs_fsize_t isize;
int nimaps;
xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
int prealloc, fsynced = 0;
@ -637,11 +628,7 @@ xfs_iomap_write_delay(
offset_fsb = XFS_B_TO_FSBT(mp, offset);
retry:
isize = ip->i_size;
if (ip->i_new_size > isize)
isize = ip->i_new_size;
error = xfs_iomap_eof_want_preallocate(mp, ip, isize, offset, count,
error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
if (error)
return error;
@ -655,8 +642,7 @@ retry:
}
if (prealloc || extsz) {
error = xfs_iomap_eof_align_last_fsb(mp, ip, isize, extsz,
&last_fsb);
error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
if (error)
return error;
}