| Message ID | 20190624055253.31183-7-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/12] list.h: add a list_pop helper | expand |
On Mon, Jun 24, 2019 at 07:52:47AM +0200, Christoph Hellwig wrote: > Instead of a magic flag for xfs_trans_alloc, just ensure all callers > that can't relclaim through the file system use memalloc_nofs_save to > set the per-task nofs flag. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Hmm this finally fixes up the mess I left where COW fork cleanup sometimes needs nofs and other times doesn't... :) > --- > fs/xfs/libxfs/xfs_shared.h | 1 - > fs/xfs/xfs_aops.c | 12 +++++++++--- > fs/xfs/xfs_file.c | 12 +++++++++--- > fs/xfs/xfs_iomap.c | 2 +- > fs/xfs/xfs_reflink.c | 4 ++-- > fs/xfs/xfs_trans.c | 4 +--- > 6 files changed, 22 insertions(+), 13 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h > index 4e909791aeac..1f2b5a0c71b4 100644 > --- a/fs/xfs/libxfs/xfs_shared.h > +++ b/fs/xfs/libxfs/xfs_shared.h > @@ -65,7 +65,6 @@ void xfs_log_get_max_trans_res(struct xfs_mount *mp, > #define XFS_TRANS_DQ_DIRTY 0x10 /* at least one dquot in trx dirty */ > #define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */ > #define XFS_TRANS_NO_WRITECOUNT 0x40 /* do not elevate SB writecount */ > -#define XFS_TRANS_NOFS 0x80 /* pass KM_NOFS to kmem_alloc */ > /* > * LOWMODE is used by the allocator to activate the lowspace algorithm - when > * free space is running low the extent allocator may choose to allocate an > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c > index 93a760f13017..633baaaff7ae 100644 > --- a/fs/xfs/xfs_aops.c > +++ b/fs/xfs/xfs_aops.c > @@ -138,8 +138,7 @@ xfs_setfilesize_trans_alloc( > struct xfs_trans *tp; > int error; > > - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, > - XFS_TRANS_NOFS, &tp); > + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp); > if (error) > return error; > > @@ -236,6 +235,7 @@ STATIC void > xfs_end_ioend( > struct xfs_ioend *ioend) > { > + unsigned int nofs_flag = memalloc_nofs_save(); > struct list_head ioend_list; > struct xfs_inode *ip = XFS_I(ioend->io_inode); > xfs_off_t offset = ioend->io_offset; > @@ -282,6 +282,8 @@ xfs_end_ioend( > list_del_init(&ioend->io_list); > xfs_destroy_ioend(ioend, error); > } > + > + memalloc_nofs_restore(nofs_flag); > } > > /* > @@ -663,8 +665,12 @@ xfs_submit_ioend( > (ioend->io_fork == XFS_COW_FORK || > ioend->io_type != IOMAP_UNWRITTEN) && > xfs_ioend_is_append(ioend) && > - !ioend->io_append_trans) > + !ioend->io_append_trans) { > + unsigned nofs_flag = memalloc_nofs_save(); unsigned int? Seeing as you use that everywhere else... --D > + > status = xfs_setfilesize_trans_alloc(ioend); > + memalloc_nofs_restore(nofs_flag); > + } > > ioend->io_bio->bi_private = ioend; > ioend->io_bio->bi_end_io = xfs_end_bio; > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 916a35cae5e9..f2d806ef8f06 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -379,6 +379,7 @@ xfs_dio_write_end_io( > struct inode *inode = file_inode(iocb->ki_filp); > struct xfs_inode *ip = XFS_I(inode); > loff_t offset = iocb->ki_pos; > + unsigned int nofs_flag; > int error = 0; > > trace_xfs_end_io_direct_write(ip, offset, size); > @@ -395,10 +396,11 @@ xfs_dio_write_end_io( > */ > XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size); > > + nofs_flag = memalloc_nofs_save(); > if (flags & IOMAP_DIO_COW) { > error = xfs_reflink_end_cow(ip, offset, size); > if (error) > - return error; > + goto out; > } > > /* > @@ -407,8 +409,10 @@ xfs_dio_write_end_io( > * earlier allows a racing dio read to find unwritten extents before > * they are converted. > */ > - if (flags & IOMAP_DIO_UNWRITTEN) > - return xfs_iomap_write_unwritten(ip, offset, size, true); > + if (flags & IOMAP_DIO_UNWRITTEN) { > + error = xfs_iomap_write_unwritten(ip, offset, size, true); > + goto out; > + } > > /* > * We need to update the in-core inode size here so that we don't end up > @@ -430,6 +434,8 @@ xfs_dio_write_end_io( > spin_unlock(&ip->i_flags_lock); > } > > +out: > + memalloc_nofs_restore(nofs_flag); > return error; > } > > diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c > index 6b29452bfba0..461ea023b910 100644 > --- a/fs/xfs/xfs_iomap.c > +++ b/fs/xfs/xfs_iomap.c > @@ -782,7 +782,7 @@ xfs_iomap_write_unwritten( > * complete here and might deadlock on the iolock. > */ > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, > - XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); > + XFS_TRANS_RESERVE, &tp); > if (error) > return error; > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 680ae7662a78..0b23c2b29609 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -572,7 +572,7 @@ xfs_reflink_cancel_cow_range( > > /* Start a rolling transaction to remove the mappings */ > error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, > - 0, 0, XFS_TRANS_NOFS, &tp); > + 0, 0, 0, &tp); > if (error) > goto out; > > @@ -631,7 +631,7 @@ xfs_reflink_end_cow_extent( > > resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, > - XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); > + XFS_TRANS_RESERVE, &tp); > if (error) > return error; > > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index 0746b329a937..21228d7455af 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -264,9 +264,7 @@ xfs_trans_alloc( > * GFP_NOFS allocation context so that we avoid lockdep false positives > * by doing GFP_KERNEL allocations inside sb_start_intwrite(). > */ > - tp = kmem_zone_zalloc(xfs_trans_zone, > - (flags & XFS_TRANS_NOFS) ? KM_NOFS : KM_SLEEP); > - > + tp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP); > if (!(flags & XFS_TRANS_NO_WRITECOUNT)) > sb_start_intwrite(mp->m_super); > > -- > 2.20.1 >
On Mon, Jun 24, 2019 at 07:52:47AM +0200, Christoph Hellwig wrote: > Instead of a magic flag for xfs_trans_alloc, just ensure all callers > that can't relclaim through the file system use memalloc_nofs_save to > set the per-task nofs flag. I'm thinking that it would be a good idea to add comments to explain exactly what the memalloc_nofs_save/restore() are protecting where they are used. Right now the XFS_TRANS_NOFS flag is largely undocumented, so a reader is left guessing as to why the flag is necessary and what contexts it may apply to. Hence I think we should fix that while we are changing over to a different GFP_NOFS allocation context mechanism.... Cheers, Dave.
On Tue, Jun 25, 2019 at 08:59:04AM +1000, Dave Chinner wrote: > On Mon, Jun 24, 2019 at 07:52:47AM +0200, Christoph Hellwig wrote: > > Instead of a magic flag for xfs_trans_alloc, just ensure all callers > > that can't relclaim through the file system use memalloc_nofs_save to > > set the per-task nofs flag. > > I'm thinking that it would be a good idea to add comments to explain > exactly what the memalloc_nofs_save/restore() are protecting where > they are used. Right now the XFS_TRANS_NOFS flag is largely > undocumented, so a reader is left guessing as to why the flag is > necessary and what contexts it may apply to. Hence I think we should > fix that while we are changing over to a different GFP_NOFS > allocation context mechanism.... Sure.
diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h index 4e909791aeac..1f2b5a0c71b4 100644 --- a/fs/xfs/libxfs/xfs_shared.h +++ b/fs/xfs/libxfs/xfs_shared.h @@ -65,7 +65,6 @@ void xfs_log_get_max_trans_res(struct xfs_mount *mp, #define XFS_TRANS_DQ_DIRTY 0x10 /* at least one dquot in trx dirty */ #define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */ #define XFS_TRANS_NO_WRITECOUNT 0x40 /* do not elevate SB writecount */ -#define XFS_TRANS_NOFS 0x80 /* pass KM_NOFS to kmem_alloc */ /* * LOWMODE is used by the allocator to activate the lowspace algorithm - when * free space is running low the extent allocator may choose to allocate an diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 93a760f13017..633baaaff7ae 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -138,8 +138,7 @@ xfs_setfilesize_trans_alloc( struct xfs_trans *tp; int error; - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, - XFS_TRANS_NOFS, &tp); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp); if (error) return error; @@ -236,6 +235,7 @@ STATIC void xfs_end_ioend( struct xfs_ioend *ioend) { + unsigned int nofs_flag = memalloc_nofs_save(); struct list_head ioend_list; struct xfs_inode *ip = XFS_I(ioend->io_inode); xfs_off_t offset = ioend->io_offset; @@ -282,6 +282,8 @@ xfs_end_ioend( list_del_init(&ioend->io_list); xfs_destroy_ioend(ioend, error); } + + memalloc_nofs_restore(nofs_flag); } /* @@ -663,8 +665,12 @@ xfs_submit_ioend( (ioend->io_fork == XFS_COW_FORK || ioend->io_type != IOMAP_UNWRITTEN) && xfs_ioend_is_append(ioend) && - !ioend->io_append_trans) + !ioend->io_append_trans) { + unsigned nofs_flag = memalloc_nofs_save(); + status = xfs_setfilesize_trans_alloc(ioend); + memalloc_nofs_restore(nofs_flag); + } ioend->io_bio->bi_private = ioend; ioend->io_bio->bi_end_io = xfs_end_bio; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 916a35cae5e9..f2d806ef8f06 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -379,6 +379,7 @@ xfs_dio_write_end_io( struct inode *inode = file_inode(iocb->ki_filp); struct xfs_inode *ip = XFS_I(inode); loff_t offset = iocb->ki_pos; + unsigned int nofs_flag; int error = 0; trace_xfs_end_io_direct_write(ip, offset, size); @@ -395,10 +396,11 @@ xfs_dio_write_end_io( */ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size); + nofs_flag = memalloc_nofs_save(); if (flags & IOMAP_DIO_COW) { error = xfs_reflink_end_cow(ip, offset, size); if (error) - return error; + goto out; } /* @@ -407,8 +409,10 @@ xfs_dio_write_end_io( * earlier allows a racing dio read to find unwritten extents before * they are converted. */ - if (flags & IOMAP_DIO_UNWRITTEN) - return xfs_iomap_write_unwritten(ip, offset, size, true); + if (flags & IOMAP_DIO_UNWRITTEN) { + error = xfs_iomap_write_unwritten(ip, offset, size, true); + goto out; + } /* * We need to update the in-core inode size here so that we don't end up @@ -430,6 +434,8 @@ xfs_dio_write_end_io( spin_unlock(&ip->i_flags_lock); } +out: + memalloc_nofs_restore(nofs_flag); return error; } diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 6b29452bfba0..461ea023b910 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -782,7 +782,7 @@ xfs_iomap_write_unwritten( * complete here and might deadlock on the iolock. */ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, - XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); + XFS_TRANS_RESERVE, &tp); if (error) return error; diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 680ae7662a78..0b23c2b29609 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -572,7 +572,7 @@ xfs_reflink_cancel_cow_range( /* Start a rolling transaction to remove the mappings */ error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - 0, 0, XFS_TRANS_NOFS, &tp); + 0, 0, 0, &tp); if (error) goto out; @@ -631,7 +631,7 @@ xfs_reflink_end_cow_extent( resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, - XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); + XFS_TRANS_RESERVE, &tp); if (error) return error; diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 0746b329a937..21228d7455af 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -264,9 +264,7 @@ xfs_trans_alloc( * GFP_NOFS allocation context so that we avoid lockdep false positives * by doing GFP_KERNEL allocations inside sb_start_intwrite(). */ - tp = kmem_zone_zalloc(xfs_trans_zone, - (flags & XFS_TRANS_NOFS) ? KM_NOFS : KM_SLEEP); - + tp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP); if (!(flags & XFS_TRANS_NO_WRITECOUNT)) sb_start_intwrite(mp->m_super);
Instead of a magic flag for xfs_trans_alloc, just ensure all callers that can't relclaim through the file system use memalloc_nofs_save to set the per-task nofs flag. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/libxfs/xfs_shared.h | 1 - fs/xfs/xfs_aops.c | 12 +++++++++--- fs/xfs/xfs_file.c | 12 +++++++++--- fs/xfs/xfs_iomap.c | 2 +- fs/xfs/xfs_reflink.c | 4 ++-- fs/xfs/xfs_trans.c | 4 +--- 6 files changed, 22 insertions(+), 13 deletions(-)