[PATCH 3/6] xfs: Convert to memalloc_nofs_save

From: Matthew Wilcox (Oracle)
Date: Thu Jun 25 2020 - 07:32:28 EST


Instead of using custom macros to set/restore PF_MEMALLOC_NOFS, use
memalloc_nofs_save() like the rest of the kernel.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/xfs/kmem.c | 2 +-
fs/xfs/xfs_aops.c | 4 ++--
fs/xfs/xfs_buf.c | 2 +-
fs/xfs/xfs_linux.h | 6 ------
fs/xfs/xfs_trans.c | 14 +++++++-------
fs/xfs/xfs_trans.h | 2 +-
6 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index f1366475c389..c2d237159bfc 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c
@@ -35,7 +35,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags)
* __vmalloc() will allocate data pages and auxiliary structures (e.g.
* pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context here. Hence
* we need to tell memory reclaim that we are in such a context via
- * PF_MEMALLOC_NOFS to prevent memory reclaim re-entering the filesystem here
+ * memalloc_nofs to prevent memory reclaim re-entering the filesystem here
* and potentially deadlocking.
*/
static void *
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index b35611882ff9..e3a4806e519d 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -62,7 +62,7 @@ xfs_setfilesize_trans_alloc(
* We hand off the transaction to the completion thread now, so
* clear the flag here.
*/
- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);
return 0;
}

@@ -125,7 +125,7 @@ xfs_setfilesize_ioend(
* thus we need to mark ourselves as being in a transaction manually.
* Similarly for freeze protection.
*/
- current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ tp->t_memalloc = memalloc_nofs_save();
__sb_writers_acquired(VFS_I(ip)->i_sb, SB_FREEZE_FS);

/* we abort the update if there was an IO error */
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 20b748f7e186..b2c3d01c690b 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -470,7 +470,7 @@ _xfs_buf_map_pages(
* vm_map_ram() will allocate auxiliary structures (e.g.
* pagetables) with GFP_KERNEL, yet we are likely to be under
* GFP_NOFS context here. Hence we need to tell memory reclaim
- * that we are in such a context via PF_MEMALLOC_NOFS to prevent
+ * that we are in such a context via memalloc_nofs to prevent
* memory reclaim re-entering the filesystem here and
* potentially deadlocking.
*/
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 9f70d2f68e05..e1daf242a53b 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -104,12 +104,6 @@ typedef __u32 xfs_nlink_t;
#define current_cpu() (raw_smp_processor_id())
#define current_pid() (current->pid)
#define current_test_flags(f) (current->flags & (f))
-#define current_set_flags_nested(sp, f) \
- (*(sp) = current->flags, current->flags |= (f))
-#define current_clear_flags_nested(sp, f) \
- (*(sp) = current->flags, current->flags &= ~(f))
-#define current_restore_flags_nested(sp, f) \
- (current->flags = ((current->flags & ~(f)) | (*(sp) & (f))))

#define NBBY 8 /* number of bits per byte */

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 3c94e5ff4316..4ef1a0ff0a11 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -118,7 +118,7 @@ xfs_trans_dup(

ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
tp->t_rtx_res = tp->t_rtx_res_used;
- ntp->t_pflags = tp->t_pflags;
+ ntp->t_memalloc = tp->t_memalloc;

/* move deferred ops over to the new tp */
xfs_defer_move(ntp, tp);
@@ -153,7 +153,7 @@ xfs_trans_reserve(
bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;

/* Mark this thread as being in a transaction */
- current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ tp->t_memalloc = memalloc_nofs_save();

/*
* Attempt to reserve the needed disk blocks by decrementing
@@ -163,7 +163,7 @@ xfs_trans_reserve(
if (blocks > 0) {
error = xfs_mod_fdblocks(mp, -((int64_t)blocks), rsvd);
if (error != 0) {
- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);
return -ENOSPC;
}
tp->t_blk_res += blocks;
@@ -240,7 +240,7 @@ xfs_trans_reserve(
tp->t_blk_res = 0;
}

- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);

return error;
}
@@ -861,7 +861,7 @@ __xfs_trans_commit(

xfs_log_commit_cil(mp, tp, &commit_lsn, regrant);

- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);
xfs_trans_free(tp);

/*
@@ -893,7 +893,7 @@ __xfs_trans_commit(
xfs_log_ticket_ungrant(mp->m_log, tp->t_ticket);
tp->t_ticket = NULL;
}
- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);
xfs_trans_free_items(tp, !!error);
xfs_trans_free(tp);

@@ -954,7 +954,7 @@ xfs_trans_cancel(
}

/* mark this thread as no longer being in a transaction */
- current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+ memalloc_nofs_restore(tp->t_memalloc);

xfs_trans_free_items(tp, dirty);
xfs_trans_free(tp);
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 8308bf6d7e40..7aa2d5ff9245 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -118,6 +118,7 @@ typedef struct xfs_trans {
unsigned int t_rtx_res; /* # of rt extents resvd */
unsigned int t_rtx_res_used; /* # of resvd rt extents used */
unsigned int t_flags; /* misc flags */
+ unsigned int t_memalloc; /* saved memalloc state */
xfs_fsblock_t t_firstblock; /* first block allocated */
struct xlog_ticket *t_ticket; /* log mgr ticket */
struct xfs_mount *t_mountp; /* ptr to fs mount struct */
@@ -144,7 +145,6 @@ typedef struct xfs_trans {
struct list_head t_items; /* log item descriptors */
struct list_head t_busy; /* list of busy extents */
struct list_head t_dfops; /* deferred operations */
- unsigned long t_pflags; /* saved process flags state */
} xfs_trans_t;

/*
--
2.27.0