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linux/fs/xfs/scrub/xfile.h

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xfs: create a big array data structure Create a simple 'big array' data structure for storage of fixed-size metadata records that will be used to reconstruct a btree index. For repair operations, the most important operations are append, iterate, and sort. Earlier implementations of the big array used linked lists and suffered from severe problems -- pinning all records in kernel memory was not a good idea and frequently lead to OOM situations; random access was very inefficient; and record overhead for the lists was unacceptably high at 40-60%. Therefore, the big memory array relies on the 'xfile' abstraction, which creates a memfd file and stores the records in page cache pages. Since the memfd is created in tmpfs, the memory pages can be pushed out to disk if necessary and we have a built-in usage limit of 50% of physical memory. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-08-10 22:48:04 +08:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2018-2023 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <djwong@kernel.org>
*/
#ifndef __XFS_SCRUB_XFILE_H__
#define __XFS_SCRUB_XFILE_H__
struct xfile {
struct file *file;
};
int xfile_create(const char *description, loff_t isize, struct xfile **xfilep);
void xfile_destroy(struct xfile *xf);
xfs: remove the xfile_pread/pwrite APIs All current and pending xfile users use the xfile_obj_load and xfile_obj_store API, so make those the actual implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-19 14:27:21 +08:00
int xfile_load(struct xfile *xf, void *buf, size_t count, loff_t pos);
int xfile_store(struct xfile *xf, const void *buf, size_t count,
xfs: create a big array data structure Create a simple 'big array' data structure for storage of fixed-size metadata records that will be used to reconstruct a btree index. For repair operations, the most important operations are append, iterate, and sort. Earlier implementations of the big array used linked lists and suffered from severe problems -- pinning all records in kernel memory was not a good idea and frequently lead to OOM situations; random access was very inefficient; and record overhead for the lists was unacceptably high at 40-60%. Therefore, the big memory array relies on the 'xfile' abstraction, which creates a memfd file and stores the records in page cache pages. Since the memfd is created in tmpfs, the memory pages can be pushed out to disk if necessary and we have a built-in usage limit of 50% of physical memory. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-08-10 22:48:04 +08:00
loff_t pos);
loff_t xfile_seek_data(struct xfile *xf, loff_t pos);
xfs: add file_{get,put}_folio Add helper similar to file_{get,set}_page, but which deal with folios and don't allocate new folio unless explicitly asked to, which map to shmem_get_folio instead of calling into the aops. Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-19 14:27:26 +08:00
#define XFILE_MAX_FOLIO_SIZE (PAGE_SIZE << MAX_PAGECACHE_ORDER)
#define XFILE_ALLOC (1 << 0) /* allocate folio if not present */
struct folio *xfile_get_folio(struct xfile *xf, loff_t offset, size_t len,
unsigned int flags);
void xfile_put_folio(struct xfile *xf, struct folio *folio);
xfs: create a big array data structure Create a simple 'big array' data structure for storage of fixed-size metadata records that will be used to reconstruct a btree index. For repair operations, the most important operations are append, iterate, and sort. Earlier implementations of the big array used linked lists and suffered from severe problems -- pinning all records in kernel memory was not a good idea and frequently lead to OOM situations; random access was very inefficient; and record overhead for the lists was unacceptably high at 40-60%. Therefore, the big memory array relies on the 'xfile' abstraction, which creates a memfd file and stores the records in page cache pages. Since the memfd is created in tmpfs, the memory pages can be pushed out to disk if necessary and we have a built-in usage limit of 50% of physical memory. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-08-10 22:48:04 +08:00
#endif /* __XFS_SCRUB_XFILE_H__ */
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