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2022-04-21xfs: reserve space and initialise xlog_op_header in item formattingDave Chinner
Current xlog_write() adds op headers to the log manually for every log item region that is in the vector passed to it. While xlog_write() needs to stamp the transaction ID into the ophdr, we already know it's length, flags, clientid, etc at CIL commit time. This means the only time that xlog write really needs to format and reserve space for a new ophdr is when a region is split across two iclogs. Adding the opheader and accounting for it as part of the normal formatted item region means we simplify the accounting of space used by a transaction and we don't have to special case reserving of space in for the ophdrs in xlog_write(). It also means we can largely initialise the ophdr in transaction commit instead of xlog_write, making the xlog_write formatting inner loop much tighter. xlog_prepare_iovec() is now too large to stay as an inline function, so we move it out of line and into xfs_log.c. Object sizes: text data bss dec hex filename 1125934 305951 484 1432369 15db31 fs/xfs/built-in.a.before 1123360 305951 484 1429795 15d123 fs/xfs/built-in.a.after So the code is a roughly 2.5kB smaller with xlog_prepare_iovec() now out of line, even though it grew in size itself. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: move log iovec alignment to preparation functionDave Chinner
To include log op headers directly into the log iovec regions that the ophdrs wrap, we need to move the buffer alignment code from xlog_finish_iovec() to xlog_prepare_iovec(). This is because the xlog_op_header is only 12 bytes long, and we need the buffer that the caller formats their data into to be 8 byte aligned. Hence once we start prepending the ophdr in xlog_prepare_iovec(), we are going to need to manage the padding directly to ensure that the buffer pointer returned is correctly aligned. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: log tickets don't need log client idDave Chinner
We currently set the log ticket client ID when we reserve a transaction. This client ID is only ever written to the log by a CIL checkpoint or unmount records, and so anything using a high level transaction allocated through xfs_trans_alloc() does not need a log ticket client ID to be set. For the CIL checkpoint, the client ID written to the journal is always XFS_TRANSACTION, and for the unmount record it is always XFS_LOG, and nothing else writes to the log. All of these operations tell xlog_write() exactly what they need to write to the log (the optype) and build their own opheaders for start, commit and unmount records. Hence we no longer need to set the client id in either the log ticket or the xfs_trans. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: embed the xlog_op_header in the commit recordDave Chinner
Remove the final case where xlog_write() has to prepend an opheader to a log transaction. Similar to the start record, the commit record is just an empty opheader with a XLOG_COMMIT_TRANS type, so we can just make this the payload for the region being passed to xlog_write() and remove the special handling in xlog_write() for the commit record. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: embed the xlog_op_header in the unmount recordDave Chinner
Remove another case where xlog_write() has to prepend an opheader to a log transaction. The unmount record + ophdr is smaller than the minimum amount of space guaranteed to be free in an iclog (2 * sizeof(ophdr)) and so we don't have to care about an unmount record being split across 2 iclogs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: only CIL pushes require a start recordDave Chinner
So move the one-off start record writing in xlog_write() out into the static header that the CIL push builds to write into the log initially. This simplifes the xlog_write() logic a lot. pahole on x86-64 confirms that the xlog_cil_trans_hdr is correctly 32 bit aligned and packed for copying the log op and transaction headers directly into the log as a single log region copy. struct xlog_cil_trans_hdr { struct xlog_op_header oph[2]; /* 0 24 */ struct xfs_trans_header thdr; /* 24 16 */ struct xfs_log_iovec lhdr[2]; /* 40 32 */ /* size: 72, cachelines: 2, members: 3 */ /* last cacheline: 8 bytes */ }; A wart is needed to handle the fact that length of the region the opheader points to doesn't include the opheader length. hence if we embed the opheader, we have to substract the opheader length from the length written into the opheader by the generic copying code. This will eventually go away when everything is converted to embedded opheaders. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: factor out the CIL transaction header buildingDave Chinner
It is static code deep in the middle of the CIL push logic. Factor it out into a helper so that it is clear and easy to modify separately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: simplify local variable assignment in file write codeKaixu Xia
Get the struct inode pointer from iocb->ki_filp->f_mapping->host directly and the other variables are unnecessary, so simplify the local variables assignment. Signed-off-by: Kaixu Xia <kaixuxia@tencent.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: reorder iunlink remove operation in xfs_ifreeDave Chinner
The O_TMPFILE creation implementation creates a specific order of operations for inode allocation/freeing and unlinked list modification. Currently both are serialised by the AGI, so the order doesn't strictly matter as long as the are both in the same transaction. However, if we want to move the unlinked list insertions largely out from under the AGI lock, then we have to be concerned about the order in which we do unlinked list modification operations. O_TMPFILE creation tells us this order is inode allocation/free, then unlinked list modification. Change xfs_ifree() to use this same ordering on unlinked list removal. This way we always guarantee that when we enter the iunlinked list removal code from this path, we already have the AGI locked and we don't have to worry about lock nesting AGI reads inside unlink list locks because it's already locked and attached to the transaction. We can do this safely as the inode freeing and unlinked list removal are done in the same transaction and hence are atomic operations with respect to log recovery. Reported-by: Frank Hofmann <fhofmann@cloudflare.com> Fixes: 298f7bec503f ("xfs: pin inode backing buffer to the inode log item") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21xfs: convert buffer flags to unsigned.Dave Chinner
5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned fields to be unsigned. This manifests as a compiler error such as: /kisskb/src/fs/xfs/./xfs_trace.h:432:2: note: in expansion of macro 'TP_printk' TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d " ^ /kisskb/src/fs/xfs/./xfs_trace.h:440:5: note: in expansion of macro '__print_flags' __print_flags(__entry->flags, "|", XFS_BUF_FLAGS), ^ /kisskb/src/fs/xfs/xfs_buf.h:67:4: note: in expansion of macro 'XBF_UNMAPPED' { XBF_UNMAPPED, "UNMAPPED" } ^ /kisskb/src/fs/xfs/./xfs_trace.h:440:40: note: in expansion of macro 'XFS_BUF_FLAGS' __print_flags(__entry->flags, "|", XFS_BUF_FLAGS), ^ /kisskb/src/fs/xfs/./xfs_trace.h: In function 'trace_raw_output_xfs_buf_flags_class': /kisskb/src/fs/xfs/xfs_buf.h:46:23: error: initializer element is not constant #define XBF_UNMAPPED (1 << 31)/* do not map the buffer */ as __print_flags assigns XFS_BUF_FLAGS to a structure that uses an unsigned long for the flag. Since this results in the value of XBF_UNMAPPED causing a signed integer overflow, the result is technically undefined behavior, which gcc-5 does not accept as an integer constant. This is based on a patch from Arnd Bergman <arnd@arndb.de>. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-17block: decouple REQ_OP_SECURE_ERASE from REQ_OP_DISCARDChristoph Hellwig
Secure erase is a very different operation from discard in that it is a data integrity operation vs hint. Fully split the limits and helper infrastructure to make the separation more clear. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nifs2] Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> [f2fs] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Chao Yu <chao@kernel.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17block: add a bdev_discard_granularity helperChristoph Hellwig
Abstract away implementation details from file systems by providing a block_device based helper to retrieve the discard granularity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Link: https://lore.kernel.org/r/20220415045258.199825-26-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17block: remove QUEUE_FLAG_DISCARDChristoph Hellwig
Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-13xfs: Add XFS_SB_FEAT_INCOMPAT_NREXT64 to the list of supported flagsChandan Babu R
This commit enables XFS module to work with fs instances having 64-bit per-inode extent counters by adding XFS_SB_FEAT_INCOMPAT_NREXT64 flag to the list of supported incompat feature flags. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-13xfs: Enable bulkstat ioctl to support 64-bit per-inode extent countersChandan Babu R
The following changes are made to enable userspace to obtain 64-bit extent counters, 1. Carve out a new 64-bit field xfs_bulkstat->bs_extents64 from xfs_bulkstat->bs_pad[] to hold 64-bit extent counter. 2. Define the new flag XFS_BULK_IREQ_BULKSTAT for userspace to indicate that it is capable of receiving 64-bit extent counters. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Suggested-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-13xfs: Decouple XFS_IBULK flags from XFS_IWALK flagsChandan Babu R
A future commit will add a new XFS_IBULK flag which will not have a corresponding XFS_IWALK flag. In preparation for the change, this commit separates XFS_IBULK_* flags from XFS_IWALK_* flags. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-13xfs: Conditionally upgrade existing inodes to use large extent countersChandan Babu R
This commit enables upgrading existing inodes to use large extent counters provided that underlying filesystem's superblock has large extent counter feature enabled. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-13xfs: Directory's data fork extent counter can never overflowChandan Babu R
The maximum file size that can be represented by the data fork extent counter in the worst case occurs when all extents are 1 block in length and each block is 1KB in size. With XFS_MAX_EXTCNT_DATA_FORK_SMALL representing maximum extent count and with 1KB sized blocks, a file can reach upto, (2^31) * 1KB = 2TB This is much larger than the theoretical maximum size of a directory i.e. XFS_DIR2_SPACE_SIZE * 3 = ~96GB. Since a directory's inode can never overflow its data fork extent counter, this commit removes all the overflow checks associated with it. xfs_dinode_verify() now performs a rough check to verify if a diretory's data fork is larger than 96GB. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-12xfs: use a separate frextents counter for rt extent reservationsDarrick J. Wong
As mentioned in the previous commit, the kernel misuses sb_frextents in the incore mount to reflect both incore reservations made by running transactions as well as the actual count of free rt extents on disk. This results in the superblock being written to the log with an underestimate of the number of rt extents that are marked free in the rtbitmap. Teaching XFS to recompute frextents after log recovery avoids operational problems in the current mount, but it doesn't solve the problem of us writing undercounted frextents which are then recovered by an older kernel that doesn't have that fix. Create an incore percpu counter to mirror the ondisk frextents. This new counter will track transaction reservations and the only time we will touch the incore super counter (i.e the one that gets logged) is when those transactions commit updates to the rt bitmap. This is in contrast to the lazysbcount counters (e.g. fdblocks), where we know that log recovery will always fix any incorrect counter that we log. As a bonus, we only take m_sb_lock at transaction commit time. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-12xfs: recalculate free rt extents after log recoveryDarrick J. Wong
I've been observing periodic corruption reports from xfs_scrub involving the free rt extent counter (frextents) while running xfs/141. That test uses an error injection knob to induce a torn write to the log, and an arbitrary number of recovery mounts, frextents will count fewer free rt extents than can be found the rtbitmap. The root cause of the problem is a combination of the misuse of sb_frextents in the incore mount to reflect both incore reservations made by running transactions as well as the actual count of free rt extents on disk. The following sequence can reproduce the undercount: Thread 1 Thread 2 xfs_trans_alloc(rtextents=3) xfs_mod_frextents(-3) <blocks> xfs_attr_set() xfs_bmap_attr_addfork() xfs_add_attr2() xfs_log_sb() xfs_sb_to_disk() xfs_trans_commit() <log flushed to disk> <log goes down> Note that thread 1 subtracts 3 from sb_frextents even though it never commits to using that space. Thread 2 writes the undercounted value to the ondisk superblock and logs it to the xattr transaction, which is then flushed to disk. At next mount, log recovery will find the logged superblock and write that back into the filesystem. At the end of log recovery, we reread the superblock and install the recovered undercounted frextents value into the incore superblock. From that point on, we've effectively leaked thread 1's transaction reservation. The correct fix for this is to separate the incore reservation from the ondisk usage, but that's a matter for the next patch. Because the kernel has been logging superblocks with undercounted frextents for a very long time and we don't demand that sysadmins run xfs_repair after a crash, fix the undercount by recomputing frextents after log recovery. Gating this on log recovery is a reasonable balance (I think) between correcting the problem and slowing down every mount attempt. Note that xfs_repair will fix undercounted frextents. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-12xfs: pass explicit mount pointer to rtalloc query functionsDarrick J. Wong
Pass an explicit xfs_mount pointer to the rtalloc query functions so that they can support transactionless queries. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-12xfs: Use generic_file_open()Matthew Wilcox (Oracle)
Remove the open-coded check of O_LARGEFILE. This changes the errno to be the same as other filesystems; it was changed generically in 2.6.24 but that fix skipped XFS. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-11xfs: Introduce per-inode 64-bit extent countersChandan Babu R
This commit introduces new fields in the on-disk inode format to support 64-bit data fork extent counters and 32-bit attribute fork extent counters. The new fields will be used only when an inode has XFS_DIFLAG2_NREXT64 flag set. Otherwise we continue to use the regular 32-bit data fork extent counters and 16-bit attribute fork extent counters. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com> Suggested-by: Dave Chinner <dchinner@redhat.com>
2022-04-11xfs: Replace numbered inode recovery error messages with descriptive onesChandan Babu R
This commit also prints inode fields with invalid values instead of printing addresses of inode and buffer instances. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com> Suggested-by: Dave Chinner <dchinner@redhat.com>
2022-04-11xfs: Introduce macros to represent new maximum extent counts for data/attr forksChandan Babu R
This commit defines new macros to represent maximum extent counts allowed by filesystems which have support for large per-inode extent counters. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Use uint64_t to count maximum blocks that can be used by BMBTChandan Babu R
Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Introduce XFS_DIFLAG2_NREXT64 and associated helpersChandan Babu R
This commit adds the new per-inode flag XFS_DIFLAG2_NREXT64 to indicate that an inode supports 64-bit extent counters. This flag is also enabled by default on newly created inodes when the corresponding filesystem has large extent counter feature bit (i.e. XFS_FEAT_NREXT64) set. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Introduce XFS_FSOP_GEOM_FLAGS_NREXT64Chandan Babu R
XFS_FSOP_GEOM_FLAGS_NREXT64 indicates that the current filesystem instance supports 64-bit per-inode extent counters. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Introduce XFS_SB_FEAT_INCOMPAT_NREXT64 and associated per-fs feature bitChandan Babu R
XFS_SB_FEAT_INCOMPAT_NREXT64 incompat feature bit will be set on filesystems which support large per-inode extent counters. This commit defines the new incompat feature bit and the corresponding per-fs feature bit (along with inline functions to work on it). Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Promote xfs_extnum_t and xfs_aextnum_t to 64 and 32-bits respectivelyChandan Babu R
A future commit will introduce a 64-bit on-disk data extent counter and a 32-bit on-disk attr extent counter. This commit promotes xfs_extnum_t and xfs_aextnum_t to 64 and 32-bits in order to correctly handle in-core versions of these quantities. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Use basic types to define xfs_log_dinode's di_nextents and di_anextentsChandan Babu R
A future commit will increase the width of xfs_extnum_t in order to facilitate larger per-inode extent counters. Hence this patch now uses basic types to define xfs_log_dinode->[di_nextents|dianextents]. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Introduce xfs_dfork_nextents() helperChandan Babu R
This commit replaces the macro XFS_DFORK_NEXTENTS() with the helper function xfs_dfork_nextents(). As of this commit, xfs_dfork_nextents() returns the same value as XFS_DFORK_NEXTENTS(). A future commit which extends inode's extent counter fields will add more logic to this helper. This commit also replaces direct accesses to xfs_dinode->di_[a]nextents with calls to xfs_dfork_nextents(). No functional changes have been made. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Use xfs_extnum_t instead of basic data typesChandan Babu R
xfs_extnum_t is the type to use to declare variables which have values obtained from xfs_dinode->di_[a]nextents. This commit replaces basic types (e.g. uint32_t) with xfs_extnum_t for such variables. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Introduce xfs_iext_max_nextents() helperChandan Babu R
xfs_iext_max_nextents() returns the maximum number of extents possible for one of data, cow or attribute fork. This helper will be extended further in a future commit when maximum extent counts associated with data/attribute forks are increased. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Define max extent length based on on-disk format definitionChandan Babu R
The maximum extent length depends on maximum block count that can be stored in a BMBT record. Hence this commit defines MAXEXTLEN based on BMBT_BLOCKCOUNT_BITLEN. While at it, the commit also renames MAXEXTLEN to XFS_MAX_BMBT_EXTLEN. Suggested-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Move extent count limits to xfs_format.hChandan Babu R
Maximum values associated with extent counters i.e. Maximum extent length, Maximum data extents and Maximum xattr extents are dictated by the on-disk format. Hence move these definitions over to xfs_format.h. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11xfs: Add XFS messages to printk indexJonathan Lassoff
In order for end users to quickly react to new issues that come up in production, it is proving useful to leverage the printk indexing system. This printk index enables kernel developers to use calls to printk() with changeable format strings (as they always have; no change of expectations), while enabling end users to examine format strings to detect changes. Since end users are using regular expressions to match messages printed through printk(), being able to detect changes in chosen format strings from release to release provides a useful signal to review printk()-matching regular expressions for any necessary updates. So that detailed XFS messages are captures by this printk index, this patch wraps the xfs_<level> and xfs_alert_tag functions. Signed-off-by: Jonathan Lassoff <jof@thejof.com> Reviewed-by: Chris Down <chris@chrisdown.name> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-11xfs: Simplify XFS logging methods.Jonathan Lassoff
Rather than have a constructor to define many nearly-identical functions, use preprocessor macros to pass down a kernel logging level to a common function. Signed-off-by: Jonathan Lassoff <jof@thejof.com> Reviewed-by: Chris Down <chris@chrisdown.name> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-01Merge tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Darrick Wong: "This fixes multiple problems in the reserve pool sizing functions: an incorrect free space calculation, a pointless infinite loop, and even more braindamage that could result in the pool being overfilled. The pile of patches from Dave fix myriad races and UAF bugs in the log recovery code that much to our mutual surprise nobody's tripped over. Dave also fixed a performance optimization that had turned into a regression. Dave Chinner is taking over as XFS maintainer starting Sunday and lasting until 5.19-rc1 is tagged so that I can focus on starting a massive design review for the (feature complete after five years) online repair feature. From then on, he and I will be moving XFS to a co-maintainership model by trading duties every other release. NOTE: I hope very strongly that the other pieces of the (X)FS ecosystem (fstests and xfsprogs) will make similar changes to spread their maintenance load. Summary: - Fix an incorrect free space calculation in xfs_reserve_blocks that could lead to a request for free blocks that will never succeed. - Fix a hang in xfs_reserve_blocks caused by an infinite loop and the incorrect free space calculation. - Fix yet a third problem in xfs_reserve_blocks where multiple racing threads can overfill the reserve pool. - Fix an accounting error that lead to us reporting reserved space as "available". - Fix a race condition during abnormal fs shutdown that could cause UAF problems when memory reclaim and log shutdown try to clean up inodes. - Fix a bug where log shutdown can race with unmount to tear down the log, thereby causing UAF errors. - Disentangle log and filesystem shutdown to reduce confusion. - Fix some confusion in xfs_trans_commit such that a race between transaction commit and filesystem shutdown can cause unlogged dirty inode metadata to be committed, thereby corrupting the filesystem. - Remove a performance optimization in the log as it was discovered that certain storage hardware handle async log flushes so poorly as to cause serious performance regressions. Recent restructuring of other parts of the logging code mean that no performance benefit is seen on hardware that handle it well" * tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: drop async cache flushes from CIL commits. xfs: shutdown during log recovery needs to mark the log shutdown xfs: xfs_trans_commit() path must check for log shutdown xfs: xfs_do_force_shutdown needs to block racing shutdowns xfs: log shutdown triggers should only shut down the log xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks xfs: shutdown in intent recovery has non-intent items in the AIL xfs: aborting inodes on shutdown may need buffer lock xfs: don't report reserved bnobt space as available xfs: fix overfilling of reserve pool xfs: always succeed at setting the reserve pool size xfs: remove infinite loop when reserving free block pool xfs: don't include bnobt blocks when reserving free block pool xfs: document the XFS_ALLOC_AGFL_RESERVE constant
2022-03-29xfs: drop async cache flushes from CIL commits.Dave Chinner
Jan Kara reported a performance regression in dbench that he bisected down to commit bad77c375e8d ("xfs: CIL checkpoint flushes caches unconditionally"). Whilst developing the journal flush/fua optimisations this cache was part of, it appeared to made a significant difference to performance. However, now that this patchset has settled and all the correctness issues fixed, there does not appear to be any significant performance benefit to asynchronous cache flushes. In fact, the opposite is true on some storage types and workloads, where additional cache flushes that can occur from fsync heavy workloads have measurable and significant impact on overall throughput. Local dbench testing shows little difference on dbench runs with sync vs async cache flushes on either fast or slow SSD storage, and no difference in streaming concurrent async transaction workloads like fs-mark. Fast NVME storage. From `dbench -t 30`, CIL scale: clients async sync BW Latency BW Latency 1 935.18 0.855 915.64 0.903 8 2404.51 6.873 2341.77 6.511 16 3003.42 6.460 2931.57 6.529 32 3697.23 7.939 3596.28 7.894 128 7237.43 15.495 7217.74 11.588 512 5079.24 90.587 5167.08 95.822 fsmark, 32 threads, create w/ 64 byte xattr w/32k logbsize create chown unlink async 1m41s 1m16s 2m03s sync 1m40s 1m19s 1m54s Slower SATA SSD storage: From `dbench -t 30`, CIL scale: clients async sync BW Latency BW Latency 1 78.59 15.792 83.78 10.729 8 367.88 92.067 404.63 59.943 16 564.51 72.524 602.71 76.089 32 831.66 105.984 870.26 110.482 128 1659.76 102.969 1624.73 91.356 512 2135.91 223.054 2603.07 161.160 fsmark, 16 threads, create w/32k logbsize create unlink async 5m06s 4m15s sync 5m00s 4m22s And on Jan's test machine: 5.18-rc8-vanilla 5.18-rc8-patched Amean 1 71.22 ( 0.00%) 64.94 * 8.81%* Amean 2 93.03 ( 0.00%) 84.80 * 8.85%* Amean 4 150.54 ( 0.00%) 137.51 * 8.66%* Amean 8 252.53 ( 0.00%) 242.24 * 4.08%* Amean 16 454.13 ( 0.00%) 439.08 * 3.31%* Amean 32 835.24 ( 0.00%) 829.74 * 0.66%* Amean 64 1740.59 ( 0.00%) 1686.73 * 3.09%* Performance and cache flush behaviour is restored to pre-regression levels. As such, we can now consider the async cache flush mechanism an unnecessary exercise in premature optimisation and hence we can now remove it and the infrastructure it requires completely. Fixes: bad77c375e8d ("xfs: CIL checkpoint flushes caches unconditionally") Reported-and-tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: shutdown during log recovery needs to mark the log shutdownDave Chinner
When a checkpoint writeback is run by log recovery, corruption propagated from the log can result in writeback verifiers failing and calling xfs_force_shutdown() from xfs_buf_delwri_submit_buffers(). This results in the mount being marked as shutdown, but the log does not get marked as shut down because: /* * If this happens during log recovery then we aren't using the runtime * log mechanisms yet so there's nothing to shut down. */ if (!log || xlog_in_recovery(log)) return false; If there are other buffers that then fail (say due to detecting the mount shutdown), they will now hang in xfs_do_force_shutdown() waiting for the log to shut down like this: __schedule+0x30d/0x9e0 schedule+0x55/0xd0 xfs_do_force_shutdown+0x1cd/0x200 ? init_wait_var_entry+0x50/0x50 xfs_buf_ioend+0x47e/0x530 __xfs_buf_submit+0xb0/0x240 xfs_buf_delwri_submit_buffers+0xfe/0x270 xfs_buf_delwri_submit+0x3a/0xc0 xlog_do_recovery_pass+0x474/0x7b0 ? do_raw_spin_unlock+0x30/0xb0 xlog_do_log_recovery+0x91/0x140 xlog_do_recover+0x38/0x1e0 xlog_recover+0xdd/0x170 xfs_log_mount+0x17e/0x2e0 xfs_mountfs+0x457/0x930 xfs_fs_fill_super+0x476/0x830 xlog_force_shutdown() always needs to mark the log as shut down, regardless of whether recovery is in progress or not, so that multiple calls to xfs_force_shutdown() during recovery don't end up waiting for the log to be shut down like this. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: xfs_trans_commit() path must check for log shutdownDave Chinner
If a shut races with xfs_trans_commit() and we have shut down the filesystem but not the log, we will still cancel the transaction. This can result in aborting dirty log items instead of committing and pinning them whilst the log is still running. Hence we can end up with dirty, unlogged metadata that isn't in the AIL in memory that can be flushed to disk via writeback clustering. This was discovered from a g/388 trace where an inode log item was having IO completed on it and it wasn't in the AIL, hence tripping asserts xfs_ail_check(). Inode cluster writeback started long after the filesystem shutdown started, and long after the transaction containing the dirty inode was aborted and the log item marked XFS_LI_ABORTED. The inode was seen as dirty and unpinned, so it was flushed. IO completion tried to remove the inode from the AIL, at which point stuff went bad: XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/xfs/xfs_fsops.c:500). Shutting down filesystem. XFS: Assertion failed: in_ail, file: fs/xfs/xfs_trans_ail.c, line: 67 XFS (pmem1): Please unmount the filesystem and rectify the problem(s) Workqueue: xfs-buf/pmem1 xfs_buf_ioend_work RIP: 0010:assfail+0x27/0x2d Call Trace: <TASK> xfs_ail_check+0xa8/0x180 xfs_ail_delete_one+0x3b/0xf0 xfs_buf_inode_iodone+0x329/0x3f0 xfs_buf_ioend+0x1f8/0x530 xfs_buf_ioend_work+0x15/0x20 process_one_work+0x1ac/0x390 worker_thread+0x56/0x3c0 kthread+0xf6/0x120 ret_from_fork+0x1f/0x30 </TASK> xfs_trans_commit() needs to check log state for shutdown, not mount state. It cannot abort dirty log items while the log is still running as dirty items must remained pinned in memory until they are either committed to the journal or the log has shut down and they can be safely tossed away. Hence if the log has not shut down, the xfs_trans_commit() path must allow completed transactions to commit to the CIL and pin the dirty items even if a mount shutdown has started. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: xfs_do_force_shutdown needs to block racing shutdownsDave Chinner
When we call xfs_forced_shutdown(), the caller often expects the filesystem to be completely shut down when it returns. However, if we have racing xfs_forced_shutdown() calls, the first caller sets the mount shutdown flag then goes to shutdown the log. The second caller sees the mount shutdown flag and returns immediately - it does not wait for the log to be shut down. Unfortunately, xfs_forced_shutdown() is used in some places that expect it to completely shut down the filesystem before it returns (e.g. xfs_trans_log_inode()). As such, returning before the log has been shut down leaves us in a place where the transaction failed to complete correctly but we still call xfs_trans_commit(). This situation arises because xfs_trans_log_inode() does not return an error and instead calls xfs_force_shutdown() to ensure that the transaction being committed is aborted. Unfortunately, we have a race condition where xfs_trans_commit() needs to check xlog_is_shutdown() because it can't abort log items before the log is shut down, but it needs to use xfs_is_shutdown() because xfs_forced_shutdown() does not block waiting for the log to shut down. To fix this conundrum, first we make all calls to xfs_forced_shutdown() block until the log is also shut down. This means we can then safely use xfs_forced_shutdown() as a mechanism that ensures the currently running transaction will be aborted by xfs_trans_commit() regardless of the shutdown check it uses. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: log shutdown triggers should only shut down the logDave Chinner
We've got a mess on our hands. 1. xfs_trans_commit() cannot cancel transactions because the mount is shut down - that causes dirty, aborted, unlogged log items to sit unpinned in memory and potentially get written to disk before the log is shut down. Hence xfs_trans_commit() can only abort transactions when xlog_is_shutdown() is true. 2. xfs_force_shutdown() is used in places to cause the current modification to be aborted via xfs_trans_commit() because it may be impractical or impossible to cancel the transaction directly, and hence xfs_trans_commit() must cancel transactions when xfs_is_shutdown() is true in this situation. But we can't do that because of #1. 3. Log IO errors cause log shutdowns by calling xfs_force_shutdown() to shut down the mount and then the log from log IO completion. 4. xfs_force_shutdown() can result in a log force being issued, which has to wait for log IO completion before it will mark the log as shut down. If #3 races with some other shutdown trigger that runs a log force, we rely on xfs_force_shutdown() silently ignoring #3 and avoiding shutting down the log until the failed log force completes. 5. To ensure #2 always works, we have to ensure that xfs_force_shutdown() does not return until the the log is shut down. But in the case of #4, this will result in a deadlock because the log Io completion will block waiting for a log force to complete which is blocked waiting for log IO to complete.... So the very first thing we have to do here to untangle this mess is dissociate log shutdown triggers from mount shutdowns. We already have xlog_forced_shutdown, which will atomically transistion to the log a shutdown state. Due to internal asserts it cannot be called multiple times, but was done simply because the only place that could call it was xfs_do_force_shutdown() (i.e. the mount shutdown!) and that could only call it once and once only. So the first thing we do is remove the asserts. We then convert all the internal log shutdown triggers to call xlog_force_shutdown() directly instead of xfs_force_shutdown(). This allows the log shutdown triggers to shut down the log without needing to care about mount based shutdown constraints. This means we shut down the log independently of the mount and the mount may not notice this until it's next attempt to read or modify metadata. At that point (e.g. xfs_trans_commit()) it will see that the log is shutdown, error out and shutdown the mount. To ensure that all the unmount behaviours and asserts track correctly as a result of a log shutdown, propagate the shutdown up to the mount if it is not already set. This keeps the mount and log state in sync, and saves a huge amount of hassle where code fails because of a log shutdown but only checks for mount shutdowns and hence ends up doing the wrong thing. Cleaning up that mess is an exercise for another day. This enables us to address the other problems noted above in followup patches. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacksDave Chinner
Brian reported a null pointer dereference failure during unmount in xfs/006. He tracked the problem down to the AIL being torn down before a log shutdown had completed and removed all the items from the AIL. The failure occurred in this path while unmount was proceeding in another task: xfs_trans_ail_delete+0x102/0x130 [xfs] xfs_buf_item_done+0x22/0x30 [xfs] xfs_buf_ioend+0x73/0x4d0 [xfs] xfs_trans_committed_bulk+0x17e/0x2f0 [xfs] xlog_cil_committed+0x2a9/0x300 [xfs] xlog_cil_process_committed+0x69/0x80 [xfs] xlog_state_shutdown_callbacks+0xce/0xf0 [xfs] xlog_force_shutdown+0xdf/0x150 [xfs] xfs_do_force_shutdown+0x5f/0x150 [xfs] xlog_ioend_work+0x71/0x80 [xfs] process_one_work+0x1c5/0x390 worker_thread+0x30/0x350 kthread+0xd7/0x100 ret_from_fork+0x1f/0x30 This is processing an EIO error to a log write, and it's triggering a force shutdown. This causes the log to be shut down, and then it is running attached iclog callbacks from the shutdown context. That means the fs and log has already been marked as xfs_is_shutdown/xlog_is_shutdown and so high level code will abort (e.g. xfs_trans_commit(), xfs_log_force(), etc) with an error because of shutdown. The umount would have been blocked waiting for a log force completion inside xfs_log_cover() -> xfs_sync_sb(). The first thing for this situation to occur is for xfs_sync_sb() to exit without waiting for the iclog buffer to be comitted to disk. The above trace is the completion routine for the iclog buffer, and it is shutting down the filesystem. xlog_state_shutdown_callbacks() does this: { struct xlog_in_core *iclog; LIST_HEAD(cb_list); spin_lock(&log->l_icloglock); iclog = log->l_iclog; do { if (atomic_read(&iclog->ic_refcnt)) { /* Reference holder will re-run iclog callbacks. */ continue; } list_splice_init(&iclog->ic_callbacks, &cb_list); >>>>>> wake_up_all(&iclog->ic_write_wait); >>>>>> wake_up_all(&iclog->ic_force_wait); } while ((iclog = iclog->ic_next) != log->l_iclog); wake_up_all(&log->l_flush_wait); spin_unlock(&log->l_icloglock); >>>>>> xlog_cil_process_committed(&cb_list); } This wakes any thread waiting on IO completion of the iclog (in this case the umount log force) before shutdown processes all the pending callbacks. That means the xfs_sync_sb() waiting on a sync transaction in xfs_log_force() on iclog->ic_force_wait will get woken before the callbacks attached to that iclog are run. This results in xfs_sync_sb() returning an error, and so unmount unblocks and continues to run whilst the log shutdown is still in progress. Normally this is just fine because the force waiter has nothing to do with AIL operations. But in the case of this unmount path, the log force waiter goes on to tear down the AIL because the log is now shut down and so nothing ever blocks it again from the wait point in xfs_log_cover(). Hence it's a race to see who gets to the AIL first - the unmount code or xlog_cil_process_committed() killing the superblock buffer. To fix this, we just have to change the order of processing in xlog_state_shutdown_callbacks() to run the callbacks before it wakes any task waiting on completion of the iclog. Reported-by: Brian Foster <bfoster@redhat.com> Fixes: aad7272a9208 ("xfs: separate out log shutdown callback processing") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: shutdown in intent recovery has non-intent items in the AILDave Chinner
generic/388 triggered a failure in RUI recovery due to a corrupted btree record and the system then locked up hard due to a subsequent assert failure while holding a spinlock cancelling intents: XFS (pmem1): Corruption of in-memory data (0x8) detected at xfs_do_force_shutdown+0x1a/0x20 (fs/xfs/xfs_trans.c:964). Shutting down filesystem. XFS (pmem1): Please unmount the filesystem and rectify the problem(s) XFS: Assertion failed: !xlog_item_is_intent(lip), file: fs/xfs/xfs_log_recover.c, line: 2632 Call Trace: <TASK> xlog_recover_cancel_intents.isra.0+0xd1/0x120 xlog_recover_finish+0xb9/0x110 xfs_log_mount_finish+0x15a/0x1e0 xfs_mountfs+0x540/0x910 xfs_fs_fill_super+0x476/0x830 get_tree_bdev+0x171/0x270 ? xfs_init_fs_context+0x1e0/0x1e0 xfs_fs_get_tree+0x15/0x20 vfs_get_tree+0x24/0xc0 path_mount+0x304/0xba0 ? putname+0x55/0x60 __x64_sys_mount+0x108/0x140 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Essentially, there's dirty metadata in the AIL from intent recovery transactions, so when we go to cancel the remaining intents we assume that all objects after the first non-intent log item in the AIL are not intents. This is not true. Intent recovery can log new intents to continue the operations the original intent could not complete in a single transaction. The new intents are committed before they are deferred, which means if the CIL commits in the background they will get inserted into the AIL at the head. Hence if we shut down the filesystem while processing intent recovery, the AIL may have new intents active at the current head. Hence this check: /* * We're done when we see something other than an intent. * There should be no intents left in the AIL now. */ if (!xlog_item_is_intent(lip)) { #ifdef DEBUG for (; lip; lip = xfs_trans_ail_cursor_next(ailp, &cur)) ASSERT(!xlog_item_is_intent(lip)); #endif break; } in both xlog_recover_process_intents() and log_recover_cancel_intents() is simply not valid. It was valid back when we only had EFI/EFD intents and didn't chain intents, but it hasn't been valid ever since intent recovery could create and commit new intents. Given that crashing the mount task like this pretty much prevents diagnosing what went wrong that lead to the initial failure that triggered intent cancellation, just remove the checks altogether. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29xfs: aborting inodes on shutdown may need buffer lockDave Chinner
Most buffer io list operations are run with the bp->b_lock held, but xfs_iflush_abort() can be called without the buffer lock being held resulting in inodes being removed from the buffer list while other list operations are occurring. This causes problems with corrupted bp->b_io_list inode lists during filesystem shutdown, leading to traversals that never end, double removals from the AIL, etc. Fix this by passing the buffer to xfs_iflush_abort() if we have it locked. If the inode is attached to the buffer, we're going to have to remove it from the buffer list and we'd have to get the buffer off the inode log item to do that anyway. If we don't have a buffer passed in (e.g. from xfs_reclaim_inode()) then we can determine if the inode has a log item and if it is attached to a buffer before we do anything else. If it does have an attached buffer, we can lock it safely (because the inode has a reference to it) and then perform the inode abort. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-28xfs: don't report reserved bnobt space as availableDarrick J. Wong
On a modern filesystem, we don't allow userspace to allocate blocks for data storage from the per-AG space reservations, the user-controlled reservation pool that prevents ENOSPC in the middle of internal operations, or the internal per-AG set-aside that prevents unwanted filesystem shutdowns due to ENOSPC during a bmap btree split. Since we now consider freespace btree blocks as unavailable for allocation for data storage, we shouldn't report those blocks via statfs either. This makes the numbers that we return via the statfs f_bavail and f_bfree fields a more conservative estimate of actual free space. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28xfs: fix overfilling of reserve poolDarrick J. Wong
Due to cycling of m_sb_lock, it's possible for multiple callers of xfs_reserve_blocks to race at changing the pool size, subtracting blocks from fdblocks, and actually putting it in the pool. The result of all this is that we can overfill the reserve pool to hilarious levels. xfs_mod_fdblocks, when called with a positive value, already knows how to take freed blocks and either fill the reserve until it's full, or put them in fdblocks. Use that instead of setting m_resblks_avail directly. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28xfs: always succeed at setting the reserve pool sizeDarrick J. Wong
Nowadays, xfs_mod_fdblocks will always choose to fill the reserve pool with freed blocks before adding to fdblocks. Therefore, we can change the behavior of xfs_reserve_blocks slightly -- setting the target size of the pool should always succeed, since a deficiency will eventually be made up as blocks get freed. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>