gfs2: Fix fallocate chunk size (174d1232) · Commits · 戴 / test

The chunk size of allocations in __gfs2_fallocate is calculated incorrectly. The size can collapse, causing __gfs2_fallocate to allocate one block at a time, which is very inefficient. This needs fixing in two places: In gfs2_quota_lock_check, always set ap->allowed to UINT_MAX to indicate that there is no quota limit. This fixes callers that rely on ap->allowed to be set even when quotas are off. In __gfs2_fallocate, reset max_blks to UINT_MAX in each iteration of the loop to make sure that allocation limits from one resource group won't spill over into another resource group. Signed-off-by:

Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by:

Bob Peterson <rpeterso@redhat.com>

fs/gfs2/file.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -809,7 +809,7 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
		struct gfs2_inode *ip = GFS2_I(inode);
		struct gfs2_alloc_parms ap = { .aflags = 0, };
		unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
		loff_t bytes, max_bytes, max_blks = UINT_MAX;
		loff_t bytes, max_bytes, max_blks;
		int error;
		const loff_t pos = offset;
		const loff_t count = len;
		@@ -861,7 +861,8 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
		return error;
		/* ap.allowed tells us how many blocks quota will allow
		* us to write. Check if this reduces max_blks */
		if (ap.allowed && ap.allowed < max_blks)
		max_blks = UINT_MAX;
		if (ap.allowed)
		max_blks = ap.allowed;

		error = gfs2_inplace_reserve(ip, &ap);

fs/gfs2/quota.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,8 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip,
		{
		struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
		int ret;

		ap->allowed = UINT_MAX; /* Assume we are permitted a whole lot */
		if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
		return 0;
		ret = gfs2_quota_lock(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);

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